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Sample records for 3d reconstructed tomosynthesis

  1. Parallelizable 3D statistical reconstruction for C-arm tomosynthesis system

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    Wang, Beilei; Barner, Kenneth; Lee, Denny

    2005-04-01

    Clinical diagnosis and security detection tasks increasingly require 3D information which is difficult or impossible to obtain from 2D (two dimensional) radiographs. As a 3D (three dimensional) radiographic and non-destructive imaging technique, digital tomosynthesis is especially fit for cases where 3D information is required while a complete projection data is not available. Nowadays, FBP (filtered back projection) is extensively used in industry for its fast speed and simplicity. However, it is hard to deal with situations where only a limited number of projections from constrained directions are available, or the SNR (signal to noises ratio) of the projections is low. In order to deal with noise and take into account a priori information of the object, a statistical image reconstruction method is described based on the acquisition model of X-ray projections. We formulate a ML (maximum likelihood) function for this model and develop an ordered-subsets iterative algorithm to estimate the unknown attenuation of the object. Simulations show that satisfied results can be obtained after 1 to 2 iterations, and after that there is no significant improvement of the image quality. An adaptive wiener filter is also applied to the reconstructed image to remove its noise. Some approximations to speed up the reconstruction computation are also considered. Applying this method to computer generated projections of a revised Shepp phantom and true projections from diagnostic radiographs of a patient"s hand and mammography images yields reconstructions with impressive quality. Parallel programming is also implemented and tested. The quality of the reconstructed object is conserved, while the computation time is considerably reduced by almost the number of threads used.

  2. Digital breast tomosynthesis: computerized detection of microcalcifications in reconstructed breast volume using a 3D approach

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    Chan, Heang-Ping; Sahiner, Berkman; Wei, Jun; Hadjiiski, Lubomir M.; Zhou, Chuan; Helvie, Mark A.

    2010-03-01

    We are developing a computer-aided detection (CAD) system for clustered microcalcifications in digital breast tomosynthesis (DBT). In this preliminary study, we investigated the approach of detecting microcalcifications in the tomosynthesized volume. The DBT volume is first enhanced by 3D multi-scale filtering and analysis of the eigenvalues of Hessian matrices with a calcification response function and signal-to-noise ratio enhancement filtering. Potential signal sites are identified in the enhanced volume and local analysis is performed to further characterize each object. A 3D dynamic clustering procedure is designed to locate potential clusters using hierarchical criteria. We collected a pilot data set of two-view DBT mammograms of 39 breasts containing microcalcification clusters (17 malignant, 22 benign) with IRB approval. A total of 74 clusters were identified by an experienced radiologist in the 78 DBT views. Our prototype CAD system achieved view-based sensitivity of 90% and 80% at an average FP rate of 7.3 and 2.0 clusters per volume, respectively. At the same levels of case-based sensitivity, the FP rates were 3.6 and 1.3 clusters per volume, respectively. For the subset of malignant clusters, the view-based detection sensitivity was 94% and 82% at an average FP rate of 6.0 and 1.5 FP clusters per volume, respectively. At the same levels of case-based sensitivity, the FP rates were 1.2 and 0.9 clusters per volume, respectively. This study demonstrated that computerized microcalcification detection in 3D is a promising approach to the development of a CAD system for DBT. Study is underway to further improve the computer-vision methods and to optimize the processing parameters using a larger data set.

  3. An Object-Oriented Simulator for 3D Digital Breast Tomosynthesis Imaging System

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    Saeed Seyyedi

    2013-01-01

    Full Text Available Digital breast tomosynthesis (DBT is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART and total variation regularized reconstruction techniques (ART+TV are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM values.

  4. Limited angle C-arm tomosynthesis reconstruction algorithms

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    Malalla, Nuhad A. Y.; Xu, Shiyu; Chen, Ying

    2015-03-01

    In this paper, C-arm tomosynthesis with digital detector was investigated as a novel three dimensional (3D) imaging technique. Digital tomosythses is an imaging technique to provide 3D information of the object by reconstructing slices passing through the object, based on a series of angular projection views with respect to the object. C-arm tomosynthesis provides two dimensional (2D) X-ray projection images with rotation (-/+20 angular range) of both X-ray source and detector. In this paper, four representative reconstruction algorithms including point by point back projection (BP), filtered back projection (FBP), simultaneous algebraic reconstruction technique (SART) and maximum likelihood expectation maximization (MLEM) were investigated. Dataset of 25 projection views of 3D spherical object that located at center of C-arm imaging space was simulated from 25 angular locations over a total view angle of 40 degrees. With reconstructed images, 3D mesh plot and 2D line profile of normalized pixel intensities on focus reconstruction plane crossing the center of the object were studied with each reconstruction algorithm. Results demonstrated the capability to generate 3D information from limited angle C-arm tomosynthesis. Since C-arm tomosynthesis is relatively compact, portable and can avoid moving patients, it has been investigated for different clinical applications ranging from tumor surgery to interventional radiology. It is very important to evaluate C-arm tomosynthesis for valuable applications.

  5. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis

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    Shaheen, Eman; Van Ongeval, Chantal; Zanca, Federica; Cockmartin, Lesley; Marshall, Nicholas; Jacobs, Jurgen; Young, Kenneth C.; Dance, David R.; Bosmans, Hilde [Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford, GU2 7XX (United Kingdom); Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium)

    2011-12-15

    Purpose: This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. Methods: A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores (''agreement'') on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. ''Poor'' agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. Results: The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically

  6. The simulation of 3D microcalcification clusters in 2D digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Purpose: This work proposes a new method of building 3D models of microcalcification clusters and describes the validation of their realistic appearance when simulated into 2D digital mammograms and into breast tomosynthesis images. Methods: A micro-CT unit was used to scan 23 breast biopsy specimens of microcalcification clusters with malignant and benign characteristics and their 3D reconstructed datasets were segmented to obtain 3D models of microcalcification clusters. These models were then adjusted for the x-ray spectrum used and for the system resolution and simulated into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. Six radiologists were asked to distinguish between 40 real and 40 simulated clusters of microcalcifications in two separate studies on 2D mammography and tomosynthesis datasets. Receiver operating characteristic (ROC) analysis was used to test the ability of each observer to distinguish between simulated and real microcalcification clusters. The kappa statistic was applied to assess how often the individual simulated and real microcalcification clusters had received similar scores (''agreement'') on their realistic appearance in both modalities. This analysis was performed for all readers and for the real and the simulated group of microcalcification clusters separately. ''Poor'' agreement would reflect radiologists' confusion between simulated and real clusters, i.e., lesions not systematically evaluated in both modalities as either simulated or real, and would therefore be interpreted as a success of the present models. Results: The area under the ROC curve, averaged over the observers, was 0.55 (95% confidence interval [0.44, 0.66]) for the 2D study, and 0.46 (95% confidence interval [0.29, 0.64]) for the tomosynthesis study, indicating no statistically significant difference between real and simulated

  7. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

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    Shaheen, Eman, E-mail: eman.shaheen@uzleuven.be; De Keyzer, Frederik; Bosmans, Hilde; Ongeval, Chantal Van [Department of Radiology, University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); Dance, David R.; Young, Kenneth C. [National Coordinating Centre for the Physics of Mammography, Royal Surrey County Hospital, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2014-08-15

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  8. The simulation of 3D mass models in 2D digital mammography and breast tomosynthesis

    International Nuclear Information System (INIS)

    Purpose: This work proposes a new method of building 3D breast mass models with different morphological shapes and describes the validation of the realism of their appearance after simulation into 2D digital mammograms and breast tomosynthesis images. Methods: Twenty-five contrast enhanced MRI breast lesions were collected and each mass was manually segmented in the three orthogonal views: sagittal, coronal, and transversal. The segmented models were combined, resampled to have isotropic voxel sizes, triangularly meshed, and scaled to different sizes. These masses were referred to as nonspiculated masses and were then used as nuclei onto which spicules were grown with an iterative branching algorithm forming a total of 30 spiculated masses. These 55 mass models were projected into 2D projection images to obtain mammograms after image processing and into tomographic sequences of projection images, which were then reconstructed to form 3D tomosynthesis datasets. The realism of the appearance of these mass models was assessed by five radiologists via receiver operating characteristic (ROC) analysis when compared to 54 real masses. All lesions were also given a breast imaging reporting and data system (BIRADS) score. The data sets of 2D mammography and tomosynthesis were read separately. The Kendall's coefficient of concordance was used for the interrater observer agreement assessment for the BIRADS scores per modality. Further paired analysis, using the Wilcoxon signed rank test, of the BIRADS assessment between 2D and tomosynthesis was separately performed for the real masses and for the simulated masses. Results: The area under the ROC curves, averaged over all observers, was 0.54 (95% confidence interval [0.50, 0.66]) for the 2D study, and 0.67 (95% confidence interval [0.55, 0.79]) for the tomosynthesis study. According to the BIRADS scores, the nonspiculated and the spiculated masses varied in their degrees of malignancy from normal (BIRADS 1) to highly

  9. Digital breast tomosynthesis (3D-mammography) screening: A pictorial review of screen-detected cancers and false recalls attributed to tomosynthesis in prospective screening trials.

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    Houssami, Nehmat; Lång, Kristina; Bernardi, Daniela; Tagliafico, Alberto; Zackrisson, Sophia; Skaane, Per

    2016-04-01

    This pictorial review highlights cancers detected only at tomosynthesis screening and screens falsely recalled in the course of breast tomosynthesis screening, illustrating both true-positive (TP) and false-positive (FP) detection attributed to tomosynthesis. Images and descriptive data were used to characterise cases of screen-detection with tomosynthesis, sourced from prospective screening trials that performed standard (2D) digital mammography (DM) and tomosynthesis (3D-mammography) in the same screening participants. Exemplar cases from four trials highlight common themes of relevance to screening practice including: the type of lesions frequently made more conspicuous or perceptible by tomosynthesis (spiculated masses, and architectural distortions); the histologic findings (both TP and FP) of tomosynthesis-only detection; and the need to extend breast work-up protocols (additional imaging including ultrasound and MRI, and tomosynthesis-guided biopsy) if tomosynthesis is adopted for primary screening. PMID:27017251

  10. Virtual 3-D Facial Reconstruction

    Directory of Open Access Journals (Sweden)

    Martin Paul Evison

    2000-06-01

    Full Text Available Facial reconstructions in archaeology allow empathy with people who lived in the past and enjoy considerable popularity with the public. It is a common misconception that facial reconstruction will produce an exact likeness; a resemblance is the best that can be hoped for. Research at Sheffield University is aimed at the development of a computer system for facial reconstruction that will be accurate, rapid, repeatable, accessible and flexible. This research is described and prototypical 3-D facial reconstructions are presented. Interpolation models simulating obesity, ageing and ethnic affiliation are also described. Some strengths and weaknesses in the models, and their potential for application in archaeology are discussed.

  11. Oblique reconstructions in tomosynthesis. II. Super-resolution

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    Acciavatti, Raymond J.; Maidment, Andrew D. A. [Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4206 (United States)

    2013-11-15

    Purpose: In tomosynthesis, super-resolution has been demonstrated using reconstruction planes parallel to the detector. Super-resolution allows for subpixel resolution relative to the detector. The purpose of this work is to develop an analytical model that generalizes super-resolution to oblique reconstruction planes.Methods: In a digital tomosynthesis system, a sinusoidal test object is modeled along oblique angles (i.e., “pitches”) relative to the plane of the detector in a 3D divergent-beam acquisition geometry. To investigate the potential for super-resolution, the input frequency is specified to be greater than the alias frequency of the detector. Reconstructions are evaluated in an oblique plane along the extent of the object using simple backprojection (SBP) and filtered backprojection (FBP). By comparing the amplitude of the reconstruction against the attenuation coefficient of the object at various frequencies, the modulation transfer function (MTF) is calculated to determine whether modulation is within detectable limits for super-resolution. For experimental validation of super-resolution, a goniometry stand was used to orient a bar pattern phantom along various pitches relative to the breast support in a commercial digital breast tomosynthesis system.Results: Using theoretical modeling, it is shown that a single projection image cannot resolve a sine input whose frequency exceeds the detector alias frequency. The high frequency input is correctly visualized in SBP or FBP reconstruction using a slice along the pitch of the object. The Fourier transform of this reconstructed slice is maximized at the input frequency as proof that the object is resolved. Consistent with the theoretical results, experimental images of a bar pattern phantom showed super-resolution in oblique reconstructions. At various pitches, the highest frequency with detectable modulation was determined by visual inspection of the bar patterns. The dependency of the highest

  12. Generalized filtered back-projection for digital breast tomosynthesis reconstruction

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    Erhard, Klaus; Grass, Michael; Hitziger, Sebastian; Iske, Armin; Nielsen, Tim

    2012-03-01

    Filtered backprojection (FBP) has been commonly used as an efficient and robust reconstruction technique in tomographic X-ray imaging during the last decades. For standard geometries like circle or helix it is known how to efficiently filter the data. However, for geometries with only few projection views or with a limited angular range, the application of FBP algorithms generally provides poor results. In digital breast tomosynthesis (DBT) these limitations give rise to image artifacts due to the limited angular range and the coarse angular sampling. In this work, a generalized FBP algorithm is presented, which uses the filtered projection data of all acquired views for backprojection along one direction. The proposed method yields a computationally efficient generalized FBP algorithm for DBT, which provides similar image quality as iterative reconstruction techniques while preserving the ability for region of interest reconstructions. To demonstrate the excellent performance of this method, examples are given with a simulated breast phantom and the hardware BR3D phantom.

  13. Digital breast tomosynthesis reconstruction with an adaptive voxel grid

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    Claus, Bernhard; Chan, Heang-Ping

    2014-03-01

    In digital breast tomosynthesis (DBT) volume datasets are typically reconstructed with an anisotropic voxel size, where the in-plane voxel size usually reflects the detector pixel size (e.g., 0.1 mm), and the slice separation is generally between 0.5-1.0 mm. Increasing the tomographic angle is expected to give better 3D image quality; however, the slice spacing in the reconstruction should be reduced, otherwise one may risk losing fine-scale image detail (e.g., small microcalcifications). An alternative strategy consists of reconstructing on an adaptive voxel grid, where the voxel height at each location is adapted based on the backprojected data at this location, with the goal to improve image quality for microcalcifications. In this paper we present an approach for generating such an adaptive voxel grid. This approach is based on an initial reconstruction step that is performed at a finer slice-spacing combined with a selection of an "optimal" height for each voxel. This initial step is followed by a (potentially iterative) reconstruction acting now on the adaptive grid only.

  14. Stereotactic vacuum-assisted biopsies on a digital breast 3D-tomosynthesis system.

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    Viala, Juliette; Gignier, Pierre; Perret, Baudouin; Hovasse, Claudie; Hovasse, Denis; Chancelier-Galan, Marie-Dominique; Bornet, Gregoire; Hamrouni, Adel; Lasry, Jean-Louis; Convard, Jean-Paul

    2013-01-01

    The purpose of this study was to describe our operating process and to report results of 118 stereotactic vacuum-assisted biopsies performed on a digital breast 3D-tomosynthesis system. From October 2009 to December 2010, 118 stereotactic vacuum assisted biopsies have been performed on a digital breast 3D-tomosynthesis system. Informed consent was obtained for all patients. A total of 106 patients had a lesion, six had two lesions. Sixty-one lesions were clusters of micro-calcifications, 54 were masses and three were architectural distortions. Patients were in lateral decubitus position to allow shortest skin-target approach (or sitting). Specific compression paddle, adapted on the system, performed, and graduated, allowing localization in X-Y. Tomosynthesis views define the depth of lesion. Graduated Coaxial localization kit determines the beginning of the biopsy window. Biopsies were performed with an ATEC-Suros, 9 Gauge handpiece. All biopsies, except one, have reached the lesions. Five hemorrhages were incurred in the process, but no interruption was needed. Eight breast hematomas, were all spontaneously resolved. One was an infection. About 40% of patients had a skin ecchymosis. Processing is fast, easy, and requires lower irradiation dose than with classical stereotactic biopsies. Histology analysis reported 45 benign clusters of micro-calcifications, 16 malignant clusters of micro-calcifications, 24 benign masses, and 33 malignant masses. Of 13 malignant lesions, digital 2D-mammography failed to detect eight lesions and underestimated the classification of five lesions. Digital breast 3D-tomosynthesis depicts malignant lesions not visualized on digital 2D-mammography. Development of tomosynthesis biopsy unit integrated to stereotactic system will permit histology analysis for suspicious lesions.

  15. Ray tracing reconstruction investigation for C-arm tomosynthesis

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    Malalla, Nuhad A. Y.; Chen, Ying

    2016-04-01

    C-arm tomosynthesis is a three dimensional imaging technique. Both x-ray source and the detector are mounted on a C-arm wheeled structure to provide wide variety of movement around the object. In this paper, C-arm tomosynthesis was introduced to provide three dimensional information over a limited view angle (less than 180o) to reduce radiation exposure and examination time. Reconstruction algorithms based on ray tracing method such as ray tracing back projection (BP), simultaneous algebraic reconstruction technique (SART) and maximum likelihood expectation maximization (MLEM) were developed for C-arm tomosynthesis. C-arm tomosynthesis projection images of simulated spherical object were simulated with a virtual geometric configuration with a total view angle of 40 degrees. This study demonstrated the sharpness of in-plane reconstructed structure and effectiveness of removing out-of-plane blur for each reconstruction algorithms. Results showed the ability of ray tracing based reconstruction algorithms to provide three dimensional information with limited angle C-arm tomosynthesis.

  16. 3D Reconstruction Technique for Tomographic PIV

    Institute of Scientific and Technical Information of China (English)

    姜楠; 包全; 杨绍琼

    2015-01-01

    Tomographic particle image velocimetry(Tomo-PIV) is a state-of-the-art experimental technique based on a method of optical tomography to achieve the three-dimensional(3D) reconstruction for three-dimensional three-component(3D-3C) flow velocity measurements. 3D reconstruction for Tomo-PIV is carried out herein. Meanwhile, a 3D simplified tomographic reconstruction model reduced from a 3D volume light inten-sity field with 2D projection images into a 2D Tomo-slice plane with 1D projecting lines, i.e., simplifying this 3D reconstruction into a problem of 2D Tomo-slice plane reconstruction, is applied thereafter. Two kinds of the most well-known algebraic reconstruction techniques, algebraic reconstruction technique(ART) and multiple algebraic reconstruction technique(MART), are compared as well. The principles of the two reconstruction algorithms are discussed in detail, which has been performed by a series of simulation images, yielding the corresponding recon-struction images that show different features between the ART and MART algorithm, and then their advantages and disadvantages are discussed. Further discussions are made for the standard particle image reconstruction when the background noise of the pre-initial particle image has been removed. Results show that the particle image recon-struction has been greatly improved. The MART algorithm is much better than the ART. Furthermore, the computa-tional analyses of two parameters(the particle density and the number of cameras), are performed to study their effects on the reconstruction. Lastly, the 3D volume particle field is reconstructed by using the improved algorithm based on the simplified 3D tomographic reconstruction model, which proves that the algorithm simplification is feasible and it can be applied to the reconstruction of 3D volume particle field in a Tomo-PIV system.

  17. Adaptive spatially dependent weighting scheme for tomosynthesis reconstruction

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    Levakhina, Yulia; Duschka, Robert; Vogt, Florian; Barkhausen, JOErg; Buzug, Thorsten M.

    2012-03-01

    Digital Tomosynthesis (DT) is an x-ray limited-angle imaging technique. An accurate image reconstruction in tomosynthesis is a challenging task due to the violation of the tomographic sufficiency conditions. A classical "shift-and-add" algorithm (or simple backprojection) suffers from blurring artifacts, produced by structures located above and below the plane of interest. The artifact problem becomes even more prominent in the presence of materials and tissues with a high x-ray attenuation, such as bones, microcalcifications or metal. The focus of the current work is on reduction of ghosting artifacts produced by bones in the musculoskeletal tomosynthesis. A novel dissimilarity concept and a modified backprojection with an adaptive spatially dependent weighting scheme (ωBP) are proposed. Simulated data of software phantom, a structured hardware phantom and a human hand raw-data acquired with a Siemens Mammomat Inspiration tomosynthesis system were reconstructed using conventional backprojection algorithm and the new ωBP-algorithm. The comparison of the results to the non-weighted case demonstrates the potential of the proposed weighted backprojection to reduce the blurring artifacts in musculoskeletal DT. The proposed weighting scheme is not limited to the tomosynthesis limitedangle geometry. It can also be adapted for Computed Tomography (CT) and included in iterative reconstruction algorithms (e.g. SART).

  18. Intrafractional 3D localization using kilovoltage digital tomosynthesis for sliding-window intensity modulated radiation therapy.

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    Zhang, Pengpeng; Hunt, Margie; Pham, Hai; Tang, Grace; Mageras, Gig

    2015-09-01

    To implement novel imaging sequences integrated into intensity modulated radiation therapy (IMRT) and determine 3D positions for intrafractional patient motion monitoring and management.In one method, we converted a static gantry IMRT beam into a series of arcs in which dose index and multileaf collimator positions for all control points were unchanged, but gantry angles were modified to oscillate ± 3° around the original angle. Kilovoltage (kV) projections were acquired continuously throughout delivery and reconstructed to provide a series of 6° arc digital tomosynthesis (DTS) images which served to evaluate the in-plane positions of embedded-fiducials/vertebral-body. To obtain out-of-plane positions via triangulation, a 20° gantry rotation with beam hold-off was inserted during delivery to produce a pair of 6° DTS images separated by 14°. In a second method, the gantry remained stationary, but both kV source and detector moved over a 15° longitudinal arc using pitch and translational adjustment of the robotic arms. Evaluation of localization accuracy in an anthropomorphic Rando phantom during simulated intrafractional motion used programmed couch translations from customized scripts. Purpose-built software was used to reconstruct DTS images, register them to reference template images and calculate 3D fiducial positions.No significant dose difference (<0.5%) was found between the original and converted IMRT beams. For a typical hypofractionated spine treatment, 200 single DTS (6° arc) and 10 paired DTS (20° arc) images were acquired for each IMRT beam, providing in-plane and out-of-plane monitoring every 1.6 and 34.5 s, respectively. Mean ± standard deviation error in predicted position was -0.3 ± 0.2 mm, -0.1 ± 0.1 mm in-plane, and 0.2 ± 0.4 mm out-of-plane with rotational gantry, 0.8 ± 0.1 mm, -0.7 ± 0.3 mm in-plane and 1.1 ± 0.1 mm out-of-plane with translational source/detector.Acquiring 3D fiducial positions from kV-DTS during fixed gantry

  19. Preliminary attempt on maximum likelihood tomosynthesis reconstruction of DEI data

    International Nuclear Information System (INIS)

    Tomosynthesis is a three-dimension reconstruction method that can remove the effect of superimposition with limited angle projections. It is especially promising in mammography where radiation dose is concerned. In this paper, we propose a maximum likelihood tomosynthesis reconstruction algorithm (ML-TS) on the apparent absorption data of diffraction enhanced imaging (DEI). The motivation of this contribution is to develop a tomosynthesis algorithm in low-dose or noisy circumstances and make DEI get closer to clinic application. The theoretical statistical models of DEI data in physics are analyzed and the proposed algorithm is validated with the experimental data at the Beijing Synchrotron Radiation Facility (BSRF). The results of ML-TS have better contrast compared with the well known 'shift-and-add' algorithm and FBP algorithm. (authors)

  20. Development of model observers applied to 3D breast tomosynthesis microcalcifications and masses

    Science.gov (United States)

    Diaz, Ivan; Timberg, Pontus; Zhang, Sheng; Abbey, Craig; Verdun, Francis; Bochud, François O.

    2011-03-01

    The development of model observers for mimicking human detection strategies has followed from symmetric signals in simple noise to increasingly complex backgrounds. In this study we implement different model observers for the complex task of detecting a signal in a 3D image stack. The backgrounds come from real breast tomosynthesis acquisitions and the signals were simulated and reconstructed within the volume. Two different tasks relevant to the early detection of breast cancer were considered: detecting an 8 mm mass and detecting a cluster of microcalcifications. The model observers were calculated using a channelized Hotelling observer (CHO) with dense difference-of-Gaussian channels, and a modified (Partial prewhitening [PPW]) observer which was adapted to realistic signals which are not circularly symmetric. The sustained temporal sensitivity function was used to filter the images before applying the spatial templates. For a frame rate of five frames per second, the only CHO that we calculated performed worse than the humans in a 4-AFC experiment. The other observers were variations of PPW and outperformed human observers in every single case. This initial frame rate was a rather low speed and the temporal filtering did not affect the results compared to a data set with no human temporal effects taken into account. We subsequently investigated two higher speeds at 5, 15 and 30 frames per second. We observed that for large masses, the two types of model observers investigated outperformed the human observers and would be suitable with the appropriate addition of internal noise. However, for microcalcifications both only the PPW observer consistently outperformed the humans. The study demonstrated the possibility of using a model observer which takes into account the temporal effects of scrolling through an image stack while being able to effectively detect a range of mass sizes and distributions.

  1. Computer-aided detection of clustered microcalcifications in digital breast tomosynthesis: A 3D approach

    Science.gov (United States)

    Sahiner, Berkman; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Helvie, Mark A.; Wei, Jun; Zhou, Chuan; Lu, Yao

    2012-01-01

    Purpose: To design a computer-aided detection (CADe) system for clustered microcalcifications in reconstructed digital breast tomosynthesis (DBT) volumes and to perform a preliminary evaluation of the CADe system. Methods: IRB approval and informed consent were obtained in this study. A data set of two-view DBT of 72 breasts containing microcalcification clusters was collected from 72 subjects who were scheduled to undergo breast biopsy. Based on tissue sampling results, 17 cases had breast cancer and 55 were benign. A separate data set of two-view DBT of 38 breasts free of clustered microcalcifications from 38 subjects was collected to independently estimate the number of false-positives (FPs) generated by the CADe system. A radiologist experienced in breast imaging marked the biopsied cluster of microcalcifications with a 3D bounding box using all available clinical and imaging information. A CADe system was designed to detect microcalcification clusters in the reconstructed volume. The system consisted of prescreening, clustering, and false-positive reduction stages. In the prescreening stage, the conspicuity of microcalcification-like objects was increased by an enhancement-modulated 3D calcification response function. An iterative thresholding and 3D object growing method was used to detect cluster seed objects, which were used as potential centers of microcalcification clusters. In the cluster detection stage, microcalcification candidates were identified using a second iterative thresholding procedure, which was applied to the signal-to-noise ratio (SNR) enhanced image voxels with a positive calcification response. Starting with each cluster seed object as the initial cluster center, a dynamic clustering algorithm formed a cluster candidate by including microcalcification candidates within a 3D neighborhood of the cluster seed object that satisfied the clustering criteria. The number, size, and SNR of the microcalcifications in a cluster candidate and the

  2. Forensic 3D Scene Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.

    1999-10-12

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  3. A task-based comparison of two reconstruction algorithms for digital breast tomosynthesis

    Science.gov (United States)

    Mahadevan, Ravi; Ikejimba, Lynda C.; Lin, Yuan; Samei, Ehsan; Lo, Joseph Y.

    2014-03-01

    Digital breast tomosynthesis (DBT) generates 3-D reconstructions of the breast by taking X-Ray projections at various angles around the breast. DBT improves cancer detection as it minimizes tissue overlap that is present in traditional 2-D mammography. In this work, two methods of reconstruction, filtered backprojection (FBP) and the Newton-Raphson iterative reconstruction were used to create 3-D reconstructions from phantom images acquired on a breast tomosynthesis system. The task based image analysis method was used to compare the performance of each reconstruction technique. The task simulated a 10mm lesion within the breast containing iodine concentrations between 0.0mg/ml and 8.6mg/ml. The TTF was calculated using the reconstruction of an edge phantom, and the NPS was measured with a structured breast phantom (CIRS 020) over different exposure levels. The detectability index d' was calculated to assess image quality of the reconstructed phantom images. Image quality was assessed for both conventional, single energy and dual energy subtracted reconstructions. Dose allocation between the high and low energy scans was also examined. Over the full range of dose allocations, the iterative reconstruction yielded a higher detectability index than the FBP for single energy reconstructions. For dual energy subtraction, detectability index was maximized when most of the dose was allocated to the high energy image. With that dose allocation, the performance trend for reconstruction algorithms reversed; FBP performed better than the corresponding iterative reconstruction. However, FBP performance varied very erratically with changing dose allocation. Therefore, iterative reconstruction is preferred for both imaging modalities despite underperforming dual energy FBP, as it provides stable results.

  4. Thin slice three dimentional (3D reconstruction versus CT 3D reconstruction of human breast cancer

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2013-01-01

    Full Text Available Background & objectives: With improvement in the early diagnosis of breast cancer, breast conserving therapy (BCT is being increasingly used. Precise preoperative evaluation of the incision margin is, therefore, very important. Utilizing three dimentional (3D images in a preoperative evaluation for breast conserving surgery has considerable significance, but the currently 3D CT scan reconstruction commonly used has problems in accurately displaying breast cancer. Thin slice 3D reconstruction is also widely used now to delineate organs and tissues of breast cancers. This study was aimed to compare 3D CT with thin slice 3D reconstruction in breast cancer patients to find a better technique for accurate evaluation of breast cancer. Methods: A total of 16-slice spiral CT scans and 3D reconstructions were performed on 15 breast cancer patients. All patients had been treated with modified radical mastectomy; 2D and 3D images of breast and tumours were obtained. The specimens were fixed and sliced at 2 mm thickness to obtain serial thin slice images, and reconstructed using 3D DOCTOR software to gain 3D images. Results: Compared with 2D CT images, thin slice images showed more clearly the morphological characteristics of tumour, breast tissues and the margins of different tissues in each slice. After 3D reconstruction, the tumour shapes obtained by the two reconstruction methods were basically the same, but the thin slice 3D reconstruction showed the tumour margins more clearly. Interpretation & conclusions: Compared with 3D CT reconstruction, thin slice 3D reconstruction of breast tumour gave clearer images, which could provide guidance for the observation and application of CT 3D reconstructed images and contribute to the accurate evaluation of tumours using CT imaging technology.

  5. 3-D Reconstruction From Satellite Images

    DEFF Research Database (Denmark)

    Denver, Troelz

    1999-01-01

    of planetary surfaces, but other purposes is considered as well. The system performance is measured with respect to the precision and the time consumption.The reconstruction process is divided into four major areas: Acquisition, calibration, matching/reconstruction and presentation. Each of these areas......, where various methods have been tested in order to optimize the performance. The match results are used in the reconstruction part to establish a 3-D digital representation and finally, different presentation forms are discussed....

  6. Neural Network Based 3D Surface Reconstruction

    Directory of Open Access Journals (Sweden)

    Vincy Joseph

    2009-11-01

    Full Text Available This paper proposes a novel neural-network-based adaptive hybrid-reflectance three-dimensional (3-D surface reconstruction model. The neural network combines the diffuse and specular components into a hybrid model. The proposed model considers the characteristics of each point and the variant albedo to prevent the reconstructed surface from being distorted. The neural network inputs are the pixel values of the two-dimensional images to be reconstructed. The normal vectors of the surface can then be obtained from the output of the neural network after supervised learning, where the illuminant direction does not have to be known in advance. Finally, the obtained normal vectors can be applied to integration method when reconstructing 3-D objects. Facial images were used for training in the proposed approach

  7. Quantification of resolution in multiplanar reconstructions for digital breast tomosynthesis

    Science.gov (United States)

    Vent, Trevor L.; Acciavatti, Raymond J.; Kwon, Young Joon; Maidment, Andrew D. A.

    2016-03-01

    Multiplanar reconstruction (MPR) in digital breast tomosynthesis (DBT) allows tomographic images to be portrayed in various orientations. We have conducted research to determine the resolution of tomosynthesis MPR. We built a phantom that houses a star test pattern to measure resolution. This phantom provides three rotational degrees of freedom. The design consists of two hemispheres with longitudinal and latitudinal grooves that reference angular increments. When joined together, the hemispheres form a dome that sits inside a cylindrical encasement. The cylindrical encasement contains reference notches to match the longitudinal and latitudinal grooves that guide the phantom's rotations. With this design, any orientation of the star-pattern can be analyzed. Images of the star-pattern were acquired using a DBT mammography system at the Hospital of the University of Pennsylvania. Images taken were reconstructed and analyzed by two different methods. First, the maximum visible frequency (in line pairs per millimeter) of the star test pattern was measured. Then, the contrast was calculated at a fixed spatial frequency. These analyses confirm that resolution decreases with tilt relative to the breast support. They also confirm that resolution in tomosynthesis MPR is dependent on object orientation. Current results verify that the existence of super-resolution depends on the orientation of the frequency; the direction parallel to x-ray tube motion shows super-resolution. In conclusion, this study demonstrates that the direction of the spatial frequency relative to the motion of the x-ray tube is a determinant of resolution in MPR for DBT.

  8. Numerical Methods for Coupled Reconstruction and Registration in Digital Breast Tomosynthesis

    CERN Document Server

    Yang, Guang; Hawkes, David J; Arridge, Simon R

    2013-01-01

    Digital Breast Tomosynthesis (DBT) provides an insight into the fine details of normal fibroglandular tissues and abnormal lesions by reconstructing a pseudo-3D image of the breast. In this respect, DBT overcomes a major limitation of conventional X-ray mammography by reducing the confounding effects caused by the superposition of breast tissue. In a breast cancer screening or diagnostic context, a radiologist is interested in detecting change, which might be indicative of malignant disease. To help automate this task image registration is required to establish spatial correspondence between time points. Typically, images, such as MRI or CT, are first reconstructed and then registered. This approach can be effective if reconstructing using a complete set of data. However, for ill-posed, limited-angle problems such as DBT, estimating the deformation is complicated by the significant artefacts associated with the reconstruction, leading to severe inaccuracies in the registration. This paper presents a mathemati...

  9. Fully 3D GPU PET reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Herraiz, J.L., E-mail: joaquin@nuclear.fis.ucm.es [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Espana, S. [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA (United States); Cal-Gonzalez, J. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain); Vaquero, J.J. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Desco, M. [Departmento de Bioingenieria e Ingenieria Espacial, Universidad Carlos III, Madrid (Spain); Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Udias, J.M. [Grupo de Fisica Nuclear, Departmento Fisica Atomica, Molecular y Nuclear, Universidad Complutense de Madrid (Spain)

    2011-08-21

    Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.

  10. Fully 3D GPU PET reconstruction

    International Nuclear Information System (INIS)

    Fully 3D iterative tomographic image reconstruction is computationally very demanding. Graphics Processing Unit (GPU) has been proposed for many years as potential accelerators in complex scientific problems, but it has not been used until the recent advances in the programmability of GPUs that the best available reconstruction codes have started to be implemented to be run on GPUs. This work presents a GPU-based fully 3D PET iterative reconstruction software. This new code may reconstruct sinogram data from several commercially available PET scanners. The most important and time-consuming parts of the code, the forward and backward projection operations, are based on an accurate model of the scanner obtained with the Monte Carlo code PeneloPET and they have been massively parallelized on the GPU. For the PET scanners considered, the GPU-based code is more than 70 times faster than a similar code running on a single core of a fast CPU, obtaining in both cases the same images. The code has been designed to be easily adapted to reconstruct sinograms from any other PET scanner, including scanner prototypes.

  11. 3D reconstruction of tensors and vectors

    Energy Technology Data Exchange (ETDEWEB)

    Defrise, Michel; Gullberg, Grant T.

    2005-02-17

    Here we have developed formulations for the reconstruction of 3D tensor fields from planar (Radon) and line-integral (X-ray) projections of 3D vector and tensor fields. Much of the motivation for this work is the potential application of MRI to perform diffusion tensor tomography. The goal is to develop a theory for the reconstruction of both Radon planar and X-ray or line-integral projections because of the flexibility of MRI to obtain both of these type of projections in 3D. The development presented here for the linear tensor tomography problem provides insight into the structure of the nonlinear MRI diffusion tensor inverse problem. A particular application of tensor imaging in MRI is the potential application of cardiac diffusion tensor tomography for determining in vivo cardiac fiber structure. One difficulty in the cardiac application is the motion of the heart. This presents a need for developing future theory for tensor tomography in a motion field. This means developing a better understanding of the MRI signal for diffusion processes in a deforming media. The techniques developed may allow the application of MRI tensor tomography for the study of structure of fiber tracts in the brain, atherosclerotic plaque, and spine in addition to fiber structure in the heart. However, the relations presented are also applicable to other fields in medical imaging such as diffraction tomography using ultrasound. The mathematics presented can also be extended to exponential Radon transform of tensor fields and to other geometric acquisitions such as cone beam tomography of tensor fields.

  12. A dynamic 3D foot reconstruction system.

    Science.gov (United States)

    Thabet, Ali K; Trucco, Emanuele; Salvi, Joaquim; Wang, Weijie; Abboud, Rami J

    2011-01-01

    Foot problems are varied and range from simple disorders through to complex diseases and joint deformities. Wherever possible, the use of insoles, or orthoses, is preferred over surgery. Current insole design techniques are based on static measurements of the foot, despite the fact that orthoses are prevalently used in dynamic conditions while walking or running. This paper presents the design and implementation of a structured-light prototype system providing dense three dimensional (3D) measurements of the foot in motion, and its use to show that foot measurements in dynamic conditions differ significantly from their static counterparts. The input to the system is a video sequence of a foot during a single step; the output is a 3D reconstruction of the plantar surface of the foot for each frame of the input. Engineering and clinical tests were carried out for the validation of the system. The accuracy of the system was found to be 0.34 mm with planar test objects. In tests with real feet, the system proved repeatable, with reconstruction differences between trials one week apart averaging 2.44 mm (static case) and 2.81 mm (dynamic case). Furthermore, a study was performed to compare the effective length of the foot between static and dynamic reconstructions using the 4D system. Results showed an average increase of 9 mm for the dynamic case. This increase is substantial for orthotics design, cannot be captured by a static system, and its subject-specific measurement is crucial for the design of effective foot orthoses.

  13. Inter-plane artifact suppression in tomosynthesis using 3D CT image data

    OpenAIRE

    Kim Jae G; Jin Seung O; Cho Min H; Lee Soo Y

    2011-01-01

    Abstract Background Despite its superb lateral resolution, flat-panel-detector (FPD) based tomosynthesis suffers from low contrast and inter-plane artifacts caused by incomplete cancellation of the projection components stemming from outside the focal plane. The incomplete cancellation of the projection components, mostly due to the limited scan angle in the conventional tomosynthesis scan geometry, often makes the image contrast too low to differentiate the malignant tissues from the backgro...

  14. A review of breast tomosynthesis. Part II. Image reconstruction, processing and analysis, and advanced applications.

    Science.gov (United States)

    Sechopoulos, Ioannis

    2013-01-01

    Many important post-acquisition aspects of breast tomosynthesis imaging can impact its clinical performance. Chief among them is the reconstruction algorithm that generates the representation of the three-dimensional breast volume from the acquired projections. But even after reconstruction, additional processes, such as artifact reduction algorithms, computer aided detection and diagnosis, among others, can also impact the performance of breast tomosynthesis in the clinical realm. In this two part paper, a review of breast tomosynthesis research is performed, with an emphasis on its medical physics aspects. In the companion paper, the first part of this review, the research performed relevant to the image acquisition process is examined. This second part will review the research on the post-acquisition aspects, including reconstruction, image processing, and analysis, as well as the advanced applications being investigated for breast tomosynthesis. PMID:23298127

  15. 3D Surface Reconstruction and Automatic Camera Calibration

    Science.gov (United States)

    Jalobeanu, Andre

    2004-01-01

    Illustrations in this view-graph presentation are presented on a Bayesian approach to 3D surface reconstruction and camera calibration.Existing methods, surface analysis and modeling,preliminary surface reconstruction results, and potential applications are addressed.

  16. Multiscale regularized reconstruction for enhancing microcalcification in digital breast tomosynthesis

    Science.gov (United States)

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir; Zhou, Chuan

    2012-03-01

    Digital breast tomosynthesis (DBT) holds strong promise for improving the sensitivity of detecting subtle mass lesions. Detection of microcalcifications is more difficult because of high noise and subtle signals in the large DBT volume. It is important to enhance the contrast-to-noise ratio (CNR) of microcalcifications in DBT reconstruction. A major challenge of implementing microcalcification enhancement or noise regularization in DBT reconstruction is to preserve the image quality of masses, especially those with ill-defined margins and subtle spiculations. We are developing a new multiscale regularization (MSR) method for the simultaneous algebraic reconstruction technique (SART) to improve the CNR of microcalcifications without compromising the quality of masses. Each DBT slice is stratified into different frequency bands via wavelet decomposition and the regularization method applies different degrees of regularization to different frequency bands to preserve features of interest and suppress noise. Regularization is constrained by a characteristic map to avoid smoothing subtle microcalcifications. The characteristic map is generated via image feature analysis to identify potential microcalcification locations in the DBT volume. The MSR method was compared to the non-convex total pvariation (TpV) method and SART with no regularization (NR) in terms of the CNR and the full width at half maximum of the line profiles intersecting calcifications and mass spiculations in DBT of human subjects. The results demonstrated that SART regularized by the MSR method was superior to the TpV method for subtle microcalcifications in terms of CNR enhancement. The MSR method preserved the quality of subtle spiculations better than the TpV method in comparison to NR.

  17. 3D Reconstruction by Kinect Sensor:A Brief Review

    Institute of Scientific and Technical Information of China (English)

    LI Shi-rui; TAO Ke-lu; WANG Si-yuan; LI Hai-yang; CAO Wei-guo; LI Hua

    2014-01-01

    While Kinect was originally designed as a motion sensing input device of the gaming console Microsoft Xbox 360 for gaming purposes, it’s easy-to-use, low-cost, reliability, speed of the depth measurement and relatively high quality of depth measurement make it can be used for 3D reconstruction. It could make 3D scanning technology more accessible to everyday users and turn 3D reconstruction models into much widely used asset for many applications. In this paper, we focus on Kinect 3D reconstruction.

  18. Reconstruction and analysis of shapes from 3D scans

    NARCIS (Netherlands)

    ter Haar, F.B.

    2009-01-01

    In this thesis we use 3D laser range scans for the acquisition, reconstruction, and analysis of 3D shapes. 3D laser range scanning has proven to be a fast and effective way to capture the surface of an object in a computer. Thousands of depth measurements represent a part of the surface geometry as

  19. 3D scene reconstruction based on 3D laser point cloud combining UAV images

    Science.gov (United States)

    Liu, Huiyun; Yan, Yangyang; Zhang, Xitong; Wu, Zhenzhen

    2016-03-01

    It is a big challenge capturing and modeling 3D information of the built environment. A number of techniques and technologies are now in use. These include GPS, and photogrammetric application and also remote sensing applications. The experiment uses multi-source data fusion technology for 3D scene reconstruction based on the principle of 3D laser scanning technology, which uses the laser point cloud data as the basis and Digital Ortho-photo Map as an auxiliary, uses 3DsMAX software as a basic tool for building three-dimensional scene reconstruction. The article includes data acquisition, data preprocessing, 3D scene construction. The results show that the 3D scene has better truthfulness, and the accuracy of the scene meet the need of 3D scene construction.

  20. 3D Equilibrium Reconstructions in DIII-D

    Science.gov (United States)

    Lao, L. L.; Ferraro, N. W.; Strait, E. J.; Turnbull, A. D.; King, J. D.; Hirshman, H. P.; Lazarus, E. A.; Sontag, A. C.; Hanson, J.; Trevisan, G.

    2013-10-01

    Accurate and efficient 3D equilibrium reconstruction is needed in tokamaks for study of 3D magnetic field effects on experimentally reconstructed equilibrium and for analysis of MHD stability experiments with externally imposed magnetic perturbations. A large number of new magnetic probes have been recently installed in DIII-D to improve 3D equilibrium measurements and to facilitate 3D reconstructions. The V3FIT code has been in use in DIII-D to support 3D reconstruction and the new magnetic diagnostic design. V3FIT is based on the 3D equilibrium code VMEC that assumes nested magnetic surfaces. V3FIT uses a pseudo-Newton least-square algorithm to search for the solution vector. In parallel, the EFIT equilibrium reconstruction code is being extended to allow for 3D effects using a perturbation approach based on an expansion of the MHD equations. EFIT uses the cylindrical coordinate system and can include the magnetic island and stochastic effects. Algorithms are being developed to allow EFIT to reconstruct 3D perturbed equilibria directly making use of plasma response to 3D perturbations from the GATO, MARS-F, or M3D-C1 MHD codes. DIII-D 3D reconstruction examples using EFIT and V3FIT and the new 3D magnetic data will be presented. Work supported in part by US DOE under DE-FC02-04ER54698, DE-FG02-95ER54309 and DE-AC05-06OR23100.

  1. Fully Automatic 3D Reconstruction of Histological Images

    CERN Document Server

    Bagci, Ulas

    2009-01-01

    In this paper, we propose a computational framework for 3D volume reconstruction from 2D histological slices using registration algorithms in feature space. To improve the quality of reconstructed 3D volume, first, intensity variations in images are corrected by an intensity standardization process which maps image intensity scale to a standard scale where similar intensities correspond to similar tissues. Second, a subvolume approach is proposed for 3D reconstruction by dividing standardized slices into groups. Third, in order to improve the quality of the reconstruction process, an automatic best reference slice selection algorithm is developed based on an iterative assessment of image entropy and mean square error of the registration process. Finally, we demonstrate that the choice of the reference slice has a significant impact on registration quality and subsequent 3D reconstruction.

  2. 3D Building Reconstruction Using Dense Photogrammetric Point Cloud

    Science.gov (United States)

    Malihi, S.; Valadan Zoej, M. J.; Hahn, M.; Mokhtarzade, M.; Arefi, H.

    2016-06-01

    Three dimensional models of urban areas play an important role in city planning, disaster management, city navigation and other applications. Reconstruction of 3D building models is still a challenging issue in 3D city modelling. Point clouds generated from multi view images of UAV is a novel source of spatial data, which is used in this research for building reconstruction. The process starts with the segmentation of point clouds of roofs and walls into planar groups. By generating related surfaces and using geometrical constraints plus considering symmetry, a 3d model of building is reconstructed. In a refinement step, dormers are extracted, and their models are reconstructed. The details of the 3d reconstructed model are in LoD3 level, with respect to modelling eaves, fractions of roof and dormers.

  3. A 3D Model Reconstruction Method Using Slice Images

    Institute of Scientific and Technical Information of China (English)

    LI Hong-an; KANG Bao-sheng

    2013-01-01

    Aiming at achieving the high accuracy 3D model from slice images, a new model reconstruction method using slice im-ages is proposed. Wanting to extract the outermost contours from slice images, the method of the improved GVF-Snake model with optimized force field and ray method is employed. And then, the 3D model is reconstructed by contour connection using the im-proved shortest diagonal method and judgment function of contour fracture. The results show that the accuracy of reconstruction 3D model is improved.

  4. ECG gated tomographic reconstruction for 3-D rotational coronary angiography

    Science.gov (United States)

    Hu, Yining; Xie, Lizhe; Nunes, Jean Claude; Bellanger, Jean Jacques; Bedossa, Marc; Toumoulin, Christine

    2010-01-01

    A method is proposed for 3-D reconstruction of coronary from a limited number of projections in rotational angiography. A Bayesian maximum a posteriori (MAP) estimation is applied with a Poisson distributed projection to reconstruct the 3D coronary tree at a given instant of the cardiac cycle. Several regularizers are investigated L0-norm, L1 and L2 -norm in order to take into account the sparsity of the data. Evaluations are reported on simulated data obtained from a 3D dynamic sequence acquired on a 64-slice GE LightSpeed CT scan. A performance study is conducted to evaluate the quality of the reconstruction of the structures. PMID:21096844

  5. Reconstruction of 3-D digital cores using a hybrid method

    Institute of Scientific and Technical Information of China (English)

    Liu Xuefeng; Sun Jianmeng; Wang Haitao

    2009-01-01

    A 3-D digital core describes the pore space microstructure of rocks. An X-ray micro CT scan is the most accurate and direct but costly method to obtain a 3-D digital core. In this study, we propose a hybrid method which combines sedimentation simulation and simulated annealing (SA) method to generate 3-D digital cores based on 2-D images of rocks. The method starts with the sedimentation simulation to build a 3-D digital core, which is the initial configuration for the SA method. We update the initial digital core using the SA method to match the auto-correlation function of the 2-D rock image and eventually build the final 3-D digital core. Compared with the typical SA method, the hybrid method has significantly reduced the computation time. Local porosity theory is applied to quantitatively compare the reconstructed 3-D digital cores with the X-ray micro CT 3-D images. The results indicate that the 3-D digital cores reconstructed by the hybrid method have homogeneity and geometric connectivity similar to those of the X-ray micro CT image. The formation factors and permeabilities of the reconstructed 3-D digital cores are estimated using the finite element method (FEM) and lattice Boltzmann method (LBM), respectively. The simulated results are in good agreement with the experimental measurements. Comparison of the simulation results suggests that the digital cores reconstructed by the hybrid method more closely reflect the true transport properties than the typical SA method alone.

  6. Interior Reconstruction Using the 3d Hough Transform

    Science.gov (United States)

    Dumitru, R.-C.; Borrmann, D.; Nüchter, A.

    2013-02-01

    Laser scanners are often used to create accurate 3D models of buildings for civil engineering purposes, but the process of manually vectorizing a 3D point cloud is time consuming and error-prone (Adan and Huber, 2011). Therefore, the need to characterize and quantify complex environments in an automatic fashion arises, posing challenges for data analysis. This paper presents a system for 3D modeling by detecting planes in 3D point clouds, based on which the scene is reconstructed at a high architectural level through removing automatically clutter and foreground data. The implemented software detects openings, such as windows and doors and completes the 3D model by inpainting.

  7. Application of CT 3D reconstruction in diagnosing atlantoaxial subluxation

    Institute of Scientific and Technical Information of China (English)

    段少银; 林清池; 庞瑞麟

    2004-01-01

    Objective:To evaluate and compare the diagnostic value in atlantoaxial subluxation by CT three-dimensional (3D) reconstruction.Methods:3D reconstruction fimdings of 41 patients with atlantoaxiai subluxation were retrospectively analyzed, and comparisons were made among images of transverse section, multiplanar reformorting (MPR), surface shade display (SSD), maximum intensity project (MIP), and volume rendering (VR). Results:Of 41 patients with atlantoaxial subluxation, 31 belonged to rotary dislocation, 5 antedislocation, and 5 hind dislocation. All the cases showed the dislocated joint panel of atlantoaxial articulation.Fifteen cases showed deviation of the odontoid process and 8 cases widened distance between the dens and anterior arch of the atlas. The dislocated joint panel of atlantoaxial articulation was more clearly seen with SSD-3D imaging than any other methods. Conclusions:Atlantoaxial subluxation can well be diagnosed by CT 3D reconstruction, in which SSD-3D imaging is optimal.

  8. Array antenna diagnostics with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Meincke, Peter; Pivnenko, Sergey;

    2012-01-01

    The 3D reconstruction algorithm is applied to a slotted waveguide array measured at the DTU-ESA Spherical Near-Field Antenna Test Facility. One slot of the array is covered by conductive tape and an error is present in the array excitation. Results show the accuracy obtainable by the 3D...

  9. Stereo Based 3D Face Reconstruction

    OpenAIRE

    Falešník, Milan

    2013-01-01

    Tato práce se zabývá vytvořením programu pro rekonstrukc trojrozměrného modelu lidské tváře za pomocí dvojice kamer. Pro řešení využívá výpočtu hloubkové mapy a následný převod do trojrozměrného prostoru. Využívá Viola-Jones detektor pro detekci tváře. Využívá knihovny OpenCV a také částečně PCL. This thesis presents a system for reconstruction of three-dimensional model of human face by using pair of cameras. To solve this problem, depth map calculation is used and then the depth map is t...

  10. Reconstruction of High Resolution 3D Objects from Incomplete Images and 3D Information

    Directory of Open Access Journals (Sweden)

    Alexander Pacheco

    2014-05-01

    Full Text Available To this day, digital object reconstruction is a quite complex area that requires many techniques and novel approaches, in which high-resolution 3D objects present one of the biggest challenges. There are mainly two different methods that can be used to reconstruct high resolution objects and images: passive methods and active methods. This methods depend on the type of information available as input for modeling 3D objects. The passive methods use information contained in the images and the active methods make use of controlled light sources, such as lasers. The reconstruction of 3D objects is quite complex and there is no unique solution- The use of specific methodologies for the reconstruction of certain objects it’s also very common, such as human faces, molecular structures, etc. This paper proposes a novel hybrid methodology, composed by 10 phases that combine active and passive methods, using images and a laser in order to supplement the missing information and obtain better results in the 3D object reconstruction. Finally, the proposed methodology proved its efficiency in two complex topological complex objects.

  11. APPLICATION OF 3D MODELING IN 3D PRINTING FOR THE LOWER JAW RECONSTRUCTION

    Directory of Open Access Journals (Sweden)

    Yu. Yu. Dikov

    2015-01-01

    Full Text Available Aim of study: improvement of functional and aesthetic results of microsurgery reconstructions of the lower jaw due to the use of the methodology of 3D modeling and 3D printing. Application of this methodology has been demonstrated on the example of treatment of 4 patients with locally distributed tumors of the mouth cavity, who underwent excision of the tumor with simultaneous reconstruction of the lower jaw with revascularized fibular graft.Before, one patient has already undergo segmental resection of the lower jaw with the defect replacement with the avascular ileac graft and a reconstruction plate. Then, a relapse of the disease and lysis of the graft has developed with him. Modeling of the graft according to the shape of the lower jaw was performed by making osteotomies of the bone part of the graft using three-dimensional virtual models created by computed tomography data. Then these 3D models were printed with a 3D printer of plastic with the scale of 1:1 with the fused deposition modeling (FDM technology and were used during the surgery in the course of modeling of the graft. Sterilizing of the plastic model was performed in the formalin chamber.This methodology allowed more specific reconstruction of the resected fragment of the lower jaw and get better functional and aesthetic results and prepare patients to further dental rehabilitation. Advantages of this methodology are the possibility of simultaneous performance of stages of reconstruction and resection and shortening of the time of surgery.

  12. A new algorithm for 3D reconstruction from support functions

    DEFF Research Database (Denmark)

    Gardner, Richard; Kiderlen, Markus

    2009-01-01

    We introduce a new algorithm for reconstructing an unknown shape from a finite number of noisy measurements of its support function. The algorithm, based on a least squares procedure, is very easy to program in standard software such as Matlab and allows, for the first time, good 3D reconstructions...

  13. Filtering of measurement noise with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Pivnenko, Sergey

    2014-01-01

    Two different antenna models are set up in GRASP and CHAMP, and noise is added to the radiated field. The noisy field is then given as input to the 3D reconstruction of DIATOOL and the SWE coefficients and the far-field radiated by the reconstructed currents are compared with the noise-free results...

  14. Light field display and 3D image reconstruction

    Science.gov (United States)

    Iwane, Toru

    2016-06-01

    Light field optics and its applications become rather popular in these days. With light field optics or light field thesis, real 3D space can be described in 2D plane as 4D data, which we call as light field data. This process can be divided in two procedures. First, real3D scene is optically reduced with imaging lens. Second, this optically reduced 3D image is encoded into light field data. In later procedure we can say that 3D information is encoded onto a plane as 2D data by lens array plate. This transformation is reversible and acquired light field data can be decoded again into 3D image with the arrayed lens plate. "Refocusing" (focusing image on your favorite point after taking a picture), light-field camera's most popular function, is some kind of sectioning process from encoded 3D data (light field data) to 2D image. In this paper at first I show our actual light field camera and our 3D display using acquired and computer-simulated light field data, on which real 3D image is reconstructed. In second I explain our data processing method whose arithmetic operation is performed not in Fourier domain but in real domain. Then our 3D display system is characterized by a few features; reconstructed image is of finer resolutions than density of arrayed lenses and it is not necessary to adjust lens array plate to flat display on which light field data is displayed.

  15. Improving automated 3D reconstruction methods via vision metrology

    Science.gov (United States)

    Toschi, Isabella; Nocerino, Erica; Hess, Mona; Menna, Fabio; Sargeant, Ben; MacDonald, Lindsay; Remondino, Fabio; Robson, Stuart

    2015-05-01

    This paper aims to provide a procedure for improving automated 3D reconstruction methods via vision metrology. The 3D reconstruction problem is generally addressed using two different approaches. On the one hand, vision metrology (VM) systems try to accurately derive 3D coordinates of few sparse object points for industrial measurement and inspection applications; on the other, recent dense image matching (DIM) algorithms are designed to produce dense point clouds for surface representations and analyses. This paper strives to demonstrate a step towards narrowing the gap between traditional VM and DIM approaches. Efforts are therefore intended to (i) test the metric performance of the automated photogrammetric 3D reconstruction procedure, (ii) enhance the accuracy of the final results and (iii) obtain statistical indicators of the quality achieved in the orientation step. VM tools are exploited to integrate their main functionalities (centroid measurement, photogrammetric network adjustment, precision assessment, etc.) into the pipeline of 3D dense reconstruction. Finally, geometric analyses and accuracy evaluations are performed on the raw output of the matching (i.e. the point clouds) by adopting a metrological approach. The latter is based on the use of known geometric shapes and quality parameters derived from VDI/VDE guidelines. Tests are carried out by imaging the calibrated Portable Metric Test Object, designed and built at University College London (UCL), UK. It allows assessment of the performance of the image orientation and matching procedures within a typical industrial scenario, characterised by poor texture and known 3D/2D shapes.

  16. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    Directory of Open Access Journals (Sweden)

    ZHANG Chunsen

    2015-07-01

    Full Text Available This paper proposes a city texture fast reconstruction method based on aerial tilt image for reconstruction of three-dimensional city model. Based on the photogrammetry and computer vision theory and using the city building digital surface model obtained by prior treatment, through collinear equation calculation geometric projection of object and image space, to obtain the three-dimensional information and texture information of the structure and through certain the optimal algorithm selecting the optimal texture on the surface of the object, realize automatic extraction of the building side texture and occlusion handling of the dense building texture. The real image texture reconstruction results show that: the method to the 3D city model texture reconstruction has the characteristics of high degree of automation, vivid effect and low cost and provides a means of effective implementation for rapid and widespread real texture rapid reconstruction of city 3D model.

  17. Building with Drones: Accurate 3D Facade Reconstruction using MAVs

    OpenAIRE

    Daftry, Shreyansh; Hoppe, Christof; Bischof, Horst

    2015-01-01

    Automatic reconstruction of 3D models from images using multi-view Structure-from-Motion methods has been one of the most fruitful outcomes of computer vision. These advances combined with the growing popularity of Micro Aerial Vehicles as an autonomous imaging platform, have made 3D vision tools ubiquitous for large number of Architecture, Engineering and Construction applications among audiences, mostly unskilled in computer vision. However, to obtain high-resolution and accurate reconstruc...

  18. 3D surface reconstruction multi-scale hierarchical approaches

    CERN Document Server

    Bellocchio, Francesco; Ferrari, Stefano; Piuri, Vincenzo

    2012-01-01

    3D Surface Reconstruction: Multi-Scale Hierarchical Approaches presents methods to model 3D objects in an incremental way so as to capture more finer details at each step. The configuration of the model parameters, the rationale and solutions are described and discussed in detail so the reader has a strong understanding of the methodology. Modeling starts from data captured by 3D digitizers and makes the process even more clear and engaging. Innovative approaches, based on two popular machine learning paradigms, namely Radial Basis Functions and the Support Vector Machines, are also introduced

  19. 3D reconstruction based on spatial vanishing information

    Institute of Scientific and Technical Information of China (English)

    Yuan Shu; Zheng Tan

    2005-01-01

    An approach for the three-dimensional (3D) reconstruction of architectural scenes from two un-calibrated images is described in this paper. From two views of one architectural structure, three pairs of corresponding vanishing points of three major mutual orthogonal directions can be extracted. The simple but powerful constraints of parallelism and orthogonal lines in architectural scenes can be used to calibrate the cameras and to recover the 3D information of the structure. This approach is applied to the real images of architectural scenes, and a 3D model of a building in virtual reality modelling language (VRML) format is presented which illustrates the method with successful performance.

  20. New Reconstruction Accuracy Metric for 3D PIV

    Science.gov (United States)

    Bajpayee, Abhishek; Techet, Alexandra

    2015-11-01

    Reconstruction for 3D PIV typically relies on recombining images captured from different viewpoints via multiple cameras/apertures. Ideally, the quality of reconstruction dictates the accuracy of the derived velocity field. A reconstruction quality parameter Q is commonly used as a measure of the accuracy of reconstruction algorithms. By definition, a high Q value requires intensity peak levels and shapes in the reconstructed and reference volumes to be matched. We show that accurate velocity fields rely only on the peak locations in the volumes and not on intensity peak levels and shapes. In synthetic aperture (SA) PIV reconstructions, the intensity peak shapes and heights vary with the number of cameras and due to spatial/temporal particle intensity variation respectively. This lowers Q but not the accuracy of the derived velocity field. We introduce a new velocity vector correlation factor Qv as a metric to assess the accuracy of 3D PIV techniques, which provides a better indication of algorithm accuracy. For SAPIV, the number of cameras required for a high Qv are lower than that for a high Q. We discuss Qv in the context of 3D PIV and also present a preliminary comparison of the performance of TomoPIV and SAPIV based on Qv.

  1. 3D Reconstruction of Human Motion from Monocular Image Sequences.

    Science.gov (United States)

    Wandt, Bastian; Ackermann, Hanno; Rosenhahn, Bodo

    2016-08-01

    This article tackles the problem of estimating non-rigid human 3D shape and motion from image sequences taken by uncalibrated cameras. Similar to other state-of-the-art solutions we factorize 2D observations in camera parameters, base poses and mixing coefficients. Existing methods require sufficient camera motion during the sequence to achieve a correct 3D reconstruction. To obtain convincing 3D reconstructions from arbitrary camera motion, our method is based on a-priorly trained base poses. We show that strong periodic assumptions on the coefficients can be used to define an efficient and accurate algorithm for estimating periodic motion such as walking patterns. For the extension to non-periodic motion we propose a novel regularization term based on temporal bone length constancy. In contrast to other works, the proposed method does not use a predefined skeleton or anthropometric constraints and can handle arbitrary camera motion. We achieve convincing 3D reconstructions, even under the influence of noise and occlusions. Multiple experiments based on a 3D error metric demonstrate the stability of the proposed method. Compared to other state-of-the-art methods our algorithm shows a significant improvement.

  2. 3D Reconstruction of Human Motion from Monocular Image Sequences.

    Science.gov (United States)

    Wandt, Bastian; Ackermann, Hanno; Rosenhahn, Bodo

    2016-08-01

    This article tackles the problem of estimating non-rigid human 3D shape and motion from image sequences taken by uncalibrated cameras. Similar to other state-of-the-art solutions we factorize 2D observations in camera parameters, base poses and mixing coefficients. Existing methods require sufficient camera motion during the sequence to achieve a correct 3D reconstruction. To obtain convincing 3D reconstructions from arbitrary camera motion, our method is based on a-priorly trained base poses. We show that strong periodic assumptions on the coefficients can be used to define an efficient and accurate algorithm for estimating periodic motion such as walking patterns. For the extension to non-periodic motion we propose a novel regularization term based on temporal bone length constancy. In contrast to other works, the proposed method does not use a predefined skeleton or anthropometric constraints and can handle arbitrary camera motion. We achieve convincing 3D reconstructions, even under the influence of noise and occlusions. Multiple experiments based on a 3D error metric demonstrate the stability of the proposed method. Compared to other state-of-the-art methods our algorithm shows a significant improvement. PMID:27093439

  3. Automated 3D reconstruction of interiors with multiple scan views

    Science.gov (United States)

    Sequeira, Vitor; Ng, Kia C.; Wolfart, Erik; Goncalves, Joao G. M.; Hogg, David C.

    1998-12-01

    This paper presents two integrated solutions for realistic 3D model acquisition and reconstruction; an early prototype, in the form of a push trolley, and a later prototype in the form of an autonomous robot. The systems encompass all hardware and software required, from laser and video data acquisition, processing and output of texture-mapped 3D models in VRML format, to batteries for power supply and wireless network communications. The autonomous version is also equipped with a mobile platform and other sensors for the purpose of automatic navigation. The applications for such a system range from real estate and tourism (e.g., showing a 3D computer model of a property to a potential buyer or tenant) or as tool for content creation (e.g., creating 3D models of heritage buildings or producing broadcast quality virtual studios). The system can also be used in industrial environments as a reverse engineering tool to update the design of a plant, or as a 3D photo-archive for insurance purposes. The system is Internet compatible: the photo-realistic models can be accessed via the Internet and manipulated interactively in 3D using a common Web browser with a VRML plug-in. Further information and example reconstructed models are available on- line via the RESOLV web-page at http://www.scs.leeds.ac.uk/resolv/.

  4. 3-D flame temperature field reconstruction with multiobjective neural network

    Institute of Scientific and Technical Information of China (English)

    Xiong Wan(万雄); Yiqing Gao(高益庆); Yuanmei Wang(汪元美)

    2003-01-01

    A novel 3-D temperature field reconstruction method is proposed in this paper, which is based on multi-wavelength thermometry and Hopfield neural network computed tomography. A mathematical modelof multi-wavelength thermometry is founded, and a neural network algorithm based on multiobjectiveoptimization is developed. Through computer simulation and comparison with the algebraic reconstructiontechnique (ART) and the filter back-projection algorithm (FBP), the reconstruction result of the newmethod is discussed in detail. The study shows that the new method always gives the best reconstructionresults. At last, temperature distribution of a section of four peaks candle flame is reconstructed with thisnovel method.

  5. [Customized 3D radiographic reconstruction of the human pelvis].

