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Sample records for 3-d reconstruction tomography

  1. 3D fast reconstruction in positron emission tomography

    The issue of long reconstruction times in positron emission tomography (PET) has been addressed from several points of view, resulting in an affordable dedicated system capable of handling routine 3D reconstructions in a few minutes per frame : on the hardware side using fast processors and a parallel architecture, and on the software side, using efficient implementation of computationally less intensive algorithms

  2. Surface reconstruction of 3D objects in computerized tomography

    This paper deals with the problem of surface reconstruction of 3D objects from their boundaries in a family of slice images in computerized tomography (CT). Its mathematical formulation is first given, in which it is considered as a problem of functional minimization. Next, the corresponding Euler partial differential equation is derived and it is then solved by the finite difference method. Numerical solution can be found by using the iterative method

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

    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.

  4. 3D image reconstruction of fiber systems using electron tomography

    Over the past several years, electron microscopists and materials researchers have shown increased interest in electron tomography (reconstruction of three-dimensional information from a tilt series of bright field images obtained in a transmission electron microscope (TEM)). In this research, electron tomography has been used to reconstruct a three-dimensional image for fiber structures from secondary electron images in a scanning electron microscope (SEM). The implementation of this technique is used to examine the structure of fiber system before and after deformation. A test sample of steel wool was tilted around a single axis from −10° to 60° by one-degree steps with images taken at every degree; three-dimensional images were reconstructed for the specimen of fine steel fibers. This method is capable of reconstructing the three-dimensional morphology of this type of lineal structure, and to obtain features such as tortuosity, contact points, and linear density that are of importance in defining the mechanical properties of these materials. - Highlights: • The electron tomography technique has been adapted to the SEM for analysis of linear structures. • Images are obtained by secondary electron imaging through a given depth of field, making them analogous to projected images. • Quantitative descriptions of the microstructure can be obtained including tortuosity and contact points per volume

  5. 3D parameter reconstruction in hyperspectral diffuse optical tomography

    Saibaba, Arvind K.; Krishnamurthy, Nishanth; Anderson, Pamela G.; Kainerstorfer, Jana M.; Sassaroli, Angelo; Miller, Eric L.; Fantini, Sergio; Kilmer, Misha E.

    2015-03-01

    The imaging of shape perturbation and chromophore concentration using Diffuse Optical Tomography (DOT) data can be mathematically described as an ill-posed and non-linear inverse problem. The reconstruction algorithm for hyperspectral data using a linearized Born model is prohibitively expensive, both in terms of computation and memory. We model the shape of the perturbation using parametric level-set approach (PaLS). We discuss novel computational strategies for reducing the computational cost based on a Krylov subspace approach for parameteric linear systems and a compression strategy for the parameter-to-observation map. We will demonstrate the validity of our approach by comparison with experiments.

  6. Advanced 3D-reconstruction of biological specimen monitored by non-invasive optical tomography

    Imaging of intricate and delicate subcellular structures along with reliable 3D-reconstruction of cells and tissues may be achieved on the basis of confocal laser scanning microscopy (optical tomography) provided that certain criteria such as proper loading of fluorescent dyes, image acquisition under defined electro-optical conditions, suitable image pre- and postprocessing, etc., are taken into account prior to volume- or surface-rendering for 3D-visualization. (author)

  7. Feasibility and value of fully 3D Monte Carlo reconstruction in single photon emission computed tomography

    The accuracy of Single Photon Emission Computed Tomography (SPECT) images is degraded by physical effects, namely photon attenuation, Compton scatter and spatially varying collimator response. The 3D nature of these effects is usually neglected by the methods used to correct for these effects. To deal with the 3D nature of the problem, a 3D projector modeling the spread of photons in 3D can be used in iterative tomographic reconstruction. The 3D projector can be estimated analytically with some approximations, or using precise Monte Carlo simulations. This latter approach has not been applied to fully 3D reconstruction yet due to impractical storage and computation time. The goal of this paper was to determine the gain to be expected from fully 3D Monte Carlo (F3DMC) modeling of the projector in iterative reconstruction, compared to conventional 2D and 3D reconstruction methods. As a proof-of-concept, two small datasets were considered. The projections of the two phantoms were simulated using the Monte Carlo simulation code GATE, as well as the corresponding projector, by taking into account all physical effects (attenuation, scatter, camera point spread function) affecting the imaging process. F3DMC was implemented by using this 3D projector in a maximum likelihood expectation maximization (MLEM) iterative reconstruction. To assess the value of F3DMC, data were reconstructed using 4 methods: filtered backprojection (FBP), MLEM without attenuation correction (MLEM), MLEM with attenuation correction, Jaszczak scatter correction and 3D correction for depth-dependent spatial resolution using an analytical model (MLEMC) and F3DMC. Our results suggest that F3DMC improves mainly imaging sensitivity and signal-to-noise ratio (SNR): sensitivity is multiplied by about 103 and SNR is increased by 20 to 70% compared to MLEMC. Computation of a more robust projector and application of the method on more realistic datasets are currently under investigation. (authors)