    Science.gov (United States)

    Gauvin, C; Dansereau, J; Petit, Y; De Guise, J A; Labelle, H

    1998-01-01

    The pelvis is an essential element in the study of scoliosis since it constitutes the base of the spine and its orientation may affects postural balance. In order to study the role of the pelvis in the evolution and treatment of this disease, a new technique for the 3D personalised reconstruction of the pelvis was developed. It consists in identifying and digitizing 19 pelvic anatomical landmarks on postero-anterior and lateral x-rays and to reconstruct them in 3D with two techniques: the DLT algorithm developed by Marzan (1976) and, for 6 of the 19 landmarks, an adaptation of it called DLT with confidence coefficients. The latter takes into account the confidence given to the identification of the landmarks on each x-rays. Two methods were used to validate the reconstruction of the pelvis. The first one, used for 11 scoliotic patients and 2 dry pelvis specimens, consists in applying the reconstruction algorithm in an inverse way on the 3D coordinates of the reconstructed landmarks to obtain their 2D retroprojection on the x-ray planes, and thus comparing the retroprojected coordinates with the 2D digitized coordinates. The second method consists in measuring a dry pelvis specimen and comparing the 3D measured landmarks with the ones reconstructed with the x-rays of this specimen. For the first validation, results have shown that the lowest retroprojection errors (less than 2.5 +/- 2.6 mm) for the scoliotic patient group are located on the superior base of the sacrum, on the sacral curve and on the acetabula, while the highest (6.4 +/- 7.2 mm) were on the iliac crests. For the dry specimens, the retroprojection errors were below the millimeter. The second validation method showed 3D differences of 2.4 +/- 1.2 mm between measured and reconstructed landmarks of a dry specimen, which is of the same order of magnitude as what is reported in the literature for vertebrae. The reconstruction of the pelvis is thus considered adequate and its graphical wireframe

  6. Recent advances in 3D SEM surface reconstruction.

    Science.gov (United States)

    Tafti, Ahmad P; Kirkpatrick, Andrew B; Alavi, Zahrasadat; Owen, Heather A; Yu, Zeyun

    2015-11-01

    The scanning electron microscope (SEM), as one of the most commonly used instruments in biology and material sciences, employs electrons instead of light to determine the surface properties of specimens. However, the SEM micrographs still remain 2D images. To effectively measure and visualize the surface attributes, we need to restore the 3D shape model from the SEM images. 3D surface reconstruction is a longstanding topic in microscopy vision as it offers quantitative and visual information for a variety of applications consisting medicine, pharmacology, chemistry, and mechanics. In this paper, we attempt to explain the expanding body of the work in this area, including a discussion of recent techniques and algorithms. With the present work, we also enhance the reliability, accuracy, and speed of 3D SEM surface reconstruction by designing and developing an optimized multi-view framework. We then consider several real-world experiments as well as synthetic data to examine the qualitative and quantitative attributes of our proposed framework. Furthermore, we present a taxonomy of 3D SEM surface reconstruction approaches and address several challenging issues as part of our future work.

  7. 3D/3D registration of coronary CTA and biplane XA reconstructions for improved image guidance

    Energy Technology Data Exchange (ETDEWEB)

    Dibildox, Gerardo, E-mail: g.dibildox@erasmusmc.nl; Baka, Nora; Walsum, Theo van [Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Punt, Mark; Aben, Jean-Paul [Pie Medical Imaging, 6227 AJ Maastricht (Netherlands); Schultz, Carl [Department of Cardiology, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands); Niessen, Wiro [Quantitative Imaging Group, Faculty of Applied Sciences, Delft University of Technology, 2628 CJ Delft, The Netherlands and Biomedical Imaging Group Rotterdam, Departments of Radiology and Medical Informatics, Erasmus Medical Center, 3015 GE Rotterdam (Netherlands)

    2014-09-15

    Purpose: The authors aim to improve image guidance during percutaneous coronary interventions of chronic total occlusions (CTO) by providing information obtained from computed tomography angiography (CTA) to the cardiac interventionist. To this end, the authors investigate a method to register a 3D CTA model to biplane reconstructions. Methods: The authors developed a method for registering preoperative coronary CTA with intraoperative biplane x-ray angiography (XA) images via 3D models of the coronary arteries. The models are extracted from the CTA and biplane XA images, and are temporally aligned based on CTA reconstruction phase and XA ECG signals. Rigid spatial alignment is achieved with a robust probabilistic point set registration approach using Gaussian mixture models (GMMs). This approach is extended by including orientation in the Gaussian mixtures and by weighting bifurcation points. The method is evaluated on retrospectively acquired coronary CTA datasets of 23 CTO patients for which biplane XA images are available. Results: The Gaussian mixture model approach achieved a median registration accuracy of 1.7 mm. The extended GMM approach including orientation was not significantly different (P > 0.1) but did improve robustness with regards to the initialization of the 3D models. Conclusions: The authors demonstrated that the GMM approach can effectively be applied to register CTA to biplane XA images for the purpose of improving image guidance in percutaneous coronary interventions.

  8. 3D reconstruction of multiple stained histology images

    Directory of Open Access Journals (Sweden)

    Yi Song

    2013-01-01

    Full Text Available Context: Three dimensional (3D tissue reconstructions from the histology images with different stains allows the spatial alignment of structural and functional elements highlighted by different stains for quantitative study of many physiological and pathological phenomena. This has significant potential to improve the understanding of the growth patterns and the spatial arrangement of diseased cells, and enhance the study of biomechanical behavior of the tissue structures towards better treatments (e.g. tissue-engineering applications. Methods: This paper evaluates three strategies for 3D reconstruction from sets of two dimensional (2D histological sections with different stains, by combining methods of 2D multi-stain registration and 3D volumetric reconstruction from same stain sections. Setting and Design: The different strategies have been evaluated on two liver specimens (80 sections in total stained with Hematoxylin and Eosin (H and E, Sirius Red, and Cytokeratin (CK 7. Results and Conclusion: A strategy of using multi-stain registration to align images of a second stain to a volume reconstructed by same-stain registration results in the lowest overall error, although an interlaced image registration approach may be more robust to poor section quality.

  9. Deformable Surface 3D Reconstruction from Monocular Images

    CERN Document Server

    Salzmann, Matthieu

    2010-01-01

    Being able to recover the shape of 3D deformable surfaces from a single video stream would make it possible to field reconstruction systems that run on widely available hardware without requiring specialized devices. However, because many different 3D shapes can have virtually the same projection, such monocular shape recovery is inherently ambiguous. In this survey, we will review the two main classes of techniques that have proved most effective so far: The template-based methods that rely on establishing correspondences with a reference image in which the shape is already known, and non-rig

  10. Use of the Hotelling observer to optimize image reconstruction in digital breast tomosynthesis.

    Science.gov (United States)

    Sánchez, Adrian A; Sidky, Emil Y; Pan, Xiaochuan

    2016-01-01

    We propose an implementation of the Hotelling observer that can be applied to the optimization of linear image reconstruction algorithms in digital breast tomosynthesis. The method is based on considering information within a specific region of interest, and it is applied to the optimization of algorithms for detectability of microcalcifications. Several linear algorithms are considered: simple back-projection, filtered back-projection, back-projection filtration, and [Formula: see text]-tomography. The optimized algorithms are then evaluated through the reconstruction of phantom data. The method appears robust across algorithms and parameters and leads to the generation of algorithm implementations which subjectively appear optimized for the task of interest. PMID:26702408

  11. 3D reconstruction methods of coronal structures by radio observations

    Science.gov (United States)

    Aschwanden, Markus J.; Bastian, T. S.; White, Stephen M.

    1992-11-01

    The ability to carry out the three dimensional (3D) reconstruction of structures in the solar corona would represent a major advance in the study of the physical properties in active regions and in flares. Methods which allow a geometric reconstruction of quasistationary coronal structures (for example active region loops) or dynamic structures (for example flaring loops) are described: stereoscopy of multi-day imaging observations by the VLA (Very Large Array); tomography of optically thin emission (in radio or soft x-rays); multifrequency band imaging by the VLA; and tracing of magnetic field lines by propagating electron beams.

  12. Low contrast 3D reconstruction from C-arm data

    Science.gov (United States)

    Zellerhoff, M.; Scholz, B.; Ruehrnschopf, E.-P.; Brunner, T.

    2005-04-01

    The integration of 3D-imaging functionality into C-arm systems combines advantages of interventional X-ray systems, e.g. good patient access and live fluoroscopy, with 3D imaging capabilities similar to those of a CT-scanner. To date 3D-imaging with a C-arm system has been mainly used to visualize high contrast objects. However, the advent of high quality flat panel detectors improves the low contrast imaging capabilities. We discuss the influence of scattered radiation, beam hardening, truncated projections, quantization and detector recording levels on the image quality. Subsequently, we present algorithms and methods to correct these effects in order to achieve low contrast resolution. The performance of our pre- and post-reconstructive correction procedures is demonstrated by first clinical cases.

  13. Twenty-fold acceleration of 3D projection reconstruction MPI

    OpenAIRE

    Konkle, Justin J.; Goodwill, Patrick W.; Saritas, Emine Ulku; Zheng, Bo; Lu, Kuan; Conolly, Steven M.

    2013-01-01

    We experimentally demonstrate a 20-fold improvement in acquisition time in projection reconstruction (PR) magnetic particle imaging (MPI) relative to the state-of-the-art PR MPI imaging results. We achieve this acceleration in our imaging system by introducing an additional Helmholtz electromagnet pair, which creates a slow shift (focus) field. Because of magnetostimulation limits in humans, we show that scan time with three-dimensional (3D) PR MPI is theoretically within the same order of ma...

  14. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    Science.gov (United States)

    Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

    2016-08-01

    Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling.

  15. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    Science.gov (United States)

    Tafti, Ahmad P; Holz, Jessica D; Baghaie, Ahmadreza; Owen, Heather A; He, Max M; Yu, Zeyun

    2016-08-01

    Structural analysis of microscopic objects is a longstanding topic in several scientific disciplines, such as biological, mechanical, and materials sciences. The scanning electron microscope (SEM), as a promising imaging equipment has been around for decades to determine the surface properties (e.g., compositions or geometries) of specimens by achieving increased magnification, contrast, and resolution greater than one nanometer. Whereas SEM micrographs still remain two-dimensional (2D), many research and educational questions truly require knowledge and facts about their three-dimensional (3D) structures. 3D surface reconstruction from SEM images leads to remarkable understanding of microscopic surfaces, allowing informative and qualitative visualization of the samples being investigated. In this contribution, we integrate several computational technologies including machine learning, contrario methodology, and epipolar geometry to design and develop a novel and efficient method called 3DSEM++ for multi-view 3D SEM surface reconstruction in an adaptive and intelligent fashion. The experiments which have been performed on real and synthetic data assert the approach is able to reach a significant precision to both SEM extrinsic calibration and its 3D surface modeling. PMID:27200484

  16. An automated 3D reconstruction method of UAV images

    Science.gov (United States)

    Liu, Jun; Wang, He; Liu, Xiaoyang; Li, Feng; Sun, Guangtong; Song, Ping

    2015-10-01

    In this paper a novel fully automated 3D reconstruction approach based on low-altitude unmanned aerial vehicle system (UAVs) images will be presented, which does not require previous camera calibration or any other external prior knowledge. Dense 3D point clouds are generated by integrating orderly feature extraction, image matching, structure from motion (SfM) and multi-view stereo (MVS) algorithms, overcoming many of the cost, time limitations of rigorous photogrammetry techniques. An image topology analysis strategy is introduced to speed up large scene reconstruction by taking advantage of the flight-control data acquired by UAV. Image topology map can significantly reduce the running time of feature matching by limiting the combination of images. A high-resolution digital surface model of the study area is produced base on UAV point clouds by constructing the triangular irregular network. Experimental results show that the proposed approach is robust and feasible for automatic 3D reconstruction of low-altitude UAV images, and has great potential for the acquisition of spatial information at large scales mapping, especially suitable for rapid response and precise modelling in disaster emergency.

  17. Projective 3D-reconstruction of Uncalibrated Endoscopic Images

    Directory of Open Access Journals (Sweden)

    P. Faltin

    2010-01-01

    Full Text Available The most common medical diagnostic method for urinary bladder cancer is cystoscopy. This inspection of the bladder is performed by a rigid endoscope, which is usually guided close to the bladder wall. This causes a very limited field of view; difficulty of navigation is aggravated by the usage of angled endoscopes. These factors cause difficulties in orientation and visual control. To overcome this problem, the paper presents a method for extracting 3D information from uncalibrated endoscopic image sequences and for reconstructing the scene content. The method uses the SURF-algorithm to extract features from the images and relates the images by advanced matching. To stabilize the matching, the epipolar geometry is extracted for each image pair using a modified RANSAC-algorithm. Afterwards these matched point pairs are used to generate point triplets over three images and to describe the trifocal geometry. The 3D scene points are determined by applying triangulation to the matched image points. Thus, these points are used to generate a projective 3D reconstruction of the scene, and provide the first step for further metric reconstructions.

  18. Weighted simultaneous algebraic reconstruction technique for tomosynthesis imaging of objects with high-attenuation features

    Energy Technology Data Exchange (ETDEWEB)

    Levakhina, Y. M. [Institute of Medical Engineering, University of Luebeck, Luebeck 23562, Germany and Graduate School for Computing in Medicine and Life Sciences, Luebeck 23562 (Germany); Mueller, J.; Buzug, T. M. [Institute of Medical Engineering, University of Luebeck, Luebeck 23562 (Germany); Duschka, R. L.; Vogt, F.; Barkhausen, J. [Clinic for Radiology, University Clinics Schleswig-Holstein, Luebeck 23562 (Germany)

    2013-03-15

    Purpose: This paper introduces a nonlinear weighting scheme into the backprojection operation within the simultaneous algebraic reconstruction technique (SART). It is designed for tomosynthesis imaging of objects with high-attenuation features in order to reduce limited angle artifacts. Methods: The algorithm estimates which projections potentially produce artifacts in a voxel. The contribution of those projections into the updating term is reduced. In order to identify those projections automatically, a four-dimensional backprojected space representation is used. Weighting coefficients are calculated based on a dissimilarity measure, evaluated in this space. For each combination of an angular view direction and a voxel position an individual weighting coefficient for the updating term is calculated. Results: The feasibility of the proposed approach is shown based on reconstructions of the following real three-dimensional tomosynthesis datasets: a mammography quality phantom, an apple with metal needles, a dried finger bone in water, and a human hand. Datasets have been acquired with a Siemens Mammomat Inspiration tomosynthesis device and reconstructed using SART with and without suggested weighting. Out-of-focus artifacts are described using line profiles and measured using standard deviation (STD) in the plane and below the plane which contains artifact-causing features. Artifacts distribution in axial direction is measured using an artifact spread function (ASF). The volumes reconstructed with the weighting scheme demonstrate the reduction of out-of-focus artifacts, lower STD (meaning reduction of artifacts), and narrower ASF compared to nonweighted SART reconstruction. It is achieved successfully for different kinds of structures: point-like structures such as phantom features, long structures such as metal needles, and fine structures such as trabecular bone structures. Conclusions: Results indicate the feasibility of the proposed algorithm to reduce typical

  19. Weighted simultaneous algebraic reconstruction technique for tomosynthesis imaging of objects with high-attenuation features

    International Nuclear Information System (INIS)

    Purpose: This paper introduces a nonlinear weighting scheme into the backprojection operation within the simultaneous algebraic reconstruction technique (SART). It is designed for tomosynthesis imaging of objects with high-attenuation features in order to reduce limited angle artifacts. Methods: The algorithm estimates which projections potentially produce artifacts in a voxel. The contribution of those projections into the updating term is reduced. In order to identify those projections automatically, a four-dimensional backprojected space representation is used. Weighting coefficients are calculated based on a dissimilarity measure, evaluated in this space. For each combination of an angular view direction and a voxel position an individual weighting coefficient for the updating term is calculated. Results: The feasibility of the proposed approach is shown based on reconstructions of the following real three-dimensional tomosynthesis datasets: a mammography quality phantom, an apple with metal needles, a dried finger bone in water, and a human hand. Datasets have been acquired with a Siemens Mammomat Inspiration tomosynthesis device and reconstructed using SART with and without suggested weighting. Out-of-focus artifacts are described using line profiles and measured using standard deviation (STD) in the plane and below the plane which contains artifact-causing features. Artifacts distribution in axial direction is measured using an artifact spread function (ASF). The volumes reconstructed with the weighting scheme demonstrate the reduction of out-of-focus artifacts, lower STD (meaning reduction of artifacts), and narrower ASF compared to nonweighted SART reconstruction. It is achieved successfully for different kinds of structures: point-like structures such as phantom features, long structures such as metal needles, and fine structures such as trabecular bone structures. Conclusions: Results indicate the feasibility of the proposed algorithm to reduce typical

  20. 3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells.

    Directory of Open Access Journals (Sweden)

    Tong Luo

    Full Text Available The 3D geometry of individual vascular smooth muscle cells (VSMCs, which are essential for understanding the mechanical function of blood vessels, are currently not available. This paper introduces a new 3D segmentation algorithm to determine VSMC morphology and orientation.A total of 112 VSMCs from six porcine coronary arteries were used in the analysis. A 3D semi-automatic segmentation method was developed to reconstruct individual VSMCs from cell clumps as well as to extract the 3D geometry of VSMCs. A new edge blocking model was introduced to recognize cell boundary while an edge growing was developed for optimal interpolation and edge verification. The proposed methods were designed based on Region of Interest (ROI selected by user and interactive responses of limited key edges. Enhanced cell boundary features were used to construct the cell's initial boundary for further edge growing. A unified framework of morphological parameters (dimensions and orientations was proposed for the 3D volume data. Virtual phantom was designed to validate the tilt angle measurements, while other parameters extracted from 3D segmentations were compared with manual measurements to assess the accuracy of the algorithm. The length, width and thickness of VSMCs were 62.9±14.9 μm, 4.6±0.6 μm and 6.2±1.8 μm (mean±SD. In longitudinal-circumferential plane of blood vessel, VSMCs align off the circumferential direction with two mean angles of -19.4±9.3° and 10.9±4.7°, while an out-of-plane angle (i.e., radial tilt angle was found to be 8±7.6° with median as 5.7°.A 3D segmentation algorithm was developed to reconstruct individual VSMCs of blood vessel walls based on optical image stacks. The results were validated by a virtual phantom and manual measurement. The obtained 3D geometries can be utilized in mathematical models and leads a better understanding of vascular mechanical properties and function.

  1. Large Scale 3D Image Reconstruction in Optical Interferometry

    CERN Document Server

    Schutz, Antony; Mary, David; Thiébaut, Eric; Soulez, Ferréol

    2015-01-01

    Astronomical optical interferometers (OI) sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid atmospheric perturbations, the phases of the complex Fourier samples (visibilities) cannot be directly exploited , and instead linear relationships between the phases are used (phase closures and differential phases). Consequently, specific image reconstruction methods have been devised in the last few decades. Modern polychromatic OI instruments are now paving the way to multiwavelength imaging. This paper presents the derivation of a spatio-spectral ("3D") image reconstruction algorithm called PAINTER (Polychromatic opticAl INTErferometric Reconstruction software). The algorithm is able to solve large scale problems. It relies on an iterative process, which alternates estimation of polychromatic images and of complex visibilities. The complex visibilities are not only estimated from squared moduli and closure phases, but also from differential phase...

  2. Dose fractionation theorem in 3-D reconstruction (tomography)

    Energy Technology Data Exchange (ETDEWEB)

    Glaeser, R.M. [Lawrence Berkeley National Lab., CA (United States)

    1997-02-01

    It is commonly assumed that the large number of projections for single-axis tomography precludes its application to most beam-labile specimens. However, Hegerl and Hoppe have pointed out that the total dose required to achieve statistical significance for each voxel of a computed 3-D reconstruction is the same as that required to obtain a single 2-D image of that isolated voxel, at the same level of statistical significance. Thus a statistically significant 3-D image can be computed from statistically insignificant projections, as along as the total dosage that is distributed among these projections is high enough that it would have resulted in a statistically significant projection, if applied to only one image. We have tested this critical theorem by simulating the tomographic reconstruction of a realistic 3-D model created from an electron micrograph. The simulations verify the basic conclusions of high absorption, signal-dependent noise, varying specimen contrast and missing angular range. Furthermore, the simulations demonstrate that individual projections in the series of fractionated-dose images can be aligned by cross-correlation because they contain significant information derived from the summation of features from different depths in the structure. This latter information is generally not useful for structural interpretation prior to 3-D reconstruction, owing to the complexity of most specimens investigated by single-axis tomography. These results, in combination with dose estimates for imaging single voxels and measurements of radiation damage in the electron microscope, demonstrate that it is feasible to use single-axis tomography with soft X-ray microscopy of frozen-hydrated specimens.

  3. 3D temperature field reconstruction using ultrasound sensing system

    Science.gov (United States)

    Liu, Yuqian; Ma, Tong; Cao, Chengyu; Wang, Xingwei

    2016-04-01

    3D temperature field reconstruction is of practical interest to the power, transportation and aviation industries and it also opens up opportunities for real time control or optimization of high temperature fluid or combustion process. In our paper, a new distributed optical fiber sensing system consisting of a series of elements will be used to generate and receive acoustic signals. This system is the first active temperature field sensing system that features the advantages of the optical fiber sensors (distributed sensing capability) and the acoustic sensors (non-contact measurement). Signals along multiple paths will be measured simultaneously enabled by a code division multiple access (CDMA) technique. Then a proposed Gaussian Radial Basis Functions (GRBF)-based approach can approximate the temperature field as a finite summation of space-dependent basis functions and time-dependent coefficients. The travel time of the acoustic signals depends on the temperature of the media. On this basis, the Gaussian functions are integrated along a number of paths which are determined by the number and distribution of sensors. The inversion problem to estimate the unknown parameters of the Gaussian functions can be solved with the measured times-of-flight (ToF) of acoustic waves and the length of propagation paths using the recursive least square method (RLS). The simulation results show an approximation error less than 2% in 2D and 5% in 3D respectively. It demonstrates the availability and efficiency of our proposed 3D temperature field reconstruction mechanism.

  4. 3D reconstruction of concave surfaces using polarisation imaging

    Science.gov (United States)

    Sohaib, A.; Farooq, A. R.; Ahmed, J.; Smith, L. N.; Smith, M. L.

    2015-06-01

    This paper presents a novel algorithm for improved shape recovery using polarisation-based photometric stereo. The majority of previous research using photometric stereo involves 3D reconstruction using both the diffuse and specular components of light; however, this paper suggests the use of the specular component only as it is the only form of light that comes directly off the surface without subsurface scattering or interreflections. Experiments were carried out on both real and synthetic surfaces. Real images were obtained using a polarisation-based photometric stereo device while synthetic images were generated using PovRay® software. The results clearly demonstrate that the proposed method can extract three-dimensional (3D) surface information effectively even for concave surfaces with complex texture and surface reflectance.

  5. 3D reconstruction of porous electrodes and microstructure modelling

    Energy Technology Data Exchange (ETDEWEB)

    Joos, Jochen; Rueger, Bernd; Weber, Andre; Ivers-Tiffee, Ellen [Karlsruher Institute fuer Technologie (KIT), Karlsruhe (DE). Inst. fuer Werkstoffe der Elektrotechnik (IWE); Carraro, Thomas [Heidelberg Univ. (Germany). Inst. fuer Angewandte Mathematik

    2010-07-01

    The performance of a solid oxide fuel cell (SOFC) is limited by electrode polarisation processes, depending both on material composition and microstructure characteristics. To understand and improve electrode performance, a detailed knowledge of the electrode microstructure is essential. Recent developments in 3D image reconstruction combined with Focused Ion Beam (FIB) and Scanning Electron Microscopy (SEM) techniques proved a way to achieve highly detailed microstructural data. From this data the determination of valuable microstructural parameters is possible. The microstructure is commonly described by parameters as volume/porosity fraction, tortuosity of pores/materal (or: tortuosity of electronic and ionic transport in 2-phase materials), three-phase boundary length (electronic conducting electrodes) or electrode surface area (mixed conducting electrodes). Based on these parameters and with the help of adequate models, the electrode performance can be estimated. It is obvious that the accurateness of the model prediction depends on the quality of the parameters. Different groups reported first trials in the reconstruction of SOFC electrodes by FIB/SEM methods. They all used the reconstruction to calculate microstructural parameters. But nevertheless a lot of questions remain, primarily questions concerning the accuracy of the reconstruction or the minimum size of the volume that has to be reconstructed to obtain meaningful results. In this contribution, a ZEISS 1540XB CrossBeam {sup registered} was used to provide over 700 consecutive images of a porous LSCF (La{sub 0.58}Sr{sub 0.4}CO{sub 0.2.}Fe{sub 0.8}O{sub 3-{delta}})-cathode. The calculation of the key microstructural parameters (i) volume/porosity fraction (ii) electrode surface area and (iii) tortuosity of pores and material from 3D FIB/SEM-data will be presented. Additionally the influence of the reconstruction-volume on the calculated parameters will be discussed. Also the presented technique is

  6. 3D Reconstruction in Spiral Multislice CT Scans

    Directory of Open Access Journals (Sweden)

    M. Ghafouri

    2005-08-01

    Full Text Available Introduction & Background: The rapid development of spiral (helical computed tomography (CT has resulted in exciting new applications for CT. One of these applications, three-dimensional (3D CT with volume ren-dering, is now a major area of clinical and academic interest. One of the greatest advantages of spiral CT with 3D volume rendering is that it provides all the necessary information in a single radiologic study (and there-fore at the lowest possible price in cases that previously required two or more studies. Three-dimensional vol-ume rendering generates clinically accurate and immediately available images from the full CT data set with-out extensive editing. It allows the radiologist and clinician to address specific questions concerning patient care by interactively exploring different aspects of the data set. Three-dimensional images integrate a series of axial CT sections into a form that is often easier to interpret than the sections themselves and can be made to appear similar to other more familiar images such as catheter angiograms. The data are organized into a 3D matrix of volume elements (voxels. The screen of the computer monitor is a 2D-surface composed of discrete picture elements (pixels. Presenting what is stored in memory (ie, floating within the monitor on a 2D-screen is a challenge, but it is the very problem that 3D reconstruc-tion software has creatively solved. Voxel selection is usually accomplished by projecting lines (rays through the data set that correspond to the pixel matrix of the desired 2D image. Differences in the images produced with various 3D rendering techniques are the result of variations in how voxels are selected and weighted. In this article, I compare 3D volume rendering of spiral CT data with other rendering techniques (shaded surface display, maximum intensity projection and present a brief history of 3D volume rendering and discuss the im-plementation of this promising technology in terms of

  7. Facial-paralysis diagnostic system based on 3D reconstruction

    Science.gov (United States)

    Khairunnisaa, Aida; Basah, Shafriza Nisha; Yazid, Haniza; Basri, Hassrizal Hassan; Yaacob, Sazali; Chin, Lim Chee

    2015-05-01

    The diagnostic process of facial paralysis requires qualitative assessment for the classification and treatment planning. This result is inconsistent assessment that potential affect treatment planning. We developed a facial-paralysis diagnostic system based on 3D reconstruction of RGB and depth data using a standard structured-light camera - Kinect 360 - and implementation of Active Appearance Models (AAM). We also proposed a quantitative assessment for facial paralysis based on triangular model. In this paper, we report on the design and development process, including preliminary experimental results. Our preliminary experimental results demonstrate the feasibility of our quantitative assessment system to diagnose facial paralysis.

  8. Computerized 3-D reconstruction of two "double teeth".

    Science.gov (United States)

    Lyroudia, K; Mikrogeorgis, G; Nikopoulos, N; Samakovitis, G; Molyvdas, I; Pitas, I

    1997-10-01

    "Double teeth" is a root malformation in the dentition and the purpose of this study was to reconstruct three-dimensionally the external and internal morphology of two "double teeth". The first set of "double teeth" was formed by the conjunction of a mandibular molar and a premolar, and the second by a conjunction of a maxillary molar and a supernumerary tooth. The process of 3-D reconstruction included serial cross-sectioning, photographs of the sections, digitization of the photographs, extraction of the boundaries of interest for each section, surface representation using triangulation and, finally, surface rendering using photorealistic effects. The resulting three-dimensional representations of the two teeth helped us visualize their external and internal anatomy. The results showed: a) in the first case, fusion of the radical and coronal dentin, as well as fusion of the pulp chambers; and b) in the second case, fusion only of the radical dentin and the pulp chambers. PMID:9550051

  9. Optimized 3D Street Scene Reconstruction from Driving Recorder Images

    Directory of Open Access Journals (Sweden)

    Yongjun Zhang

    2015-07-01

    Full Text Available The paper presents an automatic region detection based method to reconstruct street scenes from driving recorder images. The driving recorder in this paper is a dashboard camera that collects images while the motor vehicle is moving. An enormous number of moving vehicles are included in the collected data because the typical recorders are often mounted in the front of moving vehicles and face the forward direction, which can make matching points on vehicles and guardrails unreliable. Believing that utilizing these image data can reduce street scene reconstruction and updating costs because of their low price, wide use, and extensive shooting coverage, we therefore proposed a new method, which is called the Mask automatic detecting method, to improve the structure results from the motion reconstruction. Note that we define vehicle and guardrail regions as “mask” in this paper since the features on them should be masked out to avoid poor matches. After removing the feature points in our new method, the camera poses and sparse 3D points that are reconstructed with the remaining matches. Our contrast experiments with the typical pipeline of structure from motion (SfM reconstruction methods, such as Photosynth and VisualSFM, demonstrated that the Mask decreased the root-mean-square error (RMSE of the pairwise matching results, which led to more accurate recovering results from the camera-relative poses. Removing features from the Mask also increased the accuracy of point clouds by nearly 30%–40% and corrected the problems of the typical methods on repeatedly reconstructing several buildings when there was only one target building.

  10. Fast vision-based catheter 3D reconstruction

    Science.gov (United States)

    Moradi Dalvand, Mohsen; Nahavandi, Saeid; Howe, Robert D.

    2016-07-01

    Continuum robots offer better maneuverability and inherent compliance and are well-suited for surgical applications as catheters, where gentle interaction with the environment is desired. However, sensing their shape and tip position is a challenge as traditional sensors can not be employed in the way they are in rigid robotic manipulators. In this paper, a high speed vision-based shape sensing algorithm for real-time 3D reconstruction of continuum robots based on the views of two arbitrary positioned cameras is presented. The algorithm is based on the closed-form analytical solution of the reconstruction of quadratic curves in 3D space from two arbitrary perspective projections. High-speed image processing algorithms are developed for the segmentation and feature extraction from the images. The proposed algorithms are experimentally validated for accuracy by measuring the tip position, length and bending and orientation angles for known circular and elliptical catheter shaped tubes. Sensitivity analysis is also carried out to evaluate the robustness of the algorithm. Experimental results demonstrate good accuracy (maximum errors of  ±0.6 mm and  ±0.5 deg), performance (200 Hz), and robustness (maximum absolute error of 1.74 mm, 3.64 deg for the added noises) of the proposed high speed algorithms.

  11. 3D Reconstruction of virtual colon structures from colonoscopy images.

    Science.gov (United States)

    Hong, DongHo; Tavanapong, Wallapak; Wong, Johnny; Oh, JungHwan; de Groen, Piet C

    2014-01-01

    This paper presents the first fully automated reconstruction technique of 3D virtual colon segments from individual colonoscopy images. It is the basis of new software applications that may offer great benefits for improving quality of care for colonoscopy patients. For example, a 3D map of the areas inspected and uninspected during colonoscopy can be shown on request of the endoscopist during the procedure. The endoscopist may revisit the suggested uninspected areas to reduce the chance of missing polyps that reside in these areas. The percentage of the colon surface seen by the endoscopist can be used as a coarse objective indicator of the quality of the procedure. The derived virtual colon models can be stored for post-procedure training of new endoscopists to teach navigation techniques that result in a higher level of procedure quality. Our technique does not require a prior CT scan of the colon or any global positioning device. Our experiments on endoscopy images of an Olympus synthetic colon model reveal encouraging results with small average reconstruction errors (4.1 mm for the fold depths and 12.1 mm for the fold circumferences). PMID:24225230

  12. Digital 3D facial reconstruction of George Washington

    Science.gov (United States)

    Razdan, Anshuman; Schwartz, Jeff; Tocheri, Mathew; Hansford, Dianne

    2006-02-01

    PRISM is a focal point of interdisciplinary research in geometric modeling, computer graphics and visualization at Arizona State University. Many projects in the last ten years have involved laser scanning, geometric modeling and feature extraction from such data as archaeological vessels, bones, human faces, etc. This paper gives a brief overview of a recently completed project on the 3D reconstruction of George Washington (GW). The project brought together forensic anthropologists, digital artists and computer scientists in the 3D digital reconstruction of GW at 57, 45 and 19 including detailed heads and bodies. Although many other scanning projects such as the Michelangelo project have successfully captured fine details via laser scanning, our project took it a step further, i.e. to predict what that individual (in the sculpture) might have looked like both in later and earlier years, specifically the process to account for reverse aging. Our base data was GWs face mask at Morgan Library and Hudons bust of GW at Mount Vernon, both done when GW was 53. Additionally, we scanned the statue at the Capitol in Richmond, VA; various dentures, and other items. Other measurements came from clothing and even portraits of GW. The digital GWs were then milled in high density foam for a studio to complete the work. These will be unveiled at the opening of the new education center at Mt Vernon in fall 2006.

  13. 3D Reconstruction of Irregular Buildings and Buddha Statues

    Science.gov (United States)

    Zhang, K.; Li, M.-j.

    2014-04-01

    Three-dimensional laser scanning could acquire object's surface data quickly and accurately. However, the post-processing of point cloud is not perfect and could be improved. Based on the study of 3D laser scanning technology, this paper describes the details of solutions to modelling irregular ancient buildings and Buddha statues in Jinshan Temple, which aiming at data acquisition, modelling and texture mapping, etc. In order to modelling irregular ancient buildings effectively, the structure of each building is extracted manually by point cloud and the textures are mapped by the software of 3ds Max. The methods clearly combine 3D laser scanning technology with traditional modelling methods, and greatly improves the efficiency and accuracy of the ancient buildings restored. On the other hand, the main idea of modelling statues is regarded as modelling objects in reverse engineering. The digital model of statues obtained is not just vivid, but also accurate in the field of surveying and mapping. On this basis, a 3D scene of Jinshan Temple is reconstructed, which proves the validity of the solutions.

  14. The interactive presentation of 3D information obtained from reconstructed datasets and 3D placement of single histological sections with the 3D portable document format

    OpenAIRE

    de Boer, B. A.; Soufan, A. T.; Hagoort, J.; Mohun, T. J.; van den Hoff, M. J. B.; Hasman, A.; Voorbraak, F. P. J. M.; Moorman, A. F. M.; Ruijter, J.M.

    2011-01-01

    Interpretation of the results of anatomical and embryological studies relies heavily on proper visualization of complex morphogenetic processes and patterns of gene expression in a three-dimensional (3D) context. However, reconstruction of complete 3D datasets is time consuming and often researchers study only a few sections. To help in understanding the resulting 2D data we developed a program (TRACTS) that places such arbitrary histological sections into a high-resolution 3D model of the de...

  15. The interactive presentation of 3D information obtained from reconstructed datasets and 3D placement of single histological sections with the 3D portable document format

    NARCIS (Netherlands)

    B.A. de Boer; A.T. Soufan; J. Hagoort; T.J. Mohun; M.J.B. van den Hoff; A. Hasman; F.P.J.M. Voorbraak; A.F.M. Moorman; J.M. Ruijter

    2011-01-01

    Interpretation of the results of anatomical and embryological studies relies heavily on proper visualization of complex morphogenetic processes and patterns of gene expression in a three-dimensional (3D) context. However, reconstruction of complete 3D datasets is time consuming and often researchers

  16. Digital tomosynthesis of hands using simultaneous algebraic reconstruction technique with distance driven projector

    Energy Technology Data Exchange (ETDEWEB)

    Levakhina, Y.M. [Luebeck Univ. (Germany). Graduate School for Computing in Medicine and Life Sciences; Luebeck Univ. (Germany). Inst. of Medical Engineering; Duschka, R.L.; Barkhausen, J. [Universitaetsklinikum Schleswig-Holstein, Luebeck (Germany). Klinik fuer Radiologie und Nuklearmedizin; Buzug, T.M. [Luebeck Univ. (Germany). Inst. of Medical Engineering

    2011-07-01

    Digital tomosynthesis (DT) is an X-ray tomographic technique for producing a three-dimensional stack of crosssectional images, based on a limited number of low-dose two-dimensional projections, acquired over a limited angular range. Currently, DT has mainly been investigated for the breast and chest imaging. Another application of DT may be an orthopaedic imaging of hands. A three-dimensional reconstruction with a high in-plane resolution, a low dose and potentially low costs make DT attractive for hand imaging comparing with the planar radiography or computed tomography. However, it should be noted that an accurate image reconstruction in DT is a challenging task due to the high degree of data incompleteness. Images are affected by the residual blur of structures that are located above and below the plane of interest. A human hand consists of 27 bones and therefore the artifact problem becomes even more acute in this case, since the magnitude of artifacts is related not only to the chosen reconstruction type but also to the size and contrast of the artifact-generating object. The study presented in the current work has been performed to show a capability of Simultaneous Algebraic Reconstruction Technique (SART) for hand visualization in tomosynthesis. A distance-driven type for the projector and backprojector operator has been used to make the calculation fast and accurate. Studies have been carried out on a phantom with an uniform background and millimeter-sized balls, a dried finger bone and an in toto hand phantom. A Siemens Mammomat Inspiration device has been used to acquire the projection data. Experimental results show that SART is able to reduce out-of-plane artifacts caused by bone tissue. It provides reconstruction with acceptable quality in only one iteration with the recovered visibility of the obscured trabecular structures as well as the joint spaces and the margins. (orig.)

  17. Digital breast tomosynthesis reconstruction using spatially weighted non-convex regularization

    Science.gov (United States)

    Zheng, Jiabei; Fessler, Jeffrey A.; Chan, Heang-Ping

    2016-03-01

    Regularization is an effective strategy for reducing noise in tomographic reconstruction. This paper proposes a spatially weighted non-convex (SWNC) regularization method for digital breast tomosynthesis (DBT) image reconstruction. With a non-convex cost function, this method can suppress noise without blurring microcalcifications (MC) and spiculations of masses. To minimize the non-convex cost function, we apply a majorize-minimize separable quadratic surrogate algorithm (MM-SQS) that is further accelerated by ordered subsets (OS). We applied the new method to a heterogeneous breast phantom and to human subject DBT data, and observed improved image quality in both situations. A quantitative study also showed that the SWNC method can significantly enhance the contrast-to-noise ratio of MCs. By properly selecting its parameters, the SWNC regularizer can preserve the appearance of the mass margins and breast parenchyma.

  18. Robust 3D reconstruction with an RGB-D camera.

    Science.gov (United States)

    Wang, Kangkan; Zhang, Guofeng; Bao, Hujun

    2014-11-01

    We present a novel 3D reconstruction approach using a low-cost RGB-D camera such as Microsoft Kinect. Compared with previous methods, our scanning system can work well in challenging cases where there are large repeated textures and significant depth missing problems. For robust registration, we propose to utilize both visual and geometry features and combine SFM technique to enhance the robustness of feature matching and camera pose estimation. In addition, a novel prior-based multicandidates RANSAC is introduced to efficiently estimate the model parameters and significantly speed up the camera pose estimation under multiple correspondence candidates. Even when serious depth missing occurs, our method still can successfully register all frames together. Loop closure also can be robustly detected and handled to eliminate the drift problem. The missing geometry can be completed by combining multiview stereo and mesh deformation techniques. A variety of challenging examples demonstrate the effectiveness of the proposed approach.

  19. Uncertainties in polarimetric 3D reconstructions of coronal mass ejections

    CERN Document Server

    Bemporad, Alessandro

    2015-01-01

    This work is aimed at quantifying the uncertainties in the 3D reconstruction of the location of coronal mass ejections (CMEs) obtained with the polarization ratio technique. The method takes advantage of the different distributions along the line of sight (LOS) of total (tB) and polarized (pB) brightnesses to estimate the average location of the emitting plasma. To this end, we assumed two simple electron density distributions along the LOS (a constant density and Gaussian density profiles) for a plasma blob and synthesized the expected tB and pB for different distances $z$ of the blob from the plane of the sky (POS) and different projected altitudes $\\rho$. Reconstructed locations of the blob along the LOS were thus compared with the real ones, allowing a precise determination of uncertainties in the method. Independently of the analytical density profile, when the blob is centered at a small distance from the POS (i.e. for limb CMEs) the distance from the POS starts to be significantly overestimated. Polari...

  20. Evaluation of digital breast tomosynthesis reconstruction algorithms using synchrotron radiation in standard geometry

    Energy Technology Data Exchange (ETDEWEB)

    Bliznakova, K.; Kolitsi, Z.; Speller, R. D.; Horrocks, J. A.; Tromba, G.; Pallikarakis, N. [Department of Medical Physics, School of Medicine, University of Patras, Rio, Patras GR-26500 (Greece); Department of Medical Physics and Bioengineering, University College London, London WC1E 6BT (United Kingdom); Clinical Physics Group, St. Bartholomew' s Hospital, Barts and the London NHS Trust, London EC1A 7BE (United Kingdom); ELETTRA, Basovizza, Trieste I-34012 (Italy); Department of Medical Physics, School of Medicine, University of Patras, Rio, Patras GR-26500 (Greece)

    2010-04-15

    Purpose: In this article, the image quality of reconstructed volumes by four algorithms for digital tomosynthesis, applied in the case of breast, is investigated using synchrotron radiation. Methods: An angular data set of 21 images of a complex phantom with heterogeneous tissue-mimicking background was obtained using the SYRMEP beamline at ELETTRA Synchrotron Light Laboratory, Trieste, Italy. The irradiated part was reconstructed using the multiple projection algorithm (MPA) and the filtered backprojection with ramp followed by hamming windows (FBR-RH) and filtered backprojection with ramp (FBP-R). Additionally, an algorithm for reducing the noise in reconstructed planes based on noise mask subtraction from the planes of the originally reconstructed volume using MPA (MPA-NM) has been further developed. The reconstruction techniques were evaluated in terms of calculations and comparison of the contrast-to-noise ratio (CNR) and artifact spread function. Results: It was found that the MPA-NM resulted in higher CNR, comparable with the CNR of FBP-RH for high contrast details. Low contrast objects are well visualized and characterized by high CNR using the simple MPA and the MPA-NM. In addition, the image quality of the reconstructed features in terms of CNR and visual appearance as a function of the initial number of projection images and the reconstruction arc was carried out. Slices reconstructed with more input projection images result in less reconstruction artifacts and higher detail CNR, while those reconstructed from projection images acquired in reduced angular range causes pronounced streak artifacts. Conclusions: Of the reconstruction algorithms implemented, the MPA-NM and MPA are a good choice for detecting low contrast objects, while the FBP-RH, FBP-R, and MPA-NM provide high CNR and well outlined edges in case of microcalcifications.

  1. A comparison of reconstruction algorithms for C-arm mammography tomosynthesis

    International Nuclear Information System (INIS)

    Digital tomosynthesis is an imaging technique to produce a tomographic image from a series of angular digital images in a manner similar to conventional focal plane tomography. Unlike film focal plane tomography, the acquisition of the data in a C-arm geometry causes the image receptor to be positioned at various angles to the reconstruction tomogram. The digital nature of the data allows for input images to be combined into the desired plane with the flexibility of generating tomograms of many separate planes from a single set of input data. Angular datasets were obtained of a low contrast detectability (LCD) phantom and cadaver breast utilizing a Lorad stereotactic biopsy unit with a coupled source and digital detector in a C-arm configuration. Datasets of 9 and 41 low-dose projections were collected over a 30 deg. angular range. Tomographic images were reconstructed using a Backprojection (BP) algorithm, an Iterative Subtraction (IS) algorithm that allows the partial subtraction of out-of-focus planes, and an Algebraic Reconstruction (AR) algorithm. These were compared with single view digital radiographs. The methods' effectiveness at enhancing visibility of an obscured LCD phantom was quantified in terms of the Signal to Noise Ratio (SNR), and Signal to Background Ratio (SBR), all normalized to the metric value for the single projection image. The methods' effectiveness at removing ghosting artifacts in a cadaver breast was quantified in terms of the Artifact Spread Function (ASF). The technology proved effective at partially removing out of focus structures and enhancing SNR and SBR. The normalized SNR was highest at 4.85 for the obscured LCD phantom, using nine projections and IS algorithm. The normalized SBR was highest at 23.2 for the obscured LCD phantom, using 41 projections and an AR algorithm. The highest normalized metric values occurred with the obscured phantom. This supports the assertion that the greatest value of tomosynthesis is in imaging

  2. 3-D Reconstruction of Medical Image Using Wavelet Transform and Snake Model

    Directory of Open Access Journals (Sweden)

    Jinyong Cheng

    2009-12-01

    Full Text Available Medical image segmentation is an important step in 3-D reconstruction, and 3-D reconstruction from medical images is an important application of computer graphics and biomedicine image processing. An improved image segmentation method which is suitable for 3-D reconstruction is presented in this paper. A 3-D reconstruction algorithm is used to reconstruct the 3-D model from medical images. Rough edge is obtained by multi-scale wavelet transform at first. With the rough edge, improved gradient vector flow snake model is used and the object contour in the image is found. In the experiments, we reconstruct 3-D models of kidney, liver and brain putamen. The performances of the experiments indicate that the new algorithm can produce accurate 3-D reconstruction.

  3. Objective and subjective quality assessment of geometry compression of reconstructed 3D humans in a 3D virtual room

    Science.gov (United States)

    Mekuria, Rufael; Cesar, Pablo; Doumanis, Ioannis; Frisiello, Antonella

    2015-09-01

    Compression of 3D object based video is relevant for 3D Immersive applications. Nevertheless, the perceptual aspects of the degradation introduced by codecs for meshes and point clouds are not well understood. In this paper we evaluate the subjective and objective degradations introduced by such codecs in a state of art 3D immersive virtual room. In the 3D immersive virtual room, users are captured with multiple cameras, and their surfaces are reconstructed as photorealistic colored/textured 3D meshes or point clouds. To test the perceptual effect of compression and transmission, we render degraded versions with different frame rates in different contexts (near/far) in the scene. A quantitative subjective study with 16 users shows that negligible distortion of decoded surfaces compared to the original reconstructions can be achieved in the 3D virtual room. In addition, a qualitative task based analysis in a full prototype field trial shows increased presence, emotion, user and state recognition of the reconstructed 3D Human representation compared to animated computer avatars.

  4. DIACHRONIC 3D RECONSTRUCTION FOR LOST CULTURAL HERITAGE

    Directory of Open Access Journals (Sweden)

    G. Guidi

    2012-09-01

    Full Text Available Cultural Heritage artifacts can often be underestimated for their hidden presence in the landscape. Such problem is particularly large in countries like Italy, where the massive amount of "famous" artifacts tends to neglect other presences unless properly exposed, or when the remains are dramatically damaged leaving very few interpretation clues to the visitor. In such cases a virtual presentation of the Cultural Heritage site can be of great help, specially for explaining the evolution of its status, giving sometimes sense to few spare stones. The definition of these digital representations deal with two crucial aspects: on the one hand the possibility of 3D surveying the relics in order to have an accurate geometrical image of the current status of the artifact; on the other hand the presence of historical sources both in form of written text or images, that once properly matched with the current geometrical data, may help to recreate digitally a set of 3D models representing visually the various historical phases (diachronic model, up to the current one. The core of this article is the definition of an integrated methodology that starts from an high-resolution digital survey of the remains of an ancient building and develops a coherent virtual reconstruction from different historical sources, suggesting a scalable method suitable to be re-used for generating a 4D (geometry + time model of the artifact. This approach has been experimented on the "Basilica di San Giovanni in Conca" in Milan, a very significant example for its complex historic evolution that combines evident historic values with an invisible presence inside the city.

  5. Diachronic 3d Reconstruction for Lost Cultural Heritage

    Science.gov (United States)

    Guidi, G.; Russo, M.

    2011-09-01

    Cultural Heritage artifacts can often be underestimated for their hidden presence in the landscape. Such problem is particularly large in countries like Italy, where the massive amount of "famous" artifacts tends to neglect other presences unless properly exposed, or when the remains are dramatically damaged leaving very few interpretation clues to the visitor. In such cases a virtual presentation of the Cultural Heritage site can be of great help, specially for explaining the evolution of its status, giving sometimes sense to few spare stones. The definition of these digital representations deal with two crucial aspects: on the one hand the possibility of 3D surveying the relics in order to have an accurate geometrical image of the current status of the artifact; on the other hand the presence of historical sources both in form of written text or images, that once properly matched with the current geometrical data, may help to recreate digitally a set of 3D models representing visually the various historical phases (diachronic model), up to the current one. The core of this article is the definition of an integrated methodology that starts from an high-resolution digital survey of the remains of an ancient building and develops a coherent virtual reconstruction from different historical sources, suggesting a scalable method suitable to be re-used for generating a 4D (geometry + time) model of the artifact. This approach has been experimented on the "Basilica di San Giovanni in Conca" in Milan, a very significant example for its complex historic evolution that combines evident historic values with an invisible presence inside the city.

  6. FIT3D Toolbox : multiple view geometry and 3D reconstruction for MATLAB

    NARCIS (Netherlands)

    Esteban, I.; Dijk, J.; Groen, F.

    2010-01-01

    FIT3D is a Toolbox built for Matlab that aims at unifying and distributing a set of tools that will allow the researcher to obtain a complete 3D model from a set of calibrated images. In this paper we motivate and present the structure of the toolbox in a tutorial and example based approach. Given i

  7. Comparison study of reconstruction algorithms for prototype digital breast tomosynthesis using various breast phantoms.

    Science.gov (United States)

    Kim, Ye-seul; Park, Hye-suk; Lee, Haeng-Hwa; Choi, Young-Wook; Choi, Jae-Gu; Kim, Hak Hee; Kim, Hee-Joung

    2016-02-01

    Digital breast tomosynthesis (DBT) is a recently developed system for three-dimensional imaging that offers the potential to reduce the false positives of mammography by preventing tissue overlap. Many qualitative evaluations of digital breast tomosynthesis were previously performed by using a phantom with an unrealistic model and with heterogeneous background and noise, which is not representative of real breasts. The purpose of the present work was to compare reconstruction algorithms for DBT by using various breast phantoms; validation was also performed by using patient images. DBT was performed by using a prototype unit that was optimized for very low exposures and rapid readout. Three algorithms were compared: a back-projection (BP) algorithm, a filtered BP (FBP) algorithm, and an iterative expectation maximization (EM) algorithm. To compare the algorithms, three types of breast phantoms (homogeneous background phantom, heterogeneous background phantom, and anthropomorphic breast phantom) were evaluated, and clinical images were also reconstructed by using the different reconstruction algorithms. The in-plane image quality was evaluated based on the line profile and the contrast-to-noise ratio (CNR), and out-of-plane artifacts were evaluated by means of the artifact spread function (ASF). Parenchymal texture features of contrast and homogeneity were computed based on reconstructed images of an anthropomorphic breast phantom. The clinical images were studied to validate the effect of reconstruction algorithms. The results showed that the CNRs of masses reconstructed by using the EM algorithm were slightly higher than those obtained by using the BP algorithm, whereas the FBP algorithm yielded much lower CNR due to its high fluctuations of background noise. The FBP algorithm provides the best conspicuity for larger calcifications by enhancing their contrast and sharpness more than the other algorithms; however, in the case of small-size and low

  8. A Method for Interactive 3D Reconstruction of Piecewise Planar Objects from Single Images

    OpenAIRE

    Sturm, Peter; Maybank, Steve

    1999-01-01

    International audience We present an approach for 3D reconstruction of objects from a single image. Obviously, constraints on the 3D structure are needed to perform this task. Our approach is based on user-provided coplanarity, perpendicularity and parallelism constraints. These are used to calibrate the image and perform 3D reconstruction. The method is described in detail and results are provided.

  9. Reconstruction of 3-D Temperature Field in Holographic Interferometry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The tomography technique is commonly used for the reconstruction of holographic interferometry. However, the current reconstruction method doesn't consider the measurement errors which are non-avoidable in the measurement and will degrade the reconstruction quality. The factors affecting the reconstruction quality are analyzed and the distribution law of the reconstruction error with experimental errors is discussed. Finally, a method to improve the reconstruction quality—the Kalman filter method is presented.

  10. 3-D reconstruction for mass lesions in the head and neck

    International Nuclear Information System (INIS)

    3-D reconstructions in the head and neck were carried out on 21 normals and 11 patients with space-occupying lesions, both before and after the administration of Gd-DTPA. The 3-D reconstructions were obtained by the 'ray-tracing' method. For the 3-D reconstructions, portions of the skull surface image were removed to permit views of the deeper tissues. The 3-D reconstructions included an hypoglossus neurinoma, a glomus tumour, two carcinomas of the maxillary antra, three naso-pharyngeal carcinomas, a parotid adenoma, an oro-pharyngeal haemangioma and two lesions in the neck. The 3-D reconstructions provided a better understanding of the morphology than was obtained from the two-dimensional images. 3-D reconstructions of lesions in the head and neck will become a valuable diagnostic method for demonstrating space-occupying lesions, particularly with regard to surgical planning. (orig.)

  11. AUTOMATIC TEXTURE RECONSTRUCTION OF 3D CITY MODEL FROM OBLIQUE IMAGES

    OpenAIRE

    Kang, Junhua; Deng, Fei; LI, XINWEI; WAN, FANG

    2016-01-01

    In recent years, the photorealistic 3D city models are increasingly important in various geospatial applications related to virtual city tourism, 3D GIS, urban planning, real-estate management. Besides the acquisition of high-precision 3D geometric data, texture reconstruction is also a crucial step for generating high-quality and visually realistic 3D models. However, most of the texture reconstruction approaches are probably leading to texture fragmentation and memory inefficiency....

  12. Enhanced imaging of microcalcifications in digital breast tomosynthesis through improved image-reconstruction algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Sidky, Emil Y.; Pan Xiaochuan; Reiser, Ingrid S.; Nishikawa, Robert M.; Moore, Richard H.; Kopans, Daniel B. [Department of Radiology, University of Chicago, 5841 S. Maryland Avenue Chicago, Illinois 60637 (United States); Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2009-11-15

    Purpose: The authors develop a practical, iterative algorithm for image-reconstruction in undersampled tomographic systems, such as digital breast tomosynthesis (DBT). Methods: The algorithm controls image regularity by minimizing the image total p variation (TpV), a function that reduces to the total variation when p=1.0 or the image roughness when p=2.0. Constraints on the image, such as image positivity and estimated projection-data tolerance, are enforced by projection onto convex sets. The fact that the tomographic system is undersampled translates to the mathematical property that many widely varied resultant volumes may correspond to a given data tolerance. Thus the application of image regularity serves two purposes: (1) Reduction in the number of resultant volumes out of those allowed by fixing the data tolerance, finding the minimum image TpV for fixed data tolerance, and (2) traditional regularization, sacrificing data fidelity for higher image regularity. The present algorithm allows for this dual role of image regularity in undersampled tomography. Results: The proposed image-reconstruction algorithm is applied to three clinical DBT data sets. The DBT cases include one with microcalcifications and two with masses. Conclusions: Results indicate that there may be a substantial advantage in using the present image-reconstruction algorithm for microcalcification imaging.

  13. Enhanced imaging of microcalcifications in digital breast tomosynthesis through improved image-reconstruction algorithms

    Science.gov (United States)

    Sidky, Emil Y.; Pan, Xiaochuan; Reiser, Ingrid S.; Nishikawa, Robert M.; Moore, Richard H.; Kopans, Daniel B.

    2009-01-01

    Purpose: The authors develop a practical, iterative algorithm for image-reconstruction in undersampled tomographic systems, such as digital breast tomosynthesis (DBT). Methods: The algorithm controls image regularity by minimizing the image total p variation (TpV), a function that reduces to the total variation when p=1.0 or the image roughness whenp=2.0. Constraints on the image, such as image positivity and estimated projection-data tolerance, are enforced by projection onto convex sets. The fact that the tomographic system is undersampled translates to the mathematical property that many widely varied resultant volumes may correspond to a given data tolerance. Thus the application of image regularity serves two purposes: (1) Reduction in the number of resultant volumes out of those allowed by fixing the data tolerance, finding the minimum image TpV for fixed data tolerance, and (2) traditional regularization, sacrificing data fidelity for higher image regularity. The present algorithm allows for this dual role of image regularity in undersampled tomography. Results: The proposed image-reconstruction algorithm is applied to three clinical DBT data sets. The DBT cases include one with microcalcifications and two with masses. Conclusions: Results indicate that there may be a substantial advantage in using the present image-reconstruction algorithm for microcalcification imaging. PMID:19994501

  14. Image artifacts in digital breast tomosynthesis: Investigation of the effects of system geometry and reconstruction parameters using a linear system approach

    Science.gov (United States)

    Hu, Yue-Houng; Zhao, Bo; Zhao, Wei

    2008-01-01

    Digital breast tomosynthesis (DBT) is a three-dimensional (3D) x-ray imaging modality that reconstructs image slices parallel to the detector plane. Image acquisition is performed using a limited angular range (less than 50 degrees) and a limited number of projection views (less than 50 views). Due to incomplete data sampling, image artifacts are unavoidable in DBT. In this preliminary study, the image artifacts in DBT were investigated systematically using a linear system approximation. A cascaded linear system model of DBT was developed to calculate the 3D presampling modulation transfer function (MTF) with different image acquisition geometries and reconstruction filters using a filtered backprojection (FBP) algorithm. A thin, slanted tungsten (W) wire was used to measure the presampling MTF of the DBT system in the cross-sectional plane defined by the thickness (z-) and tube travel (x-) directions. The measurement was in excellent agreement with the calculation using the model. A small steel bead was used to calculate the artifact spread function (ASF) of the DBT system. The ASF was correlated with the convolution of the two-dimensional (2D) point spread function (PSF) of the system and the object function of the bead. The results showed that the cascaded linear system model can be used to predict the magnitude of image artifacts of small, high-contrast objects with different image acquisition geometry and reconstruction filters. PMID:19175083

  15. Adaptive diffusion regularization for enhancement of microcalcifications in digital breast tomosynthesis (DBT) reconstruction

    Science.gov (United States)

    Lu, Yao; Chan, Heang-Ping; Fessler, Jeffrey A.; Hadjiiski, Lubomir; Wei, Jun; Goodsitt, Mitchell M.

    2011-03-01

    Digital breast tomosynthesis (DBT) has been shown to increase mass detection. Detection of microcalcifications in DBT is challenging because of the small, subtle signals to be searched in the large breast volume and the noise in the reconstructed volume. We developed an adaptive diffusion (AD) regularization method that can differentially regularize noise and potential signal regions during reconstruction based on local contrast-to-noise ratio (CNR) information. This method adaptively applies different degrees of regularity to signal and noise regions, as guided by a CNR map for each DBT slice within the image volume, such that potential signals will be preserved while noise is suppressed. DBT scans of an American College of Radiology phantom and the breast of a subject with biopsy-proven calcifications were acquired with a GE prototype DBT system at 21 angles in 3° increments over a +/-30° range. Simultaneous algebraic reconstruction technique (SART) was used for DBT reconstruction. The AD regularization method was compared to the non-convex total p-variation (TpV) method and SART with no regularization (NR) in terms of the CNR and the full width at half maximum (FWHM) of the central gray-level line profile in the focal plane of a calcification. The results demonstrated that the SART regularized by the AD method enhanced the CNR and preserved the sharpness of microcalcifications compared to reconstruction without regularization. The AD regularization was superior to the TpV method for subtle microcalcifications in terms of the CNR while the FWHM was comparable. The AD regularized reconstruction has the potential to improve the CNR of microcalcifications in DBT for human or machine detection.

  16. Fast implementations of 3D PET reconstruction using vector and parallel programming techniques

    International Nuclear Information System (INIS)

    Computationally intensive techniques that offer potential clinical use have arisen in nuclear medicine. Examples include iterative reconstruction, 3D PET data acquisition and reconstruction, and 3D image volume manipulation including image registration. One obstacle in achieving clinical acceptance of these techniques is the computational time required. This study focuses on methods to reduce the computation time for 3D PET reconstruction through the use of fast computer hardware, vector and parallel programming techniques, and algorithm optimization. The strengths and weaknesses of i860 microprocessor based workstation accelerator boards are investigated in implementations of 3D PET reconstruction

  17. Advanced system for 3D dental anatomy reconstruction and 3D tooth movement simulation during orthodontic treatment

    Science.gov (United States)

    Monserrat, Carlos; Alcaniz-Raya, Mariano L.; Juan, M. Carmen; Grau Colomer, Vincente; Albalat, Salvador E.

    1997-05-01

    This paper describes a new method for 3D orthodontics treatment simulation developed for an orthodontics planning system (MAGALLANES). We develop an original system for 3D capturing and reconstruction of dental anatomy that avoid use of dental casts in orthodontic treatments. Two original techniques are presented, one direct in which data are acquired directly form patient's mouth by mean of low cost 3D digitizers, and one mixed in which data are obtained by 3D digitizing of hydrocollids molds. FOr this purpose we have designed and manufactured an optimized optical measuring system based on laser structured light. We apply these 3D dental models to simulate 3D movement of teeth, including rotations, during orthodontic treatment. The proposed algorithms enable to quantify the effect of orthodontic appliance on tooth movement. The developed techniques has been integrated in a system named MAGALLANES. This original system present several tools for 3D simulation and planning of orthodontic treatments. The prototype system has been tested in several orthodontic clinic with very good results.

  18. DIII-D Equilibrium Reconstructions with New 3D Magnetic Probes

    Science.gov (United States)

    Lao, Lang; Strait, E. J.; Ferraro, N. M.; Ferron, J. R.; King, J. D.; Lee, X.; Meneghini, O.; Turnbull, A. D.; Huang, Y.; Qian, J. G.; Wingen, A.

    2015-11-01

    DIII-D equilibrium reconstructions with the recently installed new 3D magnetic diagnostic are presented. In addition to providing information to allow more accurate 2D reconstructions, the new 3D probes also provide useful information to guide computation of 3D perturbed equilibria. A new more comprehensive magnetic compensation has been implemented. Algorithms are being developed to allow EFIT to reconstruct 3D perturbed equilibria making use of the new 3D probes and plasma responses from 3D MHD codes such as GATO and M3D-C1. To improve the computation efficiency, all inactive probes in one of the toroidal planes in EFIT have been replaced with new probes from other planes. Other 3D efforts include testing of 3D reconstructions using V3FIT and a new 3D variational moment equilibrium code VMOM3D. Other EFIT developments include a GPU EFIT version and new safety factor and MSE-LS constraints. The accuracy and limitation of the new probes for 3D reconstructions will be discussed. Supported by US DOE under DE-FC02-04ER54698 and DE-FG02-95ER54309.

  19. Improvement of geometrical measurements from 3D-SEM reconstructions

    DEFF Research Database (Denmark)

    Carli, Lorenzo; De Chiffre, Leonardo; Horsewell, Andy;

    2009-01-01

    The quantification of 3D geometry at the nanometric scale is a major metrological challenge. In this work geometrical measurements on cylindrical items obtained with a 3D-SEM were investigated. Two items were measured: a wire gauge having a 0.25 mm nominal diameter and a hypodermic needle having...... that the diameter estimation performed using the 3D-SEM leads to an overestimation of approx. 7% compared to the reference values obtained using a 1-D length measuring machine. Standard deviation of SEM measurements performed on the wire gauge is approx. 1.5 times lower than the one performed on the hypodermic...

  20. Integration of real-time 3D capture, reconstruction, and light-field display

    Science.gov (United States)

    Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Pei, Renjing; Liu, Yongchun; Zhang, Xiao

    2015-03-01

    Effective integration of 3D acquisition, reconstruction (modeling) and display technologies into a seamless systems provides augmented experience of visualizing and analyzing real objects and scenes with realistic 3D sensation. Applications can be found in medical imaging, gaming, virtual or augmented reality and hybrid simulations. Although 3D acquisition, reconstruction, and display technologies have gained significant momentum in recent years, there seems a lack of attention on synergistically combining these components into a "end-to-end" 3D visualization system. We designed, built and tested an integrated 3D visualization system that is able to capture in real-time 3D light-field images, perform 3D reconstruction to build 3D model of the objects, and display the 3D model on a large autostereoscopic screen. In this article, we will present our system architecture and component designs, hardware/software implementations, and experimental results. We will elaborate on our recent progress on sparse camera array light-field 3D acquisition, real-time dense 3D reconstruction, and autostereoscopic multi-view 3D display. A prototype is finally presented with test results to illustrate the effectiveness of our proposed integrated 3D visualization system.

  1. Evaluation of the possibility to use thick slabs of reconstructed outer breast tomosynthesis slice images

    Science.gov (United States)

    Petersson, Hannie; Dustler, Magnus; Tingberg, Anders; Timberg, Pontus

    2016-03-01

    The large image volumes in breast tomosynthesis (BT) have led to large amounts of data and a heavy workload for breast radiologists. The number of slice images can be decreased by combining adjacent image planes (slabbing) but the decrease in depth resolution can considerably affect the detection of lesions. The aim of this work was to assess if thicker slabbing of the outer slice images (where lesions seldom are present) could be a viable alternative in order to reduce the number of slice images in BT image volumes. The suggested slabbing (an image volume with thick outer slabs and thin slices between) were evaluated in two steps. Firstly, a survey of the depth of 65 cancer lesions within the breast was performed to estimate how many lesions would be affected by outer slabs of different thicknesses. Secondly, a selection of 24 lesions was reconstructed with 2, 6 and 10 mm slab thickness to evaluate how the appearance of lesions located in the thicker slabs would be affected. The results show that few malignant breast lesions are located at a depth less than 10 mm from the surface (especially for breast thicknesses of 50 mm and above). Reconstruction of BT volumes with 6 mm slab thickness yields an image quality that is sufficient for lesion detection for a majority of the investigated cases. Together, this indicates that thicker slabbing of the outer slice images is a promising option in order to reduce the number of slice images in BT image volumes.

  2. 3D reconstruction of SEM images by use of optical photogrammetry software.

    Science.gov (United States)

    Eulitz, Mona; Reiss, Gebhard

    2015-08-01

    Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching.

  3. Towards 3D facial reconstruction from uncalibrated CCTV footage

    NARCIS (Netherlands)

    Dam, van Chris; Veldhuis, Raymond; Spreeuwers, Luuk

    2012-01-01

    Facial comparison in 2D is an accepted method in law enforcement and forensic investigation, but pose variations, varying light conditions and low resolution video data can reduce the evidential value of the comparison. Some of these problems might be solved by comparing 3D face models: a face model

  4. 3-D Virtual and Physical Reconstruction of Bendego Iron

    Science.gov (United States)

    Belmonte, S. L. R.; Zucolotto, M. E.; Fontes, R. C.; dos Santos, J. R. L.

    2012-09-01

    The use of 3D laser scanning to meteoritic to preserve the original shape of the meteorites before cutting and the facility of saved the datas in STL format (stereolithography) to print three-dimensional physical models and generate a digital replica.