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

    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.

  9. Quantitative 3D refractive index decrement reconstruction using single-distance phase-contrast tomography data

    X-ray propagation-based phase-contrast imaging is an attractive phase-sensitive imaging technique that has found applications in many research fields. Here, we report the investigations of a method which can quantitatively reconstruct in 3D the refractive index decrement of a quasi-homogeneous object using single-distance phase-contrast tomography data. The method extends the Born-type approximation phase-retrieval algorithm, which is based on the phase-attenuation duality (ε = δ/β, with constant ε) and suitable for homogeneous objects, to tomography and we study its application to quasi-homogeneous objects. The noise performance and the phase-attenuation duality influences of the method are also investigated. In simulation, the method allows us to quantitatively reconstruct the 3D refractive index decrement for quasi-homogeneous and weakly absorbing samples and it performs well in the practical noise situation. Furthermore, it shows a substantial contrast increase and successfully distinguishes different materials in a quasi-homogeneous and weakly absorbing sample from experimental data, even with inappropriate ε value. (paper)

  10. 2D and 3D reconstructions in acousto-electric tomography

    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.

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

    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.

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

    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. Analysis of bite marks in foodstuffs by computer tomography (cone beam CT)--3D reconstruction.

    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

  14. 3D phase micro-object studies by means of digital holographic tomography supported by algebraic reconstruction technique

    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.

  15. A new approach for 3D reconstruction from bright field TEM imaging: Beam precession assisted electron tomography

    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.

  16. Fast iterative image reconstruction methods for fully 3D multispectral bioluminescence tomography

    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

  17. Feasibility and value of fully 3D Monte Carlo reconstruction in single-photon emission computed tomography

    The accuracy of Single-Photon Emission Computed Tomography images is degraded by physical effects, namely photon attenuation, Compton scatter and spatially varying collimator response. The 3D nature of these effects is usually neglected by the methods used to correct for these effects. To deal with the 3D nature of the problem, a 3D projector modeling the spread of photons in 3D can be used in iterative tomographic reconstruction. The 3D projector can be estimated analytically with some approximations, or using precise Monte Carlo simulations. This latter approach has not been applied to fully 3D reconstruction yet due to impractical storage and computation time. The goal of this paper was to determine the gain to be expected from fully 3D Monte Carlo (F3DMC) modeling of the projector in iterative reconstruction, compared to conventional 2D and 3D reconstruction methods. As a proof-of-concept, two small datasets were considered. The projections of the two phantoms were simulated using the Monte Carlo simulation code GATE, as well as the corresponding projector, by taking into account all physical effects (attenuation, scatter, camera point spread function) affecting the imaging process. F3DMC was implemented by using this 3D projector in a maximum likelihood expectation maximization (MLEM) iterative reconstruction. To assess the value of F3DMC, data were reconstructed using four methods: filtered backprojection, MLEM without attenuation correction (MLEM), MLEM with attenuation correction, Jaszczak scatter correction and 3D correction for depth-dependent spatial resolution using an analytical model (MLEMC) and F3DMC. Our results suggest that F3DMC improves mainly imaging sensitivity and signal-to-noise ratio (SNR): sensitivity is multiplied by about 103 and SNR is increased by 20-70% compared to MLEMC. Computation of a more robust projector and application of the method on more realistic datasets are currently under investigation

  18. Implementation and evaluation of a 3D one-step late reconstruction algorithm for 3D positron emission tomography brain studies using median root prior