  5. Robust 3D reconstruction system for human jaw modeling

    Science.gov (United States)

    Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.

    1999-03-01

    This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.

  6. Online reconstruction of 3D magnetic particle imaging data

    Science.gov (United States)

    Knopp, T.; Hofmann, M.

    2016-06-01

    Magnetic particle imaging is a quantitative functional imaging technique that allows imaging of the spatial distribution of super-paramagnetic iron oxide particles at high temporal resolution. The raw data acquisition can be performed at frame rates of more than 40 volumes s‑1. However, to date image reconstruction is performed in an offline step and thus no direct feedback is available during the experiment. Considering potential interventional applications such direct feedback would be mandatory. In this work, an online reconstruction framework is implemented that allows direct visualization of the particle distribution on the screen of the acquisition computer with a latency of about 2 s. The reconstruction process is adaptive and performs block-averaging in order to optimize the signal quality for a given amount of reconstruction time.

  7. Enhanced imaging of microcalcifications in digital breast tomosynthesis through improved image-reconstruction algorithms

    CERN Document Server

    Sidky, Emil Y; Reiser, Ingrid S; Nishikawa, Robert M; Moore, Richard H; Kopans, Daniel B

    2009-01-01

    PURPOSE: We develop a practical, iterative algorithm for image-reconstruction in under-sampled tomographic systems, such as digital breast tomosynthesis (DBT). METHOD: The algorithm controls image regularity by minimizing the image total $p$-variation (TpV), a function that reduces to the total variation when $p=1.0$ or the image roughness when $p=2.0$. Constraints on the image, such as image positivity and estimated projection-data tolerance, are enforced by projection onto convex sets (POCS). The fact that the tomographic system is under-sampled translates to the mathematical property that many widely varied resultant volumes may correspond to a given data tolerance. Thus the application of image regularity serves two purposes: (1) reduction of the number of resultant volumes out of those allowed by fixing the data tolerance, finding the minimum image TpV for fixed data tolerance, and (2) traditional regularization, sacrificing data fidelity for higher image regularity. The present algorithm allows for this...

  8. Three-dimensional linear system analysis for breast tomosynthesis

    Science.gov (United States)

    Zhao, Bo; Zhao, Wei

    2008-01-01

    The optimization of digital breast tomosynthesis (DBT) geometry and reconstruction is crucial for the clinical translation of this exciting new imaging technique. In the present work, the authors developed a three-dimensional (3D) cascaded linear system model for DBT to investigate the effects of detector performance, imaging geometry, and image reconstruction algorithm on the reconstructed image quality. The characteristics of a prototype DBT system equipped with an amorphous selenium flat-panel detector and filtered backprojection reconstruction were used as an example in the implementation of the linear system model. The propagation of signal and noise in the frequency domain was divided into six cascaded stages incorporating the detector performance, imaging geometry, and reconstruction filters. The reconstructed tomosynthesis imaging quality was characterized by spatial frequency dependent presampling modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) in 3D. The results showed that both MTF and NPS were affected by the angular range of the tomosynthesis scan and the reconstruction filters. For image planes parallel to the detector (in-plane), MTF at low frequencies was improved with increase in angular range. The shape of the NPS was affected by the reconstruction filters. Noise aliasing in 3D could be introduced by insufficient voxel sampling, especially in the z (slice-thickness) direction where the sampling distance (slice thickness) could be more than ten times that for in-plane images. Aliasing increases the noise at high frequencies, which causes degradation in DQE. Application of a reconstruction filter that limits the frequency components beyond the Nyquist frequency in the z direction, referred to as the slice thickness filter, eliminates noise aliasing and improves 3D DQE. The focal spot blur, which arises from continuous tube travel during tomosynthesis acquisition, could degrade DQE significantly

  9. Optical geometry calibration method for free-form digital tomosynthesis

    Science.gov (United States)

    Chtcheprov, Pavel; Hartman, Allison; Shan, Jing; Lee, Yueh Z.; Zhou, Otto; Lu, Jianping

    2016-03-01

    Digital tomosynthesis is a type of limited angle tomography that allows 3D information to be reconstructed from a set of x-ray projection images taken at various angles using an x-ray tube, a mechanical arm to rotate the tube about the object, and a digital detector. Tomosynthesis reconstruction requires the precise location of the detector with respect to each x-ray source, forcing all current clinical tomosynthesis systems to use a physically coupled source and detector so the geometry is always known and is always the same. This limits the imaging geometries and its large size is impractical for mobile or field operations. To counter this, we have developed a free form tomosynthesis with a decoupled, free-moving source and detector that uses a novel optical method for accurate and real-time geometry calibration to allow for manual, hand-held tomosynthesis and even CT imaging. We accomplish this by using a camera, attached to the source, to track the motion of the source relative to the detector. Attached to the detector is an optical pattern and the image captured by the camera is then used to determine the relative camera/pattern position and orientation by analyzing the pattern distortion and calculating the source positions for each projection, necessary for 3D reconstruction. This allows for portable imaging in the field and also as an inexpensive upgrade to existing 2D systems, such as in developing countries, to provide 3D image data. Here we report the first feasibility demonstrations of free form digital tomosynthesis systems using the method.

  10. Autonomous Planetary 3-D Reconstruction From Satellite Images

    DEFF Research Database (Denmark)

    Denver, Troelz

    1999-01-01

    A common task for many deep space missions is autonomous generation of 3-D representations of planetary surfaces onboard unmanned spacecrafts. The basic problem for this class of missions is, that the closed loop time is far too long. The closed loop time is defined as the time from when a human...... of seconds to a few minutes, the closed loop time effectively precludes active human control.The only way to circumvent this problem is to build an artificial feature extractor operating autonomously onboard the spacecraft.Different artificial feature extractors are presented and their efficiency...... is discussed.Based on such features, 3-D representations may be compiled from two or more 2-D satellite images. The main purposes of such a mapping system are extraction of landing sites, objects of scientific interest and general planetary surveying. All data processing is performed autonomously onboard...

  11. X-ray digital intra-oral tomosynthesis for quasi-three-dimensional imaging: system, reconstruction algorithm, and experiments

    Science.gov (United States)

    Li, Liang; Chen, Zhiqiang; Zhao, Ziran; Wu, Dufan

    2013-01-01

    At present, there are mainly three x-ray imaging modalities for dental clinical diagnosis: radiography, panorama and computed tomography (CT). We develop a new x-ray digital intra-oral tomosynthesis (IDT) system for quasi-three-dimensional dental imaging which can be seen as an intermediate modality between traditional radiography and CT. In addition to normal x-ray tube and digital sensor used in intra-oral radiography, IDT has a specially designed mechanical device to complete the tomosynthesis data acquisition. During the scanning, the measurement geometry is such that the sensor is stationary inside the patient's mouth and the x-ray tube moves along an arc trajectory with respect to the intra-oral sensor. Therefore, the projection geometry can be obtained without any other reference objects, which makes it be easily accepted in clinical applications. We also present a compressed sensing-based iterative reconstruction algorithm for this kind of intra-oral tomosynthesis. Finally, simulation and experiment were both carried out to evaluate this intra-oral imaging modality and algorithm. The results show that IDT has its potentiality to become a new tool for dental clinical diagnosis.

  12. 3D reconstruction of tropospheric cirrus clouds by stereovision system

    Science.gov (United States)

    Nadjib Kouahla, Mohamed; Moreels, Guy; Seridi, Hamid

    2016-07-01

    A stereo imaging method is applied to measure the altitude of cirrus clouds and provide a 3D map of the altitude of the layer centroid. They are located in the high troposphere and, sometimes in the lower stratosphere, between 6 and 10 km high. Two simultaneous images of the same scene are taken with Canon cameras (400D) in two sites distant of 37 Km. Each image processed in order to invert the perspective effect and provide a satellite-type view of the layer. Pairs of matched points that correspond to a physical emissive point in the common area are identified in calculating a correlation coefficient (ZNCC: Zero mean Normalized Cross-correlation or ZSSD: as Zero mean Sum of Squared Differences). This method is suitable for obtaining 3D representations in the case of low-contrast objects. An observational campaign was conducted in June 2014 in France. The images were taken simultaneously at Marnay (47°17'31.5" N, 5°44'58.8" E; altitude 275 m) 25 km northwest of Besancon and in Mont poupet (46°58'31.5" N, 5°52'22.7" E; altitude 600 m) southwest of Besancon at 43 km. 3D maps of the Natural cirrus clouds and artificial like "aircraft trails" are retrieved. They are compared with pseudo-relief intensity maps of the same region. The mean altitude of the cirrus barycenter is located at 8.5 ± 1km on June 11.

  13. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    Science.gov (United States)

    Hamamoto, Kazuhiko; Sato, Motoyoshi

    3D imaging technique is very important and indispensable in diagnosis. The main stream of the technique is one in which 3D image is reconstructed from a set of slice images, such as X-ray CT and MRI. However, these systems require large space and high costs. On the other hand, a low cost and small size 3D imaging system is needed in clinical veterinary medicine, for example, in the case of diagnosis in X-ray car or pasture area. We propose a novel 3D imaging technique using 2-D X-ray radiographic images. This system can be realized by cheaper system than X-ray CT and enables to get 3D image in X-ray car or portable X-ray equipment. In this paper, a 3D visualization technique from 2-D radiographic images is proposed and several reconstructions are shown. These reconstructions are evaluated by veterinarians.

  14. 3D reconstruction of worn parts for flexible remanufacture based on robotic arc welding

    Institute of Scientific and Technical Information of China (English)

    Yin Ziqiang; Zhang Guangjun; Gao Hongming; Wu Lin

    2010-01-01

    3D reconstruction of worn parts is the foundation for remanufacturing system based on robotic arc welding,because it can provide 3D geometric information for robot task plan.In this investigation,a nocwl 3D reconstruction system based on linear structured light vision sensing is developed,This system hardware consists of a MTC368-CB CCD camera,a MLH-645laser projector and a DH-CG300 image grabbing card.This system software is developed to control the image data capture.In order to reconstruct the 3D geometric information from the captured image,a two steps rapid calibration algorithm is proposed.The 3D reconstruction experiment shows a satisfactory result.

  15. Parallel-scanning tomosynthesis using a slot scanning technique: Fixed-focus reconstruction and the resulting image quality

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Koichi, E-mail: shibatak@suzuka-u.ac.jp [Department of Radiological Technology, Faculty of Health Science, Suzuka University of Medical Science 1001-1, Kishioka-cho, Suzuka 510-0293 (Japan); Notohara, Daisuke; Sakai, Takihito [R and D Department, Medical Systems Division, Shimadzu Corporation 1, Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto 604-8511 (Japan)

    2014-11-01

    Purpose: Parallel-scanning tomosynthesis (PS-TS) is a novel technique that fuses the slot scanning technique and the conventional tomosynthesis (TS) technique. This approach allows one to obtain long-view tomosynthesis images in addition to normally sized tomosynthesis images, even when using a system that has no linear tomographic scanning function. The reconstruction technique and an evaluation of the resulting image quality for PS-TS are described in this paper. Methods: The PS-TS image-reconstruction technique consists of several steps (1) the projection images are divided into strips, (2) the strips are stitched together to construct images corresponding to the reconstruction plane, (3) the stitched images are filtered, and (4) the filtered stitched images are back-projected. In the case of PS-TS using the fixed-focus reconstruction method (PS-TS-F), one set of stitched images is used for the reconstruction planes at all heights, thus avoiding the necessity of repeating steps (1)–(3). A physical evaluation of the image quality of PS-TS-F compared with that of the conventional linear TS was performed using a R/F table (Sonialvision safire, Shimadzu Corp., Kyoto, Japan). The tomographic plane with the best theoretical spatial resolution (the in-focus plane, IFP) was set at a height of 100 mm from the table top by adjusting the reconstruction program. First, the spatial frequency response was evaluated at heights of −100, −50, 0, 50, 100, and 150 mm from the IFP using the edge of a 0.3-mm-thick copper plate. Second, the spatial resolution at each height was visually evaluated using an x-ray test pattern (Model No. 38, PTW Freiburg, Germany). Third, the slice sensitivity at each height was evaluated via the wire method using a 0.1-mm-diameter tungsten wire. Phantom studies using a knee phantom and a whole-body phantom were also performed. Results: The spatial frequency response of PS-TS-F yielded the best results at the IFP and degraded slightly as the

  16. Method for 3D fibre reconstruction on a microrobotic platform.

    Science.gov (United States)

    Hirvonen, J; Myllys, M; Kallio, P

    2016-07-01

    Automated handling of a natural fibrous object requires a method for acquiring the three-dimensional geometry of the object, because its dimensions cannot be known beforehand. This paper presents a method for calculating the three-dimensional reconstruction of a paper fibre on a microrobotic platform that contains two microscope cameras. The method is based on detecting curvature changes in the fibre centreline, and using them as the corresponding points between the different views of the images. We test the developed method with four fibre samples and compare the results with the references measured with an X-ray microtomography device. We rotate the samples through 16 different orientations on the platform and calculate the three-dimensional reconstruction to test the repeatability of the algorithm and its sensitivity to the orientation of the sample. We also test the noise sensitivity of the algorithm, and record the mismatch rate of the correspondences provided. We use the iterative closest point algorithm to align the measured three-dimensional reconstructions with the references. The average point-to-point distances between the reconstructed fibre centrelines and the references are 20-30 μm, and the mismatch rate is low. Given the manipulation tolerance, this shows that the method is well suited to automated fibre grasping. This has also been demonstrated with actual grasping experiments. PMID:26695385

  17. Detection of microcalcifications in breast tomosynthesis reconstructed with multiscale bilateral filtering regularization

    Science.gov (United States)

    Samala, Ravi K.; Chan, Heang-Ping; Lu, Yao; Hadjiyski, Lubomir; Wei, Jun; Sahiner, Berkman; Helvie, Mark

    2013-03-01

    We are developing a CAD system to assist radiologists in detecting microcalcification clusters (MCs) in digital breast tomosynthesis (DBT). In this study, we investigated the feasibility of using as input to the CAD system an enhanced DBT volume that was reconstructed with the iterative simultaneous algebraic reconstruction technique (SART) regularized by a new multiscale bilateral filtering (MBiF) method. The MBiF method utilizes the multiscale structures of the breast to selectively enhance MCs and preserve mass spiculations while smoothing noise in the DBT images. The CAD system first extracted the enhancement-modulated calcification response (EMCR) in the DBT volume. Detection of the seed points for MCs and individual calcifications were guided by the EMCR. MC candidates were formed by dynamic clustering. FPs were further reduced by analysis of the feature characteristics of the MCs. With IRB approval, two-view DBT of 91 subjects with biopsy-proven MCs were collected. Seventy-eight views from 39 subjects with MCs were used for training and the remaining 52 cases were used for independent testing. For view-based detection, a sensitivity of 85% was achieved at 3.23 FPs/volume. For case-based detection, the same sensitivity was obtained at 1.63 FPs/volume. The results indicate that the new MBiF method is useful in improving the detection accuracy of clustered microcalcifications. An effective CAD system for microcalcification detection in DBT has the potential to eliminate the need for additional mammograms, thereby reducing patient dose and reading time.

  18. Two complementary model observers to evaluate reconstructions of simulated micro-calcifications in digital breast tomosynthesis

    Science.gov (United States)

    Michielsen, Koen; Zanca, Federica; Marshall, Nicholas; Bosmans, Hilde; Nuyts, Johan

    2013-03-01

    New imaging modalities need to be properly evaluated before being introduced in clinical practice. The gold standard is to perform clinical trials or dedicated clinical performance related observer experiments with experienced readers. Unfortunately this is not feasible during development or optimization of new reconstruction algorithms due to their many degrees of freedom. Our goal is to design a set of model observers to evaluate the performance of newly developed reconstruction methods on the assessment of micro-calcifications in digital breast tomosynthesis. In order to do so, the model observers need to evaluate both detection and classification of micro-calcifications. A channelized Hotelling observer was created for the detection task and a Hotelling observer working on an extracted feature vector was implemented for the classification task. These observers were evaluated on their ability to predict the results of human observers. Results from a previous observer study were used as reference to compare performance between human and model observers. This study evaluated detection of small micro-calcifications (100 { 200 _m) by a free search task in a power law filtered noise background and classification of two types of larger micro-calcifications (200 {600 _m) in the same background. Scores from the free search study were evaluated using the weighted JAFROC method and the classification scores were analyzed using the DBM MRMC method. The same analysis methods were applied to the model observer scores. Results of the detection model observer were related linearly with the human observer results with a correlation coefficient of 0.962. The correlation coefficient for the classification task was 0.959 with a power law non-linear regression.

  19. 3D model tools for architecture and archaeology reconstruction

    Science.gov (United States)

    Vlad, Ioan; Herban, Ioan Sorin; Stoian, Mircea; Vilceanu, Clara-Beatrice

    2016-06-01

    The main objective of architectural and patrimonial survey is to provide a precise documentation of the status quo of the surveyed objects (monuments, buildings, archaeological object and sites) for preservation and protection, for scientific studies and restoration purposes, for the presentation to the general public. Cultural heritage documentation includes an interdisciplinary approach having as purpose an overall understanding of the object itself and an integration of the information which characterize it. The accuracy and the precision of the model are directly influenced by the quality of the measurements realized on field and by the quality of the software. The software is in the process of continuous development, which brings many improvements. On the other side, compared to aerial photogrammetry, close range photogrammetry and particularly architectural photogrammetry is not limited to vertical photographs with special cameras. The methodology of terrestrial photogrammetry has changed significantly and various photographic acquisitions are widely in use. In this context, the present paper brings forward a comparative study of TLS (Terrestrial Laser Scanner) and digital photogrammetry for 3D modeling. The authors take into account the accuracy of the 3D models obtained, the overall costs involved for each technology and method and the 4th dimension - time. The paper proves its applicability as photogrammetric technologies are nowadays used at a large scale for obtaining the 3D model of cultural heritage objects, efficacious in their assessment and monitoring, thus contributing to historic conservation. Its importance also lies in highlighting the advantages and disadvantages of each method used - very important issue for both the industrial and scientific segment when facing decisions such as in which technology to invest more research and funds.

  20. Quantitative Reconstructions of 3D Chemical Nanostructures in Nanowires.

    Science.gov (United States)

    Rueda-Fonseca, P; Robin, E; Bellet-Amalric, E; Lopez-Haro, M; Den Hertog, M; Genuist, Y; André, R; Artioli, A; Tatarenko, S; Ferrand, D; Cibert, J

    2016-03-01

    Energy dispersive X-ray spectrometry is used to extract a quantitative 3D composition profile of heterostructured nanowires. The analysis of hypermaps recorded along a limited number of projections, with a preliminary calibration of the signal associated with each element, is compared to the intensity profiles calculated for a model structure with successive shells of circular, elliptic, or faceted cross sections. This discrete tomographic technique is applied to II-VI nanowires grown by molecular beam epitaxy, incorporating ZnTe and CdTe and their alloys with Mn and Mg, with typical size down to a few nanometers and Mn or Mg content as low as 10%. PMID:26837636

  1. 3D Image Reconstruction from Compton camera data

    CERN Document Server

    Kuchment, Peter

    2016-01-01

    In this paper, we address analytically and numerically the inversion of the integral transform (\\emph{cone} or \\emph{Compton} transform) that maps a function on $\\mathbb{R}^3$ to its integrals over conical surfaces. It arises in a variety of imaging techniques, e.g. in astronomy, optical imaging, and homeland security imaging, especially when the so called Compton cameras are involved. Several inversion formulas are developed and implemented numerically in $3D$ (the much simpler $2D$ case was considered in a previous publication).

  2. Quantitative Reconstructions of 3D Chemical Nanostructures in Nanowires.

    Science.gov (United States)

    Rueda-Fonseca, P; Robin, E; Bellet-Amalric, E; Lopez-Haro, M; Den Hertog, M; Genuist, Y; André, R; Artioli, A; Tatarenko, S; Ferrand, D; Cibert, J

    2016-03-01

    Energy dispersive X-ray spectrometry is used to extract a quantitative 3D composition profile of heterostructured nanowires. The analysis of hypermaps recorded along a limited number of projections, with a preliminary calibration of the signal associated with each element, is compared to the intensity profiles calculated for a model structure with successive shells of circular, elliptic, or faceted cross sections. This discrete tomographic technique is applied to II-VI nanowires grown by molecular beam epitaxy, incorporating ZnTe and CdTe and their alloys with Mn and Mg, with typical size down to a few nanometers and Mn or Mg content as low as 10%.

  3. Reconstruction of 3D models of cast sculptures using close-range photogrammetry

    Directory of Open Access Journals (Sweden)

    Ž. Santoši

    2015-10-01

    Full Text Available This paper presents the possibilities of application of close-range photogrammetry, based on the Structure-from- Motion (SfM approach, in 3D model’s reconstruction of bronze cast sculptures. Special attention was dedicated to the analysis of image processing strategy, and its impact on the 3D model reconstruction quality. For the purpose of analysis a bust of Nikola Tesla, placed in front of the Faculty of Technical Sciences University of Novi Sad was used. Experimental results indicate that the strategy employing multi-group photo processing provides substantial reductions in processing time while providing satisfactory results in 3D reconstruction.

  4. Assessing 3D tunnel position in ACL reconstruction using a novel single image 3D-2D registration

    Science.gov (United States)

    Kang, X.; Yau, W. P.; Otake, Y.; Cheung, P. Y. S.; Hu, Y.; Taylor, R. H.

    2012-02-01

    The routinely used procedure for evaluating tunnel positions following anterior cruciate ligament (ACL) reconstructions based on standard X-ray images is known to pose difficulties in terms of obtaining accurate measures, especially in providing three-dimensional tunnel positions. This is largely due to the variability in individual knee joint pose relative to X-ray plates. Accurate results were reported using postoperative CT. However, its extensive usage in clinical routine is hampered by its major requirement of having CT scans of individual patients, which is not available for most ACL reconstructions. These difficulties are addressed through the proposed method, which aligns a knee model to X-ray images using our novel single-image 3D-2D registration method and then estimates the 3D tunnel position. In the proposed method, the alignment is achieved by using a novel contour-based 3D-2D registration method wherein image contours are treated as a set of oriented points. However, instead of using some form of orientation weighting function and multiplying it with a distance function, we formulate the 3D-2D registration as a probability density estimation using a mixture of von Mises-Fisher-Gaussian (vMFG) distributions and solve it through an expectation maximization (EM) algorithm. Compared with the ground-truth established from postoperative CT, our registration method in an experiment using a plastic phantom showed accurate results with errors of (-0.43°+/-1.19°, 0.45°+/-2.17°, 0.23°+/-1.05°) and (0.03+/-0.55, -0.03+/-0.54, -2.73+/-1.64) mm. As for the entry point of the ACL tunnel, one of the key measurements, it was obtained with high accuracy of 0.53+/-0.30 mm distance errors.

  5. 3D reconstruction software comparison for short sequences

    Science.gov (United States)

    Strupczewski, Adam; Czupryński, BłaŻej

    2014-11-01

    Large scale multiview reconstruction is recently a very popular area of research. There are many open source tools that can be downloaded and run on a personal computer. However, there are few, if any, comparisons between all the available software in terms of accuracy on small datasets that a single user can create. The typical datasets for testing of the software are archeological sites or cities, comprising thousands of images. This paper presents a comparison of currently available open source multiview reconstruction software for small datasets. It also compares the open source solutions with a simple structure from motion pipeline developed by the authors from scratch with the use of OpenCV and Eigen libraries.

  6. Manifold Constrained Transfer of Facial Geometric Knowledge for 3D Caricature Reconstruction

    Institute of Scientific and Technical Information of China (English)

    Jun-Fa Liu; Wen-Jing He; Tao Chen; Yi-Qiang Chen

    2013-01-01

    3D caricatures are important attractive elements of the interface in virtual environment such as online game.However,very limited 3D caricatures exist in the real world.Meanwhile,creating 3D caricatures manually is rather costly,and even professional skills are needed.This paper proposes a novel and effective manifold transfer algorithm to reconstruct 3D caricatures according to their original 2D caricatures.We first manually create a small dataset with only 100 3D caricature models and use them to initialize the whole 3D dataset.After that,manifold transfer algorithm is carried out to refine the dataset.The algorithm comprises of two steps.The first is to perform manifold alignment between 2D and 3D caricatures to get a "standard" manifold map; the second is to reconstruct all the 3D caricatures based on the manifold map.The proposed approach utilizes and transfers knowledge of 2D caricatures to the target 3D caricatures well.Comparative experiments show that the approach reconstructs 3D caricatures more effectively and the results conform more to the styles of the original 2D caricatures than the Principal Components Analysis (PCA) based method.

  7. Reconstruction of 3D morphology of polyhedral nanoparticles

    International Nuclear Information System (INIS)

    The three-dimensional (3D) faceting morphology of ceria nanoparticles is analysed using transmission electron microscopy (TEM)-based computed tomography on the nanometre scale. A novel tomography mode of electron energy loss spectroscopic imaging using a single energy window for inelastically scattered electrons is introduced and found to be reliable and fast for freestanding nanoparticles. To compare the new tomographic method with other methods, we provide the first comprehensive application of three complementary TEM-based imaging techniques, including bright field TEM and annular dark field specific TEM (STEM). Traditional bright-field TEM tomography is found to be applicable, in spite of obvious artefacts, for crystalline particles of constant composition. However, the safest interpretation is achieved by a combined recording of bright field and spectroscopic images

  8. Assist feature printability prediction by 3-D resist profile reconstruction

    Science.gov (United States)

    Zheng, Xin; Huang, Jensheng; Chin, Fook; Kazarian, Aram; Kuo, Chun-Chieh

    2012-06-01

    properties may then be used to optimize the printability vs. efficacy of an SRAF either prior to or during an Optical Proximity Correction (OPC) run. The process models that are used during OPC have never been able to reliably predict which SRAFs will print. This appears to be due to the fact that OPC process models are generally created using data that does not include printed subresolution patterns. An enhancement to compact modeling capability to predict Assist Features (AF) printability is developed and discussed. A hypsometric map representing 3-D resist profile was built by applying a first principle approximation to estimate the "energy loss" from the resist top to bottom. Such a 3-D resist profile is an extrapolation of a well calibrated traditional OPC model without any additional information. Assist features are detected at either top of resist (dark field) or bottom of resist (bright field). Such detection can be done by just extracting top or bottom resist models from our 3-D resist model. There is no measurement of assist features needed when we build AF but it can be included if interested but focusing on resist calibration to account for both exposure dosage and focus change sensitivities. This approach significantly increases resist model's capability for predicting printed SRAF accuracy. And we don't need to calibrate an SRAF model in addition to the OPC model. Without increase in computation time, this compact model can draw assist feature contour with real placement and size at any vertical plane. The result is compared and validated with 3-D rigorous modeling as well as SEM images. Since this method does not change any form of compact modeling, it can be integrated into current MBAF solutions without any additional work.

  9. Digital Holographic Capture and Optoelectronic Reconstruction for 3D Displays

    Directory of Open Access Journals (Sweden)

    Damien P. Kelly

    2010-01-01

    Full Text Available The application of digital holography as a viable solution to 3D capture and display technology is examined. A review of the current state of the field is presented in which some of the major challenges involved in a digital holographic solution are highlighted. These challenges include (i the removal of the DC and conjugate image terms, which are features of the holographic recording process, (ii the reduction of speckle noise, a characteristic of a coherent imaging process, (iii increasing the angular range of perspective of digital holograms (iv and replaying captured and/or processed digital holograms using spatial light modulators. Each of these challenges are examined theoretically and several solutions are put forward. Experimental results are presented that demonstrate the validity of the theoretical solutions.

  10. Neurofunctional systems. 3D reconstructions with correlated neuroimaging

    International Nuclear Information System (INIS)

    This book introduces, for the first time, computer-generated images of the neurofunctional systems of the human brain. These images are more accurate than drawings. The main views presented are of the medial lemniscus system, auditory system, visual system, basal ganglia, corticospinal system, and the limbic system. The arteries and sulci of the cerebral hemispheres are also illustrated by computer. These images provide a three-dimensional orientation of the intracranial space and help, for example, to assess vascular functional disturbance of the brain. Clinicians will find these images valuable for the spatial interpretation of magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET) images since many neurofunctional systems cannot be visualized as isolated structures in neuroimaging. Computer-assisted surface reconstructions of the neurofunctional systems and the cerebral arteries serve as a basis for constructing these computer-generated images. The surface reconstructions are anatomically realistic having been created from brain sections with minimal deformations. The method of computer graphics, known as ray tracing, produces digital images form these reconstructions. The computer-generated methods are explained. The computer-generated images are accompanied by illustrations and texts on neuroanatomy and clinical practice. The neurofunctional systems of the human brain are also shown in sections so that the reader can mentally reconstruct the neurofunctional systems, thus facilitating the transformation of information into textbooks and atlantes of MR and CT imaging. The aim of this book is acquaint the reader with the three-dimensional aspects of the neurofunctional systems and the cerebral arteries of the human brain using methods of computer graphics. Computer scientists and those interested in this technique are provided with basic neuroanatomic and neurofunctional information. Physicians will have a clearer understanding

  11. Combinatorial clustering and Its Application to 3D Polygonal Traffic Sign Reconstruction From Multiple Images

    Science.gov (United States)

    Vallet, B.; Soheilian, B.; Brédif, M.

    2014-08-01

    The 3D reconstruction of similar 3D objects detected in 2D faces a major issue when it comes to grouping the 2D detections into clusters to be used to reconstruct the individual 3D objects. Simple clustering heuristics fail as soon as similar objects are close. This paper formulates a framework to use the geometric quality of the reconstruction as a hint to do a proper clustering. We present a methodology to solve the resulting combinatorial optimization problem with some simplifications and approximations in order to make it tractable. The proposed method is applied to the reconstruction of 3D traffic signs from their 2D detections to demonstrate its capacity to solve ambiguities.

  12. Bayesian 3D velocity field reconstruction with VIRBIUS

    Science.gov (United States)

    Lavaux, Guilhem

    2016-03-01

    I describe a new Bayesian-based algorithm to infer the full three dimensional velocity field from observed distances and spectroscopic galaxy catalogues. In addition to the velocity field itself, the algorithm reconstructs true distances, some cosmological parameters and specific non-linearities in the velocity field. The algorithm takes care of selection effects, miscalibration issues and can be easily extended to handle direct fitting of e.g. the inverse Tully-Fisher relation. I first describe the algorithm in details alongside its performances. This algorithm is implemented in the VIRBIUS (VelocIty Reconstruction using Bayesian Inference Software) software package. I then test it on different mock distance catalogues with a varying complexity of observational issues. The model proved to give robust measurement of velocities for mock catalogues of 3000 galaxies. I expect the core of the algorithm to scale to tens of thousands galaxies. It holds the promises of giving a better handle on future large and deep distance surveys for which individual errors on distance would impede velocity field inference.

  13. Bayesian 3d velocity field reconstruction with VIRBIuS

    CERN Document Server

    Lavaux, G

    2015-01-01

    I describe a new Bayesian based algorithm to infer the full three dimensional velocity field from observed distances and spectroscopic galaxy catalogues. In addition to the velocity field itself, the algorithm reconstructs true distances, some cosmological parameters and specific non-linearities in the velocity field. The algorithm takes care of selection effects, miscalibration issues and can be easily extended to handle direct fitting of, e.g., the inverse Tully-Fisher relation. I first describe the algorithm in details alongside its performances. This algorithm is implemented in the VIRBIuS (VelocIty Reconstruction using Bayesian Inference Software) software package. I then test it on different mock distance catalogues with a varying complexity of observational issues. The model proved to give robust measurement of velocities for mock catalogues of 3,000 galaxies. I expect the core of the algorithm to scale to tens of thousands galaxies. It holds the promises of giving a better handle on future large and d...

  14. GPU-Based 3D Cone-Beam CT Image Reconstruction for Large Data Volume

    OpenAIRE

    Xing Zhao; Jing-jing Hu; Peng Zhang

    2009-01-01

    Currently, 3D cone-beam CT image reconstruction speed is still a severe limitation for clinical application. The computational power of modern graphics processing units (GPUs) has been harnessed to provide impressive acceleration of 3D volume image reconstruction. For extra large data volume exceeding the physical graphic memory of GPU, a straightforward compromise is to divide data volume into blocks. Different from the conventional Octree partition method, a new partition scheme is proposed...

  15. Reconstructing 3D building models from laser scanning to calculate the heat demand

    Energy Technology Data Exchange (ETDEWEB)

    Neidhart, Hauke; Sester, Monika

    2008-09-15

    The objective of the project is to determine the heat demand of settlement areas using geospatial data, especially airborne laser scanning data. With airborne laser scanning it possible to record detailed 3D data for great areas. With this 3D data it is possible to reconstruct 3D building models. The geometry then can be used to derive information for the calculation of the heat demand

  16. TOMOGRAPHIC MAMMOGRAPHY AND TOMOSYNTHESIS USING OPENGL

    Directory of Open Access Journals (Sweden)

    S. A. Zolotarev

    2016-01-01

    Full Text Available Computed tomography is still being intensively studied and widely used to solve a number of industrial and medical applications. The simultaneous algebraic reconstruction technique (SART and Bayesian inference reconstruction (BIR are considered as advantageous iteration methods that are most suitable for improving the quality of the reconstructed 3D-images. The paper deals with the parallel iterative algorithms to ensure the reconstruction of threedimensional images of the breast, recovered from a limited set of noisy X-ray projections. Algebraic method of reconstruction with simultaneous iterations – SART and iterative method for statistical reconstruction of BIR are deemed to be the most preferred iterative methods. We believe that these methods are particularly useful for improving the quality of breast reconstructed image. We use the graphics processor (GPU to accelerate the process of reconstruction. Preliminary results show that all investigated methods are useful in breast reconstruction layered images. However, it was found that the method of classical tomosynthesis SAA is less efficient than iterative methods SART and BIR as the worst suppress the anatomical noise. Despite the fact that the estimated ratio of the contrast / noise ratio in the presence of internal structures with low contrast is higher for classical tomosynthesis method the SAA, its effectiveness in the presence of highly structured background is low. In our opinion the best results can be achieved using statistical iterative reconstruction BIR.

  17. Selective-diffusion regularization for enhancement of microcalcifications in digital breast tomosynthesis reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Lu Yao; Chan, Heang-Ping; Wei Jun; Hadjiiski, Lubomir M. [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2010-11-15

    Purpose: Digital breast tomosynthesis (DBT) has been shown to improve mass detection. Detection of microcalcifications is more challenging because of the large breast volume to be searched for subtle signals. The simultaneous algebraic reconstruction technique (SART) was found to provide good image quality for DBT, but the image noise is amplified with an increasing number of iterations. In this study, the authors developed a selective-diffusion (SD) method for noise regularization with SART to improve the contrast-to-noise ratio (CNR) of microcalcifications in the DBT slices for human or machine detection. Methods: The SD method regularizes SART reconstruction during updating with each projection view. Potential microcalcifications are differentiated from the noisy background by estimating the local gradient information. Different degrees of regularization are applied to the signal or noise classes, such that the microcalcifications will be enhanced while the noise is suppressed. The new SD method was compared to several current methods, including the quadratic Laplacian (QL) method, the total variation (TV) method, and the nonconvex total p-variation (TpV) method for noise regularization with SART. A GE GEN2 prototype DBT system with a stationary digital detector was used for the acquisition of DBT scans at 21 angles in 3 deg. increments over a {+-}30 deg. range. The reconstruction image quality without regularization and that with the different regularization methods were compared using the DBT scans of an American College of Radiology phantom and a human subject. The CNR and the full width at half maximum (FWHM) of the line profiles of microcalcifications within the in-focus DBT slices were used as image quality measures. Results: For the comparison of large microcalcifications in the DBT data of the subject, the SD method resulted in comparable CNR to the nonconvex TpV method. Both of them performed better than the other two methods. For subtle

  18. Selective-diffusion regularization for enhancement of microcalcifications in digital breast tomosynthesis reconstruction

    Science.gov (United States)

    Lu, Yao; Chan, Heang-Ping; Wei, Jun; Hadjiiski, Lubomir M.

    2010-01-01

    Purpose: Digital breast tomosynthesis (DBT) has been shown to improve mass detection. Detection of microcalcifications is more challenging because of the large breast volume to be searched for subtle signals. The simultaneous algebraic reconstruction technique (SART) was found to provide good image quality for DBT, but the image noise is amplified with an increasing number of iterations. In this study, the authors developed a selective-diffusion (SD) method for noise regularization with SART to improve the contrast-to-noise ratio (CNR) of microcalcifications in the DBT slices for human or machine detection. Methods: The SD method regularizes SART reconstruction during updating with each projection view. Potential microcalcifications are differentiated from the noisy background by estimating the local gradient information. Different degrees of regularization are applied to the signal or noise classes, such that the microcalcifications will be enhanced while the noise is suppressed. The new SD method was compared to several current methods, including the quadratic Laplacian (QL) method, the total variation (TV) method, and the nonconvex total p-variation (TpV) method for noise regularization with SART. A GE GEN2 prototype DBT system with a stationary digital detector was used for the acquisition of DBT scans at 21 angles in 3° increments over a ±30° range. The reconstruction image quality without regularization and that with the different regularization methods were compared using the DBT scans of an American College of Radiology phantom and a human subject. The CNR and the full width at half maximum (FWHM) of the line profiles of microcalcifications within the in-focus DBT slices were used as image quality measures. Results: For the comparison of large microcalcifications in the DBT data of the subject, the SD method resulted in comparable CNR to the nonconvex TpV method. Both of them performed better than the other two methods. For subtle microcalcifications

  19. Automatic Texture Reconstruction of 3d City Model from Oblique Images

    Science.gov (United States)

    Kang, Junhua; Deng, Fei; Li, Xinwei; Wan, Fang

    2016-06-01

    In recent years, the photorealistic 3D city models are increasingly important in various geospatial applications related to virtual city tourism, 3D GIS, urban planning, real-estate management. Besides the acquisition of high-precision 3D geometric data, texture reconstruction is also a crucial step for generating high-quality and visually realistic 3D models. However, most of the texture reconstruction approaches are probably leading to texture fragmentation and memory inefficiency. In this paper, we introduce an automatic framework of texture reconstruction to generate textures from oblique images for photorealistic visualization. Our approach include three major steps as follows: mesh parameterization, texture atlas generation and texture blending. Firstly, mesh parameterization procedure referring to mesh segmentation and mesh unfolding is performed to reduce geometric distortion in the process of mapping 2D texture to 3D model. Secondly, in the texture atlas generation step, the texture of each segmented region in texture domain is reconstructed from all visible images with exterior orientation and interior orientation parameters. Thirdly, to avoid color discontinuities at boundaries between texture regions, the final texture map is generated by blending texture maps from several corresponding images. We evaluated our texture reconstruction framework on a dataset of a city. The resulting mesh model can get textured by created texture without resampling. Experiment results show that our method can effectively mitigate the occurrence of texture fragmentation. It is demonstrated that the proposed framework is effective and useful for automatic texture reconstruction of 3D city model.

  20. Preoperative Planning Using 3D Reconstructions and Virtual Endoscopy for Location of the Frontal Sinus

    Directory of Open Access Journals (Sweden)

    Abreu, João Paulo Saraiva

    2011-01-01

    Full Text Available Introduction: Computed tomography (TC generated tridimensional (3D reconstructions allow the observation of cavities and anatomic structures of our body with detail. In our specialty there have been attempts to carry out virtual endoscopies and laryngoscopies. However, such application has been practically abandoned due to its complexity and need for computers with high power of graphic processing. Objective: To demonstrate the production of 3D reconstructions from CTs of patients in personal computers, with a free specific program and compare them to the surgery actual endoscopic images. Method: Prospective study in which the CTs proper files of 10 patients were reconstructed with the program Intage Realia, version 2009, 0, 0, 702 (KGT Inc., Japan. The reconstructions were carried out before the surgeries and a virtual endoscopy was made to assess the recess and frontal sinus region. After this study, the surgery was digitally performed and stored. The actual endoscopic images of the recess and frontal sinus region were compared to the virtual images. Results: The 3D reconstruction and virtual endoscopy were made in 10 patients submitted to the surgery. The virtual images had a large resemblance with the actual surgical images. Conclusion: With relatively simple tools and personal computer, we demonstrated the possibility to generate 3D reconstructions and virtual endoscopies. The preoperative knowledge of the frontal sinus natural draining path location may generate benefits during the performance of surgeries. However, more studies must be developed for the evaluation of the real roles of such 3D reconstructions and virtual endoscopies.

  1. Neural Network Based Reconstruction of a 3D Object from a 2D Wireframe

    CERN Document Server

    Johnson, Kyle; Lipson, Hod

    2010-01-01

    We propose a new approach for constructing a 3D representation from a 2D wireframe drawing. A drawing is simply a parallel projection of a 3D object onto a 2D surface; humans are able to recreate mental 3D models from 2D representations very easily, yet the process is very difficult to emulate computationally. We hypothesize that our ability to perform this construction relies on the angles in the 2D scene, among other geometric properties. Being able to reproduce this reconstruction process automatically would allow for efficient and robust 3D sketch interfaces. Our research focuses on the relationship between 2D geometry observable in the sketch and 3D geometry derived from a potential 3D construction. We present a fully automated system that constructs 3D representations from 2D wireframes using a neural network in conjunction with a genetic search algorithm.

  2. Applicability of 3D-CT facial reconstruction for forensic individual identification

    OpenAIRE

    Rocha Sara dos Santos; Ramos Dalton Luiz de Paula; Cavalcanti Marcelo de Gusmão Paraíso

    2003-01-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using craniometric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering techni...

  3. Image Reconstruction from 2D stack of MRI/CT to 3D using Shapelets

    OpenAIRE

    Arathi T; Latha Parameswaran

    2014-01-01

    Image reconstruction is an active research field, due to the increasing need for geometric 3D models in movie industry, games, virtual environments and in medical fields. 3D image reconstruction aims to arrive at the 3D model of an object, from its 2D images taken at different viewing angles. Medical images are multimodal, which includes MRI, CT scan image, PET and SPECT images. Of these, MRI and CT scan images of an organ when taken, is available as a stack of 2D images, taken at different a...

  4. Array diagnostics, spatial resolution, and filtering of undesired radiation with the 3D reconstruction algorithm

    DEFF Research Database (Denmark)

    Cappellin, C.; Pivnenko, Sergey; Jørgensen, E.;

    2013-01-01

    This paper focuses on three important features of the 3D reconstruction algorithm of DIATOOL: the identification of array elements improper functioning and failure, the obtainable spatial resolution of the reconstructed fields and currents, and the filtering of undesired radiation and scattering...

  5. The Art of Reconstruction. Documenting the process of 3D modeling: some preliminary results

    NARCIS (Netherlands)

    P.S. Lulof; L. Opgenhaffen; M.H. Sepers

    2013-01-01

    The project `The Art of Reconstruction' explores the usage of digital three-dimensional (3D) reconstructions to support research into historical and archaeological architectural settings. More specifically, the aim is to enhance the research on buildings that are nowadays partly or entirely lost, bu

  6. Application of generalized regression neural network on fast 3D reconstruction

    Institute of Scientific and Technical Information of China (English)

    Babakhani Asad; DU Zhi-jiang; SUN Li-ning; Kardan Reza; Mianji A. Fereidoun

    2007-01-01

    In robot-assisted surgery projects,researchers should be able to make fast 3 D reconstruction. Usually 2D images acquired with common diagnostic equipments such as UT, CT and MRI are not enough and complete for an accurate 3D reconstruction. There are some interpolation methods for approximating non value voxels which consume large execution time. A novel algorithm is introduced based on generalized regression neural network (GRNN) which can interpolate unknown voxles fast and reliable. The GRNN interpolation is used to produce new 2D images between each two succeeding ultrasonic images. It is shown that the composition of GRNN with image distance transformation can produce higher quality 3D shapes. The results of this method are compared with other interpolation methods practically. It shows this method can decrease overall time consumption on online 3D reconstruction.

  7. 3D reconstruction of a human heart fascicle using SurfDriver

    Science.gov (United States)

    Rader, Robert J.; Phillips, Steven J.; LaFollette, Paul S., Jr.

    2000-06-01

    The Temple University Medical School has a sequence of over 400 serial sections of adult normal ventricular human heart tissue, cut at 25 micrometer thickness. We used a Zeiss Ultraphot with a 4x planapo objective and a Pixera digital camera to make a series of 45 sequential montages to use in the 3D reconstruction of a fascicle (muscle bundle). We wrote custom software to merge 4 smaller image fields from each section into one composite image. We used SurfDriver software, developed by Scott Lozanoff of the University of Hawaii and David Moody of the University of Alberta, for registration, object boundary identification, and 3D surface reconstruction. We used an Epson Stylus Color 900 printer to get photo-quality prints. We describe the challenge and our solution to the following problems: image acquisition and digitization, image merge, alignment and registration, boundary identification, 3D surface reconstruction, 3D visualization and orientation, snapshot, and photo-quality prints.

  8. A fast 3D reconstruction system with a low-cost camera accessory.

    Science.gov (United States)

    Zhang, Yiwei; Gibson, Graham M; Hay, Rebecca; Bowman, Richard W; Padgett, Miles J; Edgar, Matthew P

    2015-06-09

    Photometric stereo is a three dimensional (3D) imaging technique that uses multiple 2D images, obtained from a fixed camera perspective, with different illumination directions. Compared to other 3D imaging methods such as geometry modeling and 3D-scanning, it comes with a number of advantages, such as having a simple and efficient reconstruction routine. In this work, we describe a low-cost accessory to a commercial digital single-lens reflex (DSLR) camera system allowing fast reconstruction of 3D objects using photometric stereo. The accessory consists of four white LED lights fixed to the lens of a commercial DSLR camera and a USB programmable controller board to sequentially control the illumination. 3D images are derived for different objects with varying geometric complexity and results are presented, showing a typical height error of <3 mm for a 50 mm sized object.

  9. Characterization of masses in digital breast tomosynthesis: Comparison of machine learning in projection views and reconstructed slices

    International Nuclear Information System (INIS)

    Purpose: In digital breast tomosynthesis (DBT), quasi-three-dimensional (3D) structural information is reconstructed from a small number of 2D projection view (PV) mammograms acquired over a limited angular range. The authors developed preliminary computer-aided diagnosis (CADx) methods for classification of malignant and benign masses and compared the effectiveness of analyzing lesion characteristics in the reconstructed DBT slices and in the PVs. Methods: A data set of MLO view DBT of 99 patients containing 107 masses (56 malignant and 51 benign) was collected at the Massachusetts General Hospital with IRB approval. The DBTs were obtained with a GE prototype system which acquired 11 PVs over a 50 deg. arc. The authors reconstructed the DBTs at 1 mm slice interval using a simultaneous algebraic reconstruction technique. The region of interest (ROI) containing the mass was marked by a radiologist in the DBT volume and the corresponding ROIs on the PVs were derived based on the imaging geometry. The subsequent processes were fully automated. For classification of masses using the DBT-slice approach, the mass on each slice was segmented by an active contour model initialized with adaptive k-means clustering. A spiculation likelihood map was generated by analysis of the gradient directions around the mass margin and spiculation features were extracted from the map. The rubber band straightening transform (RBST) was applied to a band of pixels around the segmented mass boundary. The RBST image was enhanced by Sobel filtering in the horizontal and vertical directions, from which run-length statistics texture features were extracted. Morphological features including those from the normalized radial length were designed to describe the mass shape. A feature space composed of the spiculation features, texture features, and morphological features extracted from the central slice alone and seven feature spaces obtained by averaging the corresponding features from three to 19

  10. 3D High Resolution l1-SPIRiT Reconstruction on Gadgetron based Cloud

    DEFF Research Database (Denmark)

    Xue, Hui; Kelmann, Peter; Inati, Souheil;

    framework to support distributed computing in a cloud environment. This extension is named GT-Plus. A cloud version of 3D l1-SPIRiT was implemented on the GT-Plus framework. We demonstrate that a 3mins reconstruction could be achieved for 1mm3 isotropic resolution neuro scans with significantly improved......Applying non-linear reconstruction to high resolution 3D MRI is challenging because of the lengthy computing time needed for those iterative algorithms. To achieve practical processing duration to enable clinical usage of non-linear reconstruction, we have extended previously published Gadgetron...

  11. Fully 3D PET image reconstruction with a 4D sinogram blurring kernel

    Energy Technology Data Exchange (ETDEWEB)

    Tohme, Michel S.; Qi, Jinyi [California Univ., Davis, CA (United States). Dept. of Biomedical Engineering; Zhou, Jian

    2011-07-01

    Accurately modeling PET system response is essential for high-resolution image reconstruction. Traditionally, sinogram blurring effects are modeled as a 2D blur in each sinogram plane. Such 2D blurring kernel is insufficient for fully 3D PET data, which has four dimensions. In this paper, we implement a fully 3D PET image reconstruction using a 4D sinogram blurring kernel estimated from point source scans and perform phantom experiments to evaluate the improvements in image quality over methods with existing 2D blurring kernels. The results show that the proposed reconstruction method can achieve better spatial resolution and contrast recovery than existing methods. (orig.)

  12. Technology Corner: Virtual Crime Scene Reconstruction: The Basics of 3D Modeling

    Directory of Open Access Journals (Sweden)

    Nick Flor

    2011-12-01

    Full Text Available Digital crime scenes take place in the context of physical crime scenes. Virtual crime scene reconstruction is an activity where investigators create a 3-dimensional (3-D model of an actual crime scene for the purpose of determining the events that lead to the crime. While virtual crime scene reconstruction is currently used for analyzing physical scenes, it can also help investigators visualize and explore ways digital media could have been used to perpetrate a crime. In this technology corner we explore one of the technologies underlying virtual crime scene reconstruction: 3-D modeling. 

  13. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    Science.gov (United States)

    Wouterlood, Floris G

    2014-01-01

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. Scanning of a specimen, with stepwise axial (Z-) movement of the stage in between each scan, produces Z-series of confocal images of a tissue volume, which then can be used to 3-D reconstruct structures of interest. The operator first configures separate channels (e.g., laser, filters, and detector settings) for each applied fluorochrome and then acquires Z-series of confocal images: one series per channel. Channel signal separation is extremely important. Measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is often performed to increase resolution before 3-D reconstruction takes place. In the 3-D reconstruction programs described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationships of 3-D-reconstructed structures with respect to structures visualized in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided in this protocol wherever possible.

  14. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    Science.gov (United States)

    Wouterlood, Floris G

    2014-01-01

    A confocal laser scanning microscope (CLSM) collects information from a thin, focal plane and ignores out-of-focus information. Scanning of a specimen, with stepwise axial (Z-) movement of the stage in between each scan, produces Z-series of confocal images of a tissue volume, which then can be used to 3-D reconstruct structures of interest. The operator first configures separate channels (e.g., laser, filters, and detector settings) for each applied fluorochrome and then acquires Z-series of confocal images: one series per channel. Channel signal separation is extremely important. Measures to avoid bleaching are vital. Post-acquisition deconvolution of the image series is often performed to increase resolution before 3-D reconstruction takes place. In the 3-D reconstruction programs described in this unit, reconstructions can be inspected in real time from any viewing angle. By altering viewing angles and by switching channels off and on, the spatial relationships of 3-D-reconstructed structures with respect to structures visualized in other channels can be studied. Since each brand of CLSM, computer program, and 3-D reconstruction package has its own proprietary set of procedures, a general approach is provided in this protocol wherever possible. PMID:24723320

  15. Parallel OSEM Reconstruction Algorithm for Fully 3-D SPECT on a Beowulf Cluster.

    Science.gov (United States)

    Rong, Zhou; Tianyu, Ma; Yongjie, Jin

    2005-01-01

    In order to improve the computation speed of ordered subset expectation maximization (OSEM) algorithm for fully 3-D single photon emission computed tomography (SPECT) reconstruction, an experimental beowulf-type cluster was built and several parallel reconstruction schemes were described. We implemented a single-program-multiple-data (SPMD) parallel 3-D OSEM reconstruction algorithm based on message passing interface (MPI) and tested it with combinations of different number of calculating processors and different size of voxel grid in reconstruction (64×64×64 and 128×128×128). Performance of parallelization was evaluated in terms of the speedup factor and parallel efficiency. This parallel implementation methodology is expected to be helpful to make fully 3-D OSEM algorithms more feasible in clinical SPECT studies.

  16. Evaluation of Model Recognition for Grammar-Based Automatic 3d Building Model Reconstruction

    Science.gov (United States)

    Yu, Qian; Helmholz, Petra; Belton, David

    2016-06-01

    In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.

  17. A novel 3D template for mandible and maxilla reconstruction: Rapid prototyping using stereolithography

    OpenAIRE

    Samir Kumta; Monica Kumta; Leena Jain; Shrirang Purohit; Rani Ummul

    2015-01-01

    Introduction: Replication of the exact three-dimensional (3D) structure of the maxilla and mandible is now a priority whilst attempting reconstruction of these bones to attain a complete functional and aesthetic rehabilitation. We hereby present the process of rapid prototyping using stereolithography to produce templates for modelling bone grafts and implants for maxilla/mandible reconstructions, its applications in tumour/trauma, and outcomes for primary and secondary reconstruction. Materi...

  18. GOTHIC CHURCHES IN PARIS ST GERVAIS ET ST PROTAIS IMAGE MATCHING 3D RECONSTRUCTION TO UNDERSTAND THE VAULTS SYSTEM GEOMETRY

    Directory of Open Access Journals (Sweden)

    M. Capone

    2015-02-01

    benefits and the troubles. From a methodological point of view this is our workflow: - theoretical study about geometrical configuration of rib vault systems; - 3D model based on theoretical hypothesis about geometric definition of the vaults' form; - 3D model based on image matching 3D reconstruction methods; - comparison between 3D theoretical model and 3D model based on image matching;

  19. New Algorithm for 3D Facial Model Reconstruction and Its Application in Virtual Reality

    Institute of Scientific and Technical Information of China (English)

    Rong-Hua Liang; Zhi-Geng Pan; Chun Chen

    2004-01-01

    3D human face model reconstruction is essential to the generation of facial animations that is widely used in the field of virtual reality(VR).The main issues of 3D facial model reconstruction based on images by vision technologies are in twofold: one is to select and match the corresponding features of face from two images with minimal interaction and the other is to generate the realistic-looking human face model.In this paper,a new algorithm for realistic-looking face reconstruction is presented based on stereo vision.Firstly,a pattern is printed and attached to a planar surface for camera calibration,and corners generation and corners matching between two images are performed by integrating modified image pyramid Lucas-Kanade(PLK)algorithm and local adjustment algorithm,and then 3D coordinates of corners are obtained by 3D reconstruction.Individual face model is generated by the deformation of general 3D model and interpolation of the features.Finally,realisticlooking human face model is obtained after texture mapping and eyes modeling.In addition,some application examples in the field of VR are given.Experimental result shows that the proposed algorithm is robust and the 3D model is photo-realistic.

  20. Impact of Level of Details in the 3d Reconstruction of Trees for Microclimate Modeling

    Science.gov (United States)

    Bournez, E.; Landes, T.; Saudreau, M.; Kastendeuch, P.; Najjar, G.

    2016-06-01

    In the 21st century, urban areas undergo specific climatic conditions like urban heat islands which frequency and intensity increase over the years. Towards the understanding and the monitoring of these conditions, vegetation effects on urban climate are studied. It appears that a natural phenomenon, the evapotranspiration of trees, generates a cooling effect in urban environment. In this work, a 3D microclimate model is used to quantify the evapotranspiration of trees in relation with their architecture, their physiology and the climate. These three characteristics are determined with field measurements and data processing. Based on point clouds acquired with terrestrial laser scanner (TLS), the 3D reconstruction of the tree wood architecture is performed. Then the 3D reconstruction of leaves is carried out from the 3D skeleton of vegetative shoots and allometric statistics. With the aim of extending the simulation on several trees simultaneously, it is necessary to apply the 3D reconstruction process on each tree individually. However, as well for the acquisition as for the processing, the 3D reconstruction approach is time consuming. Mobile laser scanners could provide point clouds in a faster way than static TLS, but this implies a lower point density. Also the processing time could be shortened, but under the assumption that a coarser 3D model is sufficient for the simulation. In this context, the criterion of level of details and accuracy of the tree 3D reconstructed model must be studied. In this paper first tests to assess their impact on the determination of the evapotranspiration are presented.

  1. In-line phase-contrast breast tomosynthesis: a phantom feasibility study at a synchrotron radiation facility

    Science.gov (United States)

    Bliznakova, K.; Russo, P.; Kamarianakis, Z.; Mettivier, G.; Requardt, H.; Bravin, A.; Buliev, I.

    2016-08-01

    The major objective is to adopt, apply and test developed in-house algorithms for volumetric breast reconstructions from projection images, obtained in in-line phase-contrast mode. Four angular sets, each consisting of 17 projection images obtained from four physical phantoms, were acquired at beamline ID17, European Synchroton Radiation Facility, Grenoble, France. The tomosynthesis arc was  ±32°. The physical phantoms differed in complexity of texture and introduced features of interest. Three of the used phantoms were in-house developed, and made of epoxy resin, polymethyl-methacrylate and paraffin wax, while the fourth phantom was the CIRS BR3D. The projection images had a pixel size of 47 µm  ×  47 µm. Tomosynthesis images were reconstructed with standard shift-and-add (SAA) and filtered backprojection (FBP) algorithms. It was found that the edge enhancement observed in planar x-ray images is preserved in tomosynthesis images from both phantoms with homogeneous and highly heterogeneous backgrounds. In case of BR3D, it was found that features not visible in the planar case were well outlined in the tomosynthesis slices. In addition, the edge enhancement index calculated for features of interest was found to be much higher in tomosynthesis images reconstructed with FBP than in planar images and tomosynthesis images reconstructed with SAA. The comparison between images reconstructed by the two reconstruction algorithms shows an advantage for the FBP method in terms of better edge enhancement. Phase-contrast breast tomosynthesis realized in in-line mode benefits the detection of suspicious areas in mammography images by adding the edge enhancement effect to the reconstructed slices.

  2. 3D reconstruction and digitalization of an archeological site, Itanos, Crete

    Directory of Open Access Journals (Sweden)

    Rudy Ercek

    2010-04-01

    Full Text Available The city of Itanos is situated in the North-East of Crete. Between 1994 and 2005, the French School of Archaeology at Athens (Efa and the Center for Mediterranean Studies in Rethymnon carried out excavation campaigns during which a necropolis and an Archaic building have been explored by a team of the CReA. A very close collaboration between archeologists, engineers and computer graphic designers allowed the 3D reconstruction of these remains. The archeologist was able to directly verify his hypotheses during the reconstruction process. In summer 2007 and 2008, a 3D digitalization of Itanos was made in order to insert the 3D reconstructions into the actual landscape.

  3. Reconstruction of Temperature Field in 3-D, Absorbing, Emitting,and Anisotropically Scattering Medium

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing-de; LIU Ni; ZHONG Ke

    2006-01-01

    The soft measurement technology of flame temperature field is an efficient method to learn the combustion status in furnace. Generally, it reconstructs the temperature field in furnace through the image of flame, which is a process to solve radiative inverse problem. In this paper, the flame of pulverized coal is considered as 3-D, absorbing, emitting,and anisotropically scattering non-gray medium. Through the study on inverse problem of radiative heat transfer, the temperature field in this kind of medium has been reconstructed. The mechanism of 3-D radiative heat transfer in a rectangular media, which is 2 m × 3 m × 5 m and full of CO2, N2 and carbon particles, is studied with Monte Carlo method. The 3-D temperature field in this rectangular space is reconstructed and the influence of particles density profile is discussed.

  4. Reliable Gait Recognition Using 3D Reconstructions and Random Forests - An Anthropometric Approach.

    Science.gov (United States)

    Sandau, Martin; Heimbürger, Rikke V; Jensen, Karl E; Moeslund, Thomas B; Aanaes, Henrik; Alkjaer, Tine; Simonsen, Erik B

    2016-05-01

    Photogrammetric measurements of bodily dimensions and analysis of gait patterns in CCTV are important tools in forensic investigations but accurate extraction of the measurements are challenging. This study tested whether manual annotation of the joint centers on 3D reconstructions could provide reliable recognition. Sixteen participants performed normal walking where 3D reconstructions were obtained continually. Segment lengths and kinematics from the extremities were manually extracted by eight expert observers. The results showed that all the participants were recognized, assuming the same expert annotated the data. Recognition based on data annotated by different experts was less reliable achieving 72.6% correct recognitions as some parameters were heavily affected by interobserver variability. This study verified that 3D reconstructions are feasible for forensic gait analysis as an improved alternative to conventional CCTV. However, further studies are needed to account for the use of different clothing, field conditions, etc.

  5. Real-Time Camera Tracking and 3D Reconstruction Using Signed Distance Functions

    OpenAIRE

    Bylow, Erik; Sturm, Jürgen; Kerl, Christian; Kahl, Fredrik; Cremers, Daniel

    2013-01-01

    The ability to quickly acquire 3D models is an essential capability needed in many disciplines including robotics, computer vision, geodesy, and architecture. In this paper we present a novel method for real-time camera tracking and 3D reconstruction of static indoor environments using an RGB-D sensor. We show that by representing the geometry with a signed distance function (SDF), the camera pose can be efficiently estimated by directly minimizing the error of the depth images on the SDF....

  6. Influence of camera calibration conditions on the accuracy of 3D reconstruction.

    Science.gov (United States)

    Poulin-Girard, Anne-Sophie; Thibault, Simon; Laurendeau, Denis

    2016-02-01

    For stereoscopic systems designed for metrology applications, the accuracy of camera calibration dictates the precision of the 3D reconstruction. In this paper, the impact of various calibration conditions on the reconstruction quality is studied using a virtual camera calibration technique and the design file of a commercially available lens. This technique enables the study of the statistical behavior of the reconstruction task in selected calibration conditions. The data show that the mean reprojection error should not always be used to evaluate the performance of the calibration process and that a low quality of feature detection does not always lead to a high mean reconstruction error.

  7. Feasibility study for image reconstruction in circular digital tomosynthesis (CDTS) from limited-scan angle data based on compressed-sensing theory

    International Nuclear Information System (INIS)

    In this work, we performed a feasibility study for image reconstruction in a circular digital tomosynthesis (CDTS) from limited-scan angle data based on compressed-sensing (CS) theory. Here, the X-ray source moves along an arc within a limited-scan angle (≤ 180°) on a circular path set perpendicularly to the axial direction during the image acquisition. This geometry, compared to full-angle (360°) scan geometry, allows imaging system to be designed more compactly and gives better tomographic quality than conventional linear digital tomosynthesis (DTS). We implemented an efficient CS-based reconstruction algorithm for the proposed geometry and performed systematic simulations to investigate the image characteristics. We successfully reconstructed CDTS images with incomplete projections acquired at several selected limited-scan angles of 45°, 90°, 135°, and 180° for a given tomographic angle of 80° and evaluated the reconstruction quality. Our simulation results indicate that the proposed method can provide superior tomographic quality for axial view and even for the other views (i.e., sagittal and coronal), as in computed tomography, to conventional DTS. - Highlights: • Image reconstruction is done in circular digital tomosynthesis (CDTS). • The designed geometry allows imaging system to be the better image. • An efficient compressed-sensing (CS)-based reconstruction algorithm is performed. • Proposed method can provide superior tomographic quality for the axial view

  8. 3D Reconstruction and Restoration Monitoring of Sculptural Artworks by a Multi-Sensor Framework

    Directory of Open Access Journals (Sweden)

    Sandro Barone

    2012-12-01

    Full Text Available Nowadays, optical sensors are used to digitize sculptural artworks by exploiting various contactless technologies. Cultural Heritage applications may concern 3D reconstructions of sculptural shapes distinguished by small details distributed over large surfaces. These applications require robust multi-view procedures based on aligning several high resolution 3D measurements. In this paper, the integration of a 3D structured light scanner and a stereo photogrammetric sensor is proposed with the aim of reliably reconstructing large free form artworks. The structured light scanner provides high resolution range maps captured from different views. The stereo photogrammetric sensor measures the spatial location of each view by tracking a marker frame integral to the optical scanner. This procedure allows the computation of the rotation-translation matrix to transpose the range maps from local view coordinate systems to a unique global reference system defined by the stereo photogrammetric sensor. The artwork reconstructions can be further augmented by referring metadata related to restoration processes. In this paper, a methodology has been developed to map metadata to 3D models by capturing spatial references using a passive stereo-photogrammetric sensor. The multi-sensor framework has been experienced through the 3D reconstruction of a Statue of Hope located at the English Cemetery in Florence. This sculptural artwork has been a severe test due to the non-cooperative environment and the complex shape features distributed over a large surface.

  9. GPU-Based 3D Cone-Beam CT Image Reconstruction for Large Data Volume

    Directory of Open Access Journals (Sweden)

    Xing Zhao

    2009-01-01

    Full Text Available Currently, 3D cone-beam CT image reconstruction speed is still a severe limitation for clinical application. The computational power of modern graphics processing units (GPUs has been harnessed to provide impressive acceleration of 3D volume image reconstruction. For extra large data volume exceeding the physical graphic memory of GPU, a straightforward compromise is to divide data volume into blocks. Different from the conventional Octree partition method, a new partition scheme is proposed in this paper. This method divides both projection data and reconstructed image volume into subsets according to geometric symmetries in circular cone-beam projection layout, and a fast reconstruction for large data volume can be implemented by packing the subsets of projection data into the RGBA channels of GPU, performing the reconstruction chunk by chunk and combining the individual results in the end. The method is evaluated by reconstructing 3D images from computer-simulation data and real micro-CT data. Our results indicate that the GPU implementation can maintain original precision and speed up the reconstruction process by 110–120 times for circular cone-beam scan, as compared to traditional CPU implementation.

  10. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    Energy Technology Data Exchange (ETDEWEB)

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T [Teikyo University, Itabashi-ku, Tokyo (Japan); Haga, A; Saotome, N [University of Tokyo Hospital, Bunkyo-ku, Tokyo (Japan); Arai, N [Teikyo University Hospital, Itabashi-ku, Tokyo (Japan)

    2014-06-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  11. MO-C-18A-01: Advances in Model-Based 3D Image Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G [University of Wisconsin, Madison, WI (United States); Pan, X [University Chicago, Chicago, IL (United States); Stayman, J [Johns Hopkins University, Baltimore, MD (United States); Samei, E [Duke University Medical Center, Durham, NC (United States)

    2014-06-15

    Recent years have seen the emergence of CT image reconstruction techniques that exploit physical models of the imaging system, photon statistics, and even the patient to achieve improved 3D image quality and/or reduction of radiation dose. With numerous advantages in comparison to conventional 3D filtered backprojection, such techniques bring a variety of challenges as well, including: a demanding computational load associated with sophisticated forward models and iterative optimization methods; nonlinearity and nonstationarity in image quality characteristics; a complex dependency on multiple free parameters; and the need to understand how best to incorporate prior information (including patient-specific prior images) within the reconstruction process. The advantages, however, are even greater – for example: improved image quality; reduced dose; robustness to noise and artifacts; task-specific reconstruction protocols; suitability to novel CT imaging platforms and noncircular orbits; and incorporation of known characteristics of the imager and patient that are conventionally discarded. This symposium features experts in 3D image reconstruction, image quality assessment, and the translation of such methods to emerging clinical applications. Dr. Chen will address novel methods for the incorporation of prior information in 3D and 4D CT reconstruction techniques. Dr. Pan will show recent advances in optimization-based reconstruction that enable potential reduction of dose and sampling requirements. Dr. Stayman will describe a “task-based imaging” approach that leverages models of the imaging system and patient in combination with a specification of the imaging task to optimize both the acquisition and reconstruction process. Dr. Samei will describe the development of methods for image quality assessment in such nonlinear reconstruction techniques and the use of these methods to characterize and optimize image quality and dose in a spectrum of clinical

  12. Reconstruction of 3D models of cast sculptures using close-range photogrammetry

    OpenAIRE

    Ž. Santoši; Šokac, M.; Korolija-Crkvenjakov, D.; B. Kosec; M. Soković; I. Budak

    2015-01-01

    This paper presents the possibilities of application of close-range photogrammetry, based on the Structure-from- Motion (SfM) approach, in 3D model’s reconstruction of bronze cast sculptures. Special attention was dedicated to the analysis of image processing strategy, and its impact on the 3D model reconstruction quality. For the purpose of analysis a bust of Nikola Tesla, placed in front of the Faculty of Technical Sciences University of Novi Sad was used. Experimental results indicate that...

  13. Holographic and weak-phase projection system for 3D shape reconstruction using temporal phase unwrapping

    Science.gov (United States)

    González, C. A.; Dávila, A.; Garnica, G.

    2007-09-01

    Two projection systems that use an LCoS phase modulator are proposed for 3D shape reconstruction. The LCoS is used as an holographic system or as a weak phase projector, both configurations project a set of fringe patterns that are processed by the technique known as temporal phase unwrapping. To minimize the influence of camera sampling, and the speckle noise in the projected fringes, an speckle noise reduction technique is applied to the speckle patterns generated by the holographic optical system. Experiments with 3D shape reconstruction of ophthalmic mold and other testing specimens show the viability of the proposed techniques.

  14. Reliable Gait Recognition Using 3D Reconstructions and Random Forests - An Anthropometric Approach

    DEFF Research Database (Denmark)

    Sandau, Martin; Heimbürger, Rikke V.; Jensen, Karl E.;

    2016-01-01

    Photogrammetric measurements of bodily dimensions and analysis of gait patterns in CCTV are important tools in forensic investigations but accurate extraction of the measurements are challenging. This study tested whether manual annotation of the joint centers on 3D reconstructions could provide...... expert annotated the data. Recognition based on data annotated by different experts was less reliable achieving 72.6% correct recognitions as some parameters were heavily affected by interobserver variability. This study verified that 3D reconstructions are feasible for forensic gait analysis...

  15. CUDA based Level Set Method for 3D Reconstruction of Fishes from Large Acoustic Data

    DEFF Research Database (Denmark)

    Sharma, Ojaswa; Anton, François

    2009-01-01

    Acoustic images present views of underwater dynamics, even in high depths. With multi-beam echo sounders (SONARs), it is possible to capture series of 2D high resolution acoustic images. 3D reconstruction of the water column and subsequent estimation of fish abundance and fish species identificat......Acoustic images present views of underwater dynamics, even in high depths. With multi-beam echo sounders (SONARs), it is possible to capture series of 2D high resolution acoustic images. 3D reconstruction of the water column and subsequent estimation of fish abundance and fish species...

  16. 3-D reconstruction of coastal bathymetry from AIRSAR/POLSAR data

    Institute of Scientific and Technical Information of China (English)

    Maged MARGHANY; Mazlan HASHIM; Arthur P. CRACKNELL

    2009-01-01

    This paper introduces a new method for reconstructing three-dimensional (3D) coastal bathymetry changes from Airborne AIRSAR/POLSAR synthetic aperture data. The new method is based on integration between fuzzy B-spline and Volterra algorithm. Volterra algorithm is used to simulate the ocean surface current from AIRSAR/POLSAR data. Then, the ocean surface current information used as input for continuity equation to estimate the water depths from AIRSAR/POLSAR data. This study shows that 3D ocean bathymetry can be reconstructed from AIRSAR/POLSAR data with root mean square error of ±0.03 m.

  17. Etruscanning 3D project. The 3D reconstruction of the Regolini Galassi Tomb as a research tool and a new approach in storytelling

    NARCIS (Netherlands)

    W. Hupperetz; R. Carlani; D. Pletinckx; E. Pietroni

    2012-01-01

    In the "Etruscanning3D" european project framework, the virtual reconstruction of the Regolini Galassi tomb, in Cerveteri, has been realized, in order to recontextualize its precious funerary goods, today preserved in the vatican Museums, in their ancient space, digitally represented in 3D. The reco

  18. Grammar-based Automatic 3D Model Reconstruction from Terrestrial Laser Scanning Data

    Science.gov (United States)

    Yu, Q.; Helmholz, P.; Belton, D.; West, G.

    2014-04-01

    The automatic reconstruction of 3D buildings has been an important research topic during the last years. In this paper, a novel method is proposed to automatically reconstruct the 3D building models from segmented data based on pre-defined formal grammar and rules. Such segmented data can be extracted e.g. from terrestrial or mobile laser scanning devices. Two steps are considered in detail. The first step is to transform the segmented data into 3D shapes, for instance using the DXF (Drawing Exchange Format) format which is a CAD data file format used for data interchange between AutoCAD and other program. Second, we develop a formal grammar to describe the building model structure and integrate the pre-defined grammars into the reconstruction process. Depending on the different segmented data, the selected grammar and rules are applied to drive the reconstruction process in an automatic manner. Compared with other existing approaches, our proposed method allows the model reconstruction directly from 3D shapes and takes the whole building into account.

  19. In vivo bioluminescence tomography based on multi-view projection and 3D surface reconstruction

    Science.gov (United States)

    Zhang, Shuang; Wang, Kun; Leng, Chengcai; Deng, Kexin; Hu, Yifang; Tian, Jie

    2015-03-01

    Bioluminescence tomography (BLT) is a powerful optical molecular imaging modality, which enables non-invasive realtime in vivo imaging as well as 3D quantitative analysis in preclinical studies. In order to solve the inverse problem and reconstruct inner light sources accurately, the prior structural information is commonly necessary and obtained from computed tomography or magnetic resonance imaging. This strategy requires expensive hybrid imaging system, complicated operation protocol and possible involvement of ionizing radiation. The overall robustness highly depends on the fusion accuracy between the optical and structural information. In this study we present a pure optical bioluminescence tomographic system (POBTS) and a novel BLT method based on multi-view projection acquisition and 3D surface reconstruction. The POBTS acquired a sparse set of white light surface images and bioluminescent images of a mouse. Then the white light images were applied to an approximate surface model to generate a high quality textured 3D surface reconstruction of the mouse. After that we integrated multi-view luminescent images based on the previous reconstruction, and applied an algorithm to calibrate and quantify the surface luminescent flux in 3D.Finally, the internal bioluminescence source reconstruction was achieved with this prior information. A BALB/C mouse with breast tumor of 4T1-fLuc cells mouse model were used to evaluate the performance of the new system and technique. Compared with the conventional hybrid optical-CT approach using the same inverse reconstruction method, the reconstruction accuracy of this technique was improved. The distance error between the actual and reconstructed internal source was decreased by 0.184 mm.

  20. A model-based reconstruction method for 3-D rotational coronary angiography

    Science.gov (United States)

    Xie, Lizhe; Hu, Yining; Nunes, Jean-Claude; Bellanger, Jean-Jacques; Bedossa, Marc; Luo, Limin; Toumoulin, Christine

    2010-01-01

    This paper presents a model-based reconstruction method of the coronary tree from a few number of projections in rotational angiography imaging. The reconstruction relies on projections acquired at a same cardiac phase and an energy function minimization that aims to lead the deformation of the 3D model to fit projection data whereas preserving coherence both in time and space. Some preliminary results are provided on simulated rotational angiograms. PMID:21096600

  1. Demonstration of digital hologram recording and 3D-scenes reconstruction in real-time

    Science.gov (United States)

    Cheremkhin, Pavel A.; Evtikhiev, Nikolay N.; Krasnov, Vitaly V.; Kulakov, Mikhail N.; Kurbatova, Ekaterina A.; Molodtsov, Dmitriy Y.; Rodin, Vladislav G.

    2016-04-01

    Digital holography is technique that allows to reconstruct information about 2D-objects and 3D-scenes. This is achieved by registration of interference pattern formed by two beams: object and reference ones. Pattern registered by the digital camera is processed. This allows to obtain amplitude and phase of the object beam. Reconstruction of shape of the 2D objects and 3D-scenes can be obtained numerically (using computer) and optically (using spatial light modulators - SLMs). In this work camera Megaplus II ES11000 was used for digital holograms recording. The camera has 4008 × 2672 pixels with sizes of 9 μm × 9 μm. For hologram recording, 50 mW frequency-doubled Nd:YAG laser with wavelength 532 nm was used. Liquid crystal on silicon SLM HoloEye PLUTO VIS was used for optical reconstruction of digital holograms. SLM has 1920 × 1080 pixels with sizes of 8 μm × 8 μm. At objects reconstruction 10 mW He-Ne laser with wavelength 632.8 nm was used. Setups for digital holograms recording and their optical reconstruction with the SLM were combined as follows. MegaPlus Central Control Software allows to display registered frames by the camera with a little delay on the computer monitor. The SLM can work as additional monitor. In result displayed frames can be shown on the SLM display in near real-time. Thus recording and reconstruction of the 3D-scenes was obtained in real-time. Preliminary, resolution of displayed frames was chosen equaled to the SLM one. Quantity of the pixels was limited by the SLM resolution. Frame rate was limited by the camera one. This holographic video setup was applied without additional program implementations that would increase time delays between hologram recording and object reconstruction. The setup was demonstrated for reconstruction of 3D-scenes.

  2. 3D reconstruction of complex geological bodies: Examples from the Alps

    Science.gov (United States)

    Zanchi, Andrea; Francesca, Salvi; Stefano, Zanchetta; Simone, Sterlacchini; Graziano, Guerra

    2009-01-01

    Cartographic geological and structural data collected in the field and managed by Geographic Information Systems (GIS) technology can be used for 3D reconstruction of complex geological bodies. Using a link between GIS tools and gOcad, stratigraphic and tectonic surfaces can be reconstructed taking into account any geometrical constraint derived from field observations. Complex surfaces can be reconstructed using large data sets analysed by suitable geometrical techniques. Three main typologies of geometric features and related attributes are exported from a GIS-geodatabase: (1) topographic data as points from a digital elevation model; (2) stratigraphic and tectonic boundaries, and linear features as 2D polylines; (3) structural data as points. After having imported the available information into gOcad, the following steps should be performed: (1) construction of the topographic surface by interpolation of points; (2) 3D mapping of the linear geological boundaries and linear features by vertical projection on the reconstructed topographic surface; (3) definition of geometrical constraints from planar and linear outcrop data; (4) construction of a network of cross-sections based on field observations and geometrical constraints; (5) creation of 3D surfaces, closed volumes and grids from the constructed objects. Three examples of the reconstruction of complex geological bodies from the Italian Alps are presented here. The methodology demonstrates that although only outcrop data were available, 3D modelling has allows the checking of the geometrical consistency of the interpretative 2D sections and of the field geology, through a 3D visualisation of geometrical models. Application of a 3D geometrical model to the case studies can be very useful in geomechanical modelling for slope-stability or resource evaluation.

  3. 3D Reconstruction from X-ray Fluoroscopy for Clinical Veterinary Medicine using Differential Volume Rendering

    Science.gov (United States)

    Khongsomboon, Khamphong; Hamamoto, Kazuhiko; Kondo, Shozo

    3D reconstruction from ordinary X-ray equipment which is not CT or MRI is required in clinical veterinary medicine. Authors have already proposed a 3D reconstruction technique from X-ray photograph to present bone structure. Although the reconstruction is useful for veterinary medicine, the thechnique has two problems. One is about exposure of X-ray and the other is about data acquisition process. An x-ray equipment which is not special one but can solve the problems is X-ray fluoroscopy. Therefore, in this paper, we propose a method for 3D-reconstruction from X-ray fluoroscopy for clinical veterinary medicine. Fluoroscopy is usually used to observe a movement of organ or to identify a position of organ for surgery by weak X-ray intensity. Since fluoroscopy can output a observed result as movie, the previous two problems which are caused by use of X-ray photograph can be solved. However, a new problem arises due to weak X-ray intensity. Although fluoroscopy can present information of not only bone structure but soft tissues, the contrast is very low and it is very difficult to recognize some soft tissues. It is very useful to be able to observe not only bone structure but soft tissues clearly by ordinary X-ray equipment in the field of clinical veterinary medicine. To solve this problem, this paper proposes a new method to determine opacity in volume rendering process. The opacity is determined according to 3D differential coefficient of 3D reconstruction. This differential volume rendering can present a 3D structure image of multiple organs volumetrically and clearly for clinical veterinary medicine. This paper shows results of simulation and experimental investigation of small dog and evaluation by veterinarians.

  4. The role of 3D Helical CT in the reconstructive treatment of maxillofacial cancers

    International Nuclear Information System (INIS)

    Purpose of this work is to investigate the role of Helical CT and the usefulness of three-dimensional (3D) imaging for pre-operative planning and follow-up of reconstructive maxillofacial surgery with alloplastic material in neoplastic disease involving this region. From 1996 to 1999 eleven patients were examined with Helical CT and 3D images for planning of maxillofacial plastic and reconstructive surgery for advanced cancer of this anatomically complex region. A 3D-modulated titanium mesh (100%) or micro nets was used to rebuild the anterior surface of maxillary bone and the orbital floor. The mesh was cut to the appropriate size and shape and curved where necessary. Within the residual sinusal cavity a siliconed filling was used surmounting an acrylic prosthesis with dental arch to rebuild the palate. A rehydrated bovine pericardium was affixed and moduled on the borders in two cases only. Three-dimensionally reconstructed CT images were obtained preoperatively and at least 6 months postoperatively in all patients. The images were generated on a computer workstation using the shaded surface display (SSD) software with threshold values ranging 425 to 630 HU, and a more closed window for the imaging of titanium mesh/bone interface in the post surgical follow-up. It was obtained an excellent complete spatial depiction of maxillo facial region both before and after surgery, with no artefacts so important as to affect the 3D reconstruction process and the image quality. Together with the head-neck surgical team it could be worked for preoperative planning through CT scans by different 3D points of view. The 3D reconstructed follow-up scans showed good filling of the defect in the area where the titanium mesh had been used. Then efficacious bone modelling and good biocompatibility of the alloplastic material were seen in all patients, with no inflammatory reactions. Titanium is a well-known material, which is widely used for cranioplasty. It is a radiolucent, non

  5. Sample based 3D face reconstruction from a single frontal image by adaptive locally linear embedding

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian; ZHUANG Yue-ting

    2007-01-01

    In this paper, we propose a highly automatic approach for 3D photorealistic face reconstruction from a single frontal image. The key point of our work is the implementation of adaptive manifold learning approach. Beforehand, an active appearance model (AAM) is trained for automatic feature extraction and adaptive locally linear embedding (ALLE) algorithm is utilized to reduce the dimensionality of the 3D database. Then, given an input frontal face image, the corresponding weights between 3D samples and the image are synthesized adaptively according to the AAM selected facial features. Finally, geometry reconstruction is achieved by linear weighted combination of adaptively selected samples. Radial basis function (RBF) is adopted to map facial texture from the frontal image to the reconstructed face geometry. The texture of invisible regions between the face and the ears is interpolated by sampling from the frontal image. This approach has several advantages: (1) Only a single frontal face image is needed for highly automatic face reconstruction; (2) Compared with former works, our reconstruction approach provides higher accuracy; (3) Constraint based RBF texture mapping provides natural appearance for reconstructed face.

  6. Error Evaluation in a Stereovision-Based 3D Reconstruction System

    Directory of Open Access Journals (Sweden)

    Kohler Sophie

    2010-01-01

    Full Text Available The work presented in this paper deals with the performance analysis of the whole 3D reconstruction process of imaged objects, specifically of the set of geometric primitives describing their outline and extracted from a pair of images knowing their associated camera models. The proposed analysis focuses on error estimation for the edge detection process, the starting step for the whole reconstruction procedure. The fitting parameters describing the geometric features composing the workpiece to be evaluated are used as quality measures to determine error bounds and finally to estimate the edge detection errors. These error estimates are then propagated up to the final 3D reconstruction step. The suggested error analysis procedure for stereovision-based reconstruction tasks further allows evaluating the quality of the 3D reconstruction. The resulting final error estimates enable lastly to state if the reconstruction results fulfill a priori defined criteria, for example, fulfill dimensional constraints including tolerance information, for vision-based quality control applications for example.

  7. The point-source method for 3D reconstructions for the Helmholtz and Maxwell equations

    Science.gov (United States)

    Ben Hassen, M. F.; Erhard, K.; Potthast, R.

    2006-02-01

    We use the point-source method (PSM) to reconstruct a scattered field from its associated far field pattern. The reconstruction scheme is described and numerical results are presented for three-dimensional acoustic and electromagnetic scattering problems. We give new proofs of the algorithms, based on the Green and Stratton-Chu formulae, which are more general than with the former use of the reciprocity relation. This allows us to handle the case of limited aperture data and arbitrary incident fields. Both for 3D acoustics and electromagnetics, numerical reconstructions of the field for different settings and with noisy data are shown. For shape reconstruction in acoustics, we develop an appropriate strategy to identify areas with good reconstruction quality and combine different such regions into one joint function. Then, we show how shapes of unknown sound-soft scatterers are found as level curves of the total reconstructed field.

  8. Role of 3-D CT reconstruction of laryngeal mucosal surface in preoperative staging of laryngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Sang Hwa; Park, Jong Yeon; Lee, Young Jun; Kim, Kun Il; Kim, Byung Soo; Wang, Soo Guen [Pusan National University, Busan (Korea, Republic of); Sol, Chang Hyo [Hong-In Total Imaing Diagnostic Clinic, Pusan (Korea, Republic of)

    1994-01-15

    CT or MRT is performed in preoperative staging of laryngeal cancer. These methods are used in assessment of the deep tissues and cartilage of the larynx, but cannot compete with laryngoscopy in the evaluation of the laryngeal surface. The purpose of this study is to evaluate feasibility and clinical value of the 3-D reconstruction of the mucosal surface in laryngeal cancer. Twenty two patients with laryngeal cancer proved by means of surgical exploration (pathologic) or clinical examinations including laryngoscope, imaging studies and biopsy underwent preoperative staging with computed tomography(CT) and three dimensional(3D) CT reconstruction. The TNM classification of the American Joint Committee on Cancer was used to compare the imaging findings with pathologic or clinical staging. When the extension of primary tumor(T staging) was evaluated, the findings at only transaxial CT and those at pathologic or clinical examination were concordant in 8 of 14 cases(57.1%) of supraglottic tumor, and 3 of 6 cases(50%) of glottic tumor. The overall accuracy of CT with additional 3D-reconstruction was 85.7% for assessment of supraglottic tumor, and 66.6% for glottic tumor. 3D CT reconstruction after transaxial CT may improve outcome in preoperative staging of laryngeal cancer and has a potential value in guiding management decisions.

  9. Xenobiotic metabolism in human skin and 3D human skin reconstructs: A review

    NARCIS (Netherlands)

    Gibbs, S.; Sandt, J.J.M. van de; Merk, H.F.; Lockley, D.J.; Pendlington, R.U.; Pease, C.K.

    2007-01-01

    In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental

  10. Model-free 3D face shape reconstruction from video sequences

    NARCIS (Netherlands)

    Dam, van Chris; Veldhuis, Raymond; Spreeuwers, Luuk

    2013-01-01

    In forensic comparison of facial video data, often only the best quality frontal face frames are selected, and hence much video data is ignored. To improve 2D facial comparison for law enforcement and forensic investigation, we introduce a model-free 3D shape reconstruction algorithm based on 2D lan

  11. Landmark-based model-free 3D face shape reconstruction from video sequences

    NARCIS (Netherlands)

    Dam, van Chris; Veldhuis, Raymond; Spreeuwers, Luuk; Broemme, A.; Busch, C.

    2013-01-01

    In forensic comparison of facial video data, often only the best quality frontal face frames are selected, and hence potentially useful video data is ignored. To improve 2D facial comparison for law enforcement and forensic investigation, we introduce a model-free 3D shape reconstruction algorithm b

  12. VizieR Online Data Catalog: ADAM: 3D asteroid shape reconstruction code (Viikinkoski+, 2015)

    Science.gov (United States)

    Viikinkoski, M.; Kaasalainen, M.; Durech, J.

    2015-02-01

    About the code: ADAM is a collection of routines for 3D asteroid shape reconstruction from disk-resolved observations. Any combination of lightcurves, adaptive optics images, HST/FGS data, range-Doppler radar images and disk-resolved thermal images may be used as data sources. The routines are implemented in a combination of MATLAB and C. (2 data files).

  13. Some Methods of Applied Numerical Analysis to 3d Facial Reconstruction Software

    Science.gov (United States)

    Roşu, Şerban; Ianeş, Emilia; Roşu, Doina

    2010-09-01

    This paper deals with the collective work performed by medical doctors from the University Of Medicine and Pharmacy Timisoara and engineers from the Politechnical Institute Timisoara in the effort to create the first Romanian 3d reconstruction software based on CT or MRI scans and to test the created software in clinical practice.

  14. Toward 3D Reconstruction of Outdoor Scenes Using an MMW Radar and a Monocular Vision Sensor

    Science.gov (United States)

    El Natour, Ghina; Ait-Aider, Omar; Rouveure, Raphael; Berry, François; Faure, Patrice

    2015-01-01

    In this paper, we introduce a geometric method for 3D reconstruction of the exterior environment using a panoramic microwave radar and a camera. We rely on the complementarity of these two sensors considering the robustness to the environmental conditions and depth detection ability of the radar, on the one hand, and the high spatial resolution of a vision sensor, on the other. Firstly, geometric modeling of each sensor and of the entire system is presented. Secondly, we address the global calibration problem, which consists of finding the exact transformation between the sensors’ coordinate systems. Two implementation methods are proposed and compared, based on the optimization of a non-linear criterion obtained from a set of radar-to-image target correspondences. Unlike existing methods, no special configuration of the 3D points is required for calibration. This makes the methods flexible and easy to use by a non-expert operator. Finally, we present a very simple, yet robust 3D reconstruction method based on the sensors’ geometry. This method enables one to reconstruct observed features in 3D using one acquisition (static sensor), which is not always met in the state of the art for outdoor scene reconstruction. The proposed methods have been validated with synthetic and real data. PMID:26473874

  15. Morphology and function of Bast's valve : additional insight in its functioning using 3D-reconstruction

    NARCIS (Netherlands)

    Hofman, R.; Segenhout, J. M.; Buytaert, J. A. N.; Dirckx, J. J. J.; Wit, H. P.

    2008-01-01

    The utriculo-endolymphatic valve was discovered by Bast in 1928. The function of Bast's valve is still unclear. By means of orthogonal-plane fluorescence optical sectioning (OPFOS) microscopy 3D-reconstructions of the valve and its surrounding region are depicted. The shape of the duct at the utricu

  16. Estimation of 3D reconstruction errors in a stereo-vision system

    Science.gov (United States)

    Belhaoua, A.; Kohler, S.; Hirsch, E.

    2009-06-01

    The paper presents an approach for error estimation for the various steps of an automated 3D vision-based reconstruction procedure of manufactured workpieces. The process is based on a priori planning of the task and built around a cognitive intelligent sensory system using so-called Situation Graph Trees (SGT) as a planning tool. Such an automated quality control system requires the coordination of a set of complex processes performing sequentially data acquisition, its quantitative evaluation and the comparison with a reference model (e.g., CAD object model) in order to evaluate quantitatively the object. To ensure efficient quality control, the aim is to be able to state if reconstruction results fulfill tolerance rules or not. Thus, the goal is to evaluate independently the error for each step of the stereo-vision based 3D reconstruction (e.g., for calibration, contour segmentation, matching and reconstruction) and then to estimate the error for the whole system. In this contribution, we analyze particularly the segmentation error due to localization errors for extracted edge points supposed to belong to lines and curves composing the outline of the workpiece under evaluation. The fitting parameters describing these geometric features are used as quality measure to determine confidence intervals and finally to estimate the segmentation errors. These errors are then propagated through the whole reconstruction procedure, enabling to evaluate their effect on the final 3D reconstruction result, specifically on position uncertainties. Lastly, analysis of these error estimates enables to evaluate the quality of the 3D reconstruction, as illustrated by the shown experimental results.

  17. Non-periodic 3-D motion estimation and reconstruction of coronary stents

    International Nuclear Information System (INIS)

    C-arm CT enables 3-D imaging at high spatial resolution. Image quality would be sufficient for coronary artery stents at rest. However, spatial resolution is severely degraded by cardiac motion which needs to be considered in the reconstruction step. Existing approaches are based on detecting markers in the projection images. Based on the exact marker locations in all images, motion estimation and compensation is performed in the 2-D projection image domain and thus no 3-D motion information of the stent is available. In this paper a novel method for computing the non-periodic location of the stent markers in 3-D is proposed. The motion estimation step comprises marker detection in 2-D, computation of periodic 3-D motion and computation of non-periodic 3-D motion. For motion compensation the 3- D marker positions are used to compute an affine motion model as input for a motion compensated FDK reconstruction algorithm. First clinical results suggest a high image quality and the possibility to compute physiological parameters e.g. velocity curves. (orig.)

  18. 3D Surface Reconstruction of Plant Seeds by Volume Carving: Performance and Accuracies

    Science.gov (United States)

    Roussel, Johanna; Geiger, Felix; Fischbach, Andreas; Jahnke, Siegfried; Scharr, Hanno

    2016-01-01

    We describe a method for 3D reconstruction of plant seed surfaces, focusing on small seeds with diameters as small as 200 μm. The method considers robotized systems allowing single seed handling in order to rotate a single seed in front of a camera. Even though such systems feature high position repeatability, at sub-millimeter object scales, camera pose variations have to be compensated. We do this by robustly estimating the tool center point from each acquired image. 3D reconstruction can then be performed by a simple shape-from-silhouette approach. In experiments we investigate runtimes, theoretically achievable accuracy, experimentally achieved accuracy, and show as a proof of principle that the proposed method is well sufficient for 3D seed phenotyping purposes. PMID:27375628

  19. A Computer Vision Method for 3D Reconstruction of Curves-Marked Free-Form Surfaces

    Institute of Scientific and Technical Information of China (English)

    Xiong Hanwei; Zhang Xiangwei

    2001-01-01

    Visual method is now broadly used in reverse engineering for 3D reconstruction. Thetraditional computer vision methods are feature-based, i.e., they require that the objects must revealfeatures owing to geometry or textures. For textureless free-form surfaces, dense feature points areadded artificially. In this paper, a new method is put forward combining computer vision with CAGD.The surface is subdivided into N-side Gregory patches using marked curves, and a stereo algorithm isused to reconstruct the curves. Then, the cross boundary tangent vector is computed throughreflectance analysis. At last, the whole surface can be reconstructed by jointing these patches withG1 continuity.

  20. Pragmatic fully 3D image reconstruction for the MiCES mouse imaging PET scanner

    International Nuclear Information System (INIS)

    We present a pragmatic approach to image reconstruction for data from the micro crystal elements system (MiCES) fully 3D mouse imaging positron emission tomography (PET) scanner under construction at the University of Washington. Our approach is modelled on fully 3D image reconstruction used in clinical PET scanners, which is based on Fourier rebinning (FORE) followed by 2D iterative image reconstruction using ordered-subsets expectation-maximization (OSEM). The use of iterative methods allows modelling of physical effects (e.g., statistical noise, detector blurring, attenuation, etc), while FORE accelerates the reconstruction process by reducing the fully 3D data to a stacked set of independent 2D sinograms. Previous investigations have indicated that non-stationary detector point-spread response effects, which are typically ignored for clinical imaging, significantly impact image quality for the MiCES scanner geometry. To model the effect of non-stationary detector blurring (DB) in the FORE+OSEM(DB) algorithm, we have added a factorized system matrix to the ASPIRE reconstruction library. Initial results indicate that the proposed approach produces an improvement in resolution without an undue increase in noise and without a significant increase in the computational burden. The impact on task performance, however, remains to be evaluated

  1. Automatic 3d Building Reconstruction from a Dense Image Matching Dataset

    Science.gov (United States)

    McClune, Andrew P.; Mills, Jon P.; Miller, Pauline E.; Holland, David A.

    2016-06-01

    Over the last 20 years the demand for three dimensional (3D) building models has resulted in a vast amount of research being conducted in attempts to automate the extraction and reconstruction of models from airborne sensors. Recent results have shown that current methods tend to favour planar fitting procedures from lidar data, which are able to successfully reconstruct simple roof structures automatically but fail to reconstruct more complex structures or roofs with small artefacts. Current methods have also not fully explored the potential of recent developments in digital photogrammetry. Large format digital aerial cameras can now capture imagery with increased overlap and a higher spatial resolution, increasing the number of pixel correspondences between images. Every pixel in each stereo pair can also now be matched using per-pixel algorithms, which has given rise to the approach known as dense image matching. This paper presents an approach to 3D building reconstruction to try and overcome some of the limitations of planar fitting procedures. Roof vertices, extracted from true-orthophotos using edge detection, are refined and converted to roof corner points. By determining the connection between extracted corner points, a roof plane can be defined as a closed-cycle of points. Presented results demonstrate the potential of this method for the reconstruction of complex 3D building models at CityGML LoD2 specification.

  2. Recovery and Visualization of 3D Structure of Chromosomes from Tomographic Reconstruction Images

    Directory of Open Access Journals (Sweden)

    Tsap Leonid V

    2006-01-01

    Full Text Available The objectives of this work include automatic recovery and visualization of a 3D chromosome structure from a sequence of 2D tomographic reconstruction images taken through the nucleus of a cell. Structure is very important for biologists as it affects chromosome functions, behavior of the cell, and its state. Analysis of chromosome structure is significant in the detection of diseases, identification of chromosomal abnormalities, study of DNA structural conformation, in-depth study of chromosomal surface morphology, observation of in vivo behavior of the chromosomes over time, and in monitoring environmental gene mutations. The methodology incorporates thresholding based on a histogram analysis with a polyline splitting algorithm, contour extraction via active contours, and detection of the 3D chromosome structure by establishing corresponding regions throughout the slices. Visualization using point cloud meshing generates a 3D surface. The 3D triangular mesh of the chromosomes provides surface detail and allows a user to interactively analyze chromosomes using visualization software.

  3. Internet2-based 3D PET image reconstruction using a PC cluster.

    Science.gov (United States)

    Shattuck, D W; Rapela, J; Asma, E; Chatzioannou, A; Qi, J; Leahy, R M

    2002-08-01

    We describe an approach to fast iterative reconstruction from fully three-dimensional (3D) PET data using a network of PentiumIII PCs configured as a Beowulf cluster. To facilitate the use of this system, we have developed a browser-based interface using Java. The system compresses PET data on the user's machine, sends these data over a network, and instructs the PC cluster to reconstruct the image. The cluster implements a parallelized version of our preconditioned conjugate gradient method for fully 3D MAP image reconstruction. We report on the speed-up factors using the Beowulf approach and the impacts of communication latencies in the local cluster network and the network connection between the user's machine and our PC cluster.

  4. Modifications in SIFT-based 3D reconstruction from image sequence

    Science.gov (United States)

    Wei, Zhenzhong; Ding, Boshen; Wang, Wei

    2014-11-01

    In this paper, we aim to reconstruct 3D points of the scene from related images. Scale Invariant Feature Transform( SIFT) as a feature extraction and matching algorithm has been proposed and improved for years and has been widely used in image alignment and stitching, image recognition and 3D reconstruction. Because of the robustness and reliability of the SIFT's feature extracting and matching algorithm, we use it to find correspondences between images. Hence, we describe a SIFT-based method to reconstruct 3D sparse points from ordered images. In the process of matching, we make a modification in the process of finding the correct correspondences, and obtain a satisfying matching result. By rejecting the "questioned" points before initial matching could make the final matching more reliable. Given SIFT's attribute of being invariant to the image scale, rotation, and variable changes in environment, we propose a way to delete the multiple reconstructed points occurred in sequential reconstruction procedure, which improves the accuracy of the reconstruction. By removing the duplicated points, we avoid the possible collapsed situation caused by the inexactly initialization or the error accumulation. The limitation of some cases that all reprojected points are visible at all times also does not exist in our situation. "The small precision" could make a big change when the number of images increases. The paper shows the contrast between the modified algorithm and not. Moreover, we present an approach to evaluate the reconstruction by comparing the reconstructed angle and length ratio with actual value by using a calibration target in the scene. The proposed evaluation method is easy to be carried out and with a great applicable value. Even without the Internet image datasets, we could evaluate our own results. In this paper, the whole algorithm has been tested on several image sequences both on the internet and in our shots.

  5. A novel approximation method of CTF amplitude correction for 3D single particle reconstruction

    International Nuclear Information System (INIS)

    The typical resolution of three-dimensional reconstruction by cryo-EM single particle analysis is now being pushed up to and beyond the nanometer scale. Correction of the contrast transfer function (CTF) of electron microscopic images is essential for achieving such a high resolution. Various correction methods exist and are employed in popular reconstruction software packages. Here, we present a novel approximation method that corrects the amplitude modulation introduced by the contrast transfer function by convoluting the images with a piecewise continuous function. Our new approach can easily be implemented and incorporated into other packages. The implemented method yielded higher resolution reconstructions with data sets from both highly symmetric and asymmetric structures. It is an efficient alternative correction method that allows quick convergence of the 3D reconstruction and has a high tolerance for noisy images, thus easing a bottleneck in practical reconstruction of macromolecules.

  6. 3D Maize Plant Reconstruction Based on Georeferenced Overlapping LiDAR Point Clouds

    Directory of Open Access Journals (Sweden)

    Miguel Garrido

    2015-12-01

    Full Text Available 3D crop reconstruction with a high temporal resolution and by the use of non-destructive measuring technologies can support the automation of plant phenotyping processes. Thereby, the availability of such 3D data can give valuable information about the plant development and the interaction of the plant genotype with the environment. This article presents a new methodology for georeferenced 3D reconstruction of maize plant structure. For this purpose a total station, an IMU, and several 2D LiDARs with different orientations were mounted on an autonomous vehicle. By the multistep methodology presented, based on the application of the ICP algorithm for point cloud fusion, it was possible to perform the georeferenced point clouds overlapping. The overlapping point cloud algorithm showed that the aerial points (corresponding mainly to plant parts were reduced to 1.5%–9% of the total registered data. The remaining were redundant or ground points. Through the inclusion of different LiDAR point of views of the scene, a more realistic representation of the surrounding is obtained by the incorporation of new useful information but also of noise. The use of georeferenced 3D maize plant reconstruction at different growth stages, combined with the total station accuracy could be highly useful when performing precision agriculture at the crop plant level.

  7. Multi-view 3D scene reconstruction using ant colony optimization techniques

    International Nuclear Information System (INIS)

    This paper presents a new method performing high-quality 3D object reconstruction of complex shapes derived from multiple, calibrated photographs of the same scene. The novelty of this research is found in two basic elements, namely: (i) a novel voxel dissimilarity measure, which accommodates the elimination of the lighting variations of the models and (ii) the use of an ant colony approach for further refinement of the final 3D models. The proposed reconstruction procedure employs a volumetric method based on a novel projection test for the production of a visual hull. While the presented algorithm shares certain aspects with the space carving algorithm, it is, nevertheless, first enhanced with the lightness compensating image comparison method, and then refined using ant colony optimization. The algorithm is fast, computationally simple and results in accurate representations of the input scenes. In addition, compared to previous publications, the particular nature of the proposed algorithm allows accurate 3D volumetric measurements under demanding lighting environmental conditions, due to the fact that it can cope with uneven light scenes, resulting from the characteristics of the voxel dissimilarity measure applied. Besides, the intelligent behavior of the ant colony framework provides the opportunity to formulate the process as a combinatorial optimization problem, which can then be solved by means of a colony of cooperating artificial ants, resulting in very promising results. The method is validated with several real datasets, along with qualitative comparisons with other state-of-the-art 3D reconstruction techniques, following the Middlebury benchmark. (paper)

  8. Orbital Wall Reconstruction with Two-Piece Puzzle 3D Printed Implants: Technical Note.

    Science.gov (United States)

    Mommaerts, Maurice Y; Büttner, Michael; Vercruysse, Herman; Wauters, Lauri; Beerens, Maikel

    2016-03-01

    The purpose of this article is to describe a technique for secondary reconstruction of traumatic orbital wall defects using titanium implants that act as three-dimensional (3D) puzzle pieces. We present three cases of large defect reconstruction using implants produced by Xilloc Medical B.V. (Maastricht, the Netherlands) with a 3D printer manufactured by LayerWise (3D Systems; Heverlee, Belgium), and designed using the biomedical engineering software programs ProPlan and 3-Matic (Materialise, Heverlee, Belgium). The smaller size of the implants allowed sequential implantation for the reconstruction of extensive two-wall defects via a limited transconjunctival incision. The precise fit of the implants with regard to the surrounding ledges and each other was confirmed by intraoperative 3D imaging (Mobile C-arm Systems B.V. Pulsera, Philips Medical Systems, Eindhoven, the Netherlands). The patients showed near-complete restoration of orbital volume and ocular motility. However, challenges remain, including traumatic fat atrophy and fibrosis. PMID:26889349

  9. Virtual 3D bladder reconstruction for augmented medical records from white light cystoscopy (Conference Presentation)

    Science.gov (United States)

    Lurie, Kristen L.; Zlatev, Dimitar V.; Angst, Roland; Liao, Joseph C.; Ellerbee, Audrey K.

    2016-02-01

    Bladder cancer has a high recurrence rate that necessitates lifelong surveillance to detect mucosal lesions. Examination with white light cystoscopy (WLC), the standard of care, is inherently subjective and data storage limited to clinical notes, diagrams, and still images. A visual history of the bladder wall can enhance clinical and surgical management. To address this clinical need, we developed a tool to transform in vivo WLC videos into virtual 3-dimensional (3D) bladder models using advanced computer vision techniques. WLC videos from rigid cystoscopies (1280 x 720 pixels) were recorded at 30 Hz followed by immediate camera calibration to control for image distortions. Video data were fed into an automated structure-from-motion algorithm that generated a 3D point cloud followed by a 3D mesh to approximate the bladder surface. The highest quality cystoscopic images were projected onto the approximated bladder surface to generate a virtual 3D bladder reconstruction. In intraoperative WLC videos from 36 patients undergoing transurethral resection of suspected bladder tumors, optimal reconstruction was achieved from frames depicting well-focused vasculature, when the bladder was maintained at constant volume with minimal debris, and when regions of the bladder wall were imaged multiple times. A significant innovation of this work is the ability to perform the reconstruction using video from a clinical procedure collected with standard equipment, thereby facilitating rapid clinical translation, application to other forms of endoscopy and new opportunities for longitudinal studies of cancer recurrence.

  10. Real-Time Large Scale 3d Reconstruction by Fusing Kinect and Imu Data

    Science.gov (United States)

    Huai, J.; Zhang, Y.; Yilmaz, A.

    2015-08-01

    Kinect-style RGB-D cameras have been used to build large scale dense 3D maps for indoor environments. These maps can serve many purposes such as robot navigation, and augmented reality. However, to generate dense 3D maps of large scale environments is still very challenging. In this paper, we present a mapping system for 3D reconstruction that fuses measurements from a Kinect and an inertial measurement unit (IMU) to estimate motion. Our major achievements include: (i) Large scale consistent 3D reconstruction is realized by volume shifting and loop closure; (ii) The coarse-to-fine iterative closest point (ICP) algorithm, the SIFT odometry, and IMU odometry are combined to robustly and precisely estimate pose. In particular, ICP runs routinely to track the Kinect motion. If ICP fails in planar areas, the SIFT odometry provides incremental motion estimate. If both ICP and the SIFT odometry fail, e.g., upon abrupt motion or inadequate features, the incremental motion is estimated by the IMU. Additionally, the IMU also observes the roll and pitch angles which can reduce long-term drift of the sensor assembly. In experiments on a consumer laptop, our system estimates motion at 8Hz on average while integrating color images to the local map and saving volumes of meshes concurrently. Moreover, it is immune to tracking failures, and has smaller drift than the state-of-the-art systems in large scale reconstruction.

  11. Real-Time 3d Reconstruction from Images Taken from AN Uav

    Science.gov (United States)

    Zingoni, A.; Diani, M.; Corsini, G.; Masini, A.

    2015-08-01

    We designed a method for creating 3D models of objects and areas from two aerial images acquired from an UAV. The models are generated automatically and in real-time, and consist in dense and true-colour reconstructions of the considered areas, which give the impression to the operator to be physically present within the scene. The proposed method only needs a cheap compact camera, mounted on a small UAV. No additional instrumentation is necessary, so that the costs are very limited. The method consists of two main parts: the design of the acquisition system and the 3D reconstruction algorithm. In the first part, the choices for the acquisition geometry and for the camera parameters are optimized, in order to yield the best performance. In the second part, a reconstruction algorithm extracts the 3D model from the two acquired images, maximizing the accuracy under the real-time constraint. A test was performed in monitoring a construction yard, obtaining very promising results. Highly realistic and easy-to-interpret 3D models of objects and areas of interest were produced in less than one second, with an accuracy of about 0.5m. For its characteristics, the designed method is suitable for video-surveillance, remote sensing and monitoring, especially in those applications that require intuitive and reliable information quickly, as disasters monitoring, search and rescue and area surveillance.

  12. Recursive 3D-reconstruction of structured scenes using a moving camera - application to robotics

    International Nuclear Information System (INIS)

    This thesis is devoted to the perception of a structured environment, and proposes a new method which allows a 3D-reconstruction of an interesting part of the world using a mobile camera. Our work is divided into three essential parts dedicated to 2D-information aspect, 3D-information aspect, and a validation of the method. In the first part, we present a method which produces a topologic and geometric image representation based on 'segment' and 'junction' features. Then, a 2D-matching method based on a hypothesis prediction and verification algorithm is proposed to match features issued from two successive images. The second part deals with 3D-reconstruction using a triangulation technique, and discuses our new method introducing an 'Estimation-Construction-Fusion' process. This ensures a complete and accurate 3D-representation, and a permanent position estimation of the camera with respect to the model. The merging process allows refinement of the 3D-representation using a powerful tool: a Kalman Filter. In the last part, experimental results issued from simulated and real data images are reported to show the efficiency of the method. (author)

  13. Applicability of 3D-CT facial reconstruction for forensic individual identification

    International Nuclear Information System (INIS)

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using cranio metric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10) cranio metric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution. (author)

  14. Applicability of 3D-CT facial reconstruction for forensic individual identification

    Directory of Open Access Journals (Sweden)

    Rocha Sara dos Santos

    2003-01-01

    Full Text Available Computed tomography (CT is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT. The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using craniometric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10 craniometric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution.

  15. Applicability of 3D-CT facial reconstruction for forensic individual identification.

    Science.gov (United States)

    Rocha, Sara dos Santos; Ramos, Dalton Luiz; Cavalcanti, Marcelo de Gusmão Paraíso

    2003-01-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using craniometric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10) craniometric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution.

  16. Applicability of 3D-CT facial reconstruction for forensic individual identification

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Sara dos Santos [Sao Paulo Univ., SP (Brazil). Odontologia Forense; Ramos, Dalton Luiz de Paula [Sao Paulo Univ., SP (Brazil). Dept. of Odontologia Social; Cavalcanti, Marcelo de Gusmao Paraiso [Sao Paulo Univ., SP (Brazil). Dept. de Radiologia

    2003-03-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using cranio metric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering technique with computer graphics tools. Ten (10) cranio metric measurements were determined in 3D-CT images by two examiners independently, twice each, and the standard error of intra- and inter-examiner measurements was assessed. The results demonstrated a low standard error of those measurements, from 0.85% to 3.09%. In conclusion, the linear measurements obtained in osseous and soft tissue structures were considered to be precise in 3D-CT with high imaging quality and resolution. (author)

  17. Reconstruction of 3-D cloud geometry using a scanning cloud radar

    Directory of Open Access Journals (Sweden)

    F. Ewald

    2014-11-01

    Full Text Available Clouds are one of the main reasons of uncertainties in the forecasts of weather and climate. In part, this is due to limitations of remote sensing of cloud microphysics. Present approaches often use passive spectral measurements for the remote sensing of cloud microphysical parameters. Large uncertainties are introduced by three dimensional (3-D radiative transfer effects and cloud inhomogeneities. Such effects are largely caused by unknown orientation of cloud sides or by shadowed areas on the cloud. Passive ground based remote sensing of cloud properties at high spatial resolution could be improved crucially with this kind of additional knowledge of cloud geometry. To this end, a method for the accurate reconstruction of 3-D cloud geometry from cloud radar measurements is developed in this work. Using a radar simulator and simulated passive measurements of static LES model clouds, the effects of different radar scan resolutions and varying interpolation methods are evaluated. In reality a trade-off between scan resolution and scan duration has to be found as clouds are changing quickly. A reasonable choice is a scan resolution of 1 to 2°. The most suitable interpolation procedure identified is the barycentric interpolation method. The 3-D reconstruction method is demonstrated using radar scans of convective cloud cases with the Munich miraMACS, a 35 GHz scanning cloud radar. As a successful proof of concept, camera imagery collected at the radar location is reproduced for the observed cloud cases via 3-D volume reconstruction and 3-D radiative transfer simulation. Data sets provided by the presented reconstruction method will aid passive spectral ground-based measurements of cloud sides to retrieve microphysical parameters.

  18. A Bayesian approach for suppression of limited angular sampling artifacts in single particle 3D reconstruction.

    Science.gov (United States)

    Moriya, Toshio; Acar, Erman; Cheng, R Holland; Ruotsalainen, Ulla

    2015-09-01

    In the single particle reconstruction, the initial 3D structure often suffers from the limited angular sampling artifact. Selecting 2D class averages of particle images generally improves the accuracy and efficiency of the reference-free 3D angle estimation, but causes an insufficient angular sampling to fill the information of the target object in the 3D frequency space. Similarly, the initial 3D structure by the random-conical tilt reconstruction has the well-known "missing cone" artifact. Here, we attempted to solve the limited angular sampling problem by sequentially applying maximum a posteriori estimate with expectation maximization algorithm (sMAP-EM). Using both simulated and experimental cryo-electron microscope images, the sMAP-EM was compared to the direct Fourier method on the basis of reconstruction error and resolution. To establish selection criteria of the final regularization weight for the sMAP-EM, the effects of noise level and sampling sparseness on the reconstructions were examined with evenly distributed sampling simulations. The frequency information filled in the missing cone of the conical tilt sampling simulations was assessed by developing new quantitative measurements. All the results of visual and numerical evaluations showed the sMAP-EM performed better than the direct Fourier method, regardless of the sampling method, noise level, and sampling sparseness. Furthermore, the frequency domain analysis demonstrated that the sMAP-EM can fill the meaningful information in the unmeasured angular space without detailed a priori knowledge of the objects. The current research demonstrated that the sMAP-EM has a high potential to facilitate the determination of 3D protein structures at near atomic-resolution. PMID:26193484

  19. 3D-guided CT reconstruction using time-of-flight camera

    Science.gov (United States)

    Ismail, Mahmoud; Taguchi, Katsuyuki; Xu, Jingyan; Tsui, Benjamin M. W.; Boctor, Emad M.

    2011-03-01

    We propose the use of a time-of-flight (TOF) camera to obtain the patient's body contour in 3D guided imaging reconstruction scheme in CT and C-arm imaging systems with truncated projection. In addition to pixel intensity, a TOF camera provides the 3D coordinates of each point in the captured scene with respect to the camera coordinates. Information from the TOF camera was used to obtain a digitized surface of the patient's body. The digitization points are transformed to X-Ray detector coordinates by registering the two coordinate systems. A set of points corresponding to the slice of interest are segmented to form a 2D contour of the body surface. Radon transform is applied to the contour to generate the 'trust region' for the projection data. The generated 'trust region' is integrated as an input to augment the projection data. It is used to estimate the truncated, unmeasured projections using linear interpolation. Finally the image is reconstructed using the combination of the estimated and the measured projection data. The proposed method is evaluated using a physical phantom. Projection data for the phantom were obtained using a C-arm system. Significant improvement in the reconstructed image quality near the truncation edges was observed using the proposed method as compared to that without truncation correction. This work shows that the proposed 3D guided CT image reconstruction using a TOF camera represents a feasible solution to the projection data truncation problem.

  20. Intuitive Terrain Reconstruction Using Height Observation-Based Ground Segmentation and 3D Object Boundary Estimation

    Directory of Open Access Journals (Sweden)

    Sungdae Sim

    2012-12-01

    Full Text Available Mobile robot operators must make rapid decisions based on information about the robot’s surrounding environment. This means that terrain modeling and photorealistic visualization are required for the remote operation of mobile robots. We have produced a voxel map and textured mesh from the 2D and 3D datasets collected by a robot’s array of sensors, but some upper parts of objects are beyond the sensors’ measurements and these parts are missing in the terrain reconstruction result. This result is an incomplete terrain model. To solve this problem, we present a new ground segmentation method to detect non-ground data in the reconstructed voxel map. Our method uses height histograms to estimate the ground height range, and a Gibbs-Markov random field model to refine the segmentation results. To reconstruct a complete terrain model of the 3D environment, we develop a 3D boundary estimation method for non-ground objects. We apply a boundary detection technique to the 2D image, before estimating and refining the actual height values of the non-ground vertices in the reconstructed textured mesh. Our proposed methods were tested in an outdoor environment in which trees and buildings were not completely sensed. Our results show that the time required for ground segmentation is faster than that for data sensing, which is necessary for a real-time approach. In addition, those parts of objects that were not sensed are accurately recovered to retrieve their real-world appearances.

  1. Intuitive terrain reconstruction using height observation-based ground segmentation and 3D object boundary estimation.

    Science.gov (United States)

    Song, Wei; Cho, Kyungeun; Um, Kyhyun; Won, Chee Sun; Sim, Sungdae

    2012-12-12

    Mobile robot operators must make rapid decisions based on information about the robot's surrounding environment. This means that terrain modeling and photorealistic visualization are required for the remote operation of mobile robots. We have produced a voxel map and textured mesh from the 2D and 3D datasets collected by a robot's array of sensors, but some upper parts of objects are beyond the sensors' measurements and these parts are missing in the terrain reconstruction result. This result is an incomplete terrain model. To solve this problem, we present a new ground segmentation method to detect non-ground data in the reconstructed voxel map. Our method uses height histograms to estimate the ground height range, and a Gibbs-Markov random field model to refine the segmentation results. To reconstruct a complete terrain model of the 3D environment, we develop a 3D boundary estimation method for non-ground objects. We apply a boundary detection technique to the 2D image, before estimating and refining the actual height values of the non-ground vertices in the reconstructed textured mesh. Our proposed methods were tested in an outdoor environment in which trees and buildings were not completely sensed. Our results show that the time required for ground segmentation is faster than that for data sensing, which is necessary for a real-time approach. In addition, those parts of objects that were not sensed are accurately recovered to retrieve their real-world appearances.

  2. Compton scatter and randoms corrections for origin ensembles 3D PET reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Sitek, Arkadiusz [Harvard Medical School, Boston, MA (United States). Dept. of Radiology; Brigham and Women' s Hospital, Boston, MA (United States); Kadrmas, Dan J. [Utah Univ., Salt Lake City, UT (United States). Utah Center for Advanced Imaging Research (UCAIR)

    2011-07-01

    In this work we develop a novel approach to correction for scatter and randoms in reconstruction of data acquired by 3D positron emission tomography (PET) applicable to tomographic reconstruction done by the origin ensemble (OE) approach. The statistical image reconstruction using OE is based on calculation of expectations of the numbers of emitted events per voxel based on complete-data space. Since the OE estimation is fundamentally different than regular statistical estimators such those based on the maximum likelihoods, the standard methods of implementation of scatter and randoms corrections cannot be used. Based on prompts, scatter, and random rates, each detected event is graded in terms of a probability of being a true event. These grades are utilized by the Markov Chain Monte Carlo (MCMC) algorithm used in OE approach for calculation of the expectation over the complete-data space of the number of emitted events per voxel (OE estimator). We show that the results obtained with the OE are almost identical to results obtained by the maximum likelihood-expectation maximization (ML-EM) algorithm for reconstruction for experimental phantom data acquired using Siemens Biograph mCT 3D PET/CT scanner. The developed correction removes artifacts due to scatter and randoms in investigated 3D PET datasets. (orig.)

  3. Benchmarking Close-range Structure from Motion 3D Reconstruction Software under Varying Capturing Conditions

    DEFF Research Database (Denmark)

    Nikolov, Ivan Adriyanov; Madsen, Claus B.

    2016-01-01

    . In this paper we analyse the state of the art of these software applications, by comparing the resultant 3D meshes qualitatively and quantitatively. We propose a number of testing scenarios using different lighting conditions, camera positions and image acquisition methods for the best in-depth analysis......Structure from Motion 3D reconstruction has become widely used in recent years in a number of fields such as industrial surface in- inspection, archeology, cultural heritage preservation and geomapping. A number of software solutions have been released using variations of this technique...

  4. Objective and subjective quality assessment of geometry compression of reconstructed 3D Humans in a 3D virtual room

    NARCIS (Netherlands)

    Mekuria, R.N.; Cesar Garcia, P.S.; Frisiello, A.; Doumanis, I.

    2015-01-01

    Compression of 3D object based video is relevant for 3D Immersive applications. Nevertheless, the perceptual aspects of the degradation introduced by codecs for meshes and point clouds are not well understood. In this paper we evaluate the subjective and objective degradations introduced by such cod

  5. Electrochemical fields within 3D reconstructed microstructures of mixed ionic and electronic conducting devices

    Science.gov (United States)

    Zhang, Yanxiang; Chen, Yu; Lin, Ye; Yan, Mufu; Harris, William M.; Chiu, Wilson K. S.; Ni, Meng; Chen, Fanglin

    2016-11-01

    The performance and stability of the mixed ionic and electronic conducting (MIEC) membrane devices, such as solid oxide cells (SOCs) and oxygen separation membranes (OSMs) interplay tightly with the transport properties and the three-dimensional (3D) microstructure of the membrane. However, development of the MIEC devices is hindered by the limited knowledge about the distribution of electrochemical fields within the 3D local microstructures, especially at surface and interface. In this work, a generic model conforming to local thermodynamic equilibrium is developed to calculate the electrochemical fields, such as electric potential and oxygen chemical potential, within the 3D microstructure of the MIEC membrane. Stability of the MIEC membrane is evaluated by the distribution of oxygen partial pressure. The cell-level performance such as polarization resistance and voltage vs. current curve can be further calculated. Case studies are performed to demonstrate the capability of the framework by using X-ray computed tomography reconstructed 3D microstructures of a SOC and an OSM. The calculation method demonstrates high computational efficiency for large size 3D tomographic microstructures, and permits parallel calculation. The framework can serve as a powerful tool for correlating the transport properties and the 3D microstructure to the performance and the stability of MIEC devices.

  6. Estimation of the average glandular dose on a team of tomosynthesis

    International Nuclear Information System (INIS)

    Seeking to improve the information that gives us an image of mammography the manufacturers have implemented tomosynthesis. With this method of acquisition and reconstruction of image we went from having a 2D to a 3D image image, in such a way that it reduces or eliminates the effect of overlap of tissues. The estimate of the dose, which is always a fundamental parameter in the control of quality of radiology equipment, is more in the case of mammography by the radiosensitivity of this body and the frequency of their use. The objective of this work is the determination of the mean in a team glandular dose of with tomosynthesis mammography. (Author)

  7. A novel solid-angle tomosynthesis (SAT) scanning scheme

    International Nuclear Information System (INIS)

    Purpose: Digital tomosynthesis (DTS) recently gained extensive research interests in both diagnostic and radiation therapy fields. Conventional DTS images are generated by scanning an x-ray source and flat-panel detector pair on opposite sides of an object, with the scanning trajectory on a one-dimensional curve. A novel tomosynthesis method named solid-angle tomosynthesis (SAT) is proposed, where the x-ray source scans on an arbitrary shaped two-dimensional surface. Methods: An iterative algorithm in the form of total variation regulated expectation maximization is developed for SAT image reconstruction. The feasibility and effectiveness of SAT is corroborated by computer simulation studies using three-dimensional (3D) numerical phantoms including a 3D Shepp-Logan phantom and a volumetric CT image set of a human breast. Results: SAT is able to cover more space in Fourier domain more uniformly than conventional DTS. Greater coverage and more isotropy in the frequency domain translate to fewer artifacts and more accurately restored features in the in-plane reconstruction. Conclusions: Comparing with conventional DTS, SAT allows cone-shaped x-ray beams to project from more solid angles, thus provides more coverage in the spatial-frequency domain, resulting in better quality of reconstructed image.

  8. A novel solid-angle tomosynthesis (SAT) scanning scheme

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jin; Yu, Cedric [Department of Radiation Oncology, University of Maryland School of Medicine, 22 S. Greene Street, Baltimore, Maryland 21201 and Xcision Medical System, LLC, 12707 Chapel Chase Drive, Clarksville, Maryland 21209 (United States)

    2010-08-15

    Purpose: Digital tomosynthesis (DTS) recently gained extensive research interests in both diagnostic and radiation therapy fields. Conventional DTS images are generated by scanning an x-ray source and flat-panel detector pair on opposite sides of an object, with the scanning trajectory on a one-dimensional curve. A novel tomosynthesis method named solid-angle tomosynthesis (SAT) is proposed, where the x-ray source scans on an arbitrary shaped two-dimensional surface. Methods: An iterative algorithm in the form of total variation regulated expectation maximization is developed for SAT image reconstruction. The feasibility and effectiveness of SAT is corroborated by computer simulation studies using three-dimensional (3D) numerical phantoms including a 3D Shepp-Logan phantom and a volumetric CT image set of a human breast. Results: SAT is able to cover more space in Fourier domain more uniformly than conventional DTS. Greater coverage and more isotropy in the frequency domain translate to fewer artifacts and more accurately restored features in the in-plane reconstruction. Conclusions: Comparing with conventional DTS, SAT allows cone-shaped x-ray beams to project from more solid angles, thus provides more coverage in the spatial-frequency domain, resulting in better quality of reconstructed image.

  9. GlaRe, a GIS tool to reconstruct the 3D surface of palaeoglaciers

    Science.gov (United States)

    Pellitero, Ramón; Rea, Brice R.; Spagnolo, Matteo; Bakke, Jostein; Ivy-Ochs, Susan; Frew, Craig R.; Hughes, Philip; Ribolini, Adriano; Lukas, Sven; Renssen, Hans

    2016-09-01

    Glacier reconstructions are widely used in palaeoclimatic studies and this paper presents a new semi-automated method for generating glacier reconstructions: GlaRe, is a toolbox coded in Python and operating in ArcGIS. This toolbox provides tools to generate the ice thickness from the bed topography along a palaeoglacier flowline applying the standard flow law for ice, and generates the 3D surface of the palaeoglacier using multiple interpolation methods. The toolbox performance has been evaluated using two extant glaciers, an icefield and a cirque/valley glacier from which the subglacial topography is known, using the basic reconstruction routine in GlaRe. Results in terms of ice surface, ice extent and equilibrium line altitude show excellent agreement that confirms the robustness of this procedure in the reconstruction of palaeoglaciers from glacial landforms such as frontal moraines.

  10. Dense 3D Reconstruction from High Frame-Rate Video Using a Static Grid Pattern.

    Science.gov (United States)

    Sagawa, Ryusuke; Furukawa, Ryo; Kawasaki, Hiroshi

    2014-09-01

    Dense 3D reconstruction of fast moving objects could contribute to various applications such as body structure analysis, accident avoidance, and so on. In this paper, we propose a technique based on a one-shot scanning method, which reconstructs 3D shapes for each frame of a high frame-rate video capturing the scenes projected by a static pattern. To avoid instability of image processing, we restrict the number of colors used in the pattern to less than two. The proposed technique comprises (1) an efficient algorithm to eliminate ambiguity of projected parallel-line patterns by using intersection points, (2) a batch reconstruction algorithm of multiple frames by using spatio-temporal constraints, and (3) an efficient detection method of color-encoded grid pattern based on de Bruijn sequence. In the experiments, the line detection algorithm worked effectively and the dense reconstruction algorithm produces accurate and robust results. We also show the improved results by using temporal constraints. Finally, the dense reconstructions of fast moving objects in a high frame-rate video are presented. PMID:26352228

  11. 3D tomographic reconstruction of coronary arteries using a precomputed 4D motion field

    International Nuclear Information System (INIS)

    In this paper, we present a new method to perform 3D tomographic reconstruction of coronary arteries from cone-beam rotational x-ray angiography acquisitions. We take advantage of the precomputation of the coronary artery motion, modelled as a parametric 4D motion field. Contrary to data gating or data triggering approaches, we homogeneously use all available frames, independently of the cardiac phase. In addition, we artificially subtract angiograms from their background structures. Our method significantly improves the reconstruction, by removing both motion and background artefacts. We have successfully tested it on the datasets from a synthetic phantom and 10 patients

  12. Combination of SANS and 3D stochastic reconstruction techniques for the study of nanostructured materials

    CERN Document Server

    Kikkinides, E S; Steriotis, T A; Kanellopoulos, N K; Mitropoulos, A C; Treimer, W

    2002-01-01

    Ceramic nanostructured materials have recently received scientific and industrial interest due to their unique properties. A series of such nanoporous structures were characterised by SANS techniques. The resulting scattering curves were analysed to obtain basic structural information regarding the pore size distribution and autocorrelation function of each material. Furthermore, stochastic reconstruction models were employed to generate 3D images with the same basic structural characteristics obtained from SANS. Finally, simulation results of permeation on the reconstructed images provide very good agreement with experimental data. (orig.)

  13. Improved 3D reconstruction in smart-room environments using ToF imaging

    DEFF Research Database (Denmark)

    Guðmundsson, Sigurjón Árni; Pardas, Montse; Casas, Josep R.;

    2010-01-01

    This paper presents the use of Time-of-Flight (ToF) cameras in smart-rooms and how this leads to improved results in segmenting the people in the room from the background and consequently better 3D reconstruction of foreground objects. A calibrated rig consisting of one Swissranger SR3100 Time......-of-Flight range camera and a high resolution standard CCD camera is set in a smart-room containing five other standard cameras. A probabilistic background model is used to segment each view and a shape from silhouette volume is reconstructed. It is shown that the presence of the range camera gives ways...

  14. Reconstruction of 3D ion beam micro-tomography data for applications in Cell Biology

    Energy Technology Data Exchange (ETDEWEB)

    Habchi, C. [Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, Gradignan F-33175 (France)], E-mail: habchi@cenbg.in2p3.fr; Nguyen, D.T.; Barberet, Ph. [Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, Gradignan F-33175 (France); Incerti, S. [CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, Gradignan F-33175 (France); Moretto, Ph. [Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, Gradignan F-33175 (France); Sakellariou, A. [Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia); Seznec, H. [CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, Gradignan F-33175 (France)

    2009-06-15

    The DISRA (Discrete Image Space Reconstruction Algorithm) reconstruction code, created by A. Sakellariou, was conceived for the ideal case of complete three-dimensional (3D) PIXET (Particle Induced X-ray Emission Tomography) data. This implies two major difficulties for biological samples: first, the long duration of such experiments and second, the subsequent damage that occurs on such fragile specimens. For this reason, the DISRA code was extended at CENBG in order to probe isolated PIXET slices, taking into account the sample structure and mass density provided by 3D STIMT (Scanning Transmission Ion Microscopy Tomography) in the volume of interest. This modified version was tested on a phantom sample and first results on human cancer cells are also presented.

  15. Reconstruction of 3D ion beam micro-tomography data for applications in Cell Biology

    Science.gov (United States)

    Habchi, C.; Nguyen, D. T.; Barberet, Ph.; Incerti, S.; Moretto, Ph.; Sakellariou, A.; Seznec, H.

    2009-06-01

    The DISRA (Discrete Image Space Reconstruction Algorithm) reconstruction code, created by A. Sakellariou, was conceived for the ideal case of complete three-dimensional (3D) PIXET (Particle Induced X-ray Emission Tomography) data. This implies two major difficulties for biological samples: first, the long duration of such experiments and second, the subsequent damage that occurs on such fragile specimens. For this reason, the DISRA code was extended at CENBG in order to probe isolated PIXET slices, taking into account the sample structure and mass density provided by 3D STIMT (Scanning Transmission Ion Microscopy Tomography) in the volume of interest. This modified version was tested on a phantom sample and first results on human cancer cells are also presented.

  16. 3D RECONSTRUCTION AND ANALYSIS OF THE FRAGMENTED GRAINS IN A COMPOSITE MATERIAL

    Directory of Open Access Journals (Sweden)

    Luc Gillibert

    2013-06-01

    Full Text Available X-ray microtomography from solid propellant allows studying the microstructure of fragmented grains in damaged samples. A new reconstruction algorithm of fragmented grains for 3D images is introduced. Based on a watershed transform of a morphological closing of the input image, the algorithm can be used  with different sets of markers. Two of them are compared. After the grain reconstruction, a multiscale segmentation  algorithm is used to extract each fragment of the damaged grains. This allows an original quantitative study of the  fragmentation of each grain in 3D. Experimental results on X-ray microtomographic images of a solid propellant fragmented under compression are presented and validated.

  17. Order reconstruction phenomena and temperature-driven dynamics in a 3D zenithally bistable device

    KAUST Repository

    Raisch, A.