    A fully three-dimensional (3D) one-step late (OSL), maximum a posteriori (MAP) reconstruction algorithm based on the median root prior (MRP) was implemented and evaluated for the reconstruction of 3D positron emission tomography (PET) studies. The algorithm uses the ordered subsets (OS) scheme for convergence acceleration and data update during iterations. The algorithm was implemented using the software package developed within the EU project PARAPET (www.brunel.ac.uk/ masrppet). The MRP algorithm was evaluated using experimental phantom and real 3D PET brain studies. Various experimental set-ups in terms of activity distribution and counting statistics were considered. The performance of the algorithm was assessed by calculating figures of merit such as: contrast, coefficient of variation, activity ratio between two regions and full width at half of maximum for resolution measurements. The performance of MRP was compared with that of 3D ordered subsets-expectation maximisation (OSEM) and 3D re-projection (3DRP) algorithms. In all the experimental situations considered, MRP showed: (1) convergence to a stable solution, (2) effectiveness in noise reduction, particularly for low statistics data, (3) good preservation of spatial details. Compared with the OSEM and 3DRP algorithms, MRP provides comparable or better results depending on the parameters used for the reconstruction of the images. (orig.)

  19. 3D reconstruction for partial data electrical impedance tomography using a sparsity prior

    Garde, Henrik; Knudsen, Kim

    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...

  20. Cardiac C-arm computed tomography using a 3D + time ROI reconstruction method with spatial and temporal regularization

    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.

  1. 3D Reconstruction of the Glycocalyx Structure in Mammalian Capillaries using Electron Tomography

    Arkill, Kp; Neal, Cr; Mantell, Jm;

    2012-01-01

    Visualising the molecular strands making up the glycocalyx in the lumen of small blood vessels has proved to be difficult using conventional transmission electron microscopy techniques. Images obtained from tissue stained in a variety of ways have revealed a regularity in the organisation of the...... 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 the...

  2. Dimensionality Reduction Based Optimization Algorithm for Sparse 3-D Image Reconstruction in Diffuse Optical Tomography

    Bhowmik, Tanmoy; Liu, Hanli; Ye, Zhou; Oraintara, Soontorn

    2016-03-01

    Diffuse optical tomography (DOT) is a relatively low cost and portable imaging modality for reconstruction of optical properties in a highly scattering medium, such as human tissue. The inverse problem in DOT is highly ill-posed, making reconstruction of high-quality image a critical challenge. Because of the nature of sparsity in DOT, sparsity regularization has been utilized to achieve high-quality DOT reconstruction. However, conventional approaches using sparse optimization are computationally expensive and have no selection criteria to optimize the regularization parameter. In this paper, a novel algorithm, Dimensionality Reduction based Optimization for DOT (DRO-DOT), is proposed. It reduces the dimensionality of the inverse DOT problem by reducing the number of unknowns in two steps and thereby makes the overall process fast. First, it constructs a low resolution voxel basis based on the sensing-matrix properties to find an image support. Second, it reconstructs the sparse image inside this support. To compensate for the reduced sensitivity with increasing depth, depth compensation is incorporated in DRO-DOT. An efficient method to optimally select the regularization parameter is proposed for obtaining a high-quality DOT image. DRO-DOT is also able to reconstruct high-resolution images even with a limited number of optodes in a spatially limited imaging set-up.

  3. Automatic detection of patient position for incorporation in exact 3D reconstruction for emission tomography

    Full text: SPECT involves acquiring a set of projection images using one or more rotating gamma cameras. The projections are then reconstructed to create transverse slices. Patient motion during the scan can introduce inconsistencies into the data leading to artifacts. There remains a need for robust and effective motion correction. One approach uses the (corrupt) data itself to derive the patient position at each projection angle. Corrected data is periodically incorporated into a 3-D reconstruction. Fundamental aspects of the algorithm mechanics, particularly performance in the presence of Poisson noise, have been examined. Brain SPECT studies were simulated using a digital version of the Huffman brain phantom. Projection datasets with Poisson noise imposed, generated for different positions of the phantom, were combined and reconstructed to produce motion-corrupted reconstructions. To examine the behaviour of the cost function as the object position was changed, the corrupted re-construction was forward projected and the mean square difference (MSD) between the resulting re-projections and corresponding original projections was calculated. The ability to detect mis-positioned projections for different degrees of freedom, the importance of using dual-head camera geometry, and the effect of smoothing the original projections prior to the MSD calculation were assessed. Re-projection of the corrupt reconstruction was able to correctly identify mis-positioned projection data. The degree of movement as defined by MSD was more easily identified for translations than for rotations. Noise resulted in an increasing bias that made it difficult to distinguish the minimum MSD, particularly for z-axis rotations. This was improved by median filtering of projections. Right-angled dual-head geometry is necessary to provide stability to the algorithm and to better identify motion in all 6 degrees of freedom. These findings will assist the optimisation of a fully automated motion