    2014-07-01

    We model the zenithally bistable device (ZBD) in three dimensions (3D), within the Landau-de Gennes theory, and find three stable static states in 3D without an applied field: the vertically aligned nematic (VAN) state, the hybrid aligned nematic (HAN) state and a third, high-tilt state, which we call the THAN state, with an interior and a surface defect. We recover the order reconstruction (OR) phenomenon around the defects in the HAN and THAN states and the 3D THAN and HAN solutions exhibit stable biaxial cylinders connecting defects on opposite faces of the ZBD device. We demonstrate a two-way temperature-driven switching between high-tilt and low-tilt states through controlled heating and cooling procedures in two dimensions (2D), with no applied fields. © CopyrightEPLA, 2014.

  18. 3D Indoor Building Environment Reconstruction using calibration of Range finder Data

    DEFF Research Database (Denmark)

    Jamali, Ali; Anton, François; Rahman, Alias Abdul;

    2015-01-01

    Nowadays, municipalities intend to have 3D city models for facility management, disaster management and architectural planning. 3D data acquisition can be done by laser scanning for indoor environment which is a costly and time consuming process. Currently, for indoor surveying, Electronic Distance...... Measurement (EDM) and Terrestrial Laser Scanner (TLS) are mostly used. In this paper, several techniques for indoor 3D building data acquisition have been investigated. For reducing the time and cost of indoor building data acquisition process, the Trimble LaserAce 1000 range finder is used. The accuracy...... of the rangefinder is evaluated and a simple spatial model is reconstructed from real data. This technique is rapid (it requires a shorter time as compared to others), but the results show inconsistencies in horizontal angles for short distances in indoor environments. The range finder was calibrated using a least...

  19. Renal Tumor Cryoablation Planning. The Efficiency of Simulation on Reconstructed 3D CT Scan

    Directory of Open Access Journals (Sweden)

    Ciprian Valerian LUCAN

    2010-12-01

    Full Text Available Introduction & Objective: Nephron-sparing surgical techniques risks are related to tumor relationships with adjacent anatomic structures. Complexity of the renal anatomy drives the interest to develop tools for 3D reconstruction and surgery simulation. The aim of the article was to assess the simulation on reconstructed 3D CT scan used for planning the cryoablation. Material & Method: A prospective randomized study was performed between Jan. 2007 and July 2009 on 27 patients who underwent retroperitoneoscopic T1a renal tumors cryoablation (RC. All patients were assessed preoperatively by CT scan, also used for 3D volume rendering. In the Gr.A, the patients underwent surgery planning by simulation on 3D CT scan. In the Gr.B., patients underwent standard RC. The two groups were compared in terms of surgical time, bleeding, postoperative drainage, analgesics requirement, hospital stay, time to socio-professional reintegration. Results: Fourteen patients underwent preoperative cryoablation planning (Gr.A and 13 patients underwent standard CR (Gr.B. All parameters analyzed were shorter in the Gr.A. On multivariate logistic regression, only shortens of the surgical time (138.79±5.51 min. in Gr.A. vs. 140.92±5.54 min in Gr.B. and bleeding (164.29±60.22 mL in Gr.A. vs. 215.38±100.80 mL in Gr.B. achieved statistical significance (p<0.05. The number of cryoneedles assessed by simulation had a 92.52% accuracy when compared with those effectively used. Conclusions: Simulation of the cryoablation using reconstructed 3D CT scan improves the surgical results. The application used for simulation was able to accurately assess the number of cryoneedles required for tumor ablation, their direction and approach.

  20. On the use of orientation filters for 3D reconstruction in event-driven stereo vision

    OpenAIRE

    Luis Alejandro eCamunas-Mesa; Teresa eSerrano-Gotarredona; Sio Hoi eIeng; Ryad Benjamin Benosman; Bernabe eLinares-Barranco

    2014-01-01

    The recently developed Dynamic Vision Sensors (DVS) sense visual information asynchronously and code it into trains of events with sub-micro second temporal resolution. This high temporal precision makes the output of these sensors especially suited for dynamic 3D visual reconstruction, by matching corresponding events generated by two different sensors in a stereo setup. This paper explores the use of Gabor filters to extract information about the orientation of the object edges that produce...

  1. 3D RECONSTRUCTION OF AN UNDERWATER ARCHAELOGICAL SITE: COMPARISON BETWEEN LOW COST CAMERAS

    Directory of Open Access Journals (Sweden)

    A. Capra

    2015-04-01

    Full Text Available The 3D reconstruction with a metric content of a submerged area, where objects and structures of archaeological interest are found, could play an important role in the research and study activities and even in the digitization of the cultural heritage. The reconstruction of 3D object, of interest for archaeologists, constitutes a starting point in the classification and description of object in digital format and for successive fruition by user after delivering through several media. The starting point is a metric evaluation of the site obtained with photogrammetric surveying and appropriate 3D restitution. The authors have been applying the underwater photogrammetric technique since several years using underwater digital cameras and, in this paper, digital low cost cameras (off-the-shelf. Results of tests made on submerged objects with three cameras are presented: © Canon Power Shot G12, © Intova Sport HD e © GoPro HERO 2. The experimentation had the goal to evaluate the precision in self-calibration procedures, essential for multimedia underwater photogrammetry, and to analyze the quality of 3D restitution. Precisions obtained in the calibration and orientation procedures was assessed by using three cameras, and an homogeneous set control points. Data were processed with © Agisoft Photoscan. Successively, 3D models were created and the comparison of the models derived from the use of different cameras was performed. Different potentialities of the used cameras are reported in the discussion section. The 3D restitution of objects and structures was integrated with sea bottom floor morphology in order to achieve a comprehensive description of the site. A possible methodology of survey and representation of submerged objects is therefore illustrated, considering an automatic and a semi-automatic approach.

  2. 3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Iturrondobeitia, M., E-mail: maider.iturrondobeitia@ehu.es; Okariz, A.; Fernandez-Martinez, R.; Jimbert, P.; Guraya, T.; Ibarretxe, J. [eMERG, University of the Basque Country, Rafael Moreno Pitxitxi street 2 and 3, 48013, Bilbao (Spain)

    2015-03-30

    The microstructure of laminar bio-nanocomposites (Poly (lactic acid)(PLA)/clay) depends on the amount of clay platelet opening after integration with the polymer matrix and determines the final properties of the material. Transmission electron microscopy (TEM) technique is the only one that can provide a direct observation of the layer dispersion and the degree of exfoliation. However, the orientation of the clay platelets, which affects the final properties, is practically immeasurable from a single 2D TEM image. This issue can be overcome using transmission electron tomography (ET), a technique that allows the complete 3D characterization of the structure, including the measurement of the orientation of clay platelets, their morphology and their 3D distribution. ET involves a 3D reconstruction of the study volume and a subsequent segmentation of the study object. Currently, accurate segmentation is performed manually, which is inefficient and tedious. The aim of this work is to propose an objective/automated segmentation methodology process of a 3D TEM tomography reconstruction. In this method the segmentation threshold is optimized by minimizing the variation of the dimensions of the segmented objects and matching the segmented V{sub clay} (%) and the actual one. The method is first validated using a fictitious set of objects, and then applied on a nanocomposite.

  3. PCA-based 3D Shape Reconstruction of Human Foot Using Multiple Viewpoint Cameras

    Institute of Scientific and Technical Information of China (English)

    Edmée Amstutz; Tomoaki Teshima; Makoto Kimura; Masaaki Mochimaru; Hideo Saito

    2008-01-01

    This paper describes a multiple camera-based method to reconstruct the 3D shape of a human foot. From a foot database,an initial 3D model of the foot represented by a cloud of points is built. The shape parameters, which can characterize more than 92% of a foot, are defined by using the principal component analysis method. Then, using "active shape models", the initial 3D model is adapted to the real foot captured in multiple images by applying some constraints (edge points' distance and color variance). We insist here on the experiment part where we demonstrate the efficiency of the proposed method on a plastic foot model, and also on real human feet with various shapes. We propose and compare different ways of texturing the foot which is needed for reconstruction. We present an experiment performed on the plastic foot model and on human feet and propose two different ways to improve the final 3D shape's accuracy according to the previous experiments' results. The first improvement proposed is the densification of the cloud of points used to represent the initial model and the foot database. The second improvement concerns the projected patterns used to texture the foot. We conclude by showing the obtained results for a human foot with the average computed shape error being only 1.06mm.

  4. Comparison Between Two Generic 3d Building Reconstruction Approaches - Point Cloud Based VS. Image Processing Based

    Science.gov (United States)

    Dahlke, D.; Linkiewicz, M.

    2016-06-01

    This paper compares two generic approaches for the reconstruction of buildings. Synthesized and real oblique and vertical aerial imagery is transformed on the one hand into a dense photogrammetric 3D point cloud and on the other hand into photogrammetric 2.5D surface models depicting a scene from different cardinal directions. One approach evaluates the 3D point cloud statistically in order to extract the hull of structures, while the other approach makes use of salient line segments in 2.5D surface models, so that the hull of 3D structures can be recovered. With orders of magnitudes more analyzed 3D points, the point cloud based approach is an order of magnitude more accurate for the synthetic dataset compared to the lower dimensioned, but therefor orders of magnitude faster, image processing based approach. For real world data the difference in accuracy between both approaches is not significant anymore. In both cases the reconstructed polyhedra supply information about their inherent semantic and can be used for subsequent and more differentiated semantic annotations through exploitation of texture information.

  5. Sensor Fusion of Cameras and a Laser for City-Scale 3D Reconstruction

    Directory of Open Access Journals (Sweden)

    Yunsu Bok

    2014-11-01

    Full Text Available This paper presents a sensor fusion system of cameras and a 2D laser sensorfor large-scale 3D reconstruction. The proposed system is designed to capture data on afast-moving ground vehicle. The system consists of six cameras and one 2D laser sensor,and they are synchronized by a hardware trigger. Reconstruction of 3D structures is doneby estimating frame-by-frame motion and accumulating vertical laser scans, as in previousworks. However, our approach does not assume near 2D motion, but estimates free motion(including absolute scale in 3D space using both laser data and image features. In orderto avoid the degeneration associated with typical three-point algorithms, we present a newalgorithm that selects 3D points from two frames captured by multiple cameras. The problemof error accumulation is solved by loop closing, not by GPS. The experimental resultsshow that the estimated path is successfully overlaid on the satellite images, such that thereconstruction result is very accurate.

  6. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Science.gov (United States)

    de Jesus, Kelly; de Jesus, Karla; Figueiredo, Pedro; Vilas-Boas, João Paulo; Fernandes, Ricardo Jorge; Machado, Leandro José

    2015-01-01

    This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm) with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points) was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.). Root Mean Square (RMS) error with homography of control and validations points was lower than without it for surface and underwater cameras (P ≤ 0.03). With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P ≥ 0.47). Without homography, RMS error of control points was greater for underwater than surface cameras (P ≤ 0.04) and the opposite was observed for validation points (P ≤ 0.04). It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy. PMID:26175796

  7. 3D virtual reconstruction of the Pleistocene cheetah skull from the Tangshan, Nanjing, China

    Institute of Scientific and Technical Information of China (English)

    DONG Wei; HOU Xinwen; LIU Jinyi; FANG Yingsan; JIN Changzhu; ZHU Qizhi

    2007-01-01

    The development of computer tomography and image processing has made it possible to establish virtual 3D reconstruction and non-invasive dissection of fossil specimens. We used these methods to reconstruct a virtual 3D skull of a Pleistocene cheetah skull from the Tuozi cave, Tangshan, Nanjing, and virtually dissected it for anatomic studies, and measured the volumes of different parts of the endocranium. The endocranium of the cheetah skull has showed that its frontal sinus is beehive-like, the frontal lobe of cerebra is relatively large but the temporal lobe is relatively small, its cerebral sulcus and gyrus are more complicated than those of the domestic cat, similar to those of the domestic dog, but simpler than those of giant panda, pig, cattle and horse. The technology of virtual 3D reconstruction and non-invasive dissection of fossil specimens can extend the morphological study from the exterior to the interior, and it can also help to study fragile specimens and virtually backup rare and precious specimens.

  8. Reconstruction Accuracy Assessment of Surface and Underwater 3D Motion Analysis: A New Approach

    Directory of Open Access Journals (Sweden)

    Kelly de Jesus

    2015-01-01

    Full Text Available This study assessed accuracy of surface and underwater 3D reconstruction of a calibration volume with and without homography. A calibration volume (6000 × 2000 × 2500 mm with 236 markers (64 above and 88 underwater control points—with 8 common points at water surface—and 92 validation points was positioned on a 25 m swimming pool and recorded with two surface and four underwater cameras. Planar homography estimation for each calibration plane was computed to perform image rectification. Direct linear transformation algorithm for 3D reconstruction was applied, using 1600000 different combinations of 32 and 44 points out of the 64 and 88 control points for surface and underwater markers (resp.. Root Mean Square (RMS error with homography of control and validations points was lower than without it for surface and underwater cameras (P≤0.03. With homography, RMS errors of control and validation points were similar between surface and underwater cameras (P≥0.47. Without homography, RMS error of control points was greater for underwater than surface cameras (P≤0.04 and the opposite was observed for validation points (P≤0.04. It is recommended that future studies using 3D reconstruction should include homography to improve swimming movement analysis accuracy.

  9. Quality Analysis on 3d Buidling Models Reconstructed from Uav Imagery

    Science.gov (United States)

    Jarzabek-Rychard, M.; Karpina, M.

    2016-06-01

    Recent developments in UAV technology and structure from motion techniques have effected that UAVs are becoming standard platforms for 3D data collection. Because of their flexibility and ability to reach inaccessible urban parts, drones appear as optimal solution for urban applications. Building reconstruction from the data collected with UAV has the important potential to reduce labour cost for fast update of already reconstructed 3D cities. However, especially for updating of existing scenes derived from different sensors (e.g. airborne laser scanning), a proper quality assessment is necessary. The objective of this paper is thus to evaluate the potential of UAV imagery as an information source for automatic 3D building modeling at LOD2. The investigation process is conducted threefold: (1) comparing generated SfM point cloud to ALS data; (2) computing internal consistency measures of the reconstruction process; (3) analysing the deviation of Check Points identified on building roofs and measured with a tacheometer. In order to gain deep insight in the modeling performance, various quality indicators are computed and analysed. The assessment performed according to the ground truth shows that the building models acquired with UAV-photogrammetry have the accuracy of less than 18 cm for the plannimetric position and about 15 cm for the height component.

  10. Generic camera model and its calibration for computational integral imaging and 3D reconstruction.

    Science.gov (United States)

    Li, Weiming; Li, Youfu

    2011-03-01

    Integral imaging (II) is an important 3D imaging technology. To reconstruct 3D information of the viewed objects, modeling and calibrating the optical pickup process of II are necessary. This work focuses on the modeling and calibration of an II system consisting of a lenslet array, an imaging lens, and a charge-coupled device camera. Most existing work on such systems assumes a pinhole array model (PAM). In this work, we explore a generic camera model that accommodates more generality. This model is an empirical model based on measurements, and we constructed a setup for its calibration. Experimental results show a significant difference between the generic camera model and the PAM. Images of planar patterns and 3D objects were computationally reconstructed with the generic camera model. Compared with the images reconstructed using the PAM, the images present higher fidelity and preserve more high spatial frequency components. To the best of our knowledge, this is the first attempt in applying a generic camera model to an II system.

  11. A novel 3D template for mandible and maxilla reconstruction: Rapid prototyping using stereolithography

    Directory of Open Access Journals (Sweden)

    Samir Kumta

    2015-01-01

    Full Text Available Introduction: Replication of the exact three-dimensional (3D structure of the maxilla and mandible is now a priority whilst attempting reconstruction of these bones to attain a complete functional and aesthetic rehabilitation. We hereby present the process of rapid prototyping using stereolithography to produce templates for modelling bone grafts and implants for maxilla/mandible reconstructions, its applications in tumour/trauma, and outcomes for primary and secondary reconstruction. Materials and Methods: Stereolithographic template-assisted reconstruction was used on 11 patients for the reconstruction of the mandible/maxilla primarily following tumour excision and secondarily for the realignment of post-traumatic malunited fractures or deformity corrections. Data obtained from the computed tomography (CT scans with 1-mm resolution were converted into a computer-aided design (CAD using the CT Digital Imaging and Communications in Medicine (DICOM data. Once a CAD model was constructed, it was converted into a stereolithographic format and then processed by the rapid prototyping technology to produce the physical anatomical model using a resin. This resin model replicates the native mandible, which can be thus used off table as a guide for modelling the bone grafts. Discussion: This conversion of two-dimensional (2D data from CT scan into 3D models is a very precise guide to shaping the bone grafts. Further, this CAD can reconstruct the defective half of the mandible using the mirror image principle, and the normal anatomical model can be created to aid secondary reconstructions. Conclusion: This novel approach allows a precise translation of the treatment plan directly to the surgical field. It is also an important teaching tool for implant moulding and fixation, and helps in patient counselling.

  12. 3D Coronal Density Reconstruction and Retrieving the Magnetic Field Structure during Solar Minimum

    CERN Document Server

    Kramar, M; Mikić, Z; Davila, J

    2014-01-01

    Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal phenomena at all scales. We employed STEREO/COR1 data obtained during a deep minimum of solar activity in February 2008 (Carrington rotation CR 2066) to retrieve and analyze the three-dimensional (3D) coronal electron density in the range of heights from 1.5 to 4 Rsun using a tomography method. With this, we qualitatively deduced structures of the coronal magnetic field. The 3D electron density analysis is complemented by the 3D STEREO/EUVI emissivity in the 195 A band obtained by tomography for the same CR. A global 3D MHD model of the solar corona was used to relate the reconstructed 3D density and emissivity to open/closed magnetic field structures. We show that the density maximum locations can serve as an indicator of current sheet position, while the locations of the density gradient maximum can be a reliable indicator of coronal hole boundaries. We find that the magnetic field configuration du...

  13. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Département de physique, de génie physique et d’optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de radio-oncologie et Axe Oncologie du Centre de recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Binnekamp, Dirk [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best 5680 DA (Netherlands)

    2015-03-15

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  14. Measurement Matrix Optimization and Mismatch Problem Compensation for DLSLA 3-D SAR Cross-Track Reconstruction

    Science.gov (United States)

    Bao, Qian; Jiang, Chenglong; Lin, Yun; Tan, Weixian; Wang, Zhirui; Hong, Wen

    2016-01-01

    With a short linear array configured in the cross-track direction, downward looking sparse linear array three-dimensional synthetic aperture radar (DLSLA 3-D SAR) can obtain the 3-D image of an imaging scene. To improve the cross-track resolution, sparse recovery methods have been investigated in recent years. In the compressive sensing (CS) framework, the reconstruction performance depends on the property of measurement matrix. This paper concerns the technique to optimize the measurement matrix and deal with the mismatch problem of measurement matrix caused by the off-grid scatterers. In the model of cross-track reconstruction, the measurement matrix is mainly affected by the configuration of antenna phase centers (APC), thus, two mutual coherence based criteria are proposed to optimize the configuration of APCs. On the other hand, to compensate the mismatch problem of the measurement matrix, the sparse Bayesian inference based method is introduced into the cross-track reconstruction by jointly estimate the scatterers and the off-grid error. Experiments demonstrate the performance of the proposed APCs’ configuration schemes and the proposed cross-track reconstruction method. PMID:27556471

  15. 3D nanostructure reconstruction based on the SEM imaging principle, and applications

    International Nuclear Information System (INIS)

    This paper addresses a novel 3D reconstruction method for nanostructures based on the scanning electron microscopy (SEM) imaging principle. In this method, the shape from shading (SFS) technique is employed, to analyze the gray-scale information of a single top-view SEM image which contains all the visible surface information, and finally to reconstruct the 3D surface morphology. It offers not only unobstructed observation from various angles but also the exact physical dimensions of nanostructures. A convenient and commercially available tool (NanoViewer) is developed based on this method for nanostructure analysis and characterization of properties. The reconstruction result coincides well with the SEM nanostructure image and is verified in different ways. With the extracted structure information, subsequent research of the nanostructure can be carried out, such as roughness analysis, optimizing properties by structure improvement and performance simulation with a reconstruction model. Efficient, practical and non-destructive, the method will become a powerful tool for nanostructure surface observation and characterization. (paper)

  16. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  17. Measurement Matrix Optimization and Mismatch Problem Compensation for DLSLA 3-D SAR Cross-Track Reconstruction.

    Science.gov (United States)

    Bao, Qian; Jiang, Chenglong; Lin, Yun; Tan, Weixian; Wang, Zhirui; Hong, Wen

    2016-08-22

    With a short linear array configured in the cross-track direction, downward looking sparse linear array three-dimensional synthetic aperture radar (DLSLA 3-D SAR) can obtain the 3-D image of an imaging scene. To improve the cross-track resolution, sparse recovery methods have been investigated in recent years. In the compressive sensing (CS) framework, the reconstruction performance depends on the property of measurement matrix. This paper concerns the technique to optimize the measurement matrix and deal with the mismatch problem of measurement matrix caused by the off-grid scatterers. In the model of cross-track reconstruction, the measurement matrix is mainly affected by the configuration of antenna phase centers (APC), thus, two mutual coherence based criteria are proposed to optimize the configuration of APCs. On the other hand, to compensate the mismatch problem of the measurement matrix, the sparse Bayesian inference based method is introduced into the cross-track reconstruction by jointly estimate the scatterers and the off-grid error. Experiments demonstrate the performance of the proposed APCs' configuration schemes and the proposed cross-track reconstruction method.

  18. 3D Reconstruction of Interplanetary Scintillation (IPS) Remote-Sensing Data: Global Solar Wind Boundaries for Driving 3D-MHD Models

    Science.gov (United States)

    Yu, H.-S.; Jackson, B. V.; Hick, P. P.; Buffington, A.; Odstrcil, D.; Wu, C.-C.; Davies, J. A.; Bisi, M. M.; Tokumaru, M.

    2015-09-01

    The University of California, San Diego, time-dependent analyses of the heliosphere provide three-dimensional (3D) reconstructions of solar wind velocities and densities from observations of interplanetary scintillation (IPS). Using data from the Solar-Terrestrial Environment Laboratory, Japan, these reconstructions provide a real-time prediction of the global solar-wind density and velocity throughout the whole heliosphere with a temporal cadence of about one day (ips.ucsd.edu). Updates to this modeling effort continue: in the present article, near-Sun results extracted from the time-dependent 3D reconstruction are used as inner boundary conditions to drive 3D-MHD models ( e.g. ENLIL and H3D-MHD). This allows us to explore the differences between the IPS kinematic-model data-fitting procedure and current 3D-MHD modeling techniques. The differences in these techniques provide interesting insights into the physical principles governing the expulsion of coronal mass ejections (CMEs). Here we detail for the first time several specific CMEs and an induced shock that occurred in September 2011 that demonstrate some of the issues resulting from these analyses.

  19. 3D reconstruction of digitized histological sections for vasculature quantification in the mouse hind limb

    Science.gov (United States)

    Xu, Yiwen; Pickering, J. Geoffrey; Nong, Zengxuan; Gibson, Eli; Ward, Aaron D.

    2014-03-01

    In contrast to imaging modalities such as magnetic resonance imaging and micro computed tomography, digital histology reveals multiple stained tissue features at high resolution (0.25μm/pixel). However, the two-dimensional (2D) nature of histology challenges three-dimensional (3D) quantification and visualization of the different tissue components, cellular structures, and subcellular elements. This limitation is particularly relevant to the vasculature, which has a complex and variable structure within tissues. The objective of this study was to perform a fully automated 3D reconstruction of histology tissue in the mouse hind limb preserving the accurate systemic orientation of the tissues, stained with hematoxylin and immunostained for smooth muscle α actin. We performed a 3D reconstruction using pairwise rigid registrations of 5μm thick, paraffin-embedded serial sections, digitized at 0.25μm/pixel. Each registration was performed using the iterative closest points algorithm on blood vessel landmarks. Landmarks were vessel centroids, determined according to a signed distance map of each pixel to a decision boundary in hue-saturation-value color space; this decision boundary was determined based on manual annotation of a separate training set. Cell nuclei were then automatically extracted and corresponded to refine the vessel landmark registration. Homologous nucleus landmark pairs appearing on not more than two adjacent slides were chosen to avoid registrations which force curved or non-sectionorthogonal structures to be straight and section-orthogonal. The median accumulated target registration errors ± interquartile ranges for the vessel landmark registration, and the nucleus landmark refinement were 43.4+/-42.8μm and 2.9+/-1.7μm, respectively (p<0.0001). Fully automatic and accurate 3D rigid reconstruction of mouse hind limb histology imaging is feasible based on extracted vasculature and nuclei.

  20. 3D RECONSTRUCTION OF BUILDINGS WITH GABLED AND HIPPED STRUCTURES USING LIDAR DATA

    Directory of Open Access Journals (Sweden)

    H. Amini

    2014-10-01

    Full Text Available Buildings are the most important objects in urban areas. Thus, building detection using photogrammetry and remote sensing data as well as 3D model of buildings are very useful for many applications such as mobile navigation, tourism, and disaster management. In this paper, an approach has been proposed for detecting buildings by LiDAR data and aerial images, as well as reconstructing 3D model of buildings. In this regard, firstly, building detection carried out by utilizing a Supper Vector Machine (SVM as a supervise method. The supervise methods need training data that could be collected from some features. Hence, LiDAR data and aerial images were utilized to produce some features. The features were selected by considering their abilities for separating buildings from other objects. The evaluation results of building detection showed high accuracy and precision of the utilized approach. The detected buildings were labeled in order to reconstruct buildings, individually. Then the planes of each building were separated and adjacent planes were recognized to reduce the calculation volume and to increase the accuracy. Subsequently, the bottom planes of each building were detected in order to compute the corners of hipped roofs using intersection of three adjacent planes. Also, the corners of gabled roofs were computed by both calculating the intersection line of the adjacent planes and finding the intersection between the planes intersection line and their detected parcel. Finally, the coordinates of some nodes in building floor were computed and 3D model reconstruction was carried out. In order to evaluate the proposed method, 3D model of some buildings with different complexity level were generated. The evaluation results showed that the proposed method has reached credible performance.

  1. Ion track reconstruction in 3D using alumina-based fluorescent nuclear track detectors

    Science.gov (United States)

    Niklas, M.; Bartz, J. A.; Akselrod, M. S.; Abollahi, A.; Jäkel, O.; Greilich, S.

    2013-09-01

    Fluorescent nuclear track detectors (FNTDs) based on Al2O3: C, Mg single crystal combined with confocal microscopy provide 3D information on ion tracks with a resolution only limited by light diffraction. FNTDs are also ideal substrates to be coated with cells to engineer cell-fluorescent ion track hybrid detectors (Cell-Fit-HD). This radiobiological tool enables a novel platform linking cell responses to physical dose deposition on a sub-cellular level in proton and heavy ion therapies. To achieve spatial correlation between single ion hits in the cell coating and its biological response the ion traversals have to be reconstructed in 3D using the depth information gained by the FNTD read-out. FNTDs were coated with a confluent human lung adenocarcinoma epithelial (A549) cell layer. Carbon ion irradiation of the hybrid detector was performed perpendicular and angular to the detector surface. In situ imaging of the fluorescently labeled cell layer and the FNTD was performed in a sequential read-out. Making use of the trajectory information provided by the FNTD the accuracy of 3D track reconstruction of single particles traversing the hybrid detector was studied. The accuracy is strongly influenced by the irradiation angle and therefore by complexity of the FNTD signal. Perpendicular irradiation results in highest accuracy with error of smaller than 0.10°. The ability of FNTD technology to provide accurate 3D ion track reconstruction makes it a powerful tool for radiobiological investigations in clinical ion beams, either being used as a substrate to be coated with living tissue or being implanted in vivo.

  2. Real-time 3D computed tomographic reconstruction using commodity graphics hardware

    Science.gov (United States)

    Xu, Fang; Mueller, Klaus

    2007-07-01

    The recent emergence of various types of flat-panel x-ray detectors and C-arm gantries now enables the construction of novel imaging platforms for a wide variety of clinical applications. Many of these applications require interactive 3D image generation, which cannot be satisfied with inexpensive PC-based solutions using the CPU. We present a solution based on commodity graphics hardware (GPUs) to provide these capabilities. While GPUs have been employed for CT reconstruction before, our approach provides significant speedups by exploiting the various built-in hardwired graphics pipeline components for the most expensive CT reconstruction task, backprojection. We show that the timings so achieved are superior to those obtained when using the GPU merely as a multi-processor, without a drop in reconstruction quality. In addition, we also show how the data flow across the graphics pipeline can be optimized, by balancing the load among the pipeline components. The result is a novel streaming CT framework that conceptualizes the reconstruction process as a steady flow of data across a computing pipeline, updating the reconstruction result immediately after the projections have been acquired. Using a single PC equipped with a single high-end commodity graphics board (the Nvidia 8800 GTX), our system is able to process clinically-sized projection data at speeds meeting and exceeding the typical flat-panel detector data production rates, enabling throughput rates of 40-50 projections s-1 for the reconstruction of 5123 volumes.

  3. Real-time 3D computed tomographic reconstruction using commodity graphics hardware

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fang; Mueller, Klaus [Center for Visual Computing, Computer Science Department, Stony Brook University, Stony Brook, NY 11794-4400 (United States)

    2007-07-21

    The recent emergence of various types of flat-panel x-ray detectors and C-arm gantries now enables the construction of novel imaging platforms for a wide variety of clinical applications. Many of these applications require interactive 3D image generation, which cannot be satisfied with inexpensive PC-based solutions using the CPU. We present a solution based on commodity graphics hardware (GPUs) to provide these capabilities. While GPUs have been employed for CT reconstruction before, our approach provides significant speedups by exploiting the various built-in hardwired graphics pipeline components for the most expensive CT reconstruction task, backprojection. We show that the timings so achieved are superior to those obtained when using the GPU merely as a multi-processor, without a drop in reconstruction quality. In addition, we also show how the data flow across the graphics pipeline can be optimized, by balancing the load among the pipeline components. The result is a novel streaming CT framework that conceptualizes the reconstruction process as a steady flow of data across a computing pipeline, updating the reconstruction result immediately after the projections have been acquired. Using a single PC equipped with a single high-end commodity graphics board (the Nvidia 8800 GTX), our system is able to process clinically-sized projection data at speeds meeting and exceeding the typical flat-panel detector data production rates, enabling throughput rates of 40-50 projections s{sup -1} for the reconstruction of 512{sup 3} volumes.

  4. Probabilistic fusion of angiographic and echographic images for the 3D reconstruction of vessels

    Science.gov (United States)

    Pellot-Barakat, Claire J. M.; Bloch, Isabelle; Sureda, Francisco; Herment, Alain; Sigelle, Marc; Horain, Patrick J.; Long, Anne

    1995-05-01

    In order to provide a better quantitative and morphologic description of complex vascular lesions, we propose an approach of 3D reconstruction of the vessel internal wall, based on data fusion from two different imaging sources: two x ray digital angiography projections and a stack of endovascular echography slices. After extraction of echographic and angiographic information to be fused, a geometric model leads to the determination of the unknown parameters which allow the alignment of all data in a common reference frame. Both types of data are then directly included in a probabilistic reconstruction process based on Markov random fields. The Markovian model consists of cost functions reflecting x ray and ultrasonic data consistency and regularization elements to control the anatomic reality of the reconstruction. The optimal solution according to the definition criteria is obtained by minimizing the model energy with an algorithm based on simulated annealing. Preliminary results have been obtained with data acquired on a dog aorta. The accuracy of reconstruction by data fusion is significantly improved compared with results obtained with separate reconstruction from angiographic or echographic data. Taking into account all information available about the problem, the method avoids uncertainties and ambiguities of a reconstruction based only on one modality, and the probabilistic fusion solves the possible contradictions between both acquisitions.

  5. 3D INDOOR BUILDING ENVIRONMENT RECONSTRUCTION USING CALIBRATION OF RANGEFINDER DATA

    Directory of Open Access Journals (Sweden)

    A. Jamali

    2015-10-01

    Full Text Available Nowadays, municipalities intend to have 3D city models for facility management, disaster management and architectural planning. 3D data acquisition can be done by laser scanning for indoor environment which is a costly and time consuming process. Currently, for indoor surveying, Electronic Distance Measurement (EDM and Terrestrial Laser Scanner (TLS are mostly used. In this paper, several techniques for indoor 3D building data acquisition have been investigated. For reducing the time and cost of indoor building data acquisition process, the Trimble LaserAce 1000 range finder is used. The accuracy of the rangefinder is evaluated and a simple spatial model is reconstructed from real data. This technique is rapid (it requires a shorter time as compared to others, but the results show inconsistencies in horizontal angles for short distances in indoor environments. The range finder was calibrated using a least square adjustment algorithm. To control the uncertainty of the calibration and of the reconstruction of the building from the measurements, interval analysis and homotopy continuation are used.

  6. Implementation of a fast running full core pin power reconstruction method in DYN3D

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Torres, Armando Miguel [Instituto Nacional de Investigaciones Nucleares, Department of Nuclear Systems, Carretera Mexico – Toluca s/n, La Marquesa, 52750 Ocoyoacac (Mexico); Sanchez-Espinoza, Victor Hugo, E-mail: victor.sanchez@kit.edu [Karlsruhe Institute of Technology, Institute for Neutron Physics and Reactor Technology, Hermann-vom-Helmhotz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Kliem, Sören; Gommlich, Andre [Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden (Germany)

    2014-07-01

    Highlights: • New pin power reconstruction (PPR) method for the nodal diffusion code DYN3D. • Flexible PPR method applicable to a single, a group or to all fuel assemblies (square, hex). • Combination of nodal with pin-wise solutions (non-conform geometry). • PPR capabilities shown for REA of a Minicore (REA) PWR whole core. - Abstract: This paper presents a substantial extension of the pin power reconstruction (PPR) method used in the reactor dynamics code DYN3D with the aim to better describe the heterogeneity within the fuel assembly during reactor simulations. The flexibility of the new implemented PPR permits the local spatial refinement of one fuel assembly, of a cluster of fuel assemblies, of a quarter or eight of a core or even of a whole core. The application of PPR in core regions of interest will pave the way for the coupling with sub-channel codes enabling the prediction of local safety parameters. One of the main advantages of considering regions and not only a hot fuel assembly (FA) is the fact that the cross flow within this region can be taken into account by the subchannel code. The implementation of the new PPR method has been tested analysing a rod ejection accident (REA) in a PWR minicore consisting of 3 × 3 FA. Finally, the new capabilities of DNY3D are demonstrated by the analysing a boron dilution transient in a PWR MOX core and the pin power of a VVER-1000 reactor at stationary conditions.

  7. Detectability limitations with 3-D point reconstruction algorithms using digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Erik, E-mail: erik.lindgren@chalmers.se [Department of Materials and Manufacturing Technology, Chalmers University of Technology, Göteborg, 412 96 (Sweden)

    2015-03-31

    The estimated impact of pores in clusters on component fatigue will be highly conservative when based on 2-D rather than 3-D pore positions. To 3-D position and size defects using digital radiography and 3-D point reconstruction algorithms in general require a lower inspection time and in some cases work better with planar geometries than X-ray computed tomography. However, the increase in prior assumptions about the object and the defects will increase the intrinsic uncertainty in the resulting nondestructive evaluation output. In this paper this uncertainty arising when detecting pore defect clusters with point reconstruction algorithms is quantified using simulations. The simulation model is compared to and mapped to experimental data. The main issue with the uncertainty is the possible masking (detectability zero) of smaller defects around some other slightly larger defect. In addition, the uncertainty is explored in connection to the expected effects on the component fatigue life and for different amount of prior object-defect assumptions made.

  8. Implementation of a fast running full core pin power reconstruction method in DYN3D

    International Nuclear Information System (INIS)

    Highlights: • New pin power reconstruction (PPR) method for the nodal diffusion code DYN3D. • Flexible PPR method applicable to a single, a group or to all fuel assemblies (square, hex). • Combination of nodal with pin-wise solutions (non-conform geometry). • PPR capabilities shown for REA of a Minicore (REA) PWR whole core. - Abstract: This paper presents a substantial extension of the pin power reconstruction (PPR) method used in the reactor dynamics code DYN3D with the aim to better describe the heterogeneity within the fuel assembly during reactor simulations. The flexibility of the new implemented PPR permits the local spatial refinement of one fuel assembly, of a cluster of fuel assemblies, of a quarter or eight of a core or even of a whole core. The application of PPR in core regions of interest will pave the way for the coupling with sub-channel codes enabling the prediction of local safety parameters. One of the main advantages of considering regions and not only a hot fuel assembly (FA) is the fact that the cross flow within this region can be taken into account by the subchannel code. The implementation of the new PPR method has been tested analysing a rod ejection accident (REA) in a PWR minicore consisting of 3 × 3 FA. Finally, the new capabilities of DNY3D are demonstrated by the analysing a boron dilution transient in a PWR MOX core and the pin power of a VVER-1000 reactor at stationary conditions

  9. Digital breast tomosynthesis; Digitale Tomosynthese der Brust

    Energy Technology Data Exchange (ETDEWEB)

    Haegele, Julian; Barkhausen, Joerg [Universtiaetsklinikum Schleswig-Holstein, Luebeck (Germany). Klinik fuer Radiologie und Nuklearmedizin; Pursche, Telja [Universtiaetsklinikum Schleswig-Holstein, Luebeck (Germany). Brustzentrum; Schaefer, Fritz K.W. [Universtiaetsklinikum Schleswig-Holstein, Kiel (Germany). Bereich Mammadiagnostik und Intervention

    2015-09-15

    In digital breast tomosynthesis a digital tomographic data set with a very high spatial resolution is reconstructed from low-dose projections collected over a limited rotation angle. This allows a very detailed assessment of e. g. masses and architectural distortions. The average glandular dose is comparable to 2 D mammography. First clinical studies demonstrated that tomosynthesis is able to supply important additional information in suspicious mammographic findings. In comparison to projection mammography, tomosynthesis shows an at least comparable diagnostic accuracy. In everyday practice, tomosynthesis is currently mostly used for further evaluation of suspicious findings in mammography.

  10. Automated 3D Scenes Reconstruction Using Multiple Stereo Pairs from Portable Four-Camera Photographic Measurement System

    Directory of Open Access Journals (Sweden)

    Qi Peng

    2015-01-01

    Full Text Available An effective automatic 3D reconstruction method using a portable four-camera photographic measurement system (PFCPMS is proposed. By taking advantage of the complementary stereo information from four cameras, a fast and highly accurate feature point matching algorithm is developed for 3D reconstruction. Specifically, we first utilize a projection method to obtain a large number of dense feature points. And then a reduction and clustering treatment is applied to simplify the Delaunay triangulation process and reconstruct a 3D model for each scene. In addition, a 3D model stitching approach is proposed to further improve the performance of the limited field-of-view for image-based method. The experimental results tested on the 172 cave in Mogao Grottoes indicate that the proposed method is effective to reconstruct a 3D scene with a low-cost four-camera photographic measurement system.

  11. Compressed sensing reconstruction for whole-heart imaging with 3D radial trajectories: a graphics processing unit implementation.

    Science.gov (United States)

    Nam, Seunghoon; Akçakaya, Mehmet; Basha, Tamer; Stehning, Christian; Manning, Warren J; Tarokh, Vahid; Nezafat, Reza

    2013-01-01

    A disadvantage of three-dimensional (3D) isotropic acquisition in whole-heart coronary MRI is the prolonged data acquisition time. Isotropic 3D radial trajectories allow undersampling of k-space data in all three spatial dimensions, enabling accelerated acquisition of the volumetric data. Compressed sensing (CS) reconstruction can provide further acceleration in the acquisition by removing the incoherent artifacts due to undersampling and improving the image quality. However, the heavy computational overhead of the CS reconstruction has been a limiting factor for its application. In this article, a parallelized implementation of an iterative CS reconstruction method for 3D radial acquisitions using a commercial graphics processing unit is presented. The execution time of the graphics processing unit-implemented CS reconstruction was compared with that of the C++ implementation, and the efficacy of the undersampled 3D radial acquisition with CS reconstruction was investigated in both phantom and whole-heart coronary data sets. Subsequently, the efficacy of CS in suppressing streaking artifacts in 3D whole-heart coronary MRI with 3D radial imaging and its convergence properties were studied. The CS reconstruction provides improved image quality (in terms of vessel sharpness and suppression of noise-like artifacts) compared with the conventional 3D gridding algorithm, and the graphics processing unit implementation greatly reduces the execution time of CS reconstruction yielding 34-54 times speed-up compared with C++ implementation. PMID:22392604

  12. Calibration target reconstruction for 3-D vision inspection system of large-scale engineering objects

    Science.gov (United States)

    Yin, Yongkai; Peng, Xiang; Guan, Yingjian; Liu, Xiaoli; Li, Ameng

    2010-11-01

    It is usually difficult to calibrate the 3-D vision inspection system that may be employed to measure the large-scale engineering objects. One of the challenges is how to in-situ build-up a large and precise calibration target. In this paper, we present a calibration target reconstruction strategy to solve such a problem. First, we choose one of the engineering objects to be inspected as a calibration target, on which we paste coded marks on the object surface. Next, we locate and decode marks to get homologous points. From multiple camera images, the fundamental matrix between adjacent images can be estimated, and then the essential matrix can be derived with priori known camera intrinsic parameters and decomposed to obtain camera extrinsic parameters. Finally, we are able to obtain the initial 3D coordinates with binocular stereo vision reconstruction, and then optimize them with the bundle adjustment by considering the lens distortions, leading to a high-precision calibration target. This reconstruction strategy has been applied to the inspection of an industrial project, from which the proposed method is successfully validated.

  13. Volumetric Next-best-view Planning for 3D Object Reconstruction with Positioning Error

    Directory of Open Access Journals (Sweden)

    J. Irving Vasquez-Gomez

    2014-10-01

    Full Text Available Three-dimensional (3D object reconstruction is the process of building a 3D model of a real object. This task is performed by taking several scans of an object from different locations (views. Due to the limited field of view of the sensor and the object’s self-occlusions, it is a difficult problem to solve. In addition, sensor positioning by robots is not perfect, making the actual view different from the expected one. We propose a next best view (NBV algorithm that determines each view to reconstruct an arbitrary object. Furthermore, we propose a method to deal with the uncertainty in sensor positioning. The algorithm fulfills all the constraints of a reconstruction process, such as new information, positioning constraints, sensing constraints and registration constraints. Moreover, it improves the scan’s quality and reduces the navigation distance. The algorithm is based on a search-based paradigm where a set of candidate views is generated and then each candidate view is evaluated to determine which one is the best. To deal with positioning uncertainty, we propose a second stage which re-evaluates the views according to their neighbours, such that the best view is that which is within a region of the good views. The results of simulation and comparisons with previous approaches are presented.

  14. 3D reconstruction in PET cameras with irregular sampling and depth of interaction

    International Nuclear Information System (INIS)

    We present 3D reconstruction algorithms that address fully 3D tomographic reconstruction using septa-less, stationary, and rectangular cameras. The field of view (FOV) encompasses the entire volume enclosed by detector modules capable of measuring depth of interaction (DOI). The Filtered Backprojection based algorithms incorporate DOI, accommodate irregular sampling, and minimize interpolation in the data by defining lines of response between the measured interaction points. We use fixed-width, evenly spaced radial bins in order to use the FFT, but use irregular angular sampling to minimize the number of unnormalizable zero efficiency sinogram bins. To address persisting low efficiency bins, we perform 2D nearest neighbor radial smoothing, employ a semi-iterative procedure to estimate the unsampled data, and mash the ''in plane'' and the first oblique projections to reconstruct the 2D image in the 3DRP algorithm. We present artifact free, essentially spatially isotropic images of Monte Carlo data with FWHM resolutions o 1.50 mm. 2.25 mm, and 3.00 mm at the center, in the bulk, and at the edges and corners of the FOV respectively

  15. Acceleration of EM-Based 3D CT Reconstruction Using FPGA.

    Science.gov (United States)

    Choi, Young-Kyu; Cong, Jason

    2016-06-01

    Reducing radiation doses is one of the key concerns in computed tomography (CT) based 3D reconstruction. Although iterative methods such as the expectation maximization (EM) algorithm can be used to address this issue, applying this algorithm to practice is difficult due to the long execution time. Our goal is to decrease this long execution time to an order of a few minutes, so that low-dose 3D reconstruction can be performed even in time-critical events. In this paper we introduce a novel parallel scheme that takes advantage of numerous block RAMs on field-programmable gate arrays (FPGAs). Also, an external memory bandwidth reduction strategy is presented to reuse both the sinogram and the voxel intensity. Moreover, a customized processing engine based on the FPGA is presented to increase overall throughput while reducing the logic consumption. Finally, a hardware and software flow is proposed to quickly construct a design for various CT machines. The complete reconstruction system is implemented on an FPGA-based server-class node. Experiments on actual patient data show that a 26.9 × speedup can be achieved over a 16-thread multicore CPU implementation. PMID:26462240

  16. Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

    Energy Technology Data Exchange (ETDEWEB)

    Dhillon, Shweta; Kant, Rama, E-mail: rkant@chemistry.du.ac.in

    2013-10-01

    Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

  17. 3D tracking the Brownian motion of colloidal particles using digital holographic microscopy and joint reconstruction

    CERN Document Server

    Verrier, Nicolas; Fournel, Thierry

    2015-01-01

    In-line digital holography is a valuable tool for sizing, locating and tracking micro- or nano-objects in a volume. When a parametric imaging model is available, Inverse Problems approaches provide a straightforward estimate of the object parameters by fitting data with the model, thereby allowing accurate reconstruction. As recently proposed and demonstrated, combining pixel super-resolution techniques with Inverse Problems approaches improves the estimation of particle size and 3D-position. Here we demonstrate the accurate tracking of colloidal particles in Brownian motion. Particle size and 3D-position are jointly optimized from video holograms acquired with a digital holographic microscopy set up based on a "low-end" microscope objective ($\\times 20$, $\\rm NA\\ 0.5$). Exploiting information redundancy makes it possible to characterize particles with a standard deviation of 15 nm in size and a theoretical resolution of 2 x 2 x 5 nm$^3$ for position under additive white Gaussian noise assumption.

  18. 3D Reconstruction of Coronal Loops by the Principal Component Analysis

    Directory of Open Access Journals (Sweden)

    Erwin Verwichte

    2013-10-01

    Full Text Available Knowing the three dimensional structure of plasma filaments in the uppermost part of the solar atmosphere, known as coronal loops, and especially their length, is an important parameter in the wave-based diagnostics of this part of the Sun. The combination of observations of the Sun from different points of observations in space, thanks to the most recent missions, including the Solar Dynamics Observatory (SDO and the Solar TErrestrial RElations Observatory (STEREO, allows us to infer information about the geometrical shape of coronal loops in 3D space. Here, we propose a new method to reconstruct the loop shape starting from stereoscopically determined 3D points, which sample the loop length, by principal component analysis. This method is shown to retrieve in an easy way the main parameters that define the loop, e.g., the minor and major axes, the loop plane, the azimuthal and inclination angles, for the special case of a coplanar loop.

  19. New Virtual Cutting Algorithms for 3D Surface Model Reconstructed from Medical Images

    Institute of Scientific and Technical Information of China (English)

    WANG Wei-hong; QIN Xu-Jia

    2006-01-01

    This paper proposes a practical algorithms of plane cutting, stereo clipping and arbitrary cutting for 3D surface model reconstructed from medical images. In plane cutting and stereo clipping algorithms, the 3D model is cut by plane or polyhedron. Lists of edge and vertex in every cut plane are established. From these lists the boundary contours are created and their relationship of embrace is ascertained. The region closed by the contours is triangulated using Delaunay triangulation algorithm. Arbitrary cutting operation creates cutting curve interactively.The cut model still maintains its correct topology structure. With these operations,tissues inside can be observed easily and it can aid doctors to diagnose. The methods can also be used in surgery planning of radiotherapy.

  20. 3D reconstruction in laparoscopy with close-range photometric stereo.

    Science.gov (United States)

    Collins, Toby; Bartoli, Adrien

    2012-01-01

    In this paper we present the first solution to 3D reconstruction in monocular laparoscopy using methods based on Photometric Stereo (PS). Our main contributions are to provide the new theory and practical solutions to successfully apply PS in close-range imaging conditions. We are specifically motivated by a solution with minimal hardware modification to existing laparoscopes. In fact the only physical modification we make is to adjust the colour of the laparoscope's illumination via three colour filters placed at its tip. Once calibrated, our approach can compute 3D from a single image, does not require correspondence estimation, and computes absolute depth densely. We demonstrate the potential of our approach with ground truth ex-vivo and in-vivo experimentation. PMID:23286102

  1. 3D reconstruction of hollow parts analyzing images acquired by a fiberscope

    International Nuclear Information System (INIS)

    A modified fiberscope used to reconstruct difficult-to-reach inner structures is presented. By substituting the fiberscope’s original illumination system, we can project a profile-revealing light line inside the object of study. The light line is obtained using a sandwiched power light-emitting diode (LED) attached to an extension arm on the tip of the fiberscope. Profile images from the interior of the object are then captured by a camera attached to the fiberscope’s eyepiece. Using a series of those images at different positions, the system is capable of generating a 3D reconstruction of the object with submillimeter accuracy. Also proposed is the use of a combination of known filters to remove the honeycomb structures produced by the fiberscope and the use of ring gages to obtain the extrinsic parameters of the camera attached to the fiberscope and the metrological traceability of the system. Several standard ring diameter measurements were compared against their certified values to improve the accuracy of the system. To exemplify an application, a 3D reconstruction of the interior of a refrigerator duct was conducted. This reconstruction includes accuracy assessment by comparing the measurements of the system to a coordinate measuring machine. The system, as described, is capable of 3D reconstruction of the interior of objects with uniform and non-uniform profiles from 10 to 60 mm in transversal dimensions and a depth of 1000 mm if the material of the walls of the object is translucent and allows the detection of the power LED light from the exterior through the wall. If this is not possible, we propose the use of a magnetic scale which reduces the working depth to 170 mm. The assessed accuracy is around ±0.15 mm in 2D cross-section reconstructions and ±1.3 mm in 1D position using a magnetic scale, and ±0.5 mm using a CCD camera. (paper)

  2. Grammar-Supported 3d Indoor Reconstruction from Point Clouds for As-Built Bim

    Science.gov (United States)

    Becker, S.; Peter, M.; Fritsch, D.

    2015-03-01

    The paper presents a grammar-based approach for the robust automatic reconstruction of 3D interiors from raw point clouds. The core of the approach is a 3D indoor grammar which is an extension of our previously published grammar concept for the modeling of 2D floor plans. The grammar allows for the modeling of buildings whose horizontal, continuous floors are traversed by hallways providing access to the rooms as it is the case for most office buildings or public buildings like schools, hospitals or hotels. The grammar is designed in such way that it can be embedded in an iterative automatic learning process providing a seamless transition from LOD3 to LOD4 building models. Starting from an initial low-level grammar, automatically derived from the window representations of an available LOD3 building model, hypotheses about indoor geometries can be generated. The hypothesized indoor geometries are checked against observation data - here 3D point clouds - collected in the interior of the building. The verified and accepted geometries form the basis for an automatic update of the initial grammar. By this, the knowledge content of the initial grammar is enriched, leading to a grammar with increased quality. This higher-level grammar can then be applied to predict realistic geometries to building parts where only sparse observation data are available. Thus, our approach allows for the robust generation of complete 3D indoor models whose quality can be improved continuously as soon as new observation data are fed into the grammar-based reconstruction process. The feasibility of our approach is demonstrated based on a real-world example.

  3. TReMAP: Automatic 3D Neuron Reconstruction Based on Tracing, Reverse Mapping and Assembling of 2D Projections.

    Science.gov (United States)

    Zhou, Zhi; Liu, Xiaoxiao; Long, Brian; Peng, Hanchuan

    2016-01-01

    Efficient and accurate digital reconstruction of neurons from large-scale 3D microscopic images remains a challenge in neuroscience. We propose a new automatic 3D neuron reconstruction algorithm, TReMAP, which utilizes 3D Virtual Finger (a reverse-mapping technique) to detect 3D neuron structures based on tracing results on 2D projection planes. Our fully automatic tracing strategy achieves close performance with the state-of-the-art neuron tracing algorithms, with the crucial advantage of efficient computation (much less memory consumption and parallel computation) for large-scale images.

  4. Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera.

    Science.gov (United States)

    Motta, A; Guerra, A Del; Belcari, N; Moehrs, S; Panetta, D; Righi, S; Valentini, D

    2005-12-01

    At the University of Pisa we are building a PEM prototype, the YAP-PEM camera, consisting of two opposite 6 x 6 x 3 cm3 detector heads of 30 x 30 YAP:Ce finger crystals, 2 x 2 x 30 mm3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix {p(ij)}; therefore is highly time-consuming. We use the sparse and symmetry properties of the matrix {p(ij)} to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p(ij) value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p(ij) values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus, while the others lie outside. All of the possible p(ij) values are obtainable by tracking only the LORs of this nucleus. The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p(ij) values are computed and

  5. Cell volume and geometric parameters determination in living cells using confocal microscopy and 3D reconstruction

    OpenAIRE

    sprotocols

    2015-01-01

    Authors: David Hevia, Aida Rodriguez-Garcia, Marta Alonso-Gervós, Isabel Quirós-González, Henar M Cimadevilla, Carmen Gómez-Cordovés, Rosa M Sainz & Juan C Mayo ### Abstract The protocol reported here describes a simple, easy, fast and reproducible method aimed to know the geometric parameters of living cells based on confocal laser scanning microscopy combined with 3D reconstruction software. Briefly, the method is based on intrinsic fluorescence properties of acridine orange (AO...

  6. Cryptotomography: reconstructing 3D Fourier intensities from randomly oriented single-shot diffraction patterns

    CERN Document Server

    Loh, N D; Elser, V; Barty, A; Boutet, S; Bajt, S; Hajdu, J; Ekeberg, T; Maia, F R N C; Schulz, J; Seibert, M M; Iwan, B; Timneanu, N; Marchesini, S; Schlichting, I; Shoeman, R L; Lomb, L; Frank, M; Liang, M; Chapman, H N

    2010-01-01

    We reconstructed the 3D Fourier intensity distribution of mono-disperse prolate nano-particles using single-shot 2D coherent diffraction patterns collected at DESY's FLASH facility when a bright, coherent, ultrafast X-ray pulse intercepted individual particles of random, unmeasured orientations. This first experimental demonstration of cryptotomography extended the Expansion-Maximization-Compression (EMC) framework to accommodate unmeasured fluctuations in photon fluence and loss of data due to saturation or background scatter. This work is an important step towards realizing single-shot diffraction imaging of single biomolecules.

  7. Cryptotomography: Reconstructing 3D Fourier Intensities from Randomly Oriented Single-Shot Diffraction Patterns

    Science.gov (United States)

    Loh, N. D.; Bogan, M. J.; Elser, V.; Barty, A.; Boutet, S.; Bajt, S.; Hajdu, J.; Ekeberg, T.; Maia, F. R. N. C.; Schulz, J.; Seibert, M. M.; Iwan, B.; Timneanu, N.; Marchesini, S.; Schlichting, I.; Shoeman, R. L.; Lomb, L.; Frank, M.; Liang, M.; Chapman, H. N.

    2010-06-01

    We reconstructed the 3D Fourier intensity distribution of monodisperse prolate nanoparticles using single-shot 2D coherent diffraction patterns collected at DESY’s FLASH facility when a bright, coherent, ultrafast x-ray pulse intercepted individual particles of random, unmeasured orientations. This first experimental demonstration of cryptotomography extended the expansion-maximization-compression framework to accommodate unmeasured fluctuations in photon fluence and loss of data due to saturation or background scatter. This work is an important step towards realizing single-shot diffraction imaging of single biomolecules.

  8. 3D CAD model reconstruction of a human femur from MRI images

    Directory of Open Access Journals (Sweden)

    Benaissa EL FAHIME

    2013-05-01

    Full Text Available Medical practice and life sciences take full advantage of progress in engineering disciplines, in particular the computer assisted placement technique in hip surgery. This paper describes the three dimensional model reconstruction of human femur from MRI images. The developed program enables to obtain digital shape of 3D femur recognized by all CAD software and allows an accurate placement of the femoral component. This technic provides precise measurement of implant alignment during hip resurfacing or total hip arthroplasty, thereby reducing the risk of component mal-positioning and femoral neck notching.

  9. Molecular-Frame 3D Photoelectron Momentum Distributions by Tomographic Reconstruction

    DEFF Research Database (Denmark)

    Maurer, Jochen; Dimitrovski, Darko; Christensen, Lauge;

    2012-01-01

    Naphthalene molecules are fixed in space by a laser field and rotated, in 2° steps, over 180°. For each orientation, they are ionized by an intense, circularly polarized femtosecond laser pulse, and the 2D projection of the photoelectron momentum distribution is recorded. The molecular-frame 3D...... momentum distribution is obtained by tomographic reconstruction from all 90 projections. It reveals an anisotropic electron distribution, angularly shifted in the polarization plane, that is not accessible by the 2D momentum images. Our theoretical analysis shows that the magnitude of the angular shift...

  10. Incremental Multi-view 3D Reconstruction Starting from Two Images Taken by a Stereo Pair of Cameras

    Science.gov (United States)

    El hazzat, Soulaiman; Saaidi, Abderrahim; Karam, Antoine; Satori, Khalid

    2015-03-01

    In this paper, we present a new method for multi-view 3D reconstruction based on the use of a binocular stereo vision system constituted of two unattached cameras to initialize the reconstruction process. Afterwards , the second camera of stereo vision system (characterized by varying parameters) moves to capture more images at different times which are used to obtain an almost complete 3D reconstruction. The first two projection matrices are estimated by using a 3D pattern with known properties. After that, 3D scene points are recovered by triangulation of the matched interest points between these two images. The proposed approach is incremental. At each insertion of a new image, the camera projection matrix is estimated using the 3D information already calculated and new 3D points are recovered by triangulation from the result of the matching of interest points between the inserted image and the previous image. For the refinement of the new projection matrix and the new 3D points, a local bundle adjustment is performed. At first, all projection matrices are estimated, the matches between consecutive images are detected and Euclidean sparse 3D reconstruction is obtained. So, to increase the number of matches and have a more dense reconstruction, the Match propagation algorithm, more suitable for interesting movement of the camera, was applied on the pairs of consecutive images. The experimental results show the power and robustness of the proposed approach.

  11. 2D and 3D reconstructions in acousto-electric tomography

    KAUST Repository

    Kuchment, Peter

    2011-04-18

    We propose and test stable algorithms for the reconstruction of the internal conductivity of a biological object using acousto-electric measurements. Namely, the conventional impedance tomography scheme is supplemented by scanning the object with acoustic waves that slightly perturb the conductivity and cause the change in the electric potential measured on the boundary of the object. These perturbations of the potential are then used as the data for the reconstruction of the conductivity. The present method does not rely on \\'perfectly focused\\' acoustic beams. Instead, more realistic propagating spherical fronts are utilized, and then the measurements that would correspond to perfect focusing are synthesized. In other words, we use synthetic focusing. Numerical experiments with simulated data show that our techniques produce high-quality images, both in 2D and 3D, and that they remain accurate in the presence of high-level noise in the data. Local uniqueness and stability for the problem also hold. © 2011 IOP Publishing Ltd.

  12. GPS tomography: validation of reconstructed 3-D humidity fields with radiosonde profiles

    Directory of Open Access Journals (Sweden)

    M. Shangguan

    2013-09-01

    Full Text Available Water vapor plays an important role in meteorological applications; GeoForschungsZentrum (GFZ therefore developed a tomographic system to derive 3-D distributions of the tropospheric water vapor above Germany using GPS data from about 300 ground stations. Input data for the tomographic reconstructions are generated by the Earth Parameter and Orbit determination System (EPOS software of the GFZ, which provides zenith total delay (ZTD, integrated water vapor (IWV and slant total delay (STD data operationally with a temporal resolution of 2.5 min (STD and 15 min (ZTD, IWV. The water vapor distribution in the atmosphere is derived by tomographic reconstruction techniques. The quality of the solution is dependent on many factors such as the spatial coverage of the atmosphere with slant paths, the spatial distribution of their intersections and the accuracy of the input observations. Independent observations are required to validate the tomographic reconstructions and to get precise information on the accuracy of the derived 3-D water vapor fields. To determine the quality of the GPS tomography, more than 8000 vertical water vapor profiles at 13 German radiosonde stations were used for the comparison. The radiosondes were launched twice a day (at 00:00 UTC and 12:00 UTC in 2007. In this paper, parameters of the entire profiles such as the wet refractivity, and the zenith wet delay have been compared. Before the validation the temporal and spatial distribution of the slant paths, serving as a basis for tomographic reconstruction, as well as their angular distribution were studied. The mean wet refractivity differences between tomography and radiosonde data for all points vary from −1.3 to 0.3, and the root mean square is within the range of 6.5–9. About 32% of 6803 profiles match well, 23% match badly and 45% are difficult to classify as they match only in parts.

  13. GPS tomography. Validation of reconstructed 3-D humidity fields with radiosonde profiles

    Energy Technology Data Exchange (ETDEWEB)

    Shangguan, M.; Bender, M.; Ramatschi, M.; Dick, G.; Wickert, J. [Helmholtz Centre Potsdam, German Research Centre for Geosciences (GFZ), Potsdam (Germany); Raabe, A. [Leipzig Institute for Meteorology (LIM), Leipzig (Germany); Galas, R. [Technische Univ. Berlin (Germany). Dept. for Geodesy and Geoinformation Sciences

    2013-11-01

    Water vapor plays an important role in meteorological applications; GeoForschungsZentrum (GFZ) therefore developed a tomographic system to derive 3-D distributions of the tropospheric water vapor above Germany using GPS data from about 300 ground stations. Input data for the tomographic reconstructions are generated by the Earth Parameter and Orbit determination System (EPOS) software of the GFZ, which provides zenith total delay (ZTD), integrated water vapor (IWV) and slant total delay (STD) data operationally with a temporal resolution of 2.5 min (STD) and 15 min (ZTD, IWV). The water vapor distribution in the atmosphere is derived by tomographic reconstruction techniques. The quality of the solution is dependent on many factors such as the spatial coverage of the atmosphere with slant paths, the spatial distribution of their intersections and the accuracy of the input observations. Independent observations are required to validate the tomographic reconstructions and to get precise information on the accuracy of the derived 3-D water vapor fields. To determine the quality of the GPS tomography, more than 8000 vertical water vapor profiles at 13 German radiosonde stations were used for the comparison. The radiosondes were launched twice a day (at 00:00 UTC and 12:00 UTC) in 2007. In this paper, parameters of the entire profiles such as the wet refractivity, and the zenith wet delay have been compared. Before the validation the temporal and spatial distribution of the slant paths, serving as a basis for tomographic reconstruction, as well as their angular distribution were studied. The mean wet refractivity differences between tomography and radiosonde data for all points vary from -1.3 to 0.3, and the root mean square is within the range of 6.5-9. About 32% of 6803 profiles match well, 23% match badly and 45% are difficult to classify as they match only in parts.

  14. Implementation of a close range photogrammetric system for 3D reconstruction of a scoliotic torso

    Science.gov (United States)

    Detchev, Ivan Denislavov

    Scoliosis is a deformity of the human spine most commonly encountered with children. After being detected, periodic examinations via x-rays are traditionally used to measure its progression. However, due to the increased risk of cancer, a non-invasive and radiation-free scoliosis detection and progression monitoring methodology is needed. Quantifying the scoliotic deformity through the torso surface is a valid alternative, because of its high correlation with the internal spine curvature. This work proposes a low-cost multi-camera photogrammetric system for semi-automated 3D reconstruction of a torso surface with sub-millimetre level accuracy. The thesis describes the system design and calibration for optimal accuracy. It also covers the methodology behind the reconstruction and registration procedures. The experimental results include the complete reconstruction of a scoliotic torso mannequin. The final accuracy is evaluated through the goodness of fit between the reconstructed surface and a more accurate set of points measured by a coordinate measuring machine.

  15. Linear stratified approach using full geometric constraints for 3D scene reconstruction and camera calibration.

    Science.gov (United States)

    Kim, Jae-Hean; Koo, Bon-Ki

    2013-02-25

    This paper presents a new linear framework to obtain 3D scene reconstruction and camera calibration simultaneously from uncalibrated images using scene geometry. Our strategy uses the constraints of parallelism, coplanarity, colinearity, and orthogonality. These constraints can be obtained in general man-made scenes frequently. This approach can give more stable results with fewer images and allow us to gain the results with only linear operations. In this paper, it is shown that all the geometric constraints used in the previous works performed independently up to now can be implemented easily in the proposed linear method. The study on the situations that cannot be dealt with by the previous approaches is also presented and it is shown that the proposed method being able to handle the cases is more flexible in use. The proposed method uses a stratified approach, in which affine reconstruction is performed first and then metric reconstruction. In this procedure, the additional constraints newly extracted in this paper have an important role for affine reconstruction in practical situations.

  16. Reconstruction Error of Calibration Volume’s Coordinates for 3D Swimming Kinematics

    Science.gov (United States)

    Figueiredo, Pedro; Machado, Leandro; Vilas-Boas, João Paulo; Fernandes, Ricardo J.

    2011-01-01

    The aim of this study was to investigate the accuracy and reliability of above and underwater 3D reconstruction of three calibration volumes with different control points disposal (#1 - on vertical and horizontal rods; #2 - on vertical and horizontal rods and facets; #3 - on crossed horizontal rods). Each calibration volume (3 × 2 × 3 m) was positioned in a 25 m swimming pool (half above and half below the water surface) and recorded with four underwater and two above water synchronised cameras (50 Hz). Reconstruction accuracy was determined calculating the RMS error of twelve validation points. The standard deviation across all digitisation of the same marker was used for assessing the reliability estimation. Comparison among different number of control points showed that the set of 24 points produced the most accurate results. The volume #2 presented higher accuracy (RMS errors: 5.86 and 3.59 mm for x axis, 3.45 and 3.11 mm for y axis and 4.38 and 4.00 mm for z axis, considering under and above water, respectively) and reliability (SD: underwater cameras ± [0.2; 0.6] mm; above water cameras ± [0.2; 0.3] mm) that may be considered suitable for 3D swimming kinematic analysis. Results revealed that RMS error was greater during underwater analysis, possibly due to refraction. PMID:23486761

  17. Reconstructing 3D coastal cliffs from airborne oblique photographs without ground control points

    Science.gov (United States)

    Dewez, T. J. B.

    2014-05-01

    Coastal cliff collapse hazard assessment requires measuring cliff face topography at regular intervals. Terrestrial laser scanner techniques have proven useful so far but are expensive to use either through purchasing the equipment or through survey subcontracting. In addition, terrestrial laser surveys take time which is sometimes incompatible with the time during with the beach is accessible at low-tide. By comparison, structure from motion techniques (SFM) are much less costly to implement, and if airborne, acquisition of several kilometers of coastline can be done in a matter of minutes. In this paper, the potential of GPS-tagged oblique airborne photographs and SFM techniques is examined to reconstruct chalk cliff dense 3D point clouds without Ground Control Points (GCP). The focus is put on comparing the relative 3D point of views reconstructed by Visual SFM with their synchronous Solmeta Geotagger Pro2 GPS locations using robust estimators. With a set of 568 oblique photos, shot from the open door of an airplane with a triplet of synchronized Nikon D7000, GPS and SFM-determined view point coordinates converge to X: ±31.5 m; Y: ±39.7 m; Z: ±13.0 m (LE66). Uncertainty in GPS position affects the model scale, angular attitude of the reference frame (the shoreline ends up tilted by 2°) and absolute positioning. Ground Control Points cannot be avoided to orient such models.

  18. MULTIPARAMETER MEASUREMENT FOR RACEWAY GROOVE OF BEARING BASED ON 3D RECONSTRUCTION WITH DIGITAL STRUCTURED LIGHT

    Institute of Scientific and Technical Information of China (English)

    He Tao; Zhong Ming; Li Wei; Zhong Yuning; Shi Tielin

    2005-01-01

    A fast 3D reconstruction method based on structured light to measure various parameters of the raceway groove is presented. Digital parallel grating stripes distributed with sine density are projected onto the raceway groove by a DLP projector, and distorting of stripes is happened on the raceway. Simultaneously, aided by three-step phase-shifting approach, three images covered by different stripes are obtained by a high-resolution CCD camera at the same location, thus a more accuracy local topography can be obtained. And then the bearing is rotated on a high precision computer controlled rotational stage. Three images are also obtained as the former step at next planned location triggered by the motor. After one cycle, all images information is combined through the mosaics. As a result, the 3D information of raceway groove can be gained. Not only geometric properties but also surface flaws can be extracted by software. A preliminary hardware system has been built, with which some geometric parameters have been extracted from reconstructed local topography.

  19. A 3D endoscopy reconstruction as a saliency map for analysis of polyp shapes

    Science.gov (United States)

    Ruano, Josue; Martínez, Fabio; Gómez, Martín.; Romero, Eduardo

    2015-01-01

    A first diagnosis of colorectal cancer is performed by examination of polyp shape and appearance during an endoscopy routine procedure. However, the video-endoscopy is highly noisy because exacerbated physiological conditions like increased motility or secretion may limit the visual analysis of lesions. In this work a 3D reconstruction of the digestive tract is proposed, facilitating the polyp shape evaluation by highlighting its surface geometry and allowing an analysis from different perspectives. The method starts by a spatio-temporal map, constructed to group the different regions of the tract by their similar dynamic patterns during the sequence. Then, such map was convolved with a second derivative of a Gaussian kernel that emulates the camera distortion and allows to highlight the polyp surface. The position initialization in each frame of the kernel was computed from expert manual delineation and propagated along the sequence based on. Results show reliable reconstructions, with a salient 3D polyp structure that can then be better observed.

  20. Stereo-vision and 3D reconstruction for nuclear mobile robots

    International Nuclear Information System (INIS)

    In order to perceive the geometric structure of the surrounding environment of a mobile robot, a 3D reconstruction system has been developed. Its main purpose is to provide geometric information to an operator who has to telepilot the vehicle in a nuclear power plant. The perception system is split into two parts: the vision part and the map building part. Vision is enhanced with a fusion process that rejects bas samples over space and time. The vision is based on trinocular stereo-vision which provides a range image of the image contours. It performs line contour correlation on horizontal image pairs and vertical image pairs. The results are then spatially fused in order to have one distance image, with a quality independent of the orientation of the contour. The 3D reconstruction is based on grid-based sensor fusion. As the robot moves and perceives its environment, distance data is accumulated onto a regular square grid, taking into account the uncertainty of the sensor through a sensor measurement statistical model. This approach allows both spatial and temporal fusion. Uncertainty due to sensor position and robot position is also integrated into the absolute local map. This system is modular and generic and can integrate 2D laser range finder and active vision. (author)

  1. On the 3-D reconstruction of Coronal Mass Ejections using coronagraph data

    Directory of Open Access Journals (Sweden)

    M. Mierla

    2010-01-01

    Full Text Available Coronal Mass ejections (CMEs are enormous eruptions of magnetized plasma expelled from the Sun into the interplanetary space, over the course of hours to days. They can create major disturbances in the interplanetary medium and trigger severe magnetic storms when they collide with the Earth's magnetosphere. It is important to know their real speed, propagation direction and 3-D configuration in order to accurately predict their arrival time at the Earth. Using data from the SECCHI coronagraphs onboard the STEREO mission, which was launched in October 2006, we can infer the propagation direction and the 3-D structure of such events. In this review, we first describe different techniques that were used to model the 3-D configuration of CMEs in the coronagraph field of view (up to 15 R⊙. Then, we apply these techniques to different CMEs observed by various coronagraphs. A comparison of results obtained from the application of different reconstruction algorithms is presented and discussed.

  2. AN IMAGE-BASED TECHNIQUE FOR 3D BUILDING RECONSTRUCTION USING MULTI-VIEW UAV IMAGES

    Directory of Open Access Journals (Sweden)

    F. Alidoost

    2015-12-01

    Full Text Available Nowadays, with the development of the urban areas, the automatic reconstruction of the buildings, as an important objects of the city complex structures, became a challenging topic in computer vision and photogrammetric researches. In this paper, the capability of multi-view Unmanned Aerial Vehicles (UAVs images is examined to provide a 3D model of complex building façades using an efficient image-based modelling workflow. The main steps of this work include: pose estimation, point cloud generation, and 3D modelling. After improving the initial values of interior and exterior parameters at first step, an efficient image matching technique such as Semi Global Matching (SGM is applied on UAV images and a dense point cloud is generated. Then, a mesh model of points is calculated using Delaunay 2.5D triangulation and refined to obtain an accurate model of building. Finally, a texture is assigned to mesh in order to create a realistic 3D model. The resulting model has provided enough details of building based on visual assessment.

  3. A new combined prior based reconstruction method for compressed sensing in 3D ultrasound imaging

    Science.gov (United States)

    Uddin, Muhammad S.; Islam, Rafiqul; Tahtali, Murat; Lambert, Andrew J.; Pickering, Mark R.

    2015-03-01

    Ultrasound (US) imaging is one of the most popular medical imaging modalities, with 3D US imaging gaining popularity recently due to its considerable advantages over 2D US imaging. However, as it is limited by long acquisition times and the huge amount of data processing it requires, methods for reducing these factors have attracted considerable research interest. Compressed sensing (CS) is one of the best candidates for accelerating the acquisition rate and reducing the data processing time without degrading image quality. However, CS is prone to introduce noise-like artefacts due to random under-sampling. To address this issue, we propose a combined prior-based reconstruction method for 3D US imaging. A Laplacian mixture model (LMM) constraint in the wavelet domain is combined with a total variation (TV) constraint to create a new regularization regularization prior. An experimental evaluation conducted to validate our method using synthetic 3D US images shows that it performs better than other approaches in terms of both qualitative and quantitative measures.

  4. Automatic Reconstruction of 3D Building Models from Terrestrial Laser Scanner Data

    Science.gov (United States)

    El Meouche, R.; Rezoug, M.; Hijazi, I.; Maes, D.

    2013-11-01

    With modern 3D laser scanners we can acquire a large amount of 3D data in only a few minutes. This technology results in a growing number of applications ranging from the digitalization of historical artifacts to facial authentication. The modeling process demands a lot of time and work (Tim Volodine, 2007). In comparison with the other two stages, the acquisition and the registration, the degree of automation of the modeling stage is almost zero. In this paper, we propose a new surface reconstruction technique for buildings to process the data obtained by a 3D laser scanner. These data are called a point cloud which is a collection of points sampled from the surface of a 3D object. Such a point cloud can consist of millions of points. In order to work more efficiently, we worked with simplified models which contain less points and so less details than a point cloud obtained in situ. The goal of this study was to facilitate the modeling process of a building starting from 3D laser scanner data. In order to do this, we wrote two scripts for Rhinoceros 5.0 based on intelligent algorithms. The first script finds the exterior outline of a building. With a minimum of human interaction, there is a thin box drawn around the surface of a wall. This box is able to rotate 360° around an axis in a corner of the wall in search for the points of other walls. In this way we can eliminate noise points. These are unwanted or irrelevant points. If there is an angled roof, the box can also turn around the edge of the wall and the roof. With the different positions of the box we can calculate the exterior outline. The second script draws the interior outline in a surface of a building. By interior outline we mean the outline of the openings like windows or doors. This script is based on the distances between the points and vector characteristics. Two consecutive points with a relative big distance will form the outline of an opening. Once those points are found, the interior outline

  5. AUTOMATIC MODEL SELECTION FOR 3D RECONSTRUCTION OF BUILDINGS FROM SATELLITE IMAGARY

    Directory of Open Access Journals (Sweden)

    T. Partovi

    2013-09-01

    Full Text Available Through the improvements of satellite sensor and matching technology, the derivation of 3D models from space borne stereo data obtained a lot of interest for various applications such as mobile navigation, urban planning, telecommunication, and tourism. The automatic reconstruction of 3D building models from space borne point cloud data is still an active research topic. The challenging problem in this field is the relatively low quality of the Digital Surface Model (DSM generated by stereo matching of satellite data comparing to airborne LiDAR data. In order to establish an efficient method to achieve high quality models and complete automation from the mentioned DSM, in this paper a new method based on a model-driven strategy is proposed. For improving the results, refined orthorectified panchromatic images are introduced into the process as additional data. The idea of this method is based on ridge line extraction and analysing height values in direction of and perpendicular to the ridgeline direction. After applying pre-processing to the orthorectified data, some feature descriptors are extracted from the DSM, to improve the automatic ridge line detection. Applying RANSAC a line is fitted to each group of ridge points. Finally these ridge lines are refined by matching them or closing gaps. In order to select the type of roof model the heights of point in extension of the ridge line and height differences perpendicular to the ridge line are analysed. After roof model selection, building edge information is extracted from canny edge detection and parameters derived from the roof parts. Then the best model is fitted to extracted façade roofs based on detected type of model. Each roof is modelled independently and final 3D buildings are reconstructed by merging the roof models with the corresponding walls.

  6. RECONSTRUCTION OF 3D VECTOR MODELS OF BUILDINGS BY COMBINATION OF ALS, TLS AND VLS DATA

    Directory of Open Access Journals (Sweden)

    H. Boulaassal

    2012-09-01

    Full Text Available Airborne Laser Scanning (ALS, Terrestrial Laser Scanning (TLS and Vehicle based Laser Scanning (VLS are widely used as data acquisition methods for 3D building modelling. ALS data is often used to generate, among others, roof models. TLS data has proven its effectiveness in the geometric reconstruction of building façades. Although the operating algorithms used in the processing chain of these two kinds of data are quite similar, their combination should be more investigated. This study explores the possibility of combining ALS and TLS data for simultaneously producing 3D building models from bird point of view and pedestrian point of view. The geometric accuracy of roofs and façades models is different due to the acquisition techniques. In order to take these differences into account, the surfaces composing roofs and façades are extracted with the same algorithm of segmentation. Nevertheless the segmentation algorithm must be adapted to the properties of the different point clouds. It is based on the RANSAC algorithm, but has been applied in a sequential way in order to extract all potential planar clusters from airborne and terrestrial datasets. Surfaces are fitted to planar clusters, allowing edge detection and reconstruction of vector polygons. Models resulting from TLS data are obviously more accurate than those generated from ALS data. Therefore, the geometry of the roofs is corrected and adapted according to the geometry of the corresponding façades. Finally, the effects of the differences between raw ALS and TLS data on the results of the modeling process are analyzed. It is shown that such combination could be used to produce reliable 3D building models.

  7. Ultra-fast digital tomosynthesis reconstruction using general-purpose GPU programming for image-guided radiation therapy.

    Science.gov (United States)

    Park, Justin C; Park, Sung Ho; Kim, Jin Sung; Han, Youngyih; Cho, Min Kook; Kim, Ho Kyung; Liu, Zhaowei; Jiang, Steve B; Song, Bongyong; Song, William Y

    2011-08-01

    The purpose of this work is to demonstrate an ultra-fast reconstruction technique for digital tomosynthesis (DTS) imaging based on the algorithm proposed by Feldkamp, Davis, and Kress (FDK) using standard general-purpose graphics processing unit (GPGPU) programming interface. To this end, the FDK-based DTS algorithm was programmed "in-house" with C language with utilization of 1) GPU and 2) central processing unit (CPU) cards. The GPU card consisted of 480 processing cores (2 x 240 dual chip) with 1,242 MHz processing clock speed and 1,792 MB memory space. In terms of CPU hardware, we used 2.68 GHz clock speed, 12.0 GB DDR3 RAM, on a 64-bit OS. The performance of proposed algorithm was tested on twenty-five patient cases (5 lung, 5 liver, 10 prostate, and 5 head-and-neck) scanned either with a full-fan or half-fan mode on our cone-beam computed tomography (CBCT) system. For the full-fan scans, the projections from 157.5°-202.5° (45°-scan) were used to reconstruct coronal DTS slices, whereas for the half-fan scans, the projections from both 157.5°-202.5° and 337.5°-22.5° (2 x 45°-scan) were used to reconstruct larger FOV coronal DTS slices. For this study, we chose 45°-scan angle that contained ~80 projections for the full-fan and ~160 projections with 2 x 45°-scan angle for the half-fan mode, each with 1024 x 768 pixels with 32-bit precision. Absolute pixel value differences, profiles, and contrast-to-noise ratio (CNR) calculations were performed to compare and evaluate the images reconstructed using GPU- and CPU-based implementations. The time dependence on the reconstruction volume was also tested with (512 x 512) x 16, 32, 64, 128, and 256 slices. In the end, the GPU-based implementation achieved, at most, 1.3 and 2.5 seconds to complete full reconstruction of 512 x 512 x 256 volume, for the full-fan and half-fan modes, respectively. In turn, this meant that our implementation can process > 13 projections-per-second (pps) and > 18 pps for the full

  8. 3D reconstruction and spatial auralization of the "Painted Dolmen" of Antelas

    Science.gov (United States)

    Dias, Paulo; Campos, Guilherme; Santos, Vítor; Casaleiro, Ricardo; Seco, Ricardo; Sousa Santos, Beatriz

    2008-02-01

    This paper presents preliminary results on the development of a 3D audiovisual model of the Anta Pintada (painted dolmen) of Antelas, a Neolithic chamber tomb located in Oliveira de Frades and listed as Portuguese national monument. The final aim of the project is to create a highly accurate Virtual Reality (VR) model of this unique archaeological site, capable of providing not only visual but also acoustic immersion based on its actual geometry and physical properties. The project started in May 2006 with in situ data acquisition. The 3D geometry of the chamber was captured using a Laser Range Finder. In order to combine the different scans into a complete 3D visual model, reconstruction software based on the Iterative Closest Point (ICP) algorithm was developed using the Visualization Toolkit (VTK). This software computes the boundaries of the room on a 3D uniform grid and populates its interior with "free-space nodes", through an iterative algorithm operating like a torchlight illuminating a dark room. The envelope of the resulting set of "free-space nodes" is used to generate a 3D iso-surface approximating the interior shape of the chamber. Each polygon of this surface is then assigned the acoustic absorption coefficient of the corresponding boundary material. A 3D audiovisual model operating in real-time was developed for a VR Environment comprising head-mounted display (HMD) I-glasses SVGAPro, an orientation sensor (tracker) InterTrax 2 with 3 Degrees Of Freedom (3DOF) and stereo headphones. The auralisation software is based on a geometric model. This constitutes a first approach, since geometric acoustics have well-known limitations in rooms with irregular surfaces. The immediate advantage lies in their inherent computational efficiency, which allows real-time operation. The program computes the early reflections forming the initial part of the chamber's impulse response (IR), which carry the most significant cues for source localisation. These early

  9. 3D-ANTLERS: Virtual Reconstruction and Three-Dimensional Measurement

    Science.gov (United States)

    Barba, S.; Fiorillo, F.; De Feo, E.

    2013-02-01

    The main objective of this paper is to establish a procedural method for measuring and cataloguing antlers through the use of laser scanner and of a 3D reconstruction of complex modeling. The deer's antlers have been used as a test and subjected to capture and measurement. For this purpose multiple data sources techniques have been studied and compared, (also considering low-cost sensors) estimating the accuracy and its errors in order to demonstrate the validity of the process. A further development is the comparison of results with applications of digital photogrammetry, considering also cloud computing software. The study has began with an introduction to sensors, addressing the underlying characteristics of the technology available, the scope and the limits of these applications. We have focused particularly on the "structured light", as the acquisition will be completed through three-dimensional scanners: DAVID and the ARTEC MH. The first is a low-cost sensor, a basic webcam and a linear laser pointer, red coloured, that leads to acquisition of three-dimensional strips. The other one is a hand scanner; even in this case we will explain how to represent a 3D model, with a pipeline that provides data export from the "proprietary" to a "reverse engineering" software. Typically, these are the common steps to the two approaches that have been performed in WRAP format: point sampling, manual and global registration, repair normals, surface editing and texture projection. In fact, after a first and common data processing was done with the use of a software supplied with the equipment, the proto-models thus obtained were treated in Geomagic Studio, which was also chosen to allow the homogenization and standardization of data in order to make a more objective comparison. It is commonplace to observe that the editing of the digital mock-up obtained with the DAVID - which had not yet been upgraded to the 3.5 release at the time of this study - is substantially different

  10. X-ray imaging and 3D reconstruction of in-flight exploding foil initiator flyers

    Science.gov (United States)

    Willey, T. M.; Champley, K.; Hodgin, R.; Lauderbach, L.; Bagge-Hansen, M.; May, C.; Sanchez, N.; Jensen, B. J.; Iverson, A.; van Buuren, T.

    2016-06-01

    Exploding foil initiators (EFIs), also known as slapper initiators or detonators, offer clear safety and timing advantages over other means of initiating detonation in high explosives. This work outlines a new capability for imaging and reconstructing three-dimensional images of operating EFIs. Flyer size and intended velocity were chosen based on parameters of the imaging system. The EFI metal plasma and plastic flyer traveling at 2.5 km/s were imaged with short ˜80 ps pulses spaced 153.4 ns apart. A four-camera system acquired 4 images from successive x-ray pulses from each shot. The first frame was prior to bridge burst, the 2nd images the flyer about 0.16 mm above the surface but edges of the foil and/or flyer are still attached to the substrate. The 3rd frame captures the flyer in flight, while the 4th shows a completely detached flyer in a position that is typically beyond where slappers strike initiating explosives. Multiple acquisitions at different incident angles and advanced computed tomography reconstruction algorithms were used to produce a 3-dimensional image of the flyer at 0.16 and 0.53 mm above the surface. Both the x-ray images and the 3D reconstruction show a strong anisotropy in the shape of the flyer and underlying foil parallel vs. perpendicular to the initiating current and electrical contacts. These results provide detailed flyer morphology during the operation of the EFI.

  11. 3D VIRTUAL RECONSTRUCTION OF AN URBAN HISTORICAL SPACE: A CONSIDERATION ON THE METHOD

    Directory of Open Access Journals (Sweden)

    M. Galizia

    2012-09-01

    Full Text Available Urban historical spaces are often characterized by a variety of shapes, geometries, volumes, materials. Their virtual reconstruction requires a critical approach in terms of acquired data's density, timing optimization, final product's quality and slimness. The research team has focused its attention on the study on Francesco Neglia square (previously named Saint Thomas square in Enna. This square is an urban space fronted by architectures which present historical and stylistic differences. For example you can find the Saint Thomas'church belfry (in aragounese-catalan stile dated XIV century and the porch, the Anime Sante baroque's church (XVII century, Saint Mary of the Grace's nunnery (XVIII century and as well as some civil buildings of minor importance built in the mid twentieth century. The research has compared two different modeling tools approaches: the first one is based on the construction of triangulated surfaces which are segmented and simplified; the second one is based on the detection of surfaces geometrical features, the extraction of the more significant profiles by using a software dedicated to the elaboration of cloud points and the subsequent mathematical reconstruction by using a 3d modelling software. The following step was aimed to process the virtual reconstruction of urban scene by assembling the single optimized models. This work highlighted the importance of the image of the operator and of its cultural contribution, essential to recognize geometries which generates surfaces in order to create high quality semantic models.

  12. THE PERFORMANCE EVALUATION OF MULTI-IMAGE 3D RECONSTRUCTION SOFTWARE WITH DIFFERENT SENSORS

    Directory of Open Access Journals (Sweden)

    V. Mousavi

    2015-12-01

    Full Text Available Today, multi-image 3D reconstruction is an active research field and generating three dimensional model of the objects is one the most discussed issues in Photogrammetry and Computer Vision that can be accomplished using range-based or image-based methods. Very accurate and dense point clouds generated by range-based methods such as structured light systems and laser scanners has introduced them as reliable tools in the industry. Image-based 3D digitization methodologies offer the option of reconstructing an object by a set of unordered images that depict it from different viewpoints. As their hardware requirements are narrowed down to a digital camera and a computer system, they compose an attractive 3D digitization approach, consequently, although range-based methods are generally very accurate, image-based methods are low-cost and can be easily used by non-professional users. One of the factors affecting the accuracy of the obtained model in image-based methods is the software and algorithm used to generate three dimensional model. These algorithms are provided in the form of commercial software, open source and web-based services. Another important factor in the accuracy of the obtained model is the type of sensor used. Due to availability of mobile sensors to the public, popularity of professional sensors and the advent of stereo sensors, a comparison of these three sensors plays an effective role in evaluating and finding the optimized method to generate three-dimensional models. Lots of research has been accomplished to identify a suitable software and algorithm to achieve an accurate and complete model, however little attention is paid to the type of sensors used and its effects on the quality of the final model. The purpose of this paper is deliberation and the introduction of an appropriate combination of a sensor and software to provide a complete model with the highest accuracy. To do this, different software, used in previous

  13. The Performance Evaluation of Multi-Image 3d Reconstruction Software with Different Sensors

    Science.gov (United States)

    Mousavi, V.; Khosravi, M.; Ahmadi, M.; Noori, N.; Naveh, A. Hosseini; Varshosaz, M.

    2015-12-01

    Today, multi-image 3D reconstruction is an active research field and generating three dimensional model of the objects is one the most discussed issues in Photogrammetry and Computer Vision that can be accomplished using range-based or image-based methods. Very accurate and dense point clouds generated by range-based methods such as structured light systems and laser scanners has introduced them as reliable tools in the industry. Image-based 3D digitization methodologies offer the option of reconstructing an object by a set of unordered images that depict it from different viewpoints. As their hardware requirements are narrowed down to a digital camera and a computer system, they compose an attractive 3D digitization approach, consequently, although range-based methods are generally very accurate, image-based methods are low-cost and can be easily used by non-professional users. One of the factors affecting the accuracy of the obtained model in image-based methods is the software and algorithm used to generate three dimensional model. These algorithms are provided in the form of commercial software, open source and web-based services. Another important factor in the accuracy of the obtained model is the type of sensor used. Due to availability of mobile sensors to the public, popularity of professional sensors and the advent of stereo sensors, a comparison of these three sensors plays an effective role in evaluating and finding the optimized method to generate three-dimensional models. Lots of research has been accomplished to identify a suitable software and algorithm to achieve an accurate and complete model, however little attention is paid to the type of sensors used and its effects on the quality of the final model. The purpose of this paper is deliberation and the introduction of an appropriate combination of a sensor and software to provide a complete model with the highest accuracy. To do this, different software, used in previous studies, were compared and

  14. The effect of angular dose distribution on the detection of microcalcifications in digital breast tomosynthesis

    OpenAIRE

    Hu, Yue-Houng; Zhao, Wei

    2011-01-01

    Purpose: Substantial effort has been devoted to the clinical development of digital breast tomosynthesis (DBT). DBT is a three-dimensional (3D) x-ray imaging modality that reconstructs a number of thin image slices parallel to a stationary detector plane. Preliminary clinical studies have shown that the removal of overlapping breast tissue reduces image clutter and increases detectability of large, low contrast lesions. However, some studies, as well as anecdotal evidence, suggested decreased...

  15. Clinical anatomy and 3D virtual reconstruction of the lumbar plexus with respect to lumbar surgery

    Directory of Open Access Journals (Sweden)

    Ding Zi-hai

    2011-04-01

    Full Text Available Abstract Background Exposure of the anterior or lateral lumbar via the retroperitoneal approach easily causes injuries to the lumbar plexus. Lumbar plexus injuries which occur during anterior or transpsoas lumbar spine exposure and placement of instruments have been reported. This study aims is to provide more anatomical data and surgical landmarks in operations concerning the lumbar plexus in order to prevent lumbar plexus injuries and to increase the possibility of safety in anterior approach lumbar surgery. Methods To study the applied anatomy related to the lumbar plexus of fifteen formaldehyde-preserved cadavers, Five sets of Virtual Human (VH data set were prepared and used in the study. Three-dimensional (3D computerized reconstructions of the lumbar plexus and their adjacent structures were conducted from the VH female data set. Results The order of lumbar nerves is regular. From the anterior view, lumbar plexus nerves are arranged from medial at L5 to lateral at L2. From the lateral view, lumbar nerves are arranged from ventral at L2 to dorsal at L5. The angle of each nerve root exiting outward to the corresponding intervertebral foramen increases from L1 to L5. The lumbar plexus nerves are observed to be in close contact with transverse processes (TP. All parts of the lumbar plexus were located by sectional anatomy in the dorsal third of the psoas muscle. Thus, access to the psoas major muscle at the ventral 2/3 region can safely prevent nerve injuries. 3D reconstruction of the lumbar plexus based on VCH data can clearly show the relationships between the lumbar plexus and the blood vessels, vertebral body, kidney, and psoas muscle. Conclusion The psoas muscle can be considered as a surgical landmark since incision at the ventral 2/3 of the region can prevent lumbar plexus injuries for procedures requiring exposure of the lateral anterior of the lumbar. The transverse process can be considered as a landmark and reference in surgical

  16. Inlining 3d Reconstruction, Multi-Source Texture Mapping and Semantic Analysis Using Oblique Aerial Imagery

    Science.gov (United States)

    Frommholz, D.; Linkiewicz, M.; Poznanska, A. M.

    2016-06-01

    This paper proposes an in-line method for the simplified reconstruction of city buildings from nadir and oblique aerial images that at the same time are being used for multi-source texture mapping with minimal resampling. Further, the resulting unrectified texture atlases are analyzed for façade elements like windows to be reintegrated into the original 3D models. Tests on real-world data of Heligoland/ Germany comprising more than 800 buildings exposed a median positional deviation of 0.31 m at the façades compared to the cadastral map, a correctness of 67% for the detected windows and good visual quality when being rendered with GPU-based perspective correction. As part of the process building reconstruction takes the oriented input images and transforms them into dense point clouds by semi-global matching (SGM). The point sets undergo local RANSAC-based regression and topology analysis to detect adjacent planar surfaces and determine their semantics. Based on this information the roof, wall and ground surfaces found get intersected and limited in their extension to form a closed 3D building hull. For texture mapping the hull polygons are projected into each possible input bitmap to find suitable color sources regarding the coverage and resolution. Occlusions are detected by ray-casting a full-scale digital surface model (DSM) of the scene and stored in pixel-precise visibility maps. These maps are used to derive overlap statistics and radiometric adjustment coefficients to be applied when the visible image parts for each building polygon are being copied into a compact texture atlas without resampling whenever possible. The atlas bitmap is passed to a commercial object-based image analysis (OBIA) tool running a custom rule set to identify windows on the contained façade patches. Following multi-resolution segmentation and classification based on brightness and contrast differences potential window objects are evaluated against geometric constraints and

  17. Analysis of bite marks in foodstuffs by computer tomography (cone beam CT)--3D reconstruction.

    Science.gov (United States)

    Marques, Jeidson; Musse, Jamilly; Caetano, Catarina; Corte-Real, Francisco; Corte-Real, Ana Teresa

    2013-12-01

    The use of three-dimensional (3D) analysis of forensic evidence is highlighted in comparison with traditional methods. This three-dimensional analysis is based on the registration of the surface from a bitten object. The authors propose to use Cone Beam Computed Tomography (CBCT), which is used in dental practice, in order to study the surface and interior of bitten objects and dental casts of suspects. In this study, CBCT is applied to the analysis of bite marks in foodstuffs, which may be found in a forensic case scenario. 6 different types of foodstuffs were used: chocolate, cheese, apple, chewing gum, pizza and tart (flaky pastry and custard). The food was bitten into and dental casts of the possible suspects were made. The dental casts and bitten objects were registered using an x-ray source and the CBCT equipment iCAT® (Pennsylvania, EUA). The software InVivo5® (Anatomage Inc, EUA) was used to visualize and analyze the tomographic slices and 3D reconstructions of the objects. For each material an estimate of its density was assessed by two methods: HU values and specific gravity. All the used materials were successfully reconstructed as good quality 3D images. The relative densities of the materials in study were compared. Amongst the foodstuffs, the chocolate had the highest density (median value 100.5 HU and 1,36 g/cm(3)), while the pizza showed to have the lowest (median value -775 HU and 0,39 g/cm(3)), on both scales. Through tomographic slices and three-dimensional reconstructions it was possible to perform the metric analysis of the bite marks in all the foodstuffs, except for the pizza. These measurements could also be obtained from the dental casts. The depth of the bite mark was also successfully determined in all the foodstuffs except for the pizza. Cone Beam Computed Tomography has the potential to become an important tool for forensic sciences, namely for the registration and analysis of bite marks in foodstuffs that may be found in a crime

  18. Design and performance of the prototype full field breast tomosynthesis system with selenium based flat panel detector

    Science.gov (United States)

    Ren, Baorui; Ruth, Chris; Stein, Jay; Smith, Andrew; Shaw, Ian; Jing, Zhenxue

    2005-04-01

    We have developed a breast tomosynthesis system utilizing a selenium-based direct conversion flat panel detector. This prototype system is a modification of Selenia, Hologic"s full field digital mammography system, using an add-on breast holding device to allow 3D tomosynthetic imaging. During a tomosynthesis scan, the breast is held stationary while the x-ray source and detector mounted on a c-arm rotate continuously around the breast over an angular range up to 30 degrees. The x-ray tube is pulsed to acquire 11 projections at desired c-arm angles. Images are reconstructed in planes parallel to the breastplate using a filtered backprojection algorithm. Processing time is typically 1 minute for a 50 mm thick breast at 0.1 mm in-plane pixel size, 1 mm slice-to-slice separation. Clinical studies are in progress. Performance evaluations were carried out at the system and the subsystem levels including spatial resolution, signal-to-noise ratio, spectra optimization, imaging technique, and phantom and patient studies. Experimental results show that we have successfully built a tomosynthesis system with images showing less structure noise and revealing 3D information compared with the conventional mammogram. We introduce, for the first time, the definition of "Depth of Field" for tomosynthesis based on a spatial resolution study. This parameter is used together with Modulation Transfer Function (MTF) to evaluate 3D resolution of a tomosynthesis system as a function of system design, imaging technique, and reconstruction algorithm. Findings from the on-going clinical studies will help the design of the next generation tomosynthesis system offering improved performance.

  19. Computer-aided detection of clustered microcalcifications in multiscale bilateral filtering regularized reconstructed digital breast tomosynthesis volume

    Energy Technology Data Exchange (ETDEWEB)

    Samala, Ravi K., E-mail: rsamala@umich.edu; Chan, Heang-Ping; Lu, Yao; Hadjiiski, Lubomir; Wei, Jun; Helvie, Mark A. [Department of Radiology, University of Michigan, Ann Arbor, Michigan 48109-5842 (United States); Sahiner, Berkman [Center for Devices and Radiological Health, U.S. Food and Drug Administration, Maryland 20993 (United States)

    2014-02-15

    Purpose: Develop a computer-aided detection (CADe) system for clustered microcalcifications in digital breast tomosynthesis (DBT) volume enhanced with multiscale bilateral filtering (MSBF) regularization. Methods: With Institutional Review Board approval and written informed consent, two-view DBT of 154 breasts, of which 116 had biopsy-proven microcalcification (MC) clusters and 38 were free of MCs, was imaged with a General Electric GEN2 prototype DBT system. The DBT volumes were reconstructed with MSBF-regularized simultaneous algebraic reconstruction technique (SART) that was designed to enhance MCs and reduce background noise while preserving the quality of other tissue structures. The contrast-to-noise ratio (CNR) of MCs was further improved with enhancement-modulated calcification response (EMCR) preprocessing, which combined multiscale Hessian response to enhance MCs by shape and bandpass filtering to remove the low-frequency structured background. MC candidates were then located in the EMCR volume using iterative thresholding and segmented by adaptive region growing. Two sets of potential MC objects, cluster centroid objects and MC seed objects, were generated and the CNR of each object was calculated. The number of candidates in each set was controlled based on the breast volume. Dynamic clustering around the centroid objects grouped the MC candidates to form clusters. Adaptive criteria were designed to reduce false positive (FP) clusters based on the size, CNR values and the number of MCs in the cluster, cluster shape, and cluster based maximum intensity projection. Free-response receiver operating characteristic (FROC) and jackknife alternative FROC (JAFROC) analyses were used to assess the performance and compare with that of a previous study. Results: Unpaired two-tailedt-test showed a significant increase (p < 0.0001) in the ratio of CNRs for MCs with and without MSBF regularization compared to similar ratios for FPs. For view-based detection, a

  20. Computer-aided detection of clustered microcalcifications in multiscale bilateral filtering regularized reconstructed digital breast tomosynthesis volume

    International Nuclear Information System (INIS)

    Purpose: Develop a computer-aided detection (CADe) system for clustered microcalcifications in digital breast tomosynthesis (DBT) volume enhanced with multiscale bilateral filtering (MSBF) regularization. Methods: With Institutional Review Board approval and written informed consent, two-view DBT of 154 breasts, of which 116 had biopsy-proven microcalcification (MC) clusters and 38 were free of MCs, was imaged with a General Electric GEN2 prototype DBT system. The DBT volumes were reconstructed with MSBF-regularized simultaneous algebraic reconstruction technique (SART) that was designed to enhance MCs and reduce background noise while preserving the quality of other tissue structures. The contrast-to-noise ratio (CNR) of MCs was further improved with enhancement-modulated calcification response (EMCR) preprocessing, which combined multiscale Hessian response to enhance MCs by shape and bandpass filtering to remove the low-frequency structured background. MC candidates were then located in the EMCR volume using iterative thresholding and segmented by adaptive region growing. Two sets of potential MC objects, cluster centroid objects and MC seed objects, were generated and the CNR of each object was calculated. The number of candidates in each set was controlled based on the breast volume. Dynamic clustering around the centroid objects grouped the MC candidates to form clusters. Adaptive criteria were designed to reduce false positive (FP) clusters based on the size, CNR values and the number of MCs in the cluster, cluster shape, and cluster based maximum intensity projection. Free-response receiver operating characteristic (FROC) and jackknife alternative FROC (JAFROC) analyses were used to assess the performance and compare with that of a previous study. Results: Unpaired two-tailedt-test showed a significant increase (p < 0.0001) in the ratio of CNRs for MCs with and without MSBF regularization compared to similar ratios for FPs. For view-based detection, a

  1. A new multiresolution method applied to the 3D reconstruction of small bodies

    Science.gov (United States)

    Capanna, C.; Jorda, L.; Lamy, P. L.; Gesquiere, G.

    2012-12-01

    The knowledge of the three-dimensional (3D) shape of small solar system bodies, such as asteroids and comets, is essential in determining their global physical properties (volume, density, rotational parameters). It also allows performing geomorphological studies of their surface through the characterization of topographic features, such as craters, faults, landslides, grooves, hills, etc.. In the case of small bodies, the shape is often only constrained by images obtained by interplanetary spacecrafts. Several techniques are available to retrieve 3D global shapes from these images. Stereography which relies on control points has been extensively used in the past, most recently to reconstruct the nucleus of comet 9P/Tempel 1 [Thomas (2007)]. The most accurate methods are however photogrammetry and photoclinometry, often used in conjunction with stereography. Stereophotogrammetry (SPG) has been used to reconstruct the shapes of the nucleus of comet 19P/Borrelly [Oberst (2004)] and of the asteroid (21) Lutetia [Preusker (2012)]. Stereophotoclinometry (SPC) has allowed retrieving an accurate shape of the asteroids (25143) Itokawa [Gaskell (2008)] and (2867) Steins [Jorda (2012)]. We present a new photoclinometry method based on the deformation of a 3D triangular mesh [Capanna (2012)] using a multi-resolution scheme which starts from a sphere of 300 facets and yields a shape model with 100; 000 facets. Our strategy is inspired by the "Full Multigrid" method [Botsch (2007)] and consists in going alternatively between two resolutions in order to obtain an optimized shape model at a given resolution before going to the higher resolution. In order to improve the robustness of our method, we use a set of control points obtained by stereography. Our method has been tested on images acquired by the OSIRIS visible camera, aboard the Rosetta spacecraft of the European Space Agency, during the fly-by of asteroid (21) Lutetia in July 2010. We present the corresponding 3D shape

  2. Operator-free, film-based 3D seed reconstruction in brachytherapy

    International Nuclear Information System (INIS)

    In brachytherapy implants, the accuracy of dose calculation depends on the ability to localize radioactive sources correctly. If performed manually using planar images, this is a time-consuming and often error-prone process - primarily because each seed must be identified on (at least) two films. In principle, three films should allow automatic seed identification and position reconstruction; however, practical implementation of the numerous algorithms proposed so far appears to have only limited reliability. The motivation behind this work is to create a fast and reliable system for real-time implant evaluation using digital planar images obtained from radiotherapy simulators, or mobile x-ray/fluoroscopy systems. We have developed algorithms and code for 3D seed coordinate reconstruction. The input consists of projections of seed positions in each of three isocentric images taken at arbitrary angles. The method proposed here consists of a set of heuristic rules (in a sense, a learning algorithm) that attempts to minimize seed misclassifications. In the clinic, this means that the system must be impervious to errors resulting from patient motion as well as from finite tolerances accepted in equipment settings. The software program was tested with simulated data, a pelvic phantom and patient data. One hundred and twenty permanent prostate implants were examined (105125I and 15103Pd) with the number of seeds ranging from 35 to 138 (average 79). The mean distance between actual and reconstructed seed positions is in the range 0.03-0.11 cm. On a Pentium III computer at 600 MHz the reconstruction process takes 10-30 s. The total number of seeds is independently validated. The process is robust and able to account for errors introduced in the clinic. (author)

  3. 3-D reconstruction of an ancient Egyptian mummy using X-ray computer tomography.

    Science.gov (United States)

    Baldock, C; Hughes, S W; Whittaker, D K; Taylor, J; Davis, R; Spencer, A J; Tonge, K; Sofat, A

    1994-12-01

    Computer tomography has been used to image and reconstruct in 3-D an Egyptian mummy from the collection of the British Museum. This study of Tjentmutengebtiu, a priestess from the 22nd dynasty (945-715 BC) revealed invaluable information of a scientific, Egyptological and palaeopathological nature without mutilation and destruction of the painted cartonnage case or linen wrappings. Precise details on the removal of the brain through the nasal cavity and the viscera from the abdominal cavity were obtained. The nature and composition of the false eyes were investigated. The detailed analysis of the teeth provided a much closer approximation of age at death. The identification of materials used for the various amulets including that of the figures placed in the viscera was graphically demonstrated using this technique.

  4. Sparse Bayesian framework applied to 3D super-resolution reconstruction in fetal brain MRI

    Science.gov (United States)

    Becerra, Laura C.; Velasco Toledo, Nelson; Romero Castro, Eduardo

    2015-01-01

    Fetal Magnetic Resonance (FMR) is an imaging technique that is becoming increasingly important as allows assessing brain development and thus make an early diagnostic of congenital abnormalities, spatial resolution is limited by the short acquisition time and the unpredictable fetus movements, in consequence the resulting images are characterized by non-parallel projection planes composed by anisotropic voxels. The sparse Bayesian representation is a flexible strategy which is able to model complex relationships. The Super-resolution is approached as a regression problem, the main advantage is the capability to learn data relations from observations. Quantitative performance evaluation was carried out using synthetic images, the proposed method demonstrates a better reconstruction quality compared with standard interpolation approach. The presented method is a promising approach to improve the information quality related with the 3-D fetal brain structure. It is important because allows assessing brain development and thus make an early diagnostic of congenital abnormalities.

  5. QUALITY ASSESSMENT OF 3D RECONSTRUCTION USING FISHEYE AND PERSPECTIVE SENSORS

    Directory of Open Access Journals (Sweden)

    C. Strecha

    2015-03-01

    Full Text Available Recent mathematical advances, growing alongside the use of unmanned aerial vehicles, have not only overcome the restriction of roll and pitch angles during flight but also enabled us to apply non-metric cameras in photogrammetric method, providing more flexibility for sensor selection. Fisheye cameras, for example, advantageously provide images with wide coverage; however, these images are extremely distorted and their non-uniform resolutions make them more difficult to use for mapping or terrestrial 3D modelling. In this paper, we compare the usability of different camera-lens combinations, using the complete workflow implemented in Pix4Dmapper to achieve the final terrestrial reconstruction result of a well-known historical site in Switzerland: the Chillon Castle. We assess the accuracy of the outcome acquired by consumer cameras with perspective and fisheye lenses, comparing the results to a laser scanner point cloud.

  6. Data Management Framework of Drone-Based 3d Model Reconstruction of Disaster Site

    Science.gov (United States)

    Kim, C.; Moon, H.; Lee, W.

    2016-06-01

    To rescue peoples in the disaster site in time, information acquisition of current feature of collapsed buildings and terrain is quite important for disaster site rescue manager. Based on information about disaster site, they can accurately plan the rescue process and remove collapsed buildings or other facilities. However, due to the harsh condition of disaster areas, rapid and accurate acquisition of disaster site information is not an easy task. There are possibilities of further damages in the collapse and there are also difficulties in acquiring information about current disaster situation due to large disaster site and limited rescue resources. To overcome these circumstances of disaster sites, an unmanned aerial vehicle, commonly known as a drone is used to rapidly and effectively acquire current image data of the large disaster areas. Then, the procedure of drone-based 3D model reconstruction visualization function of developed system is presented.

  7. 3D reconstruction of the source and scale of buried young flood channels on Mars.

    Science.gov (United States)

    Morgan, Gareth A; Campbell, Bruce A; Carter, Lynn M; Plaut, Jeffrey J; Phillips, Roger J

    2013-05-01

    Outflow channels on Mars are interpreted as the product of gigantic floods due to the catastrophic eruption of groundwater that may also have initiated episodes of climate change. Marte Vallis, the largest of the young martian outflow channels (Mars hydrologic activity during a period otherwise considered to be cold and dry. Using data from the Shallow Radar sounder on the Mars Reconnaissance Orbiter, we present a three-dimensional (3D) reconstruction of buried channels on Mars and provide estimates of paleohydrologic parameters. Our work shows that Cerberus Fossae provided the waters that carved Marte Vallis, and it extended an additional 180 kilometers to the east before the emplacement of the younger lava flows. We identified two stages of channel incision and determined that channel depths were more than twice those of previous estimates.

  8. EFFECT OF DIGITAL FRINGE PROJECTION PARAMETERS ON 3D RECONSTRUCTION ACCURACY

    Directory of Open Access Journals (Sweden)

    A. Babaei

    2013-09-01

    This paper aims to evaluate different parameters which affect the accuracy of the final results. For this purpose, some test were designed and implemented. These tests assess the number of phase shifts, spatial frequency of the fringe pattern, light condition, noise level of images, and the color and material of target objects on the quality of resulted phase map. The evaluation results demonstrate that digital fringe projection method is capable of obtaining depth map of complicated object with high accuracy. The contrast test results showed that this method is able to work under different ambient light condition; although at places with high light condition will not work properly. The results of implementation on different objects with various materials, color and shapes demonstrate the high capability of this method of 3D reconstruction.

  9. 3D Reconstruction Using Interval Methods on The Kinect Device Coupled With an IMU

    Directory of Open Access Journals (Sweden)

    Aymeric Bethencourt

    2013-02-01

    Full Text Available The principle behind VSLAM applications like 3D object reconstruction or indoor mapping is to estimate the spatial transformation between two large clouds of points, which represent two poses of the same scene. They can further be processed to obtain detailed surfaces. Since its introduction in 1992, the standard algorithm for finding the alignment between two point clouds is ICP (Iterative Closest Point and its variants, combined with RANSAC (RANdom SAmple Consensus. This paper presents a new approach using interval analysis. The idea is to define large intervals for the transformation parameters between the poses then to successively contract those intervals using the equations of the transformation of corresponding points between the poses. To contract those intervals faster, we added an IMU (Inertial Measurement Unit to our system so the initial intervals of the parameters are already small before applying the contractions. We implemented our algorithm using the middleware ROS (Robot Operating System and stated our performances.

  10. 3D optical phase reconstruction within PMMA samples using a spectral OCT system

    Science.gov (United States)

    Briones-R., Manuel d. J.; De La Torre-Ibarra, Manuel H.; Mendoza Santoyo, Fernando

    2015-08-01

    The optical coherence tomography (OCT) technique has proved to be a useful method in biomedical areas such as ophthalmology, dentistry, dermatology, among many others. In all these applications the main target is to reconstruct the internal structure of the samples from which the physician's expertise may recognize and diagnose the existence of a disease. Nowadays OCT has been applied one step further and is used to study the mechanics of some particular type of materials, where the resulting information involves more than just their internal structure and the measurement of parameters such as displacements, stress and strain. Here we report on a spectral OCT system used to image the internal 3D microstructure and displacement maps from a PMMA (Poly-methyl-methacrylate) sample, subjected to a deformation by a controlled three point bending and tilting. The internal mechanical response of the polymer is shown as consecutive 2D images.

  11. 3D Power Line Reconstruction from Airborne LiDAR Point Cloud of Overhead Electric Power Transmission Corridors

    OpenAIRE

    LIN Xiangguo; Zhang, Jixian

    2016-01-01

    3D power line reconstruction is one of the main tasks in power line patrols using LiDAR systems mounted on helicopters. A 3D reconstruction method is proposed to reconstruct the power lines from the airborne LiDAR point clouds of the overhead electric power transmission corridors. Firstly, the pylons' LiDAR points and the initial routine trajectory of the transmission lines are employed to derive the precise information such as the locations and number of the pylons, the real routine trajecto...

  12. Region-Based 3d Surface Reconstruction Using Images Acquired by Low-Cost Unmanned Aerial Systems

    Science.gov (United States)

    Lari, Z.; Al-Rawabdeh, A.; He, F.; Habib, A.; El-Sheimy, N.

    2015-08-01

    Accurate 3D surface reconstruction of our environment has become essential for an unlimited number of emerging applications. In the past few years, Unmanned Aerial Systems (UAS) are evolving as low-cost and flexible platforms for geospatial data collection that could meet the needs of aforementioned application and overcome limitations of traditional airborne and terrestrial mobile mapping systems. Due to their payload restrictions, these systems usually include consumer-grade imaging and positioning sensor which will negatively impact the quality of the collected geospatial data and reconstructed surfaces. Therefore, new surface reconstruction surfaces are needed to mitigate the impact of using low-cost sensors on the final products. To date, different approaches have been proposed to for 3D surface construction using overlapping images collected by imaging sensor mounted on moving platforms. In these approaches, 3D surfaces are mainly reconstructed based on dense matching techniques. However, generated 3D point clouds might not accurately represent the scanned surfaces due to point density variations and edge preservation problems. In order to resolve these problems, a new region-based 3D surface renostruction trchnique is introduced in this paper. This approach aims to generate a 3D photo-realistic model of individually scanned surfaces within the captured images. This approach is initiated by a Semi-Global dense Matching procedure is carried out to generate a 3D point cloud from the scanned area within the collected images. The generated point cloud is then segmented to extract individual planar surfaces. Finally, a novel region-based texturing technique is implemented for photorealistic reconstruction of the extracted planar surfaces. Experimental results using images collected by a camera mounted on a low-cost UAS demonstrate the feasibility of the proposed approach for photorealistic 3D surface reconstruction.

  13. REGION-BASED 3D SURFACE RECONSTRUCTION USING IMAGES ACQUIRED BY LOW-COST UNMANNED AERIAL SYSTEMS

    Directory of Open Access Journals (Sweden)

    Z. Lari

    2015-08-01

    Full Text Available Accurate 3D surface reconstruction of our environment has become essential for an unlimited number of emerging applications. In the past few years, Unmanned Aerial Systems (UAS are evolving as low-cost and flexible platforms for geospatial data collection that could meet the needs of aforementioned application and overcome limitations of traditional airborne and terrestrial mobile mapping systems. Due to their payload restrictions, these systems usually include consumer-grade imaging and positioning sensor which will negatively impact the quality of the collected geospatial data and reconstructed surfaces. Therefore, new surface reconstruction surfaces are needed to mitigate the impact of using low-cost sensors on the final products. To date, different approaches have been proposed to for 3D surface construction using overlapping images collected by imaging sensor mounted on moving platforms. In these approaches, 3D surfaces are mainly reconstructed based on dense matching techniques. However, generated 3D point clouds might not accurately represent the scanned surfaces due to point density variations and edge preservation problems. In order to resolve these problems, a new region-based 3D surface renostruction trchnique is introduced in this paper. This approach aims to generate a 3D photo-realistic model of individually scanned surfaces within the captured images. This approach is initiated by a Semi-Global dense Matching procedure is carried out to generate a 3D point cloud from the scanned area within the collected images. The generated point cloud is then segmented to extract individual planar surfaces. Finally, a novel region-based texturing technique is implemented for photorealistic reconstruction of the extracted planar surfaces. Experimental results using images collected by a camera mounted on a low-cost UAS demonstrate the feasibility of the proposed approach for photorealistic 3D surface reconstruction.

  14. The Avignon Bridge: a 3d Reconstruction Project Integrating Archaeological, Historical and Gemorphological Issues

    Science.gov (United States)

    Berthelot, M.; Nony, N.; Gugi, L.; Bishop, A.; De Luca, L.

    2015-02-01

    The history and identity of the Avignon's bridge is inseparable from that of the Rhône river. Therefore, in order to share the history and memory of the Rhône, it is essential to get to know this bridge and especially to identify and make visible the traces of its past, its construction, its interaction with the river dynamics, which greatly influenced his life. These are the objectives of the PAVAGE project that focuses on digitally surveying, modelling and re-visiting a heritage site of primary importance with the aim of virtually restoring the link between the two sides which, after the disappearance of the Roman bridge of Arles, constituted for a long time the only connection between Lyon or Vienna and the sea. Therefore, this project has an important geo-historical dimension for which geo-morphological and paleoenvironmental studies were implemented in connection with the latest digital simulation methods exploiting geographic information systems. By integrating knowledge and reflections of archaeologists, historians, geomorphologists, environmentalists, architects, engineers and computer scientists, the result of this project (which involved 5 laboratories during 4 years) is a 3D digital model covering an extension of 50 km2 achieved by integrating satellite imagery, UAV-based acquisitions, terrestrial laser scanning and photogrammetry, etc. Beyond the actions of scientific valorisation concerning the historical and geomorphological dimensions of the project, the results of this work of this interdisciplinary investigation and interpretation of this site are today integrated within a location-based augmented reality application allowing tourists to exploring the virtual reconstruction of the bridge and its environment through tablets inside the portion of territory covered by this project (between Avignon and Villeneuve-lez-Avignon). This paper presents the main aspects of the 3D virtual reconstruction approach.

  15. 3D Reconstruction of Human Laryngeal Dynamics Based on Endoscopic High-Speed Recordings.

    Science.gov (United States)

    Semmler, Marion; Kniesburges, Stefan; Birk, Veronika; Ziethe, Anke; Patel, Rita; Dollinger, Michael

    2016-07-01

    Standard laryngoscopic imaging techniques provide only limited two-dimensional insights into the vocal fold vibrations not taking the vertical component into account. However, previous experiments have shown a significant vertical component in the vibration of the vocal folds. We present a 3D reconstruction of the entire superior vocal fold surface from 2D high-speed videoendoscopy via stereo triangulation. In a typical camera-laser set-up the structured laser light pattern is projected on the vocal folds and captured at 4000 fps. The measuring device is suitable for in vivo application since the external dimensions of the miniaturized set-up barely exceed the size of a standard rigid laryngoscope. We provide a conservative estimate on the resulting resolution based on the hardware components and point out the possibilities and limitations of the miniaturized camera-laser set-up. In addition to the 3D vocal fold surface, we extended previous approaches with a G2-continuous model of the vocal fold edge. The clinical applicability was successfully established by the reconstruction of visual data acquired from 2D in vivo high-speed recordings of a female and a male subject. We present extracted dynamic parameters like maximum amplitude and velocity in the vertical direction. The additional vertical component reveals deeper insights into the vibratory dynamics of the vocal folds by means of a non-invasive method. The successful miniaturization allows for in vivo application giving access to the most realistic model available and hence enables a comprehensive understanding of the human phonation process. PMID:26829782

  16. Compressed Sensing Reconstruction of 3D Ultrasound Data Using Dictionary Learning and Line-Wise Subsampling.

    Science.gov (United States)

    Lorintiu, Oana; Liebgott, Hervé; Alessandrini, Martino; Bernard, Olivier; Friboulet, Denis

    2015-12-01

    In this paper we present a compressed sensing (CS) method adapted to 3D ultrasound imaging (US). In contrast to previous work, we propose a new approach based on the use of learned overcomplete dictionaries that allow for much sparser representations of the signals since they are optimized for a particular class of images such as US images. In this study, the dictionary was learned using the K-SVD algorithm and CS reconstruction was performed on the non-log envelope data by removing 20% to 80% of the original data. Using numerically simulated images, we evaluate the influence of the training parameters and of the sampling strategy. The latter is done by comparing the two most common sampling patterns, i.e., point-wise and line-wise random patterns. The results show in particular that line-wise sampling yields an accuracy comparable to the conventional point-wise sampling. This indicates that CS acquisition of 3D data is feasible in a relatively simple setting, and thus offers the perspective of increasing the frame rate by skipping the acquisition of RF lines. Next, we evaluated this approach on US volumes of several ex vivo and in vivo organs. We first show that the learned dictionary approach yields better performances than conventional fixed transforms such as Fourier or discrete cosine. Finally, we investigate the generality of the learned dictionary approach and show that it is possible to build a general dictionary allowing to reliably reconstruct different volumes of different ex vivo or in vivo organs.

  17. 3D Surface Reconstruction of Rills in a Spanish Olive Grove

    Science.gov (United States)

    Brings, Christine; Gronz, Oliver; Seeger, Manuel; Wirtz, Stefan; Taguas, Encarnación; Ries, Johannes B.

    2016-04-01

    The low-cost, user-friendly photogrammetric Structure from Motion (SfM) technique is used for 3D surface reconstruction and difference calculation of an 18 meter long rill in South Spain (Andalusia, Puente Genil). The images were taken with a Canon HD video camera before and after a rill experiment in an olive grove. Recording with a video camera has compared to a photo camera a huge time advantage and the method also guarantees more than adequately overlapping sharp images. For each model, approximately 20 minutes of video were taken. As SfM needs single images, the sharpest image was automatically selected from 8 frame intervals. The sharpness was estimated using a derivative-based metric. Then, VisualSfM detects feature points in each image, searches matching feature points in all image pairs and recovers the camera and feature positions. Finally, by triangulation of camera positions and feature points the software reconstructs a point cloud of the rill surface. From the point cloud, 3D surface models (meshes) are created and via difference calculations of the pre and post model a visualization of the changes (erosion and accumulation areas) and quantification of erosion volumes are possible. The calculated volumes are presented in spatial units of the models and so real values must be converted via references. The results show that rills in olive groves have a high dynamic due to the lack of vegetation cover under the trees, so that the rill can incise until the bedrock. Another reason for the high activity is the intensive employment of machinery.

  18. Reconstructing the Vulcano Island evolution from 3D modeling of magnetic signatures

    Science.gov (United States)

    Napoli, Rosalba; Currenti, Gilda

    2016-06-01

    High-resolution ground and marine magnetic data are exploited for a detailed definition of a 3D model of the Vulcano Island volcanic complex. The resulting 3D magnetic imaging, obtained by 3-D inverse modeling technique, has delivered useful constraints both to reconstruct the Vulcano Island evolution and to be used as input data for volcanic hazard assessment models. Our results constrained the depth and geometry of the main geo-structural features revealing more subsurface volcanic structures than exposed ones and allowing to elucidate the relationships between them. The recognition of two different magnetization sectors, approximatively coincident with the structural depressions of Piano caldera, in the southern half of the island, and La Fossa caldera at the north, suggests a complex structural and volcanic evolution. Magnetic highs identified across the southern half of the island reflect the main crystallized feeding systems, intrusions and buried vents, whose NNW-SSE preferential alignment highlights the role of the NNW-SSE Tindari-Letojanni regional system from the initial activity of the submarine edifice, to the more recent activity of the Vulcano complex. The low magnetization area, in the middle part of the island may result from hydrothermally altered rocks. Their presence not only in the central part of the volcano edifice but also in other peripheral areas, is a sign of a more diffuse historical hydrothermal activity than in present days. Moreover, the high magnetization heterogeneity within the upper flanks of La Fossa cone edifice is an imprint of a composite distribution of unaltered and altered rocks with different mechanical properties, which poses in this area a high risk level for failure processes especially during volcanic or hydrothermal crisis.

  19. GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

    Science.gov (United States)

    Dorgham, Osama M; Laycock, Stephen D; Fisher, Mark H

    2012-09-01

    Recent advances in programming languages for graphics processing units (GPUs) provide developers with a convenient way of implementing applications which can be executed on the CPU and GPU interchangeably. GPUs are becoming relatively cheap, powerful, and widely available hardware components, which can be used to perform intensive calculations. The last decade of hardware performance developments shows that GPU-based computation is progressing significantly faster than CPU-based computation, particularly if one considers the execution of highly parallelisable algorithms. Future predictions illustrate that this trend is likely to continue. In this paper, we introduce a way of accelerating 2-D/3-D image registration by developing a hybrid system which executes on the CPU and utilizes the GPU for parallelizing the generation of digitally reconstructed radiographs (DRRs). Based on the advancements of the GPU over the CPU, it is timely to exploit the benefits of many-core GPU technology by developing algorithms for DRR generation. Although some previous work has investigated the rendering of DRRs using the GPU, this paper investigates approximations which reduce the computational overhead while still maintaining a quality consistent with that needed for 2-D/3-D registration with sufficient accuracy to be clinically acceptable in certain applications of radiation oncology. Furthermore, by comparing implementations of 2-D/3-D registration on the CPU and GPU, we investigate current performance and propose an optimal framework for PC implementations addressing the rigid registration problem. Using this framework, we are able to render DRR images from a 256×256×133 CT volume in ~24 ms using an NVidia GeForce 8800 GTX and in ~2 ms using NVidia GeForce GTX 580. In addition to applications requiring fast automatic patient setup, these levels of performance suggest image-guided radiation therapy at video frame rates is technically feasible using relatively low cost PC

  20. 3D Reconstruction of the Vortex in a Human Right Ventricle Model using High Speed PIV

    Science.gov (United States)

    Kheradvar, Arash; Falahatpisheh, Ahmad

    2011-11-01

    This work aims to characterize the formation process and translation of the vortex, which forms along with the trans-tricuspid jet in a realistic model of a human right ventricle (RV). A clear model of the RV made of silicone rubber was carefully casted in real size from echocardiographic data of an adult human heart. The RV model was used in our heart pulsed-flow simulator at KLAB at UCI to perform experiments. Bioprosthetic heart valves in appropriate sizes were used at tricuspid and pulmonary positions. Multi-planar high-speed PIV was performed to capture and reconstruct the 3D flow field with a 1-millisecond time gap between each two velocity frames. λ2 iso-surfaces were used to illustrate the evolution of vortex cores. The highly asymmetric shape of the RV chamber results in a complex 3D trans-tricuspid vortex that forms and translates toward right ventricular outflow tract, and finally departs RV from pulmonary valve. Through this study, -for the first time- the formation, evolution and pathway of the RV vortex have been characterized in vitro.

  1. Ion track reconstruction in 3D using alumina-based fluorescent nuclear track detectors

    CERN Document Server

    Niklas, Martin; Akselrod, Mark S; Abollahi, Amir; Jäkel, Oliver; Greilich, Steffen

    2013-01-01

    Fluorescent nuclear track detectors (FNTDs) based on Al2O3:C,Mg single crystal combined with confocal microscopy provide 3D information on ion tracks with a resolution only limited by light diffraction. FNTDs are also ideal substrates to be coated with cells to engineer cell-fluorescent ion track hybrid detectors. This radiobiological tool enables a novel platform linking cell responses to physical dose deposition on a sub-cellular level in proton and heavy ion therapies. To achieve spatial correlation between single ion hits in the cell coating and its biological response the ion traversals have to be reconstructed in 3D using the depth information gained by the FNTD read-out. FNTDs were coated with a confluent human lung adenocarcinoma epithelial cell layer. Carbon ion irradiation of the hybrid detector was performed perpendicular and angular to the detector surface. In-situ imaging of the fluorescently labeled cell layer and the FNTD was performed in a sequential read-out. Making use of the trajectory info...

  2. Computational 3D reconstructions by optimization for cryo-electron microscopy

    Science.gov (United States)

    Yin, Zhye; Zheng, Yili; Doerschuk, Peter C.; Johnson, John E.

    2003-06-01

    An algorithm for the simultaneous 3-D reconstruction of several types of object, where each type of object may possibly have a rotational symmetry, from 2-D projection images, where for each image the type of object imaged, the projection orientation used to create the image, and the location of the object in the image are unknown, is described. The motivating application is the determination of the 3-D structure of small spherical viruses from cryo electron microscopy images. The algorithm is a maximum likelihood estimator which is computed by expectation maximization (EM). Due to the structure of the statistical model, the maximization step of EM can be easily computed but the expectation step requires 5-D numerical quadrature. The computational burden of the quadratures necessitates parallel computation and three different implementations of two different types of parallelism have been developed using pthreads (for shared memory processors) and MPI (for distributed memory processors). An example applying one of the MPI implementations, running on a 32 node PC cluster, to experimental images of Flock House Virus with comparison to the x-ray crystal diffraction structure of the virus is described.

  3. Introduction to 3D reconstruction of macromolecules using single particle electron microscopy

    Institute of Scientific and Technical Information of China (English)

    Oscar LLORCA

    2005-01-01

    Single-particle electron microscopy has now reached maturity, becoming a commonly used method in the examination ofmacromolecular structure. Using a small amount of purified protein, isolated molecules are observed under the electron microscope and the data collected can be averaged into a 3D reconstruction.Single-particle electron microscopy is an appropriate tool for the analysis of proteins that can only be obtained in modest quantities, like many of the large complexes currently of interest in biomedicine. Whilst the use of electron microscopy expands, new methods are being developed and improved to deal with further challenges, such as reaching higher resolutions and the combination of information at different levels of structural detail. More importantly, present methodology is still not robust enough when studying certain "tricky" proteins like those displaying extensive conformational flexibility and a great deal of user expertise is required, posing a threat to the consistency of the final structure. This mini review describes a brief outline of the methods currently used in the 3D analysis of macromolecules using single-particle electron microscopy, intended for those first approaching this field. A summary of methods, techniques, software, and some recent work is presented. The spectacular improvements to the technique in recent years, its advantages and limitations compared to other structural methods,and its future developments are discussed.

  4. Semi-automated 3D leaf reconstruction and analysis of trichome patterning from light microscopic images.

    Directory of Open Access Journals (Sweden)

    Henrik Failmezger

    2013-04-01

    Full Text Available Trichomes are leaf hairs that are formed by single cells on the leaf surface. They are known to be involved in pathogen resistance. Their patterning is considered to emerge from a field of initially equivalent cells through the action of a gene regulatory network involving trichome fate promoting and inhibiting factors. For a quantitative analysis of single and double mutants or the phenotypic variation of patterns in different ecotypes, it is imperative to statistically evaluate the pattern reliably on a large number of leaves. Here we present a method that enables the analysis of trichome patterns at early developmental leaf stages and the automatic analysis of various spatial parameters. We focus on the most challenging young leaf stages that require the analysis in three dimensions, as the leaves are typically not flat. Our software TrichEratops reconstructs 3D surface models from 2D stacks of conventional light-microscope pictures. It allows the GUI-based annotation of different stages of trichome development, which can be analyzed with respect to their spatial distribution to capture trichome patterning events. We show that 3D modeling removes biases of simpler 2D models and that novel trichome patterning features increase the sensitivity for inter-accession comparisons.

  5. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wenyang [Department of Bioengineering, University of California, Los Angeles, California 90095 (United States); Cheung, Yam; Sabouri, Pouya; Arai, Tatsuya J.; Sawant, Amit [Department of Radiation Oncology, University of Texas Southwestern, Dallas, Texas 75390 (United States); Ruan, Dan, E-mail: druan@mednet.ucla.edu [Department of Bioengineering, University of California, Los Angeles, California 90095 and Department of Radiation Oncology, University of California, Los Angeles, California 90095 (United States)

    2015-11-15

    achieved submillimeter reconstruction RMSE under different configurations, demonstrating quantitatively the faith of the proposed method in preserving local structural properties of the underlying surface in the presence of noise and missing measurements, and its robustness toward variations of such characteristics. On point clouds from the human subject, the proposed method successfully reconstructed all patient surfaces, filling regions where raw point coordinate readings were missing. Within two comparable regions of interest in the chest area, similar mean curvature distributions were acquired from both their reconstructed surface and CT surface, with mean and standard deviation of (μ{sub recon} = − 2.7 × 10{sup −3} mm{sup −1}, σ{sub recon} = 7.0 × 10{sup −3} mm{sup −1}) and (μ{sub CT} = − 2.5 × 10{sup −3} mm{sup −1}, σ{sub CT} = 5.3 × 10{sup −3} mm{sup −1}), respectively. The agreement of local geometry properties between the reconstructed surfaces and the CT surface demonstrated the ability of the proposed method in faithfully representing the underlying patient surface. Conclusions: The authors have integrated and developed an accurate level-set based continuous surface reconstruction method on point clouds acquired by a 3D surface photogrammetry system. The proposed method has generated a continuous representation of the underlying phantom and patient surfaces with good robustness against noise and missing measurements. It serves as an important first step for further development of motion tracking methods during radiotherapy.

  6. 3D reconstruction of single rising bubble in water using digital image processing and characteristic matrix

    Institute of Scientific and Technical Information of China (English)

    Yuchen Bian; Feng Dong; Weida Zhang; Hongyi Wang; Chao Tan; Zhiqiang Zhang

    2013-01-01

    Reconstructing the shape of a bubble will lay a firm foundation for further description of the dynamic characteristics of bubbly flow,especially for a single rising bubble or separate bubbles whose interaction could be neglected.In this case,the rising bubble is usually simulated as an ellipsoid consisting of two semi-ellipsoids up and down.Thus the projected image of a bubble consists of two semi-ellipses.In this paper,a method for reconstructing the ellipsoid bubble model is described following digital image processing,using the Hough transform in 2D ellipse parameter extraction which could cover most of the bubble edge points in the image.Then a method based on characteristic symmetric matrix is described to detect 3D bubble ellipsoid model parameters from 2D ellipse parameters of projection planes.This method can be applied to bubbles rising with low-velocity in static flow field much in conformity with the projection theory and the shape variation of the rising bubble.This method does not need to solve nonlinear equation sets and provides an easy way to calculate the characteristic matrix of a space ellipsoid model for deformed bubble.For bubble application,two assumed conditions and a calibration factor are proposed to simplify calculation and detection.Errors of ellipsoid center and three axes are minor.Errors of the three rotation angles have no negative effect on further study on bubbly flow.

  7. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez D, J.; Cordova F, T. [Universidad de Guanajuato, Campus Leon, Departamento de Ingenieria Fisica, Loma del Bosque No. 103, Lomas del Campestre, 37150 Leon, Guanajuato (Mexico); Cruz A, I., E-mail: hernandezdj.gto@gmail.com [CONACYT, Centro de Investigacion en Matematicas, A. C., Jalisco s/n, Col. Valenciana, 36000 Guanajuato, Gto. (Mexico)

    2015-10-15

    This paper presents a novel presents an approach based on differences of intensities for the identification of vascular structures in medical images from MRI studies of type time of flight method (TOF). The plating method hypothesis gave high intensities belonging to the vascular system image type TOF can be segmented by thresholding of the histogram. The enhanced vascular structures is performed using the filter Vesselness, upon completion of a decision based on fuzzy thresholding minimizes error in the selection of vascular structures. It will give a brief introduction to the vascular system problems and how the images have helped diagnosis, is summarized the physical history of the different imaging modalities and the evolution of digital images with computers. Segmentation and 3-D reconstruction became image type time of flight; these images are typically used in medical diagnosis of cerebrovascular diseases. The proposed method has less error in segmentation and reconstruction of volumes related to the vascular system, clear images and less noise compared with edge detection methods. (Author)

  8. 3D cardiac motion reconstruction from CT data and tagged MRI.

    Science.gov (United States)

    Wang, Xiaoxu; Mihalef, Viorel; Qian, Zhen; Voros, Szilard; Metaxas, Dimitris

    2012-01-01

    In this paper we present a novel method for left ventricle (LV) endocardium motion reconstruction using high resolution CT data and tagged MRI. High resolution CT data provide anatomic details on the LV endocardial surface, such as the papillary muscle and trabeculae carneae. Tagged MRI provides better time resolution. The combination of these two imaging techniques can give us better understanding on left ventricle motion. The high resolution CT images are segmented with mean shift method and generate the LV endocardium mesh. The meshless deformable model built with high resolution endocardium surface from CT data fit to the tagged MRI of the same phase. 3D deformation of the myocardium is computed with the Lagrangian dynamics and local Laplacian deformation. The segmented inner surface of left ventricle is compared with the heart inner surface picture and show high agreement. The papillary muscles are attached to the inner surface with roots. The free wall of the left ventricle inner surface is covered with trabeculae carneae. The deformation of the heart wall and the papillary muscle in the first half of the cardiac cycle is presented. The motion reconstruction results are very close to the live heart video. PMID:23366825

  9. 3D building reconstruction from ALS data using unambiguous decomposition into elementary structures

    Science.gov (United States)

    Jarząbek-Rychard, M.; Borkowski, A.

    2016-08-01

    The objective of the paper is to develop an automated method that enables for the recognition and semantic interpretation of topological building structures. The novelty of the proposed modeling approach is an unambiguous decomposition of complex objects into predefined simple parametric structures, resulting in the reconstruction of one topological unit without independent overlapping elements. The aim of a data processing chain is to generate complete polyhedral models at LOD2 with an explicit topological structure and semantic information. The algorithms are performed on 3D point clouds acquired by airborne laser scanning. The presented methodology combines data-based information reflected in an attributed roof topology graph with common knowledge about buildings stored in a library of elementary structures. In order to achieve an appropriate balance between reconstruction precision and visualization aspects, the implemented library contains a set of structure-depended soft modeling rules instead of strictly defined geometric primitives. The proposed modeling algorithm starts with roof plane extraction performed by the segmentation of building point clouds, followed by topology identification and recognition of predefined structures. We evaluate the performance of the novel procedure by the analysis of the modeling accuracy and the degree of modeling detail. The assessment according to the validation methods standardized by the International Society for Photogrammetry and Remote Sensing shows that the completeness of the algorithm is above 80%, whereas the correctness exceeds 98%.

  10. In-line monitoring and reverse 3D model reconstruction in additive manufacturing

    DEFF Research Database (Denmark)

    Pedersen, David Bue; Hansen, Hans Nørgaard; Nielsen, Jakob Skov

    2010-01-01

    Additive manufacturing allows for close-to unrestrained geometrical freedom in part design. The ability to manufacture geometries of such complexity is however limited by the fact that it proves difficult to verify tolerances of these parts. Tolerancs of featuress that are inaccessible with tradi......D printing (3DP), or Selective Laser Sintering (SLS) equipment. The system will be implemented and tested on a 3DP machine with modifications developed at the author's university.......Additive manufacturing allows for close-to unrestrained geometrical freedom in part design. The ability to manufacture geometries of such complexity is however limited by the fact that it proves difficult to verify tolerances of these parts. Tolerancs of featuress that are inaccessible...... with traditional measuring equipment such as Coordinate Measurement Machines (CMM's) can not easily be verified. This paradox is addresses by the proposal of an in-line reverse engineering and 3D reconstruction method that alows for a true to scale reconstruction of a part that is being additivelymanufactures on 3...

  11. 3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm

    CERN Document Server

    Słomski, Artur; Bednarski, Tomasz; Białas, Piotr; Czerwiński, Eryk; Kapłon, Łukasz; Kochanowski, Andrzej; Korcyl, Grzegorz; Kowal, Jakub; Kowalski, Paweł; Kozik, Tomasz; Krzemień, Wojciech; Molenda, Marcin; Moskal, Paweł; Niedźwiecki, Szymon; Pałka, Marek; Pawlik, Monika; Raczyński, Lech; Salabura, Piotr; Gupta-Sharma, Neha; Silarski, Michał; Smyrski, Jerzy; Strzelecki, Adam; Wiślicki, Wojciech; Zieliński, Marcin; Zoń, Natalia

    2015-01-01

    Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines connecting two detectors. As there is a multitude of detectors build-in typical PET tomograph structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Decisive improvement in PET image quality was reached with the introduction of iterative reconstruction techniques. This stage was reached already twenty years ago (with the advent of new powerful computing processors). However, three dimensional (3D) imaging remains still a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines-of-responce (LOR) and millions of detected photons to produce an image showing the distribution of the l...

  12. A 3D photogrammetric reconstruction attempt of specimens of Badenian echinoids

    Science.gov (United States)

    Polonkai, Bálint; Raveloson, Andrea; Görög, Ágnes; Bodor, Emese; Székely, Balázs

    2016-04-01

    The rich echinoid fauna of the Badenian (Middle Miocene) from Budapest (Hungary) is well known for more than one hundred years. Along the road cuts and due to the construction of large buildings from 1960 to 2011, new Badenian outcrops with rich and well preserved echinoids were found in the city. Thus the main aim of this study was to revise historically collected echinoids (in the collection of Geological and Geophysical Institute of Hungary) from different parts of the city (Örs Vezér Square, Gyakorló Street, Rákos and District of Budafok-Tétény) and to classify the newly collected fossils, moreover to carry out the palaeoenvironmental reconstruction of the different localities. The specimens studied are from the Upper Badenian Leithakalk Formation Rákos Member, which consists of sandy limestone, calcareous loose sandstone with volcanic clast and/or calcarenite without terrigenous or volcanic clast. One of the most common echinoidea in the Badenian, the Parascutella gibbercula DE SERRES, 1829 is well known and researched in both morphological and taxonomic aspects. However there are some intraspecific morphological features that show sharp differences across the specimens: the adapical conical convexity is considerably different between several forms. The petalodium's length/width ratio is also different between many specimens. Other morphological characters for example peristomal and periproctal aperture and the food groove can also be different. These differences within this relatively small area could be determined by ecological conditions (such as substrate, palaeodepth), or can be related to taxonomical or pathological changes. For an appropriate comparison, quantification of these features is necessary. Photogrammetry is in general a useful and well-developed tool to reconstruct 3D surfaces of artefacts (e.g., in archaeology, cultural heritage, and also in palaeontology). In order to evaluate the differences found in P. gibbercula specimens various

  13. Optimal relaxation parameters of DRAMA (dynamic RAMLA) aiming at one-pass image reconstruction for 3D-PET

    Science.gov (United States)

    Tanaka, Eiichi; Kudo, Hiroyuki

    2010-05-01

    We have reported a block-iterative algorithm named DRAMA for image reconstruction for emission tomography (Tanaka and Kudo 2003 Phys. Med. Biol. 48 1405-22). DRAMA is a modified version of the row-action maximum likelihood algorithm (RAMLA), in which the relaxation parameter is subset dependent and is changed in such a way that the noise propagation from subsets to the reconstructed image is substantially independent of the access order of the subsets. The algorithm provides fast convergence with a reasonable signal-to-noise ratio. The optimal relaxation parameter has been derived assuming a two-dimensional (2D)-PET model, and detailed performance in three-dimensional (3D) reconstruction has not been clear enough. We have developed the new version 'DRAMA-3D', based on the 3D-PET model. The optimal relaxation parameter is a function of the access order of the subsets and the ring difference, and its value is determined by simple formulas from the design parameters of the PET scanner, the operating conditions and the post-smoothing resolution. In this paper, we present the theory of DRAMA-3D, the results of simulation studies on the performance of DRAMA-3D and the comparative studies of the related algorithms. It is shown that DRAMA-3D is robust for various access orders of subsets and is suitable to realize one-pass (single-iteration) reconstruction.

  14. A LabVIEW based user-friendly nano-CT image alignment and 3D reconstruction platform

    CERN Document Server

    Wang, Shenghao; Wang, Zhili; Gao, Kun; Wu, Zhao; Zhu, Peiping; Wu, Ziyu

    2014-01-01

    X-ray nanometer computed tomography (nano-CT) offers applications and opportunities in many scientific researches and industrial areas. Here we present a user-friendly and fast LabVIEW based package running, after acquisition of the raw projection images, a procedure to obtain the inner structure of the sample under analysis. At first, a reliable image alignment procedure fixes possible misalignments among image series due to mechanical errors, thermal expansion and other external contributions, then a novel fast parallel beam 3D reconstruction performs the tomographic reconstruction. The remarkable improved reconstruction after the image calibration confirms the fundamental role of the image alignment procedure. It minimizes blurring and additional streaking artifacts present in a reconstructed slice that cause loss of information and faked structures in the observed material. The nano-CT image alignment and 3D reconstruction LabVIEW package significantly reducing the data process, makes faster and easier th...

  15. Etruscanning 3D project. The 3D reconstruction of the Regolini Galassi Tomb as a research tool and a new approach in storytelling

    Directory of Open Access Journals (Sweden)

    Wim Hupperetz

    2012-11-01

    Full Text Available In the “Etruscanning3D” european project framework, the virtual reconstruction of the Regolini Galassi tomb, in Cerveteri, has been realized, in order to recontextualize its precious funerary goods, today preserved in the vatican Museums, in their ancient space, digitally represented in 3D. The reconstruction has been preceded by a huge work of data collection, reinterpretations, topographical acquisitions through a variety of techniques, digital restorations, in order to create a plausible simulation of how the tomb could appear when it was closed, at the half of the VII century BC. The final purpose of the VR application is communication inside museums, so the narrative approach and the metaphors of interactions played another key role.

  16. Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization

    Energy Technology Data Exchange (ETDEWEB)

    Mory, Cyril, E-mail: cyril.mory@philips.com [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Auvray, Vincent; Zhang, Bo [Philips Research Medisys, 33 rue de Verdun, 92156 Suresnes (France); Grass, Michael; Schäfer, Dirk [Philips Research, Röntgenstrasse 24–26, D-22335 Hamburg (Germany); Chen, S. James; Carroll, John D. [Department of Medicine, Division of Cardiology, University of Colorado Denver, 12605 East 16th Avenue, Aurora, Colorado 80045 (United States); Rit, Simon [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France); Centre Léon Bérard, 28 rue Laënnec, F-69373 Lyon (France); Peyrin, Françoise [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1, F-69621 Villeurbanne Cedex (France); X-ray Imaging Group, European Synchrotron, Radiation Facility, BP 220, F-38043 Grenoble Cedex (France); Douek, Philippe; Boussel, Loïc [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Lyon 1 (France); Hospices Civils de Lyon, 28 Avenue du Doyen Jean Lépine, 69500 Bron (France)

    2014-02-15

    Purpose: Reconstruction of the beating heart in 3D + time in the catheter laboratory using only the available C-arm system would improve diagnosis, guidance, device sizing, and outcome control for intracardiac interventions, e.g., electrophysiology, valvular disease treatment, structural or congenital heart disease. To obtain such a reconstruction, the patient's electrocardiogram (ECG) must be recorded during the acquisition and used in the reconstruction. In this paper, the authors present a 4D reconstruction method aiming to reconstruct the heart from a single sweep 10 s acquisition. Methods: The authors introduce the 4D RecOnstructiOn using Spatial and TEmporal Regularization (short 4D ROOSTER) method, which reconstructs all cardiac phases at once, as a 3D + time volume. The algorithm alternates between a reconstruction step based on conjugate gradient and four regularization steps: enforcing positivity, averaging along time outside a motion mask that contains the heart and vessels, 3D spatial total variation minimization, and 1D temporal total variation minimization. Results: 4D ROOSTER recovers the different temporal representations of a moving Shepp and Logan phantom, and outperforms both ECG-gated simultaneous algebraic reconstruction technique and prior image constrained compressed sensing on a clinical case. It generates 3D + time reconstructions with sharp edges which can be used, for example, to estimate the patient's left ventricular ejection fraction. Conclusions: 4D ROOSTER can be applied for human cardiac C-arm CT, and potentially in other dynamic tomography areas. It can easily be adapted to other problems as regularization is decoupled from projection and back projection.

  17. Low-amplitude craniofacial EMG power spectral density and 3D muscle reconstruction from MRI

    Directory of Open Access Journals (Sweden)

    Lukas Wiedemann

    2015-03-01

    Full Text Available Improving EEG signal interpretation, specificity, and sensitivity is a primary focus of many current investigations, and the successful application of EEG signal processing methods requires a detailed knowledge of both the topography and frequency spectra of low-amplitude, high-frequency craniofacial EMG. This information remains limited in clinical research, and as such, there is no known reliable technique for the removal of these artifacts from EEG data. The results presented herein outline a preliminary investigation of craniofacial EMG high-frequency spectra and 3D MRI segmentation that offers insight into the development of an anatomically-realistic model for characterizing these effects. The data presented highlights the potential for confounding signal contribution from around 60 to 200 Hz, when observed in frequency space, from both low and high-amplitude EMG signals. This range directly overlaps that of both low γ (30-50 Hz and high γ (50-80 Hz waves, as defined traditionally in standatrd EEG measurements, and mainly with waves presented in dense-array EEG recordings. Likewise, average EMG amplitude comparisons from each condition highlights the similarities in signal contribution of low-activity muscular movements and resting, control conditions. In addition to the FFT analysis performed, 3D segmentation and reconstruction of the craniofacial muscles whose EMG signals were measured was successful. This recapitulation of the relevant EMG morphology is a crucial first step in developing an anatomical model for the isolation and removal of confounding low-amplitude craniofacial EMG signals from EEG data. Such a model may be eventually applied in a clinical setting to ultimately help to extend the use of EEG in various clinical roles.

  18. Low-Amplitude Craniofacial EMG Power Spectral Density and 3D Muscle Reconstruction from MRI.

    Science.gov (United States)

    Wiedemann, Lukas; Chaberova, Jana; Edmunds, Kyle; Einarsdóttir, Guðrún; Ramon, Ceon; Gargiulo, Paolo

    2015-03-11

    Improving EEG signal interpretation, specificity, and sensitivity is a primary focus of many current investigations, and the successful application of EEG signal processing methods requires a detailed knowledge of both the topography and frequency spectra of low-amplitude, high-frequency craniofacial EMG. This information remains limited in clinical research, and as such, there is no known reliable technique for the removal of these artifacts from EEG data. The results presented herein outline a preliminary investigation of craniofacial EMG high-frequency spectra and 3D MRI segmentation that offers insight into the development of an anatomically-realistic model for characterizing these effects. The data presented highlights the potential for confounding signal contribution from around 60 to 200 Hz, when observed in frequency space, from both low and high-amplitude EMG signals. This range directly overlaps that of both low γ (30-50 Hz) and high γ (50-80 Hz) waves, as defined traditionally in standatrd EEG measurements, and mainly with waves presented in dense-array EEG recordings. Likewise, average EMG amplitude comparisons from each condition highlights the similarities in signal contribution of low-activity muscular movements and resting, control conditions. In addition to the FFT analysis performed, 3D segmentation and reconstruction of the craniofacial muscles whose EMG signals were measured was successful. This recapitulation of the relevant EMG morphology is a crucial first step in developing an anatomical model for the isolation and removal of confounding low-amplitude craniofacial EMG signals from EEG data. Such a model may be eventually applied in a clinical setting to ultimately help to extend the use of EEG in various clinical roles.

  19. 3D phase micro-object studies by means of digital holographic tomography supported by algebraic reconstruction technique

    Science.gov (United States)

    Bilski, B. J.; Jozwicka, A.; Kujawinska, M.

    2007-09-01

    Constant development of microelements' technology requires a creation of new instruments to determine their basic physical parameters in 3D. The most efficient non-destructive method providing 3D information is tomography. In this paper we present Digital Holographic Tomography (DHT), in which input data is provided by means of Di-git- al Holography (DH). The main advantage of DH is the capability to capture several projections with a single hologram [1]. However, these projections have uneven angular distribution and their number is significantly limited. Therefore - Algebraic Reconstruction Technique (ART), where a few phase projections may be sufficient for proper 3D phase reconstruction, is implemented. The error analysis of the method and its additional limitations due to shape and dimensions of investigated object are presented. Finally, the results of ART application to DHT method are also presented on data reconstructed from numerically generated hologram of a multimode fibre.

  20. Advancement of 31P Magnetic Resonance Spectroscopy Using GRAPPA Reconstruction on a 3D Volume

    Science.gov (United States)

    Clevenger, Tony

    The overall objective of this research is to improve currently available metabolic imaging techniques for clinical use in monitoring and predicting treatment response to radiation therapy in liver cancer. Liver metabolism correlates with inflammatory and neoplastic liver diseases, which alter the intracellular concentration of phosphorus- 31 (31P) metabolites [1]. It is assumed that such metabolic changes occur prior to physical changes of the tissue. Therefore, information on regional changes of 31P metabolites in the liver, obtained by Magnetic Resonance Spectroscopic Imaging (MRSI) [1,2], can help in diagnosis and follow-up of various liver diseases. Specifically, there appears to be an immediate need of this technology for both the assessment of tumor response in patients with Hepatocellular Carcinoma (HCC) treated with Stereotactic Body Radiation Therapy (SBRT) [3--5], as well as assessment of radiation toxicity, which can result in worsening liver dysfunction [6]. Pilot data from our lab has shown that 31P MRSI has the potential to identify treatment response five months sooner than conventional methods [7], and to assess the biological response of liver tissue to radiation 24 hours post radiation therapy [8]. While this data is very promising, commonly occurring drawbacks for 31P MRSI are patient discomfort due to long scan times and prone positioning within the scanner, as well as reduced data quality due to patient motion and respiration. To further advance the full potential of 31P MRSI as a clinical diagnostic tool in the management of liver cancer, this PhD research project had the following aims: I) Reduce the long acquisition time of 3D 31P MRS by formulating and imple- menting an appropriate GRAPPA undersampling scheme and reconstruction on a clinical MRI scanner II) Testing and quantitative validation of GRAPPA reconstruction on 3D 31P MRSI on developmental phantoms and healthy volunteers At completion, this work should considerably advance 31P MRSI

  1. Extreme 3D reconstruction of the final ROSETTA/PHILAE landing site

    Science.gov (United States)

    Capanna, Claire; Jorda, Laurent; Lamy, Philippe; Gesquiere, Gilles; Delmas, Cédric; Durand, Joelle; Garmier, Romain; Gaudon, Philippe; Jurado, Eric

    2016-04-01

    The Philae lander aboard the Rosetta spacecraft successfully landed at the surface of comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G) after two rebounds on November 12, 2014. The final landing site, now known as « Abydos », has been identified on images acquired by the OSIRIS imaging system onboard the Rosetta orbiter[1]. The available images of Abydos are very limited in number and reveal a very extreme topography containing cliffs and overhangs. Furthermore, the surface is only observed under very high incidence angles of 60° on average, which implies that the images also exhibit lots of cast shadows. This makes it very difficult to reconstruct the 3D topography with standard methods such as photogrammetry or standard clinometry. We apply a new method called ''Multiresolution PhotoClinometry by Deformation'' (MPCD, [2]) to retrieve the 3D topography of the area around Abydos. The method works in two main steps: (i) a DTM of this region is extracted from a low resolution MPCD global shape model of comet 67P/C-G, and (ii) the resulting triangular mesh is progressively deformed at increasing spatial sampling down to 0.25 m in order to match a set of 14 images of Abydos with projected pixel scales between 1 and 8 m. The method used to perform the image matching is a quasi-Newton non-linear optimization method called L-BFGS-b[3] especially suited to large-scale problems. Finally, we also checked the compatibility of the final MPCD digital terrain model with a set of five panoramic images obtained by the CIVA-P instrument aboard Philae[4]. [1] Lamy et al., 2016, submitted. [2] Capanna et al., Three dimensional reconstruction using multiresoluton photoclinometry by deformation, The visual Computer, v. 29(6-8) pp. 825-835, 2013. [3] Morales et al., Remark on "Algorithm 778: L-BFGS-B: Fortran subroutines for large-scale bound constrained optimization", v.38(1) pp.1-4, ACM Trans. Math. Softw., 2011 [4] Bibring et al., 67P/Churyumov-Gerasimenko surface properties as

  2. Joint Cross-Range Scaling and 3D Geometry Reconstruction of ISAR Targets Based on Factorization Method.

    Science.gov (United States)

    Lei Liu; Feng Zhou; Xue-Ru Bai; Ming-Liang Tao; Zi-Jing Zhang

    2016-04-01

    Traditionally, the factorization method is applied to reconstruct the 3D geometry of a target from its sequential inverse synthetic aperture radar images. However, this method requires performing cross-range scaling to all the sub-images and thus has a large computational burden. To tackle this problem, this paper proposes a novel method for joint cross-range scaling and 3D geometry reconstruction of steadily moving targets. In this method, we model the equivalent rotational angular velocity (RAV) by a linear polynomial with time, and set its coefficients randomly to perform sub-image cross-range scaling. Then, we generate the initial trajectory matrix of the scattering centers, and solve the 3D geometry and projection vectors by the factorization method with relaxed constraints. After that, the coefficients of the polynomial are estimated from the projection vectors to obtain the RAV. Finally, the trajectory matrix is re-scaled using the estimated rotational angle, and accurate 3D geometry is reconstructed. The two major steps, i.e., the cross-range scaling and the factorization, are performed repeatedly to achieve precise 3D geometry reconstruction. Simulation results have proved the effectiveness and robustness of the proposed method. PMID:26886991

  3. Joint Cross-Range Scaling and 3D Geometry Reconstruction of ISAR Targets Based on Factorization Method.

    Science.gov (United States)

    Lei Liu; Feng Zhou; Xue-Ru Bai; Ming-Liang Tao; Zi-Jing Zhang

    2016-04-01

    Traditionally, the factorization method is applied to reconstruct the 3D geometry of a target from its sequential inverse synthetic aperture radar images. However, this method requires performing cross-range scaling to all the sub-images and thus has a large computational burden. To tackle this problem, this paper proposes a novel method for joint cross-range scaling and 3D geometry reconstruction of steadily moving targets. In this method, we model the equivalent rotational angular velocity (RAV) by a linear polynomial with time, and set its coefficients randomly to perform sub-image cross-range scaling. Then, we generate the initial trajectory matrix of the scattering centers, and solve the 3D geometry and projection vectors by the factorization method with relaxed constraints. After that, the coefficients of the polynomial are estimated from the projection vectors to obtain the RAV. Finally, the trajectory matrix is re-scaled using the estimated rotational angle, and accurate 3D geometry is reconstructed. The two major steps, i.e., the cross-range scaling and the factorization, are performed repeatedly to achieve precise 3D geometry reconstruction. Simulation results have proved the effectiveness and robustness of the proposed method.

  4. Analysis of a 3D imaging device by reconstruction from cone beam X ray radiographs

    International Nuclear Information System (INIS)

    The aim of our study is to analyse the principle of a 3D imaging device which attempts to restore the local density on a cuberill from a set of digital radiographs taken around the object. We have to use a ponctual radiation source to localize the acquisition lines. Therefore the attenuation measurements are modelled by the cone beam X ray transform. In the analysis of the inverse problem, we work out two inversion diagrams which compute the original function, the image of the object, by a sequence of transforms. The theoretical and algorithmical difficulty comes from the fact that, even in the simple case of a circular acquisition trajectory, the cone-shaped geometry prohibits splitting the problem into a superposition of reconstructions in two dimensions. We describe a novel theoretical framework based on the Radon transform. In this new representation space, it becomes possible by a rebinning operation to redistribute the integral values associated to planes from the coordinates system linked to source positions to the spherical coordinates system of the domain. To ensure this shift of space, we have established two formulas, the first approximate but leading to faster processing, related to the Radon transform, the second exact, related to the first derivative of the Radon transform. The inversion of these transforms completes the reconstruction. We state a theorem where we present the hypothesis under which the exact diagram does restore the original function. These are not verified for a circular trajectory, owing to a shadow zone in the Radon domain associated to the planes which intersect the object but not the trajectory. We propose either to restore the missing information or to use an oscillating trajectory

  5. ESTIMATION OF TORTUOSITY AND RECONSTRUCTION OF GEODESIC PATHS IN 3D

    Directory of Open Access Journals (Sweden)

    Charles Peyrega

    2013-03-01

    Full Text Available The morphological tortuosity of a geodesic path in a medium can be defined as the ratio between its geodesic length and the Euclidean distance between its two extremities. Thus, the minimum tortuosity of all the geodesic paths into a medium in 2D or in 3D can be estimated by image processing methodsusing mathematical morphology. Considering a medium, the morphological tortuosities of its internal paths are estimated according to one direction, which is perpendicular to both starting and ending opposite extremities of the geodesicpaths. The used algorithm estimates the morphological tortuosities from geodesic distance maps, which are obtained from geodesic propagations. The shape of the propagated structuring element used to estimate the geodesic distance maps on a discrete grid has a direct influence on the morphological tortuosity and has to be chosen very carefully. The results of our algorithm is an image with pixels p having a value equal to the length of the shortest path containing p and connected to two considered opposite boundaries A and B of the image. The analysis of the histogram of the morphological tortuosities gives access to their statistical distribution. Moreover, for each tortuosity the paths can be extracted from the original image, which highlights the location of them into the sample. However, these geodesic paths have to be reconstructed for further processing. The extraction, because applying a threshold on the tortuosities, results in disconnected components, especially for highly tortuous paths. This reconstruction consists in reconnecting these components to the geodesic path linking the two opposite faces, by means of a backtracking algorithm.

  6. 3D reconstruction of the structure of a residual limb for customising the design of a prosthetic socket.

    Science.gov (United States)

    Shuxian, Zheng; Wanhua, Zhao; Bingheng, Lu

    2005-01-01

    Aiming at overcoming the limitations of the plaster-casting method in traditional prosthetic socket fabrication, the idea of reconstructing the 3D models for bones and skin of the residual limb is proposed. Given the two-dimensional obtained image through CT scanning, using image processing and reverse engineering techniques, the 3D solid model of the residual limb can be successfully reconstructed. The new approach can reproduce both the internal and the external structure of the residual limb. It can moreover avoid making a positive mould by the way of manual modifications. In addition to this, it can provide a scientific basis for the individualization of prosthetic socket design.

  7. AX-PET A novel PET detector concept with full 3D reconstruction

    CERN Document Server

    Braem, A; Séguinot, J; Dissertori, G; Djambazov, L; Lustermann, W; Nessi-Tedaldi, F; Pauss, F; Schinzel, D; Solevi, P; Lacasta, C; Oliver, J F; Rafecas, M; De Leo, R; Nappi, E; Vilardi, I; Chesi, E; Cochran, E; Honscheid, K; Kagan, H; Rudge, A; Smith, S; Weilhammer, P; Johnson, I; Renker, D; Clinthorne, N; Huh, S; Bolle, E; Stapnes, S; Meddi, F

    2009-01-01

    We describe the concept and first experimental tests of a novel 3D axial Positron Emission Tomography (PET) geometry. It allows for a new way of measuring the interaction point in the detector with very high precision. It is based on a matrix of long Lutetium-Yttrium OxyorthoSilicate (LYSO) crystals oriented in the axial direction, each coupled to one Geiger Mode Avalanche Photodiode (G-APD) array. To derive the axial coordinate, Wave Length Shifter (WLS) strips are mounted orthogonally and interleaved between the crystals. The light from the WLS strips is read by custom-made G-APDs. The weighted mean of the signals in the WLS strips has proven to give very precise axial resolution. The achievable resolution along the three axes is mainly driven by the dimensions of the LYSO crystals and WLS strips. This concept is inherently free of parallax errors. Furthermore, it will allow identification of Compton interactions in the detector and for reconstruction of a fraction of them, which is expected to enhance imag...

  8. 3D Velocity and Density Reconstructions of the Local Universe with Cosmicflows-1

    CERN Document Server

    Courtois, Helene M; Tully, R Brent; Gottlober, Stefan

    2011-01-01

    This paper presents an analysis of the local peculiar velocity field based on the Wiener Filter reconstruction method. We used our currently available catalog of distance measurements containing 1,797 galaxies within 3000 km/s: Cosmicflows-1. The Wiener Filter method is used to recover the full 3D peculiar velocity field from the observed map of radial velocities and to recover the underlying linear density field. The velocity field within a data zone of 3000 km/s is decomposed into a local component that is generated within the data zone and a tidal one that is generated by the mass distribution outside that zone. The tidal component is characterized by a coherent flow toward the Norma-Hydra-Centaurus (Great Attractor) region while the local component is dominated by a flow toward the Virgo Cluster and away from the Local Void. A detailed analysis shows that the local flow is predominantly governed by the Local Void and the Virgo Cluster plays a lesser role. The analysis procedure was tested against a mock c...

  9. Real time reconstruction of 3-D electron density distribution over Europe with TaD profiler

    Science.gov (United States)

    Kutiev, Ivan; Marinov, Pencho; Belehaki, Anna

    2015-04-01

    TaD (TSM-assisted Digisonde) profiler, developed on the base of Topside Sounder Model (TSM), provides vertical electron density profile (EDP) from the bottom of ionosphere up to the GNSS orbit heights over Digisonde sounding stations. TaD EDP uses the bottomside profile provided by Digisonde software and extends it above the F layer peak by representing O+ distribution by α-Chapman formula and H+ distribution by a single exponent. The profile above F layer peak takes the topside scale height HT and transition height hT from TSM and plasmasphere scale height Hp defined as a function of HT. All these profile parameters are adjusted to the current conditions by comparing the profile integral with measured GNSS TEC. The latter is taken from GNSS TEC maps produced by Royal Observatory of Belgium in the area (35˚, 60˚)N and (-15˚, 25˚)E. Maps of foF2 and hmF2 are produced in the same area on the base of DIAS (European Digital Upper Atmosphere Server) network of Digisonde stations and TaD profiles are calculated at all grid nodes (1˚x1˚) on latitude and longitude. Electron density at any point of the 3-D space is then obtained by simple interpolation between nodes. Possible use of reconstruction technique to GNSS applications is demonstrated by calculating the distribution of electron density along various ray paths of GNSS signals.

  10. Positron discrimination in large-volume liquid scintillator detectors using 3D topological reconstruction

    International Nuclear Information System (INIS)

    Over the last 20 years, large-volume liquid scintillator detectors have been very successful in measuring neutrinos with energies of a few MeV. One main feature responsible for this is the coincidence between a prompt positron signal and the delayed neutron signal coming from an inverse beta decay. This is used to identify electron anti-neutrinos with high efficiency. However, background mimicking this coincidence e.g. from cosmogenics can still be a limiting factor for this kind of experiments. Therefore, the possibility to individually identify positrons is highly desirable. In addition, this capability would enable the discrimination of beta+ decays and thus increase the potential to discover CNO-neutrinos from the Sun where the beta+ decay of C-11 is a major background source. In this talk, we present a new reconstruction method delivering 3D topological pictures of the energy deposition in large-volume liquid scintillator detectors with a resolution of better than 20 cm. This method was originally developed for high-energy particles of a few GeV. However, it turned out that even at low energies it can reveal some topological information containing hints on the presence of photons accompanying a positron annihilation.

  11. Evaluating Dense 3d Reconstruction Software Packages for Oblique Monitoring of Crop Canopy Surface

    Science.gov (United States)

    Brocks, S.; Bareth, G.

    2016-06-01

    Crop Surface Models (CSMs) are 2.5D raster surfaces representing absolute plant canopy height. Using multiple CMSs generated from data acquired at multiple time steps, a crop surface monitoring is enabled. This makes it possible to monitor crop growth over time and can be used for monitoring in-field crop growth variability which is useful in the context of high-throughput phenotyping. This study aims to evaluate several software packages for dense 3D reconstruction from multiple overlapping RGB images on field and plot-scale. A summer barley field experiment located at the Campus Klein-Altendorf of University of Bonn was observed by acquiring stereo images from an oblique angle using consumer-grade smart cameras. Two such cameras were mounted at an elevation of 10 m and acquired images for a period of two months during the growing period of 2014. The field experiment consisted of nine barley cultivars that were cultivated in multiple repetitions and nitrogen treatments. Manual plant height measurements were carried out at four dates during the observation period. The software packages Agisoft PhotoScan, VisualSfM with CMVS/PMVS2 and SURE are investigated. The point clouds are georeferenced through a set of ground control points. Where adequate results are reached, a statistical analysis is performed.

  12. 3D reconstruction method and connectivity rules of fracture networks generated under different mining layouts

    Institute of Scientific and Technical Information of China (English)

    Zhang Ru; Ai Ting; Li Hegui; Zhang Zetian; Liu Jianfeng

    2013-01-01

    In current research, a series of triaxial tests, which were employed to simulate three typical mining lay-outs (i.e., top-coal caving, non-pillar mining and protected coal seam mining), were conducted on coal by using MTS815 Flex Test GT rock mechanics test system, and the fracture networks in the broken coal samples were qualitatively and quantitatively investigated by employing CT scanning and 3D reconstruc-tion techniques. This work aimed at providing a detail description on the micro-structure and fracture-connectivity characteristics of rupture coal samples under different mining layouts. The results show that: (i) for protected coal seam mining layout, the coal specimens failure is in a compression-shear manner and oppositely, (ii) the tension-shear failure phenomenon is observed for top-coal caving and non-pillar mining layouts. By investigating the connectivity features of the generated fractures in the direction of r1 under different mining layouts, it is found that the connectivity level of the fractures of the samples corresponding to non-pillar mining layout was the highest.

  13. A 3D approach to reconstruct continuous optical images using lidar and MODIS

    Institute of Scientific and Technical Information of China (English)

    HuaGuo; Huang; Jun; Lian

    2015-01-01

    Background: Monitoring forest health and biomass for changes over time in the global environment requires the provision of continuous satellite images. However, optical images of land surfaces are generally contaminated when clouds are present or rain occurs.Methods: To estimate the actual reflectance of land surfaces masked by clouds and potential rain, 3D simulations by the RAPID radiative transfer model were proposed and conducted on a forest farm dominated by birch and larch in Genhe City, Da Xing’An Ling Mountain in Inner Mongolia, China. The canopy height model(CHM) from lidar data were used to extract individual tree structures(location, height, crown width). Field measurements related tree height to diameter of breast height(DBH), lowest branch height and leaf area index(LAI). Series of Landsat images were used to classify tree species and land cover. MODIS LAI products were used to estimate the LAI of individual trees. Combining all these input variables to drive RAPID, high-resolution optical remote sensing images were simulated and validated with available satellite images.Results: Evaluations on spatial texture, spectral values and directional reflectance were conducted to show comparable results.Conclusions: The study provides a proof-of-concept approach to link lidar and MODIS data in the parameterization of RAPID models for high temporal and spatial resolutions of image reconstruction in forest dominated areas.

  14. Fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography

    International Nuclear Information System (INIS)

    We investigate fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography for applications in small animal imaging. Our forward model uses a diffusion approximation for optically inhomogeneous tissue, which we solve using a finite element method (FEM). We examine two approaches to incorporating the forward model into the solution of the inverse problem. In a conventional direct calculation approach one computes the full forward model by repeated solution of the FEM problem, once for each potential source location. We describe an alternative on-the-fly approach where one does not explicitly solve for the full forward model. Instead, the solution to the forward problem is included implicitly in the formulation of the inverse problem, and the FEM problem is solved at each iteration for the current image estimate. We evaluate the convergence speeds of several representative iterative algorithms. We compare the computation cost of those two approaches, concluding that the on-the-fly approach can lead to substantial reductions in total cost when combined with a rapidly converging iterative algorithm

  15. Automatic Reconstruction of Fault Networks from Seismicity Catalogs: 3D Optimal Anisotropic Dynamic Clustering

    CERN Document Server

    Ouillon, G; Sornette, D; Ouillon, Guy; Ducorbier, Caroline; Sornette, Didier

    2007-01-01

    We propose a new pattern recognition method that is able to reconstruct the 3D structure of the active part of a fault network using the spatial location of earthquakes. The method is a generalization of the so-called dynamic clustering method, that originally partitions a set of datapoints into clusters, using a global minimization criterion over the spatial inertia of those clusters. The new method improves on it by taking into account the full spatial inertia tensor of each cluster, in order to partition the dataset into fault-like, anisotropic clusters. Given a catalog of seismic events, the output is the optimal set of plane segments that fits the spatial structure of the data. Each plane segment is fully characterized by its location, size and orientation. The main tunable parameter is the accuracy of the earthquake localizations, which fixes the resolution, i.e. the residual variance of the fit. The resolution determines the number of fault segments needed to describe the earthquake catalog, the better...

  16. Observer success rates for identification of 3D surface reconstructed facial images and implications for patient privacy and security

    Science.gov (United States)

    Chen, Joseph J.; Siddiqui, Khan M.; Fort, Leslie; Moffitt, Ryan; Juluru, Krishna; Kim, Woojin; Safdar, Nabile; Siegel, Eliot L.

    2007-03-01

    3D and multi-planar reconstruction of CT images have become indispensable in the routine practice of diagnostic imaging. These tools cannot only enhance our ability to diagnose diseases, but can also assist in therapeutic planning as well. The technology utilized to create these can also render surface reconstructions, which may have the undesired potential of providing sufficient detail to allow recognition of facial features and consequently patient identity, leading to violation of patient privacy rights as described in the HIPAA (Health Insurance Portability and Accountability Act) legislation. The purpose of this study is to evaluate whether 3D reconstructed images of a patient's facial features can indeed be used to reliably or confidently identify that specific patient. Surface reconstructed images of the study participants were created used as candidates for matching with digital photographs of participants. Data analysis was performed to determine the ability of observers to successfully match 3D surface reconstructed images of the face with facial photographs. The amount of time required to perform the match was recorded as well. We also plan to investigate the ability of digital masks or physical drapes to conceal patient identity. The recently expressed concerns over the inability to truly "anonymize" CT (and MRI) studies of the head/face/brain are yet to be tested in a prospective study. We believe that it is important to establish whether these reconstructed images are a "threat" to patient privacy/security and if so, whether minimal interventions from a clinical perspective can substantially reduce this possibility.

  17. A 3D reconstruction solution to ultrasound Joule heat density tomography based on acousto-electric effect: a simulation study

    Science.gov (United States)

    Yang, R.; Song, A.; Li, X. D.; Lu, Y.; Yan, R.; Xu, B.; Li, X.

    2014-10-01

    A 3D reconstruction solution to ultrasound Joule heat density tomography based on acousto-electric effect by deconvolution is proposed for noninvasive imaging of biological tissue. Compared with ultrasound current source density imaging, ultrasound Joule heat density tomography doesn't require any priori knowledge of conductivity distribution and lead fields, so it can gain better imaging result, more adaptive to environment and with wider application scope. For a general 3D volume conductor with broadly distributed current density field, in the AE equation the ultrasound pressure can't simply be separated from the 3D integration, so it is not a common modulation and basebanding (heterodyning) method is no longer suitable to separate Joule heat density from the AE signals. In the proposed method the measurement signal is viewed as the output of Joule heat density convolving with ultrasound wave. As a result, the internal 3D Joule heat density can be reconstructed by means of Wiener deconvolution. A series of computer simulations set for breast cancer imaging applications, with consideration of ultrasound beam diameter, noise level, conductivity contrast, position dependency and size of simulated tumors, have been conducted to evaluate the feasibility and performance of the proposed reconstruction method. The computer simulation results demonstrate that high spatial resolution 3D ultrasound Joule heat density imaging is feasible using the proposed method, and it has potential applications to breast cancer detection and imaging of other organs.

  18. Reconstruction of high-resolution 3D dose from matrix measurements : error detection capability of the COMPASS correction kernel method

    NARCIS (Netherlands)

    Godart, J.; Korevaar, E. W.; Visser, R.; Wauben, D. J. L.; van t Veld, Aart

    2011-01-01

    TheCOMPASS system (IBADosimetry) is a quality assurance (QA) tool which reconstructs 3D doses inside a phantom or a patient CT. The dose is predicted according to the RT plan with a correction derived from 2D measurements of a matrix detector. This correction method is necessary since a direct recon

  19. Experimental investigation on 3D-SEM reconstructions of a wire gauge using stereo-pair technique

    DEFF Research Database (Denmark)

    Carli, Lorenzo; Genta, G.; Cantatore, Angela;

    2011-01-01

    In this work an experimental investigation is addressed concerning 3D-SEM reconstructions obtained from the so-called stereo-pair technique. Three-dimensional topography of an object can be derived from two SEM images acquired from two different angles, through item rotation by means of the SEM s...... resorting to factorial experimentation and statistical analysis of results....

  20. 3D Indoor Building Environment Reconstruction using Polynomial Kernel, Least Square Adjustment, Interval Analysis and Homotopy Continuation

    DEFF Research Database (Denmark)

    Jamali, Ali; Rahman, Alias Abdul; Antón Castro, Francesc/François;

    2016-01-01

    to be tested to see if the observation accuracy is sufficient for the 3D building modelling. The accuracy of the rangefinder is evaluated and a simple spatial model is reconstructed from real data. This technique is rapid (it requires a shorter time as compared to others), but the results show inconsistencies......Nowadays, municipalities intend to have 3D city models for facility management, disaster management and architectural planning. Indoor models can be reconstructed from construction plans but sometimes, they are not available or very often, they differ from ‘as-built’ plans. In this case......, the buildings and their rooms must be surveyed. One of the most utilized methods of indoor surveying is laser scanning. The laser scanning method allows taking accurate and detailed measurements. However, Terrestrial Laser Scanner is costly and time consuming. In this paper, several techniques for indoor 3D...

  1. Grating-based phase contrast tomosynthesis imaging: Proof-of-concept experimental studies

    International Nuclear Information System (INIS)

    Purpose: This paper concerns the feasibility of x-ray differential phase contrast (DPC) tomosynthesis imaging using a grating-based DPC benchtop experimental system, which is equipped with a commercial digital flat-panel detector and a medical-grade rotating-anode x-ray tube. An extensive system characterization was performed to quantify its imaging performance. Methods: The major components of the benchtop system include a diagnostic x-ray tube with a 1.0 mm nominal focal spot size, a flat-panel detector with 96 μm pixel pitch, a sample stage that rotates within a limited angular span of ±30°, and a Talbot-Lau interferometer with three x-ray gratings. A total of 21 projection views acquired with 3° increments were used to reconstruct three sets of tomosynthetic image volumes, including the conventional absorption contrast tomosynthesis image volume (AC-tomo) reconstructed using the filtered-backprojection (FBP) algorithm with the ramp kernel, the phase contrast tomosynthesis image volume (PC-tomo) reconstructed using FBP with a Hilbert kernel, and the differential phase contrast tomosynthesis image volume (DPC-tomo) reconstructed using the shift-and-add algorithm. Three inhouse physical phantoms containing tissue-surrogate materials were used to characterize the signal linearity, the signal difference-to-noise ratio (SDNR), the three-dimensional noise power spectrum (3D NPS), and the through-plane artifact spread function (ASF). Results: While DPC-tomo highlights edges and interfaces in the image object, PC-tomo removes the differential nature of the DPC projection data and its pixel values are linearly related to the decrement of the real part of the x-ray refractive index. The SDNR values of polyoxymethylene in water and polystyrene in oil are 1.5 and 1.0, respectively, in AC-tomo, and the values were improved to 3.0 and 2.0, respectively, in PC-tomo. PC-tomo and AC-tomo demonstrate equivalent ASF, but their noise characteristics quantified by the 3D NPS

  2. Reconstruction of 3d grain boundaries from rock thin sections, using polarised light

    Science.gov (United States)

    Markus Hammes, Daniel; Peternell, Mark

    2016-04-01

    Grain boundaries affect the physical and chemical properties of polycrystalline materials significantly by initiating reactions and collecting impurities (Birchenall, 1959), and play an essential role in recrystallization (Doherty et al. 1997). In particular, the shape and crystallographic orientation of grain boundaries reveal the deformation and annealing history of rocks (Kruhl and Peternell 2002, Kuntcheva et al. 2006). However, there is a lack of non-destructive and easy-to-use computer supported methods to determine grain boundary geometries in 3D. The only available instrument using optical light to measure grain boundary angles is still the polarising microscope with attached universal stage; operated manually and time-consuming in use. Here we present a new approach to determine 3d grain boundary orientations from 2D rock thin sections. The data is recorded by using an automatic fabric analyser microscope (Peternell et al., 2010). Due to its unique arrangement of 9 light directions the highest birefringence colour due to each light direction and crystal orientation (retardation) can be determined at each pixel in the field of view. Retardation profiles across grain boundaries enable the calculation of grain boundary angle and direction. The data for all positions separating the grains are combined and further processed. In combination with the lateral position of the grain boundary, acquired using the FAME software (Hammes and Peternell, in review), the data is used to reconstruct a 3d grain boundary model. The processing of data is almost fully automatic by using MATLAB®. Only minor manual input is required. The applicability was demonstrated on quartzite samples, but the method is not solely restricted on quartz grains and other birefringent polycrystalline materials could be used instead. References: Birchenall, C.E., 1959: Physical Metallurgy. McGraw-Hill, New York. Doherty, R.D., Hughes, D.A., Humphreys, F.J., Jonas, J.J., Juul Jensen, D., Kassner, M

  3. Interventional C-arm tomosynthesis for vascular imaging: initial results

    Science.gov (United States)

    Langan, David A.; Claus, Bernhard E. H.; Al Assad, Omar; Trousset, Yves; Riddell, Cyril; Avignon, Gregoire; Solomon, Stephen B.; Lai, Hao; Wang, Xin

    2015-03-01

    As percutaneous endovascular procedures address more complex and broader disease states, there is an increasing need for intra-procedure 3D vascular imaging. In this paper, we investigate C-Arm 2-axis tomosynthesis ("Tomo") as an alternative to C-Arm Cone Beam Computed Tomography (CBCT) for workflow situations in which the CBCT acquisition may be inconvenient or prohibited. We report on our experience in performing tomosynthesis acquisitions with a digital angiographic imaging system (GE Healthcare Innova 4100 Angiographic Imaging System, Milwaukee, WI). During a tomo acquisition the detector and tube each orbit on a plane above and below the table respectively. The tomo orbit may be circular or elliptical, and the tomographic half-angle in our studies varied from approximately 16 to 28 degrees as a function of orbit period. The trajectory, geometric calibration, and gantry performance are presented. We overview a multi-resolution iterative reconstruction employing compressed sensing techniques to mitigate artifacts associated with incomplete data reconstructions. In this work, we focus on the reconstruction of small high contrast objects such as iodinated vasculature and interventional devices. We evaluate the overall performance of the acquisition and reconstruction through phantom acquisitions and a swine study. Both tomo and comparable CBCT acquisitions were performed during the swine study thereby enabling the use of CBCT as a reference in the evaluation of tomo vascular imaging. We close with a discussion of potential clinical applications for tomo, reflecting on the imaging and workflow results achieved.

  4. i-BRUSH: a gaze-contingent virtual paintbrush for dense 3D reconstruction in robotic assisted surgery.

    Science.gov (United States)

    Visentini-Scarzanella, Marco; Mylonas, George P; Stoyanov, Danail; Yang, Guang-Zhong

    2009-01-01

    With increasing demand on intra-operative navigation and motion compensation during robotic assisted minimally invasive surgery, real-time 3D deformation recovery remains a central problem. Currently the majority of existing methods rely on salient features, where the inherent paucity of distinctive landmarks implies either a semi-dense reconstruction or the use of strong geometrical constraints. In this study, we propose a gaze-contingent depth reconstruction scheme by integrating human perception with semi-dense stereo and p-q based shading information. Depth inference is carried out in real-time through a novel application of Bayesian chains without smoothness priors. The practical value of the scheme is highlighted by detailed validation using a beating heart phantom model with known geometry to verify the performance of gaze-contingent 3D surface reconstruction and deformation recovery. PMID:20426007

  5. i-BRUSH: a gaze-contingent virtual paintbrush for dense 3D reconstruction in robotic assisted surgery.

    Science.gov (United States)

    Visentini-Scarzanella, Marco; Mylonas, George P; Stoyanov, Danail; Yang, Guang-Zhong

    2009-01-01

    With increasing demand on intra-operative navigation and motion compensation during robotic assisted minimally invasive surgery, real-time 3D deformation recovery remains a central problem. Currently the majority of existing methods rely on salient features, where the inherent paucity of distinctive landmarks implies either a semi-dense reconstruction or the use of strong geometrical constraints. In this study, we propose a gaze-contingent depth reconstruction scheme by integrating human perception with semi-dense stereo and p-q based shading information. Depth inference is carried out in real-time through a novel application of Bayesian chains without smoothness priors. The practical value of the scheme is highlighted by detailed validation using a beating heart phantom model with known geometry to verify the performance of gaze-contingent 3D surface reconstruction and deformation recovery.

  6. Research and development of fringe projection-based methods in 3D shape reconstruction

    Institute of Scientific and Technical Information of China (English)

    WU Lu-shen; PENG Qing-jin

    2006-01-01

    This paper discusses current research and development of fringe projection-based techniques. A system based on Fourier transform profilometry (FTP) is proposed for three-dimensional (3D) shape recovery. The system improves the method of phase unwrapping to gain accurate 3D shapes of objects. The method uses a region-growing algorithm for the path prediction guided by the quality map to increase the recovering accuracy and provides a fast and simple tool for 3D shape recovery. The shape measurement and data recovery are integrated to offer a new method of 3D modelling. Examples are presented to verify the feasibility of the proposed method.

  7. Possibility of reconstruction of dental plaster cast from 3D digital study models

    OpenAIRE

    Kasparova, Magdalena; Grafova, Lucie; Dvorak, Petr; Dostalova, Tatjana; Prochazka, Ales; Eliasova, Hana; Prusa, Josef; Kakawand, Soroush

    2013-01-01

    Objectives To compare traditional plaster casts, digital models and 3D printed copies of dental plaster casts based on various criteria. To determine whether 3D printed copies obtained using open source system RepRap can replace traditional plaster casts in dental practice. To compare and contrast the qualities of two possible 3D printing options – open source system RepRap and commercially available 3D printing. Design and settings A method comparison study on 10 dental plaster casts from th...

  8. An open-source Matlab code package for improved rank-reduction 3D seismic data denoising and reconstruction

    Science.gov (United States)

    Chen, Yangkang; Huang, Weilin; Zhang, Dong; Chen, Wei

    2016-10-01

    Simultaneous seismic data denoising and reconstruction is a currently popular research subject in modern reflection seismology. Traditional rank-reduction based 3D seismic data denoising and reconstruction algorithm will cause strong residual noise in the reconstructed data and thus affect the following processing and interpretation tasks. In this paper, we propose an improved rank-reduction method by modifying the truncated singular value decomposition (TSVD) formula used in the traditional method. The proposed approach can help us obtain nearly perfect reconstruction performance even in the case of low signal-to-noise ratio (SNR). The proposed algorithm is tested via one synthetic and field data examples. Considering that seismic data interpolation and denoising source packages are seldom in the public domain, we also provide a program template for the rank-reduction based simultaneous denoising and reconstruction algorithm by providing an open-source Matlab package.

  9. Holographic microscopy reconstruction in both object and image half spaces with undistorted 3D grid

    CERN Document Server

    Verrier, Nicolas; Tessier, Gilles; Gross, Michel

    2015-01-01

    We propose a holographic microscopy reconstruction method, which propagates the hologram, in the object half space, in the vicinity of the object. The calibration yields reconstructions with an undistorted reconstruction grid i.e. with orthogonal x, y and z axis and constant pixels pitch. The method is validated with an USAF target imaged by a x60 microscope objective, whose holograms are recorded and reconstructed for different USAF locations along the longitudinal axis:-75 to +75 {\\mu}m. Since the reconstruction numerical phase mask, the reference phase curvature and MO form an afocal device, the reconstruction can be interpreted as occurring equivalently in the object or in image half space.

  10. Workflows and the Role of Images for Virtual 3d Reconstruction of no Longer Extant Historic Objects

    Science.gov (United States)

    Münster, S.

    2013-07-01

    3D reconstruction technologies have gained importance as tools for the research and visualization of no longer extant historic objects during the last decade. Within such reconstruction processes, visual media assumes several important roles: as the most important sources especially for a reconstruction of no longer extant objects, as a tool for communication and cooperation within the production process, as well as for a communication and visualization of results. While there are many discourses about theoretical issues of depiction as sources and as visualization outcomes of such projects, there is no systematic research about the importance of depiction during a 3D reconstruction process and based on empirical findings. Moreover, from a methodological perspective, it would be necessary to understand which role visual media plays during the production process and how it is affected by disciplinary boundaries and challenges specific to historic topics. Research includes an analysis of published work and case studies investigating reconstruction projects. This study uses methods taken from social sciences to gain a grounded view of how production processes would take place in practice and which functions and roles images would play within them. For the investigation of these topics, a content analysis of 452 conference proceedings and journal articles related to 3D reconstruction modeling in the field of humanities has been completed. Most of the projects described in those publications dealt with data acquisition and model building for existing objects. Only a small number of projects focused on structures that no longer or never existed physically. Especially that type of project seems to be interesting for a study of the importance of pictures as sources and as tools for interdisciplinary cooperation during the production process. In the course of the examination the authors of this paper applied a qualitative content analysis for a sample of 26 previously

  11. 3D reconstruction of carotid atherosclerotic plaque: comparison between spatial compound ultrasound models and anatomical models

    DEFF Research Database (Denmark)

    Lind, Bo L.; Fagertun, Jens; Wilhjelm, Jens E.;

    2007-01-01

    This study deals with the creation of 3D models that can work as a tool for discriminating between tissue and background in the development of tissue classification methods. Ten formalin-fixed atherosclerotic carotid plaques removed by endarterectomy were scanned with 3D multi-angle spatial...... compound ultrasound (US) and subsequently sliced and photographed to produce a 3D anatomical data set. Outlines in the ultrasound data were found by means of active contours and combined into 10 3D ultrasound models. The plaque regions of the anatomical photographs were outlined manually and then combined...... into 10 3D anatomical models. The volumes of the anatomical models correlated with the volume found by a water displacement method (r = 0.95), except for an offset. The models were compared in three ways. Visual inspection showed quite good agreement between the models. The volumes of the ultrasound...

  12. The quality of reconstructed 3D images in multidetector-row helical CT: experimental study involving scan parameters

    International Nuclear Information System (INIS)

    To determine which multidetector-row helical CT scanning technique provides the best-quality reconstructed 3D images, and to assess differences in image quality according to the levels of the scanning parameters used. Four objects with different surfaces and contours were scanned using multidetector-row helical CT at three detector-row collimations (1.25, 2.50, 5.00 mm), two pitches (3.0, 6.0), and three different degrees of overlap between the reconstructed slices (0%, 25%, 50%). Reconstructed 3D images of the resulting 72 sets of data were produced using volumetric rendering. The 72 images were graded on a scale from 1 (worst) to 5 (best) for each of four rating criteria, giving a mean score for each criterion and an overall mean score. Statistical analysis was used to assess differences in image quality according to scanning parameter levels. The mean score for each rating criterion, and the overall mean score, varied significantly according to the scanning parameter levels used. With regard to detector-row collimation and pitch, all levels of scanning parameters gave rise to significant differences, while in the degree of overlap of reconstructed slices, there were significant differences between overlap of 0% and of 50% in all levels of scanning parameters, and between overlap of 25% and of 50% in overall accuracy and overall mean score. Among the 18 scanning sequences, the highest score (4.94) was achieved with 1.25 mm detector-row collimation, 3.0 pitch, and 50% overlap between reconstructed slices. Comparison of the quality of reconstructed 3D images obtained using multidetector-row helical CT and various scanning techniques indicated that the 1.25 mm, 3.0, 50% scanning sequence was best. Quality improved as detector-row collimation decreased; as pitch was reduced from 6.0 to 3.0; and as overlap between reconstructed slices increased

  13. GPU-based rapid reconstruction of cellular 3D refractive index maps from tomographic phase microscopy (Conference Presentation)

    Science.gov (United States)

    Dardikman, Gili; Shaked, Natan T.

    2016-03-01

    We present highly parallel and efficient algorithms for real-time reconstruction of the quantitative three-dimensional (3-D) refractive-index maps of biological cells without labeling, as obtained from the interferometric projections acquired by tomographic phase microscopy (TPM). The new algorithms are implemented on the graphic processing unit (GPU) of the computer using CUDA programming environment. The reconstruction process includes two main parts. First, we used parallel complex wave-front reconstruction of the TPM-based interferometric projections acquired at various angles. The complex wave front reconstructions are done on the GPU in parallel, while minimizing the calculation time of the Fourier transforms and phase unwrapping needed. Next, we implemented on the GPU in parallel the 3-D refractive index map retrieval using the TPM filtered-back projection algorithm. The incorporation of algorithms that are inherently parallel with a programming environment such as Nvidia's CUDA makes it possible to obtain real-time processing rate, and enables high-throughput platform for label-free, 3-D cell visualization and diagnosis.

  14. A new approach for 3D reconstruction from bright field TEM imaging: Beam precession assisted electron tomography

    International Nuclear Information System (INIS)

    The successful combination of electron beam precession and bright field electron tomography for 3D reconstruction is reported. Beam precession is demonstrated to be a powerful technique to reduce the contrast artifacts due to diffraction and curvature in thin foils. Taking advantage of these benefits, Precession assisted electron tomography has been applied to reconstruct the morphology of Sn precipitates embedded in an Al matrix, from a tilt series acquired in a range from +49o to -61o at intervals of 2o and with a precession angle of 0.6o in bright field mode. The combination of electron tomography and beam precession in conventional TEM mode is proposed as an alternative procedure to obtain 3D reconstructions of nano-objects without a scanning system or a high angle annular dark field detector. -- Highlights: → Electron beam precession reduces spurious diffraction contrast in bright field mode. → Bend contour related contrast depends on precession angle. → Electron beam precession is combined with bright field electron tomography. → Precession assisted BF tomography allowed 3D reconstruction of a Sn precipitate.

  15. "High-precision, reconstructed 3D model" of skull scanned by conebeam CT: Reproducibility verified using CAD/CAM data.

    Science.gov (United States)

    Katsumura, Seiko; Sato, Keita; Ikawa, Tomoko; Yamamura, Keiko; Ando, Eriko; Shigeta, Yuko; Ogawa, Takumi

    2016-01-01

    Computed tomography (CT) scanning has recently been introduced into forensic medicine and dentistry. However, the presence of metal restorations in the dentition can adversely affect the quality of three-dimensional reconstruction from CT scans. In this study, we aimed to evaluate the reproducibility of a "high-precision, reconstructed 3D model" obtained from a conebeam CT scan of dentition, a method that might be particularly helpful in forensic medicine. We took conebeam CT and helical CT images of three dry skulls marked with 47 measuring points; reconstructed three-dimensional images; and measured the distances between the points in the 3D images with a computer-aided design/computer-aided manufacturing (CAD/CAM) marker. We found that in comparison with the helical CT, conebeam CT is capable of reproducing measurements closer to those obtained from the actual samples. In conclusion, our study indicated that the image-reproduction from a conebeam CT scan was more accurate than that from a helical CT scan. Furthermore, the "high-precision reconstructed 3D model" facilitates reliable visualization of full-sized oral and maxillofacial regions in both helical and conebeam CT scans. PMID:26832374

  16. 3D RECONSTRUCTION OF PHALANGEAL AND METACARPAL BONES OF MALE JUDO PLAYERS AND SEDENTARY MEN BY MDCT IMAGES

    Directory of Open Access Journals (Sweden)

    Ibrahim Kalayci

    2008-12-01

    Full Text Available This study has been performed to reveal hand bone peculiarities of elite male judoists by comparing their phalangeal and metacarpal bones with those of sedentary men on the basis of biometric ratio of the bones by means of three-dimensional (3D reconstruction of multidetector computed tomography (MDCT images. For this purpose, the axial images of the right and left hands of 8 elite male judo players (mean age: 22.0 ± 2.9 years, mean weight: 64.0 ± 4.9 kg and 8 sedentary men (mean age: 26.0 ± 2.8 years, mean weight: 69.0 ± 3.6 kg were obtained from MDCT. After semi-automatic segmentation and manual editing, the tracings of bone surfaces were stacked and overlaid to be reconstructed as the 3D images by the 3D program. All biometrical measurements of the reconstructed images of the bones were automatically calculated by this program to analyze statistically. This study showed that the differences between biometric ratios of judoist and sedentary men's hand bones were significant contrary to null hypothesis which was established as there is no difference between biometric hand bone ratios of these men of both groups. Therefore null hypothesis was rejected. Author suggests that intense clutching actions practised in judo sports can most probably lead to some hand bone proliferations. 3D reconstructed results belonging to the judo players and sedentary men help orthopaedists to diagnose pathological formations related to hand bones of judoists and may be used for anatomical education in medicine faculties, respectively. We hope that the results from the biometric and reconstructive techniques carried out in this work will contribute to the present knowledge on judoist and shed light on the future studies on sports medicine related to skeletal structure of other sportsmen

  17. Portable high-intensity focused ultrasound system with 3D electronic steering, real-time cavitation monitoring, and 3D image reconstruction algorithms: a preclinical study in pigs

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Lee, Jae Young; Hwang, Eui Jin; Hwang, In Pyeong; Woo, Sung Min; Lee, Chang Joo; Park, Eun Joo; Choi, Byung Ihn [Dept. of Radiology and Institute of Radiation Medicine, Seoul National University Hospital, Seoul (Korea, Republic of)

    2014-10-15

    The aim of this study was to evaluate the safety and accuracy of a new portable ultrasonography-guided high-intensity focused ultrasound (USg-HIFU) system with a 3-dimensional (3D) electronic steering transducer, a simultaneous ablation and imaging module, real-time cavitation monitoring, and 3D image reconstruction algorithms. To address the accuracy of the transducer, hydrophones in a water chamber were used to assess the generation of sonic fields. An animal study was also performed in five pigs by ablating in vivo thighs by single-point sonication (n=10) or volume sonication (n=10) and ex vivo kidneys by single-point sonication (n=10). Histological and statistical analyses were performed. In the hydrophone study, peak voltages were detected within 1.0 mm from the targets on the y- and z-axes and within 2.0-mm intervals along the x-axis (z-axis, direction of ultrasound propagation; y- and x-axes, perpendicular to the direction of ultrasound propagation). Twenty-nine of 30 HIFU sessions successfully created ablations at the target. The in vivo porcine thigh study showed only a small discrepancy (width, 0.5-1.1 mm; length, 3.0 mm) between the planning ultrasonograms and the pathological specimens. Inordinate thermal damage was not observed in the adjacent tissues or sonic pathways in the in vivo thigh and ex vivo kidney studies. Our study suggests that this new USg-HIFU system may be a safe and accurate technique for ablating soft tissues and encapsulated organs.

  18. Sieving Scattered 3D Point Clouds Using Clustering Analysis for 3D Surface Reconstruction%三维重建中散乱点云的聚类筛选与网格重建

    Institute of Scientific and Technical Information of China (English)

    陈晓霞; 陈孝威

    2011-01-01

    During the course of 3d surface reconstruction, there are a large number of noises and isolated 3d points in raw 3d point clouds, which obtained from images. If we directly use these data to reconstruct surface, the algorithm will make surface sharply prominent and ineffective reconstruction. Because of above problems, a method that sieving 3d point clouds based on DBSCAN is presented in this paper, and then 3d surface is reconstructed using filtered 3d point clouds. Experiments show that good 3d surface reconstruction is obtained using this algorithm.%三维重建过程中获得的初始海量数据存在大量的噪声和孤立点,使得直接使用这些数据进行网格重建时,将会产生尖锐的凸出,导致重建效果不好,甚至是网格重建失败.针对以上问题,提出首先采用基于密度聚类的方法筛选三维点云,然后进行网格重建.实验表明本文算法获得了较好的网格重建效果.

  19. An image-based approach to the reconstruction of ancient architectures by extracting and arranging 3D spatial components

    Institute of Scientific and Technical Information of China (English)

    Divya Udayan J; HyungSeok KIM; Jee-In KIM

    2015-01-01

    The objective of this research is the rapid reconstruction of ancient buildings of historical importance using a single image. The key idea of our approach is to reduce the infi nite solutions that might otherwise arise when recovering a 3D geometry from 2D photographs. The main outcome of our research shows that the proposed methodology can be used to reconstruct ancient monuments for use as proxies for digital effects in applications such as tourism, games, and entertainment, which do not require very accurate modeling. In this article, we consider the reconstruction of ancient Mughal architecture including the Taj Mahal. We propose a modeling pipeline that makes an easy reconstruction possible using a single photograph taken from a single view, without the need to create complex point clouds from multiple images or the use of laser scanners. First, an initial model is automatically reconstructed using locally fi tted planar primitives along with their boundary polygons and the adjacency relation among parts of the polygons. This approach is faster and more accurate than creating a model from scratch because the initial reconstruction phase provides a set of structural information together with the adjacency relation, which makes it possible to estimate the approximate depth of the entire structural monument. Next, we use manual extrapolation and editing techniques with modeling software to assemble and adjust different 3D components of the model. Thus, this research opens up the opportunity for the present generation to experience remote sites of architectural and cultural importance through virtual worlds and real-time mobile applications. Variations of a recreated 3D monument to represent an amalgam of various cultures are targeted for future work.

  20. Reliability of trunk shape measurements based on 3-D surface reconstructions

    OpenAIRE

    Pazos, Valérie; Cheriet, Farida; Danserau, Jean; Ronsky, Janet; Zernicke, Ronald F.; Labelle, Hubert

    2007-01-01

    This study aimed to estimate the reliability of 3-D trunk surface measurements for the characterization of external asymmetry associated with scoliosis. Repeated trunk surface acquisitions using the Inspeck system (Inspeck Inc., Montreal, Canada), with two different postures A (anatomical position) and B (‘‘clavicle’’ position), were obtained from patients attending a scoliosis clinic. For each acquisition, a 3-D model of the patient’s trunk was built and a series of measurements was computed...

  1. Complex adaptation-based LDR image rendering for 3D image reconstruction

    Science.gov (United States)

    Lee, Sung-Hak; Kwon, Hyuk-Ju; Sohng, Kyu-Ik

    2014-07-01

    A low-dynamic tone-compression technique is developed for realistic image rendering that can make three-dimensional (3D) images similar to realistic scenes by overcoming brightness dimming in the 3D display mode. The 3D surround provides varying conditions for image quality, illuminant adaptation, contrast, gamma, color, sharpness, and so on. In general, gain/offset adjustment, gamma compensation, and histogram equalization have performed well in contrast compression; however, as a result of signal saturation and clipping effects, image details are removed and information is lost on bright and dark areas. Thus, an enhanced image mapping technique is proposed based on space-varying image compression. The performance of contrast compression is enhanced with complex adaptation in a 3D viewing surround combining global and local adaptation. Evaluating local image rendering in view of tone and color expression, noise reduction, and edge compensation confirms that the proposed 3D image-mapping model can compensate for the loss of image quality in the 3D mode.

  2. A user-friendly nano-CT image alignment and 3D reconstruction platform based on LabVIEW

    Science.gov (United States)

    Wang, Sheng-Hao; Zhang, Kai; Wang, Zhi-Li; Gao, Kun; Wu, Zhao; Zhu, Pei-Ping; Wu, Zi-Yu

    2015-01-01

    X-ray computed tomography at the nanometer scale (nano-CT) offers a wide range of applications in scientific and industrial areas. Here we describe a reliable, user-friendly, and fast software package based on LabVIEW that may allow us to perform all procedures after the acquisition of raw projection images in order to obtain the inner structure of the investigated sample. A suitable image alignment process to address misalignment problems among image series due to mechanical manufacturing errors, thermal expansion, and other external factors has been considered, together with a novel fast parallel beam 3D reconstruction procedure that was developed ad hoc to perform the tomographic reconstruction. We have obtained remarkably improved reconstruction results at the Beijing Synchrotron Radiation Facility after the image calibration, the fundamental role of this image alignment procedure was confirmed, which minimizes the unwanted blurs and additional streaking artifacts that are always present in reconstructed slices. Moreover, this nano-CT image alignment and its associated 3D reconstruction procedure are fully based on LabVIEW routines, significantly reducing the data post-processing cycle, thus making the activity of the users faster and easier during experimental runs.

  3. A collaborative computing framework of cloud network and WBSN applied to fall detection and 3-D motion reconstruction.

    Science.gov (United States)

    Lai, Chin-Feng; Chen, Min; Pan, Jeng-Shyang; Youn, Chan-Hyun; Chao, Han-Chieh

    2014-03-01

    As cloud computing and wireless body sensor network technologies become gradually developed, ubiquitous healthcare services prevent accidents instantly and effectively, as well as provides relevant information to reduce related processing time and cost. This study proposes a co-processing intermediary framework integrated cloud and wireless body sensor networks, which is mainly applied to fall detection and 3-D motion reconstruction. In this study, the main focuses includes distributed computing and resource allocation of processing sensing data over the computing architecture, network conditions and performance evaluation. Through this framework, the transmissions and computing time of sensing data are reduced to enhance overall performance for the services of fall events detection and 3-D motion reconstruction.

  4. Hardware Implementation and Validation of 3D Underwater Shape Reconstruction Algorithm Using a Stereo-Catadioptric System

    Directory of Open Access Journals (Sweden)

    Rihab Hmida

    2016-08-01

    Full Text Available In this paper, we present a new stereo vision-based system and its efficient hardware implementation for real-time underwater environments exploration throughout 3D sparse reconstruction based on a number of feature points. The proposed underwater 3D shape reconstruction algorithm details are presented. The main concepts and advantages are discussed and comparison with existing systems is performed. In order to achieve real-time video constraints, a hardware implementation of the algorithm is performed using Xilinx System Generator. The pipelined stereo vision system has been implemented using Field Programmable Gate Arrays (FPGA technology. Both timing constraints and mathematical operations precision have been evaluated in order to validate the proposed hardware implementation of our system. Experimental results show that the proposed system presents high accuracy and execution time performances.

  5. Digital tomosynthesis (DTS) with a Circular X-ray tube: Its image reconstruction based on total-variation minimization and the image characteristics

    Science.gov (United States)

    Park, Y. O.; Hong, D. K.; Cho, H. S.; Je, U. K.; Oh, J. E.; Lee, M. S.; Kim, H. J.; Lee, S. H.; Jang, W. S.; Cho, H. M.; Choi, S. I.; Koo, Y. S.

    2013-09-01

    In this paper, we introduce an effective imaging system for digital tomosynthesis (DTS) with a circular X-ray tube, the so-called circular-DTS (CDTS) system, and its image reconstruction algorithm based on the total-variation (TV) minimization method for low-dose, high-accuracy X-ray imaging. Here, the X-ray tube is equipped with a series of cathodes distributed around a rotating anode, and the detector remains stationary throughout the image acquisition. We considered a TV-based reconstruction algorithm that exploited the sparsity of the image with substantially high image accuracy. We implemented the algorithm for the CDTS geometry and successfully reconstructed images of high accuracy. The image characteristics were investigated quantitatively by using some figures of merit, including the universal-quality index (UQI) and the depth resolution. For selected tomographic angles of 20, 40, and 60°, the corresponding UQI values in the tomographic view were estimated to be about 0.94, 0.97, and 0.98, and the depth resolutions were about 4.6, 3.1, and 1.2 voxels in full width at half maximum (FWHM), respectively. We expect the proposed method to be applicable to developing a next-generation dental or breast X-ray imaging system.

  6. Method for 3D Object Reconstruction Using Several Portion of 2D Images from the Different Aspects Acquired with Image Scopes Included in the Fiber Retractor

    Directory of Open Access Journals (Sweden)

    Kohei Arai

    2012-12-01

    Full Text Available Method for 3D object reconstruction using several portions of 2D images from the different aspects which are acquired with image scopes included in the fiber retractor is proposed. Experimental results show a great possibilityfor reconstruction of acceptable quality of 3D object on the computer with several imageswhich are viewed from the different aspects of 2D images.

  7. Applicability of 3D-CT facial reconstruction for forensic individual identification Aplicabilidade da reconstrução facial em 3D-TC para identificação individual forense

    OpenAIRE

    Sara dos Santos Rocha; Dalton Luiz de Paula Ramos; Marcelo Gusmão Paraíso Cavalcanti

    2003-01-01

    Computed tomography (CT) is used in several clinical dentistry applications even by axial slices and two and three-dimensional reconstructed images (2D-CT and 3D-CT). The purpose of the current study is to assess the precision of linear measurements made in 3D-CT using craniometric patterns for individual identification in Forensic Dentistry. Five cadaver heads were submitted to a spiral computed tomography using axial slices, and 3D-CT reconstructions were obtained by volume rendering techni...

  8. On the evaluation of photogrammetric methods for dense 3D surface reconstruction in a metrological context

    Science.gov (United States)

    Toschi, I.; Capra, A.; De Luca, L.; Beraldin, J.-A.; Cournoyer, L.

    2014-05-01

    This paper discusses a methodology to evaluate the accuracy of recently developed image-based 3D modelling techniques. So far, the emergence of these novel methods has not been supported by the definition of an internationally recognized standard which is fundamental for user confidence and market growth. In order to provide an element of reflection and solution to the different communities involved in 3D imaging, a promising approach is presented in this paper for the assessment of both metric quality and limitations of an open-source suite of tools (Apero/MicMac), developed for the extraction of dense 3D point clouds from a set of unordered 2D images. The proposed procedural workflow is performed within a metrological context, through inter-comparisons with "reference" data acquired with two hemispherical laser scanners, one total station, and one laser tracker. The methodology is applied to two case studies, designed in order to analyse the software performances in dealing with both outdoor and environmentally controlled conditions, i.e. the main entrance of Cathédrale de la Major (Marseille, France) and a custom-made scene located at National Research Council of Canada 3D imaging Metrology Laboratory (Ottawa). Comparative data and accuracy evidence produced for both tests allow the study of some key factors affecting 3D model accuracy.

  9. Effects of CT image segmentation methods on the accuracy of long bone 3D reconstructions.

    Science.gov (United States)

    Rathnayaka, Kanchana; Sahama, Tony; Schuetz, Michael A; Schmutz, Beat

    2011-03-01

    An accurate and accessible image segmentation method is in high demand for generating 3D bone models from CT scan data, as such models are required in many areas of medical research. Even though numerous sophisticated segmentation methods have been published over the years, most of them are not readily available to the general research community. Therefore, this study aimed to quantify the accuracy of three popular image segmentation methods, two implementations of intensity thresholding and Canny edge detection, for generating 3D models of long bones. In order to reduce user dependent errors associated with visually selecting a threshold value, we present a new approach of selecting an appropriate threshold value based on the Canny filter. A mechanical contact scanner in conjunction with a microCT scanner was utilised to generate the reference models for validating the 3D bone models generated from CT data of five intact ovine hind limbs. When the overall accuracy of the bone model is considered, the three investigated segmentation methods generated comparable results with mean errors in the range of 0.18-0.24 mm. However, for the bone diaphysis, Canny edge detection and Canny filter based thresholding generated 3D models with a significantly higher accuracy compared to those generated through visually selected thresholds. This study demonstrates that 3D models with sub-voxel accuracy can be generated utilising relatively simple segmentation methods that are available to the general research community.

  10. 3-D reconstructions of the early-November 2004 CDAW geomagnetic storms: analysis of Ooty IPS speed and density data

    Directory of Open Access Journals (Sweden)

    M. M. Bisi

    2009-12-01

    Full Text Available Interplanetary scintillation (IPS remote-sensing observations provide a view of the solar wind covering a wide range of heliographic latitudes and heliocentric distances from the Sun between ~0.1 AU and 3.0 AU. Such observations are used to study the development of solar coronal transients and the solar wind while propagating out through interplanetary space. They can also be used to measure the inner-heliospheric response to the passage of coronal mass ejections (CMEs and co-rotating heliospheric structures. IPS observations can, in general, provide a speed estimate of the heliospheric material crossing the observing line of site; some radio antennas/arrays can also provide a radio scintillation level. We use a three-dimensional (3-D reconstruction technique which obtains perspective views from outward-flowing solar wind and co-rotating structure as observed from Earth by iteratively fitting a kinematic solar wind model to these data. Using this 3-D modelling technique, we are able to reconstruct the velocity and density of CMEs as they travel through interplanetary space. For the time-dependent model used here with IPS data taken from the Ootacamund (Ooty Radio Telescope (ORT in India, the digital resolution of the tomography is 10° by 10° in both latitude and longitude with a half-day time cadence. Typically however, the resolutions range from 10° to 20° in latitude and longitude, with a half- to one-day time cadence for IPS data dependant upon how much data are used as input to the tomography. We compare reconstructed structures during early-November 2004 with in-situ measurements from the Wind spacecraft orbiting the Sun-Earth L1-Point to validate the 3-D tomographic reconstruction results and comment on how these improve upon prior reconstructions.

  11. Evaluation of accuracy of 3D reconstruction images using multi-detector CT and cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Ja [Graduate School of Clinical Dentistry, Hallym University, Seoul (Korea, Republic of); Huh, Kyung Hoe; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [School of Dentistry, Seoul National University, Seoul (Korea, Republic of)

    2012-03-15

    This study was performed to determine the accuracy of linear measurements on three-dimensional (3D) images using multi-detector computed tomography (MDCT) and cone-beam computed tomography (CBCT). MDCT and CBCT were performed using 24 dry skulls. Twenty-one measurements were taken on the dry skulls using digital caliper. Both types of CT data were imported into OnDemand software and identification of landmarks on the 3D surface rendering images and calculation of linear measurements were performed. Reproducibility of the measurements was assessed using repeated measures ANOVA and ICC, and the measurements were statistically compared using a Student t-test. All assessments under the direct measurement and image-based measurements on the 3D CT surface rendering images using MDCT and CBCT showed no statistically difference under the ICC examination. The measurements showed no differences between the direct measurements of dry skull and the image-based measurements on the 3D CT surface rendering images (P>.05). Three-dimensional reconstructed surface rendering images using MDCT and CBCT would be appropriate for 3D measurements.

  12. Reconstruction of 3D Shapes of Opaque Cumulus Clouds from Airborne Multiangle Imaging: A Proof-of-Concept

    Science.gov (United States)

    Davis, A. B.; Bal, G.; Chen, J.

    2015-12-01

    Operational remote sensing of microphysical and optical cloud properties is invariably predicated on the assumption of plane-parallel slab geometry for the targeted cloud. The sole benefit of this often-questionable assumption about the cloud is that it leads to one-dimensional (1D) radiative transfer (RT)---a textbook, computationally tractable model. We present new results as evidence that, thanks to converging advances in 3D RT, inverse problem theory, algorithm implementation, and computer hardware, we are at the dawn of a new era in cloud remote sensing where we can finally go beyond the plane-parallel paradigm. Granted, the plane-parallel/1D RT assumption is reasonable for spatially extended stratiform cloud layers, as well as the smoothly distributed background aerosol layers. However, these 1D RT-friendly scenarios exclude cases that are critically important for climate physics. 1D RT---whence operational cloud remote sensing---fails catastrophically for cumuliform clouds that have fully 3D outer shapes and internal structures driven by shallow or deep convection. For these situations, the first order of business in a robust characterization by remote sensing is to abandon the slab geometry framework and determine the 3D geometry of the cloud, as a first step toward bone fide 3D cloud tomography. With this specific goal in mind, we deliver a proof-of-concept for an entirely new kind of remote sensing applicable to 3D clouds. It is based on highly simplified 3D RT and exploits multi-angular suites of cloud images at high spatial resolution. Airborne sensors like AirMSPI readily acquire such data. The key element of the reconstruction algorithm is a sophisticated solution of the nonlinear inverse problem via linearization of the forward model and an iteration scheme supported, where necessary, by adaptive regularization. Currently, the demo uses a 2D setting to show how either vertical profiles or horizontal slices of the cloud can be accurately reconstructed

  13. Efficient and robust 3D CT image reconstruction based on total generalized variation regularization using the alternating direction method.

    Science.gov (United States)

    Chen, Jianlin; Wang, Linyuan; Yan, Bin; Zhang, Hanming; Cheng, Genyang

    2015-01-01

    Iterative reconstruction algorithms for computed tomography (CT) through total variation regularization based on piecewise constant assumption can produce accurate, robust, and stable results. Nonetheless, this approach is often subject to staircase artefacts and the loss of fine details. To overcome these shortcomings, we introduce a family of novel image regularization penalties called total generalized variation (TGV) for the effective production of high-quality images from incomplete or noisy projection data for 3D reconstruction. We propose a new, fast alternating direction minimization algorithm to solve CT image reconstruction problems through TGV regularization. Based on the theory of sparse-view image reconstruction and the framework of augmented Lagrange function method, the TGV regularization term has been introduced in the computed tomography and is transformed into three independent variables of the optimization problem by introducing auxiliary variables. This new algorithm applies a local linearization and proximity technique to make the FFT-based calculation of the analytical solutions in the frequency domain feasible, thereby significantly reducing the complexity of the algorithm. Experiments with various 3D datasets corresponding to incomplete projection data demonstrate the advantage of our proposed algorithm in terms of preserving fine details and overcoming the staircase effect. The computation cost also suggests that the proposed algorithm is applicable to and is effective for CBCT imaging. Theoretical and technical optimization should be investigated carefully in terms of both computation efficiency and high resolution of this algorithm in application-oriented research.

  14. Program package for accurate 3D field reconstruction from boundary measurements

    International Nuclear Information System (INIS)

    The problem of the magnetic field reconstruction inside a subregion in R3 from magnetic measurements on the closed boundary of this subregion is considered. The efficiency of the proposed method, algorithm and associated software for the precision magnet system is discussed. The results of the software verification, numerical experiments as well as the ones of the field reconstruction using boundary measurements in the magnet M1 of the separator COMBAS are given. Requirements to the position accuracy of sensors consistent with the required accuracy of the magnetic field reconstruction are defined. Recommendations on the magnetic scheme design for the field mapping are given. (author)

  15. Spatial resolution of the HRRT PET scanner using 3D-OSEM PSF reconstruction

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Sibomana, Merence; Keller, Sune Høgild;

    2009-01-01

    The spatial resolution of the Siemens High Resolution Research Tomograph (HRRT) dedicated brain PET scanner installed at Copenhagen University Hospital (Rigshospitalet) was measured using a point-source phantom with high statistics. Further, it was demonstrated how the newly developed 3D-OSEM PSF...

  16. Automatic 3D building reconstruction from airbornelaser scanning and cadastral data using hough transform

    DEFF Research Database (Denmark)

    Bodum, Lars; Overby, Jens; Kjems, Erik;

    2004-01-01

    degree of details. However, it is possible to create virtual 3D models of buildings, by processing these data. Roof polygons are generated using airborne laser scanning of 1x1 meter grid and ground plans (footprints) extracted from technical feature maps. An effective algorithm is used for fixing...

  17. Ground truth evaluation of computer vision based 3D reconstruction of synthesized and real plant images

    DEFF Research Database (Denmark)

    Nielsen, Michael; Andersen, Hans Jørgen; Slaughter, David;

    2007-01-01

    There is an increasing interest in using 3D computer vision in precision agriculture. This calls for better quantitative evaluation and understanding of computer vision methods. This paper proposes a test framework using ray traced crop scenes that allows in-depth analysis of algorithm performanc...

  18. 3D reconstruction for partial data electrical impedance tomography using a sparsity prior

    DEFF Research Database (Denmark)

    Garde, Henrik; Knudsen, Kim

    2015-01-01

    In electrical impedance tomography the electrical conductivity inside a physical body is computed from electro-static boundary measurements. The focus of this paper is to extend recent results for the 2D problem to 3D: prior information about the sparsity and spatial distribution of the conductiv...

  19. 3D Reconstruction of the Glycocalyx Structure in Mammalian Capillaries using Electron Tomography

    DEFF Research Database (Denmark)

    Arkill, Kp; Neal, Cr; Mantell, Jm;

    2012-01-01

    success (e.g. freeze fracture). A new approach is therefore needed. Here we demonstrate the effectiveness of using the relatively novel electron microscopy technique of 3D electron tomography ontwo differently stained preparations to reveal details of the architecture of the glycocalyx just above...

  20. Reconstruction for Time-Domain In Vivo EPR 3D Multigradient Oximetric Imaging—A Parallel Processing Perspective

    Directory of Open Access Journals (Sweden)

    Christopher D. Dharmaraj

    2009-01-01

    Full Text Available Three-dimensional Oximetric Electron Paramagnetic Resonance Imaging using the Single Point Imaging modality generates unpaired spin density and oxygen images that can readily distinguish between normal and tumor tissues in small animals. It is also possible with fast imaging to track the changes in tissue oxygenation in response to the oxygen content in the breathing air. However, this involves dealing with gigabytes of data for each 3D oximetric imaging experiment involving digital band pass filtering and background noise subtraction, followed by 3D Fourier reconstruction. This process is rather slow in a conventional uniprocessor system. This paper presents a parallelization framework using OpenMP runtime support and parallel MATLAB to execute such computationally intensive programs. The Intel compiler is used to develop a parallel C++ code based on OpenMP. The code is executed on four Dual-Core AMD Opteron shared memory processors, to reduce the computational burden of the filtration task significantly. The results show that the parallel code for filtration has achieved a speed up factor of 46.66 as against the equivalent serial MATLAB code. In addition, a parallel MATLAB code has been developed to perform 3D Fourier reconstruction. Speedup factors of 4.57 and 4.25 have been achieved during the reconstruction process and oximetry computation, for a data set with 23×23×23 gradient steps. The execution time has been computed for both the serial and parallel implementations using different dimensions of the data and presented for comparison. The reported system has been designed to be easily accessible even from low-cost personal computers through local internet (NIHnet. The experimental results demonstrate that the parallel computing provides a source of high computational power to obtain biophysical parameters from 3D EPR oximetric imaging, almost in real-time.

  1. Reconstruction for time-domain in vivo EPR 3D multigradient oximetric imaging--a parallel processing perspective.

    Science.gov (United States)

    Dharmaraj, Christopher D; Thadikonda, Kishan; Fletcher, Anthony R; Doan, Phuc N; Devasahayam, Nallathamby; Matsumoto, Shingo; Johnson, Calvin A; Cook, John A; Mitchell, James B; Subramanian, Sankaran; Krishna, Murali C

    2009-01-01

    Three-dimensional Oximetric Electron Paramagnetic Resonance Imaging using the Single Point Imaging modality generates unpaired spin density and oxygen images that can readily distinguish between normal and tumor tissues in small animals. It is also possible with fast imaging to track the changes in tissue oxygenation in response to the oxygen content in the breathing air. However, this involves dealing with gigabytes of data for each 3D oximetric imaging experiment involving digital band pass filtering and background noise subtraction, followed by 3D Fourier reconstruction. This process is rather slow in a conventional uniprocessor system. This paper presents a parallelization framework using OpenMP runtime support and parallel MATLAB to execute such computationally intensive programs. The Intel compiler is used to develop a parallel C++ code based on OpenMP. The code is executed on four Dual-Core AMD Opteron shared memory processors, to reduce the computational burden of the filtration task significantly. The results show that the parallel code for filtration has achieved a speed up factor of 46.66 as against the equivalent serial MATLAB code. In addition, a parallel MATLAB code has been developed to perform 3D Fourier reconstruction. Speedup factors of 4.57 and 4.25 have been achieved during the reconstruction process and oximetry computation, for a data set with 23 x 23 x 23 gradient steps. The execution time has been computed for both the serial and parallel implementations using different dimensions of the data and presented for comparison. The reported system has been designed to be easily accessible even from low-cost personal computers through local internet (NIHnet). The experimental results demonstrate that the parallel computing provides a source of high computational power to obtain biophysical parameters from 3D EPR oximetric imaging, almost in real-time.

  2. One-step reconstruction with a 3D-printed, biomechanically evaluated custom implant after complex pelvic tumor resection.

    Science.gov (United States)

    Wong, K C; Kumta, S M; Geel, N V; Demol, J

    2015-01-01

    Resection of a pelvic tumor is challenging because of its complex three-dimensional (3D) anatomy and deep-seated location with nearby vital structures. The resection is technically demanding if a custom implant is used for reconstruction of the bone defect as the surgeon needs to ensure the resection margin is sufficiently wide and the orientation of intended resection planes must match that of the custom implant. We describe a novel workflow of performing a partial acetabular resection in a patient with pelvic chondrosarcoma and reconstruction with a custom pelvic implant in a one-step operation. A multi-planar bone resection was virtually planned. A computer-aided design implant that both matched the bone defect and biomechanically evaluated was prefabricated with 3D printing technology. The 3D-printed patient-specific instruments (PSIs) were used to reproduce the same planned resection. The histology of the tumor specimen showed a clear resection margin. The errors of the achieved resection and implant position were deviating (1-4 mm) from the planned. The patient could walk unaided with a good hip function. No tumor recurrence and implant loosening were noted at 11 months after surgery. The use of this novel CT-based method for surgical planning, the engineering software for implant design and validation, together with 3D printing technology for implant and PSI fabrication makes it possible to generate a personalized, biomechanically evaluated implant for accurate reconstruction after a pelvic tumor resection in a one-step operation. Further study in a larger population is needed to assess the clinical efficacy of the workflow in complex bone tumor surgery.

  3. High Performance 3D PET Reconstruction Using Spherical Basis Functions on a Polar Grid

    Directory of Open Access Journals (Sweden)

    J. Cabello

    2012-01-01

    Full Text Available Statistical iterative methods are a widely used method of image reconstruction in emission tomography. Traditionally, the image space is modelled as a combination of cubic voxels as a matter of simplicity. After reconstruction, images are routinely filtered to reduce statistical noise at the cost of spatial resolution degradation. An alternative to produce lower noise during reconstruction is to model the image space with spherical basis functions. These basis functions overlap in space producing a significantly large number of non-zero elements in the system response matrix (SRM to store, which additionally leads to long reconstruction times. These two problems are partly overcome by exploiting spherical symmetries, although computation time is still slower compared to non-overlapping basis functions. In this work, we have implemented the reconstruction algorithm using Graphical Processing Unit (GPU technology for speed and a precomputed Monte-Carlo-calculated SRM for accuracy. The reconstruction time achieved using spherical basis functions on a GPU was 4.3 times faster than the Central Processing Unit (CPU and 2.5 times faster than a CPU-multi-core parallel implementation using eight cores. Overwriting hazards are minimized by combining a random line of response ordering and constrained atomic writing. Small differences in image quality were observed between implementations.

  4. MDCT angiography with 3D image reconstructions in the evaluation of failing arteriovenous fistulas and grafts in hemodialysis patients

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulou, Angeliki; Raland, Hans; Magnusson, Anders (Dept. of Radiology, Univ. Hospital, Uppsala (Sweden)), email: angeliki.dimopoulou@akademiska.se; Wikstroem, Bjoern (Dept. of Medical Sciences, Renal Section, Univ. Hospital, Uppsala (Sweden))

    2011-11-15

    Background. Arteriovenous fistulas and grafts are the methods of choice for vascular access in renal failure patients in need of hemodialysis. Their major complication, however, is stenosis, which might lead to thrombosis. Purpose. To demonstrate the usefulness of 16-MDCTA with 3D image reconstructions, in long-term hemodialysis patients with dysfunctional arteriovenous fistulas and grafts (AVF and AVG). Material and Methods. During a 17-month period, 31 patients with dysfunctional AVF and AVG (24 AVF and seven AVG) were examined with MDCTA with 3D image postprocessing. Parameters such as comprehension of the anatomy, quality of contrast enhancement, and pathological vascular changes were measured. DSA was then performed in 24 patients. Results. MDCTA illustrated the anatomy of the AVF/AVG and the entire vascular tree to the heart, in a detailed and comprehensive manner in 93.5% of the evaluated segments, and depicted pathology of AVF/AVG or pathology of the associated vasculature. MDCTA demonstrated a total of 38 significant stenoses in 25 patients. DSA verified 37 stenoses in 24 patients and demonstrated two additional stenoses. MDCTA had thus a sensitivity of 95%. All 24 patients were treated with percutaneous transluminal angioplasty (PTA) with good technical results. Conclusion. MDCTA with 3D reconstructions of dysfunctioning AVFs and AVGs in hemodialysis patients is an accurate and reliable diagnostic method helping customize future intervention

  5. Preclinical, fluorescence and diffuse optical tomography: non-contact instrumentation, modeling and time-resolved 3D reconstruction

    International Nuclear Information System (INIS)

    Time-Resolved Diffuse Optical Tomography (TR-DOT) is a new non-invasive imaging technique increasingly used in the clinical and preclinical fields. It yields optical absorption and scattering maps of the explored organs, and related physiological parameters. Time-Resolved Fluorescence Diffuse Optical Tomography (TR-FDOT) is based on the detection of fluorescence photons. It provides spatio-temporal maps of fluorescent probe concentrations and life times, and allows access to metabolic and molecular imaging which is important for diagnosis and therapeutic monitoring, particularly in oncology. The main goal of this thesis was to reconstruct 3D TR-DOT/TR-FDOT images of small animals using time-resolved optical technology. Data were acquired using optical fibers fixed around the animal without contact with its surface. The work was achieved in four steps: 1)- Setting up an imaging device to record the 3D coordinates of an animal's surface; 2)- Modeling the no-contact approach to solve the forward problem; 3)- Processing of the measured signals taking into account the impulse response of the device; 4)- Implementation of a new image reconstruction method based on a selection of carefully chosen points. As a result, good-quality 3D optical images were obtained owing to reduced cross-talk between absorption and scattering. Moreover, the computation time was cut down, compared to full-time methods using whole temporal profiles. (author)

  6. Lossless 3-D reconstruction and registration of semi-quantitative gene expression data in the mouse brain.

    Science.gov (United States)

    Enlow, Matthew A; Ju, Tao; Kakadiaris, Ioannis A; Carson, James P

    2011-01-01

    As imaging, computing, and data storage technologies improve, there is an increasing opportunity for multiscale analysis of three-dimensional datasets (3-D). Such analysis enables, for example, microscale elements of multiple macroscale specimens to be compared throughout the entire macroscale specimen. Spatial comparisons require bringing datasets into co-alignment. One approach for co-alignment involves elastic deformations of data in addition to rigid alignments. The elastic deformations distort space, and if not accounted for, can distort the information at the microscale. The algorithms developed in this work address this issue by allowing multiple data points to be encoded into a single image pixel, appropriately tracking each data point to ensure lossless data mapping during elastic spatial deformation. This approach was developed and implemented for both 2-D and 3D registration of images. Lossless reconstruction and registration was applied to semi-quantitative cellular gene expression data in the mouse brain, enabling comparison of multiple spatially registered 3-D datasets without any augmentation of the cellular data. Standard reconstruction and registration without the lossless approach resulted in errors in cellular quantities of ∼ 8%.

  7. Automatic techniques for 3D reconstruction of critical workplace body postures from range imaging data

    Science.gov (United States)

    Westfeld, Patrick; Maas, Hans-Gerd; Bringmann, Oliver; Gröllich, Daniel; Schmauder, Martin

    2013-11-01

    The paper shows techniques for the determination of structured motion parameters from range camera image sequences. The core contribution of the work presented here is the development of an integrated least squares 3D tracking approach based on amplitude and range image sequences to calculate dense 3D motion vector fields. Geometric primitives of a human body model are fitted to time series of range camera point clouds using these vector fields as additional information. Body poses and motion information for individual body parts are derived from the model fit. On the basis of these pose and motion parameters, critical body postures are detected. The primary aim of the study is to automate ergonomic studies for risk assessments regulated by law, identifying harmful movements and awkward body postures in a workplace.

  8. 3D Reconstruction of Intricate Archean Microbial Structures Using Neutron Computed Tomography and Serial Sectioning

    Science.gov (United States)

    Huerta, N. J.; Murphy, M. A.; Natarajan, V.; Weber, G.; Hamann, B.; Sumner, D. Y.

    2005-12-01

    Three-dimensional visualization of intricate microbial structures in rocks is essential to understand the growth of ancient microbial communities. We have imaged and reconstructed the three-dimensional morphology of 2.5-2.6 billion year old intricate microbialites preserved in carbonate using both serial sectioning and neutron computed tomography (NCT). Reconstruction techniques vary with data type and sample preservation. NCT is a non-destructive technique for imaging organic-containing samples with sufficiently high hydrogen concentrations. The resolution of reconstruction is finer than 500 microns. We reconstructed microbialites preserved as organic inclusions in calcite using NCT. Reconstructions are interpreted using volume rendering, segmentation, and an interactive Matlab/visualization environment. Visualizations demonstrate the intricacy of the structures. Noise currently limits automatic growth surface extraction, but growth of structures can be qualitatively evaluated. One of the largest obstacles to date is efficient manipulation of large data sets. Our current visualization approach always renders the supplied data set at full resolution, which requires down-sampling of datasets larger than 256 pixels3 (acquired volume data consists of up to 2048 pixels3) to isolate regions of interest and extract important features. We are exploring the use of multi-resolution techniques that store a dataset at different levels of detail and chose an appropriate resolution during user-interaction. Such an approach will allow us to visualize raw data at full resolution. Serial sectioning and scanning successive horizons provides reconstructions of samples lacking sufficient hydrogen for NCT. This technique destroys the sample and has a lower resolution than NCT. However, intricate networks of microbial laminae surrounded by cement-filled voids can be characterized using this technique. After microbial surfaces are manually interpreted on slices, the images lack noise

  9. Architectural Reconstruction of 3D Building Objects through Semantic Knowledge Management

    OpenAIRE

    Yucong, Duan; Cruz, Christophe; Nicolle, Christophe

    2010-01-01

    International audience This paper presents an ongoing research which aims at combining geometrical analysis of point clouds and semantic rules to detect 3D building objects. Firstly by applying a previous semantic formalization investigation, we propose a classification of related knowledge as definition, partial knowledge and ambiguous knowledge to facilitate the understanding and design. Secondly an empirical implementation is conducted on a simplified building prototype complying with t...

  10. 3D pulmonary airway color image reconstruction via shape from shading and virtual bronchoscopy imaging techniques

    Science.gov (United States)

    Suter, Melissa; Reinhardt, Joseph M.; Hoffman, Eric A.; McLennan, Geoffrey

    2005-04-01

    The dependence on macro-optical imaging of the human body in the assessment of possible disease is rapidly increasing concurrent with, and as a direct result of, advancements made in medical imaging technologies. Assessing the pulmonary airways through bronchoscopy is performed extensively in clinical practice however remains highly subjective due to limited visualization techniques and the lack of quantitative analyses. The representation of 3D structures in 2D visualization modes, although providing an insight to the structural content of the scene, may in fact skew the perception of the structural form. We have developed two methods for visualizing the optically derived airway mucosal features whilst preserving the structural scene integrity. Shape from shading (SFS) techniques can be used to extract 3D structural information from 2D optical images. The SFS technique presented addresses many limitations previously encountered in conventional techniques resulting in high-resolution 3D color images. The second method presented to combine both color and structural information relies on combined CT and bronchoscopy imaging modalities. External imaging techniques such as CT provide a means of determining the gross structural anatomy of the pulmonary airways, however lack the important optically derived mucosal color. Virtual bronchoscopy is used to provide a direct link between the CT derived structural anatomy and the macro-optically derived mucosal color. Through utilization of a virtual and true bronchoscopy matching technique we are able to directly extract combined structurally sound 3D color segments of the pulmonary airways. Various pulmonary airway diseases are assessed and the resulting combined color and texture results are presented demonstrating the effectiveness of the presented techniques.

  11. 3D-printed scaffolds based on PLA/HA nanocomposites for trabecular bone reconstruction

    Science.gov (United States)

    Niaza, K. V.; Senatov, F. S.; Kaloshkin, S. D.; Maksimkin, A. V.; Chukov, D. I.

    2016-08-01

    In the present work porous PLA scaffolds filled with micro- and nano- HA were studied. Both composites with micro- and nano-HA were obtained by extrusion in the same conditions. Scaffolds were obtained by 3D-printing by fused filament fabrication method. Structure of porous scaffolds was pre-modeled by computer software. Compression and three - point flexural tests were used to study mechanical properties of the scaffolds.

  12. 3D Reconstruction of Coronary Arteries from Angiographic Images: A Survey

    OpenAIRE

    Mahima Goyal; Jian Yang; Arun PrakashAgrawal

    2013-01-01

    X-Ray angiographyis considered to be the “golden standard” ofall times in the medical imaging field due to its wide range ofapplications. In this paper, a survey is performed on the basictechniques and the methodologies that have already beenproposed by various researchers in the field of 3D reconstructionof coronary arteries using one or more angiograms as inmonoplane or biplane angiographic systems or a volume of dataas in rotational angiographic systems. Also, the variousprocedures that ne...

  13. Cranial reconstruction with prefabricated 3D implant after a gunshot injury: A case report

    Directory of Open Access Journals (Sweden)

    Malivuković Ana

    2016-01-01

    Full Text Available Introduction. Complex defects of skull bones with different etiology, still present the challenge in reconstructive surgery. The goldstandard for cranioplasty is the autologous calvarial bone graft removed during surgery which cannot be always applied, especially in gunshot wounds for sometimes complete bone destruction. Autologous reconstruction with split calvarial, rib bones or iliac bone graft is also possible. Materials routinely used for reconstructions like titanium mesh, polymethyl metacrylate (PMMA, and other have numerous disadvantages and limitations. Case report. We presented a patient with gunshot injury to the head with residual large bone defect in the frontal region, with involvement of the skull base, and open frontal sinus. After conservative treatment, six months after the injury, reconstruction of the residual bone defect was performed. The chosen material was computerdesigned PEEK-OPTIMA® implant, manufactured on the basis of MSCT scan. This material has not been used in this region so far. The postoperative and follow-up period of the next 12 months passed without surgical complications, neurological deficit, with satisfactory functional and aesthetic results. Conclusion. Implanted bone replacement was designed and manufactured precisely according to the skull defect, and we found it suitable for the treatment of complex defects of the cranium. Early results are in favor of this cranioplasty method over standardized materials. Therefore, this material is expected to become a method of choice for reconstructive surgery of bony defects of the face and skull especially in complex cases.

  14. 3D reconstruction of grains in polycrystalline materials using a tessellation model with curved grain boundaries

    Science.gov (United States)

    Šedivý, Ondřej; Brereton, Tim; Westhoff, Daniel; Polívka, Leoš; Beneš, Viktor; Schmidt, Volker; Jäger, Aleš

    2016-06-01

    A compact and tractable representation of the grain structure of a material is an extremely valuable tool when carrying out an empirical analysis of the material's microstructure. Tessellations have proven to be very good choices for such representations. Most widely used tessellation models have convex cells with planar boundaries. Recently, however, a new tessellation model - called the generalised balanced power diagram (GBPD) - has been developed that is very flexible and can incorporate features such as curved boundaries and non-convexity of cells. In order to use a GBPD to describe the grain structure observed in empirical image data, the parameters of the model must be chosen appropriately. This typically involves solving a difficult optimisation problem. In this paper, we describe a method for fitting GBPDs to tomographic image data. This method uses simulated annealing to solve a suitably chosen optimisation problem. We then apply this method to both artificial data and experimental 3D electron backscatter diffraction (3D EBSD) data obtained in order to study the properties of fine-grained materials with superplastic behaviour. The 3D EBSD data required new alignment and segmentation procedures, which we also briefly describe. Our numerical experiments demonstrate the effectiveness of the simulated annealing approach (compared to heuristic fitting methods) and show that GBPDs are able to describe the structures of polycrystalline materials very well.

  15. Macromolecular 3D SEM reconstruction strategies: Signal to noise ratio and resolution

    International Nuclear Information System (INIS)

    Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications. - Highlights: • F-actin SEM datasets were collected using 8 different preparation/ imaging techniques. • Datasets were reconstructed by back projection and compared/analyzed • 3DSEM actin reconstructions can be produced with <100 views of the asymmetric unit. • Negatively stained macromolecules can be reconstructed by 3DSEM to ∼3 nm resolution

  16. Study on the fast neutron imaging and 3D image reconstruction method with Geant4

    International Nuclear Information System (INIS)

    Detecting the shielded highly enriched nuclear material by fast neutron is very significant for homeland security. With Gean4-based Monte Carlo simulation program developed by our group, the interaction of 14 MeV fast neutrons with highly enriched nuclear material (Highly enriched Uranium) and ordinary materials (lead, iron, and polyethylene) were simulated and the simulation data were analyzed with ROOT. The three-dimensional images of detected materials were obtained by the position and time data of gamma rays produced by the interaction of 14 MeV fast neutron and these materials. The reconstruction results show that the data of gamma rays can be used to reconstruct the three-dimensional imaging of detected materials. Additionally, the relative contrast of reconstructed imaging can be used to distinguish the different materials qualitatively. (authors)

  17. Custom Anatomical 3D Spacer for Temporomandibular Joint Resection and Reconstruction.

    Science.gov (United States)

    Green, John Marshall; Lawson, Sarah T; Liacouras, Peter C; Wise, Edward M; Gentile, Michael A; Grant, Gerald Thomas

    2016-03-01

    Two cases are presented using a two-stage approach and a custom antibiotic spacer placement. Temporomandibular reconstruction can be very demanding and accomplished with a variety of methods in preparation of a total joint and ramus reconstruction with total joint prostheses (TMJ Concepts, Ventura, CA). Three-dimensional reconstructions from diagnostic computed tomography were used to establish a virtually planned resection which included the entire condyle-ramus complex. From these data, digital designs were used to manufacture molds to facilitate intraoperative fabrication of precise custom anatomic spacers from rapidly setting antibiotic-impregnated polymethyl methacrylate. Molds were manufactured using vat polymerization (stereolithography) with a photopolymer in the first case and powder bed fusion (electron beam melting) with Ti6AL4V for the second. Surgical methodology and the use of molds for intraoperative spacer fabrication for each case are discussed. PMID:26889353

  18. Personalized x-ray reconstruction of the proximal femur via a non-rigid 2D-3D registration

    Science.gov (United States)

    Yu, Weimin; Zysset, Philippe; Zheng, Guoyan

    2015-03-01

    In this paper we present a new approach for a personalized X-ray reconstruction of the proximal femur via a non-rigid registration of a 3D volumetric template to 2D calibrated C-arm images. The 2D-3D registration is done with a hierarchical two-stage strategy: the global scaled rigid registration stage followed by a regularized deformable b-spline registration stage. In both stages, a set of control points with uniform spacing are placed over the domain of the 3D volumetric template and the registrations are driven by computing updated positions of these control points, which then allows to accurately register the 3D volumetric template to the reference space of the C-arm images. Comprehensive experiments on simulated images, on images of cadaveric femurs and on clinical datasets are designed and conducted to evaluate the performance of the proposed approach. Quantitative and qualitative evaluation results are given, which demonstrate the efficacy of the present approach.

  19. Validation of 3D EM Reconstructions: The Phantom in the Noise

    Directory of Open Access Journals (Sweden)

    J Bernard Heymann

    2015-03-01

    Full Text Available Validation is a necessity to trust the structures solved by electron microscopy by single particle techniques. The impressive achievements in single particle reconstruction fuel its expansion beyond a small community of image processing experts. This poses the risk of inappropriate data processing with dubious results. Nowhere is it more clearly illustrated than in the recovery of a reference density map from pure noise aligned to that map—a phantom in the noise. Appropriate use of existing validating methods such as resolution-limited alignment and the processing of independent data sets (“gold standard” avoid this pitfall. However, these methods can be undermined by biases introduced in various subtle ways. How can we test that a map is a coherent structure present in the images selected from the micrographs? In stead of viewing the phantom emerging from noise as a cautionary tale, it should be used as a defining baseline. Any map is always recoverable from noise images, provided a sufficient number of images are aligned and used in reconstruction. However, with smaller numbers of images, the expected coherence in the real particle images should yield better reconstructions than equivalent numbers of noise or background images, even without masking or imposing resolution limits as potential biases. The validation test proposed is therefore a simple alignment of a limited number of micrograph and noise images against the final reconstruction as reference, demonstrating that the micrograph images yield a better reconstruction. I examine synthetic cases to relate the resolution of a reconstruction to the alignment error as a function of the signal-to-noise ratio. I also administered the test to real cases of publicly available data. Adopting such a test can aid the microscopist in assessing the usefulness of the micrographs taken before committing to lengthy processing with questionable outcomes.

  20. Tracking of Multiple objects Using 3D Scatter Plot Reconstructed by Linear Stereo Vision

    Directory of Open Access Journals (Sweden)

    Safaa Moqqaddem

    2014-10-01

    Full Text Available This paper presents a new method for tracking objects using stereo vision with linear cameras. Edge points extracted from the stereo linear images are first matched to reconstruct points that represent the objects in the scene. To detect the objects, a clustering process based on a spectral analysis is then applied to the reconstructed points. The obtained clusters are finally tracked throughout their center of gravity using Kalman filter and a Nearest Neighbour based data association algorithm. Experimental results using real stereo linear images are shown to demonstrate the effectiveness of the proposed method for obstacle tracking in front of a vehicle.

  1. STXM goes 3D: digital reconstruction of focal stacks as novel approach towards confocal soft x-ray microscopy.

    Science.gov (United States)

    Späth, Andreas; Scho Ll, Simon; Riess, Christian; Schmidtel, Daniel; Paradossi, Gaio; Raabe, Jo Rg; Hornegger, Joachim; Fink, Rainer H

    2014-09-01

    Fresnel zone plate based soft x-ray transmission microspectroscopy has developed into a routine technique for high-resolution elemental or chemical 2D imaging of thin film specimens. The availability of high resolution Fresnel lenses with short depth of focus offers the possibility of optical slicing (in the third dimension) by focus series with resolutions in the submicron regime. We introduce a 3D reconstruction algorithm that uses a variance-based metric to assign a focus measure as basis for volume rendering. The algorithm is applied to simulated geometries and opaque soft matter specimens thus enabling 3D visualization. These studies with z-resolution of few 100nm serve as important step towards the vision of a confocal transmission x-ray microscope.

  2. Reconstruction of an incident using video images and 3D models

    NARCIS (Netherlands)

    Iersel, M. van; Bijhold, J.; Edelman, G.

    2008-01-01

    The growing amount of security cameras increases the chance that there is important video footage available for the reconstruction of an incident. Using the right methods for analysis of large amounts of videos, it is possible to use this relevant information. In collaboration with the Netherlands F

  3. BigNeuron: Large-Scale 3D Neuron Reconstruction from Optical Microscopy Images.

    Science.gov (United States)

    Peng, Hanchuan; Hawrylycz, Michael; Roskams, Jane; Hill, Sean; Spruston, Nelson; Meijering, Erik; Ascoli, Giorgio A

    2015-07-15

    Understanding the structure of single neurons is critical for understanding how they function within neural circuits. BigNeuron is a new community effort that combines modern bioimaging informatics, recent leaps in labeling and microscopy, and the widely recognized need for openness and standardization to provide a community resource for automated reconstruction of dendritic and axonal morphology of single neurons.

  4. Implicit Shape Reconstruction of Unorganized Points Using PDE-Based Deformable 3D Manifolds

    Institute of Scientific and Technical Information of China (English)

    Elena

    2010-01-01

    In this work we consider the problem of shape reconstruction from an unorganized data set which has many important applications in medical imaging, scientific computing, reverse engineering and geometric modelling. The reconstructed surface is obtained by continuously deforming an initial surface following the Partial Differential Equation (PDE)-based diffusion model derived by a minimal volume-like variational formulation. The evolution is driven both by the distance from the data set and by the curvature analytically computed by it. The distance function is computed by implicit local interpolants defined in terms of radial basis functions. Space discretization of the PDE model is obtained by finite co-volume schemes and semi-implicit approach is used in time/scale. The use of a level set method for the numerical computation of the surface reconstruction allows us to handle complex geometry and even changing topology,without the need of user-interaction. Numerical examples demonstrate the ability of the proposed method to produce high quality reconstructions. Moreover, we show the effectiveness of the new approach to solve hole filling problems and Boolean operations between different data sets.

  5. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    Energy Technology Data Exchange (ETDEWEB)

    Wong, S.T.C. [Univ. of California, San Francisco, CA (United States)

    1997-02-01

    The purpose of this presentation is to discuss the computer processing techniques of tomographic images, after they have been generated by imaging scanners, for volume visualization. Volume visualization is concerned with the representation, manipulation, and rendering of volumetric data. Since the first digital images were produced from computed tomography (CT) scanners in the mid 1970s, applications of visualization in medicine have expanded dramatically. Today, three-dimensional (3D) medical visualization has expanded from using CT data, the first inherently digital source of 3D medical data, to using data from various medical imaging modalities, including magnetic resonance scanners, positron emission scanners, digital ultrasound, electronic and confocal microscopy, and other medical imaging modalities. We have advanced from rendering anatomy to aid diagnosis and visualize complex anatomic structures to planning and assisting surgery and radiation treatment. New, more accurate and cost-effective procedures for clinical services and biomedical research have become possible by integrating computer graphics technology with medical images. This trend is particularly noticeable in current market-driven health care environment. For example, interventional imaging, image-guided surgery, and stereotactic and visualization techniques are now stemming into surgical practice. In this presentation, we discuss only computer-display-based approaches of volumetric medical visualization. That is, we assume that the display device available is two-dimensional (2D) in nature and all analysis of multidimensional image data is to be carried out via the 2D screen of the device. There are technologies such as holography and virtual reality that do provide a {open_quotes}true 3D screen{close_quotes}. To confine the scope, this presentation will not discuss such approaches.

  6. Automatic segmentation and 3D reconstruction of intravascular ultrasound images for a fast preliminar evaluation of vessel pathologies.

    Science.gov (United States)

    Sanz-Requena, Roberto; Moratal, David; García-Sánchez, Diego Ramón; Bodí, Vicente; Rieta, José Joaquín; Sanchis, Juan Manuel

    2007-03-01

    Intravascular ultrasound (IVUS) imaging is used along with X-ray coronary angiography to detect vessel pathologies. Manual analysis of IVUS images is slow and time-consuming and it is not feasible for clinical purposes. A semi-automated method is proposed to generate 3D reconstructions from IVUS video sequences, so that a fast diagnose can be easily done, quantifying plaque length and severity as well as plaque volume of the vessels under study. The methodology described in this work has four steps: a pre-processing of IVUS images, a segmentation of media-adventitia contour, a detection of intima and plaque and a 3D reconstruction of the vessel. Preprocessing is intended to remove noise from the images without blurring the edges. Segmentation of media-adventitia contour is achieved using active contours (snakes). In particular, we use the gradient vector flow (GVF) as external force for the snakes. The detection of lumen border is obtained taking into account gray-level information of the inner part of the previously detected contours. A knowledge-based approach is used to determine which level of gray corresponds statistically to the different regions of interest: intima, plaque and lumen. The catheter region is automatically discarded. An estimate of plaque type is also given. Finally, 3D reconstruction of all detected regions is made. The suitability of this methodology has been verified for the analysis and visualization of plaque length, stenosis severity, automatic detection of the most problematic regions, calculus of plaque volumes and a preliminary estimation of plaque type obtaining for automatic measures of lumen and vessel area an average error smaller than 1mm(2) (equivalent aproximately to 10% of the average measure), for calculus of plaque and lumen volume errors smaller than 0.5mm(3) (equivalent approximately to 20% of the average measure) and for plaque type estimates a mismatch of less than 8% in the analysed frames. PMID:17215103

  7. The 3D reconstruction of greenhouse tomato plant based on real organ samples and parametric L-system

    Science.gov (United States)

    Xin, Longjiao; Xu, Lihong; Li, Dawei; Fu, Daichang

    2014-04-01

    In this paper, a fast and effective 3D reconstruction method for the growth of greenhouse tomato plant is proposed by using real organ samples and a parametric L-system. By analyzing the stereo structure of tomato plant, we extracts rules and parameters to assemble an L-system that is able to simulate the plant growth, and then the components of the L-system are translated into plant organ entities via image processing and computer graphics techniques. This method can efficiently and faithfully simulate the growing process of the greenhouse tomato plant.

  8. A 3D reconstruction method of the body envelope from biplanar X-rays: Evaluation of its accuracy and reliability

    OpenAIRE

    NEROT, Agathe; CHOISNE, Julie; AMABILE, Célia; TRAVERT, Christophe; PILLET, Hélène; WANG Xuguang; Skalli, W.

    2015-01-01

    The aim of this study was to propose a novel method for reconstructing the external body envelope from the low dose biplanar X-rays of a person. The 3D body envelope was obtained by deforming a template to match the surface profiles in two X-rays images in three successive steps: global morphing to adopt the position of a person and scale the templateós body segments, followed by a gross deformation and a fine deformation using two sets of pre-defined control points. To evaluate the method, a...

  9. SF3M 2.0: improvement of 3D photo-reconstruction interface based on freely available software

    Science.gov (United States)

    Castillo, Carlos; James, Michael R.; Pérez, Rafael; Gómez, Jose A.

    2016-04-01

    During recent years, a number of tools based on Structure-from-Motion algorithms have been released for full image-based 3D reconstruction either freely (e.g. Bundler, PMVS2, VisualSFM, MicMac) or commercially (e.g. Agisoft PhotoScan). The SF3M interface was developed in Matlab® to use link software developments (VisualSFM, CloudCompare) and new applications to create a semi-automated workflow including reconstruction, georeferencing and point-cloud filtering, and has been tested for gully erosion assessment with terrestrial images (Castillo et al., 2015). The main aim of this work to provide an improved freely-available and easy-to-use alternative for 3D reconstruction intended for public agencies, non-profit organisations, researchers and other stakeholders interested in 3D modelling. In this communication we present SF3M 2.0, a new version of the graphical user interface. In this case, the SfM module is based on MicMac, an open-software tool (Pierrot-Deseilligny and Cléry, 2011) which provides advanced features such as camera calibration and constrained bundle adjustment using ground control points. SF3M 2.0 will be tested in two scenarios: a) using the same ground-based image set tested in Castillo et al. (2015) to compare the performance of both versions and b) using aerial images taken from a helium balloon to assess a gully network in a 40-hectares catchment. In this study we explore the advantages of SF3M 2.0, explain its operation and evaluate its accuracy and performance. This tool will be also available for free download. References Castillo, C., James, M.R., Redel-Macías, M. D., Pérez, R., and Gómez, J.A.: SF3M software: 3-D photo-reconstruction for non-expert users and its application to a gully network, SOIL, 1, 583-594. Pierrot-Deseilligny, M and Cléry, I. APERO, an Open Source Bundle Adjusment Software for Automatic Calibration and Orientation of a Set of Images. Proceedings of the ISPRS Commission V Symposium, Image Engineering and Vision

  10. Reconstructing the Thermal Sunyaev-Zel'dovich Effect in 3D

    CERN Document Server

    Pratten, Geraint

    2014-01-01

    The thermal Sunyaev-Zel'dovich (tSZ) effect is one of the most promising tools we have for probing the baryonic Universe. Unfortunately, the tSZ effect is defined as a line of sight projection of the thermal pressure fluctuations of free-electrons, compromising our ability to probe the thermal history of the Universe by smearing out the tSZ observables. This results in a loss of redshift information diminishing the power of tSZ observations. It is hoped that by cross-correlating the tSZ effect with external tracers we can recover a good fraction of the lost information. Weak lensing (WL) is thought to provide a relatively unbiased probe of the dark Universe in 3D with many upcoming WL surveys having sky coverage that overlaps with current tSZ surveys. Generalising the commonly used tomographic approach, we advocate the use of the spherical Fourier-Bessel (sFB) expansion as a means to perform a full analysis of cross-correlations between the projected (2D) tSZ Compton y-parameter maps and 3D WL-convergence kap...

  11. MR neurography with multiplanar reconstruction of 3D MRI datasets: an anatomical study and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Wolfgang; Aschoff, Andrik J.; Stuber, Gregor; Schmitz, Bernd [University Hospitals Ulm, Clinic for Diagnostic and Interventional Radiology, Ulm (Germany); Brinkmann, Alexander; Wagner, Florian; Dinse, Alexander [University Hospitals Ulm, Department of Anesthesiology, Ulm (Germany)

    2007-04-15

    Extracranial MR neurography has so far mainly been used with 2D datasets. We investigated the use of 3D datasets for peripheral neurography of the sciatic nerve. A total of 40 thighs (20 healthy volunteers) were examined with a coronally oriented magnetization-prepared rapid acquisition gradient echo sequence with isotropic voxels of 1 x 1 x 1 mm and a field of view of 500 mm. Anatomical landmarks were palpated and marked with MRI markers. After MR scanning, the sciatic nerve was identified by two readers independently in the resulting 3D dataset. In every volunteer, the sciatic nerve could be identified bilaterally over the whole length of the thigh, even in areas of close contact to isointense muscles. The landmark of the greater trochanter was falsely palpated by 2.2 cm, and the knee joint by 1 cm. The mean distance between the bifurcation of the sciatic nerve and the knee-joint gap was 6 cm ({+-}1.8 cm). The mean results of the two readers differed by 1-6%. With the described method of MR neurography, the sciatic nerve was depicted reliably and objectively in great anatomical detail over the whole length of the thigh. Important anatomical information can be obtained. The clinical applications of MR neurography for the brachial plexus and lumbosacral plexus/sciatic nerve are discussed. (orig.)

  12. 3D Reconstruction of Coronary Arteries from Angiographic Images: A Survey

    Directory of Open Access Journals (Sweden)

    Mahima Goyal

    2013-06-01

    Full Text Available X-Ray angiographyis considered to be the “golden standard” ofall times in the medical imaging field due to its wide range ofapplications. In this paper, a survey is performed on the basictechniques and the methodologies that have already beenproposed by various researchers in the field of 3D reconstructionof coronary arteries using one or more angiograms as inmonoplane or biplane angiographic systems or a volume of dataas in rotational angiographic systems. Also, the variousprocedures that need to be performed are stated and describedshowing the contribution of each step in the reconstructionprocess. These procedures include distortion correction, motioncompensation, feature extraction, background removal,projection geometry optimization and topology identification,surface visualization etc.X-Ray angiographyis considered to be the “golden standard” ofall times in the medical imaging field due to its wide range ofapplications. In this paper, a survey is performed on the basictechniques and the methodologies that have already beenproposed by various researchers in the field of 3D reconstructionof coronary arteries using one or more angiograms as inmonoplane or biplane angiographic systems or a volume of dataas in rotational angiographic systems. Also, the variousprocedures that need to be performed are stated and describedshowing the contribution of each step in the reconstructionprocess. These procedures include distortion correction, motioncompensation, feature extraction, background removal,projection geometry optimization and topology identification,surface visualization etc.

  13. CMOS array of photodiodes with electronic processing for 3D optical reconstruction

    Science.gov (United States)

    Hornero, Gemma; Montane, Enric; Chapinal, Genis; Moreno, Mauricio; Herms, Atila

    2001-04-01

    It is well known that laser time-of-flight (TOF) and optical triangulation are the most useful optical techniques for distance measurements. The first one is more suitable for large distances, since for short range of distances high modulation frequencies of laser diodes (©200-500MHz) are needed. For these ranges, optical triangulation is simpler, as it is only necessary to read the projection of the laser point over a linear optical sensor without any laser modulation. Laser triangulation is based on the rotation of the object. This motion shifts the projected point over the linear sensor, resulting on 3D information, by means of the whole readout of the linear sensor in each angle position. On the other hand, a hybrid method of triangulation and TOF can be implemented. In this case, a synchronized scanning of a laser beam over the object results in different arrival times of light to each pixel. The 3D information is carried by these delays. Only a single readout of the linear sensor is needed. In this work we present the design of two different linear arrays of photodiodes in CMOS technology, the first one based on the Optical triangulation measurement and the second one based in this hybrid method (TFO). In contrast to PSD (Position Sensitive Device) and CCDs, CMOS technology can include, on the same chip, photodiodes, control and processing electronics, that in the other cases should be implemented with external microcontrollers.

  14. Rapid and Inexpensive Reconstruction of 3D Structures for Micro-Objects Using Common Optical Microscopy

    CERN Document Server

    Berejnov, V V

    2009-01-01

    A simple method of constructing the 3D surface of non-transparent micro-objects by extending the depth-of-field on the whole attainable surface is presented. The series of images of a sample are recorded by the sequential movement of the sample with respect to the microscope focus. The portions of the surface of the sample appear in focus in the different images in the series. The indexed series of the in-focus portions of the sample surface is combined in one sharp 2D image and interpolated into the 3D surface representing the surface of an original micro-object. For an image acquisition and processing we use a conventional upright stage microscope that is operated manually, the inexpensive Helicon Focus software, and the open source MeshLab software. Three objects were tested: an inclined flat glass slide with an imprinted 10 um calibration grid, a regular metal 100x100 per inch mesh, and a highly irregular surface of a material known as a porous electrode used in polyelectrolyte fuel cells. The accuracy of...

  15. Eccentricity in Images of Circular and Spherical Targets and its Impact to 3D Object Reconstruction

    Science.gov (United States)

    Luhmann, T.

    2014-06-01

    This paper discusses a feature of projective geometry which causes eccentricity in the image measurement of circular and spherical targets. While it is commonly known that flat circular targets can have a significant displacement of the elliptical image centre with respect to the true imaged circle centre, it can also be shown that the a similar effect exists for spherical targets. Both types of targets are imaged with an elliptical contour. As a result, if measurement methods based on ellipses are used to detect the target (e.g. best-fit ellipses), the calculated ellipse centre does not correspond to the desired target centre in 3D space. This paper firstly discusses the use and measurement of circular and spherical targets. It then describes the geometrical projection model in order to demonstrate the eccentricity in image space. Based on numerical simulations, the eccentricity in the image is further quantified and investigated. Finally, the resulting effect in 3D space is estimated for stereo and multi-image intersections. It can be stated that the eccentricity is larger than usually assumed, and must be compensated for high-accuracy applications. Spherical targets do not show better results than circular targets. The paper is an updated version of Luhmann (2014) new experimental investigations on the effect of length measurement errors.

  16. Future capabilities of CME polarimetric 3D reconstructions with the METIS instrument: A numerical test

    Science.gov (United States)

    Pagano, P.; Bemporad, A.; Mackay, D. H.

    2015-10-01

    Context. Understanding the 3D structure of coronal mass ejections (CMEs) is crucial for understanding the nature and origin of solar eruptions. However, owing to the optical thinness of the solar corona we can only observe the line of sight integrated emission. As a consequence the resulting projection effects hide the true 3D structure of CMEs. To derive information on the 3D structure of CMEs from white-light (total and polarized brightness) images, the polarization ratio technique is widely used. The soon-to-be-launched METIS coronagraph on board Solar Orbiter will use this technique to produce new polarimetric images. Aims: This work considers the application of the polarization ratio technique to synthetic CME observations from METIS. In particular we determine the accuracy at which the position of the centre of mass, direction and speed of propagation, and the column density of the CME can be determined along the line of sight. Methods: We perform a 3D MHD simulation of a flux rope ejection where a CME is produced. From the simulation we (i) synthesize the corresponding METIS white-light (total and polarized brightness) images and (ii) apply the polarization ratio technique to these synthesized images and compare the results with the known density distribution from the MHD simulation. In addition, we use recent results that consider how the position of a single blob of plasma is measured depending on its projected position in the plane of the sky. From this we can interpret the results of the polarization ratio technique and give an estimation of the error associated with derived parameters. Results: We find that the polarization ratio technique reproduces with high accuracy the position of the centre of mass along the line of sight. However, some errors are inherently associated with this determination. The polarization ratio technique also allows information to be derived on the real 3D direction of propagation of the CME. The determination of this is of

  17. Interaction and behaviour imaging: a novel method to measure mother-infant interaction using video 3D reconstruction.

    Science.gov (United States)

    Leclère, C; Avril, M; Viaux-Savelon, S; Bodeau, N; Achard, C; Missonnier, S; Keren, M; Feldman, R; Chetouani, M; Cohen, D

    2016-01-01

    Studying early interaction is essential for understanding development and psychopathology. Automatic computational methods offer the possibility to analyse social signals and behaviours of several partners simultaneously and dynamically. Here, 20 dyads of mothers and their 13-36-month-old infants were videotaped during mother-infant interaction including 10 extremely high-risk and 10 low-risk dyads using two-dimensional (2D) and three-dimensional (3D) sensors. From 2D+3D data and 3D space reconstruction, we extracted individual parameters (quantity of movement and motion activity ratio for each partner) and dyadic parameters related to the dynamics of partners heads distance (contribution to heads distance), to the focus of mutual engagement (percentage of time spent face to face or oriented to the task) and to the dynamics of motion activity (synchrony ratio, overlap ratio, pause ratio). Features are compared with blind global rating of the interaction using the coding interactive behavior (CIB). We found that individual and dyadic parameters of 2D+3D motion features perfectly correlates with rated CIB maternal and dyadic composite scores. Support Vector Machine classification using all 2D-3D motion features classified 100% of the dyads in their group meaning that motion behaviours are sufficient to distinguish high-risk from low-risk dyads. The proposed method may present a promising, low-cost methodology that can uniquely use artificial technology to detect meaningful features of human interactions and may have several implications for studying dyadic behaviours in psychiatry. Combining both global rating scales and computerized methods may enable a continuum of time scale from a summary of entire interactions to second-by-second dynamics.

  18. Spatial decomposition of molecular ions within 3D atom probe reconstructions.

    Science.gov (United States)

    Breen, Andrew; Moody, Michael P; Gault, Baptiste; Ceguerra, Anna V; Xie, Kelvin Y; Du, Sichao; Ringer, Simon P

    2013-09-01

    Two methods for separating the constituent atoms of molecular ions within atom probe tomography reconstructions are presented. The Gaussian Separation Method efficiently deconvolutes molecular ions containing two constituent atoms and is tested on simulated data before being applied to an experimental HSLA steel dataset containing NbN. The Delaunay Separation Method extends separation to larger complex ions and is also tested on simulated data before being applied to an experimental GaAs dataset containing many large (>3 atoms) complex ions. First nearest neighbour (1NN) distributions and images of the reconstruction before and after the separations are used to show the effect of the algorithms and their validity and practicality are also discussed. PMID:23522847

  19. Biometric assessment of deep-sea vent megabenthic communities using multi-resolution 3D image <