  4. 3D Reconstruction of Intricate Archean Microbial Structures Using Neutron Computed Tomography and Serial Sectioning

    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

  5. Preclinical, fluorescence and diffuse optical tomography: non-contact instrumentation, modeling and time-resolved 3D reconstruction

    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. 3D Reconstruction Technique for Tomographic PIV

    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.

  7. Bayesian 3D X-ray computed tomography image reconstruction with a scaled Gaussian mixture prior model

    In order to improve quality of 3D X-ray tomography reconstruction for Non Destructive Testing (NDT), we investigate in this paper hierarchical Bayesian methods. In NDT, useful prior information on the volume like the limited number of materials or the presence of homogeneous area can be included in the iterative reconstruction algorithms. In hierarchical Bayesian methods, not only the volume is estimated thanks to the prior model of the volume but also the hyper parameters of this prior. This additional complexity in the reconstruction methods when applied to large volumes (from 5123 to 81923 voxels) results in an increasing computational cost. To reduce it, the hierarchical Bayesian methods investigated in this paper lead to an algorithm acceleration by Variational Bayesian Approximation (VBA) [1] and hardware acceleration thanks to projection and back-projection operators paralleled on many core processors like GPU [2]. In this paper, we will consider a Student-t prior on the gradient of the image implemented in a hierarchical way [3, 4, 1]. Operators H (forward or projection) and Ht (adjoint or back-projection) implanted in multi-GPU [2] have been used in this study. Different methods will be evalued on synthetic volume 'Shepp and Logan' in terms of quality and time of reconstruction. We used several simple regularizations of order 1 and order 2. Other prior models also exists [5]. Sometimes for a discrete image, we can do the segmentation and reconstruction at the same time, then the reconstruction can be done with less projections

  8. 3D mouse shape reconstruction based on phase-shifting algorithm for fluorescence molecular tomography imaging system.

    Zhao, Yue; Zhu, Dianwen; Baikejiang, Reheman; Li, Changqing

    2015-11-10

    This work introduces a fast, low-cost, robust method based on fringe pattern and phase shifting to obtain three-dimensional (3D) mouse surface geometry for fluorescence molecular tomography (FMT) imaging. We used two pico projector/webcam pairs to project and capture fringe patterns from different views. We first calibrated the pico projectors and the webcams to obtain their system parameters. Each pico projector/webcam pair had its own coordinate system. We used a cylindrical calibration bar to calculate the transformation matrix between these two coordinate systems. After that, the pico projectors projected nine fringe patterns with a phase-shifting step of 2π/9 onto the surface of a mouse-shaped phantom. The deformed fringe patterns were captured by the corresponding webcam respectively, and then were used to construct two phase maps, which were further converted to two 3D surfaces composed of scattered points. The two 3D point clouds were further merged into one with the transformation matrix. The surface extraction process took less than 30 seconds. Finally, we applied the Digiwarp method to warp a standard Digimouse into the measured surface. The proposed method can reconstruct the surface of a mouse-sized object with an accuracy of 0.5 mm, which we believe is sufficient to obtain a finite element mesh for FMT imaging. We performed an FMT experiment using a mouse-shaped phantom with one embedded fluorescence capillary target. With the warped finite element mesh, we successfully reconstructed the target, which validated our surface extraction approach. PMID:26560789

  9. 3D Ion Temperature Reconstruction

    Tanabe, Hiroshi; You, Setthivoine; Balandin, Alexander; Inomoto, Michiaki; Ono, Yasushi

    2009-11-01

    The TS-4 experiment at the University of Tokyo collides two spheromaks to form a single high-beta compact toroid. Magnetic reconnection during the merging process heats and accelerates the plasma in toroidal and poloidal directions. The reconnection region has a complex 3D topology determined by the pitch of the spheromak magnetic fields at the merging plane. A pair of multichord passive spectroscopic diagnostics have been established to measure the ion temperature and velocity in the reconnection volume. One setup measures spectral lines across a poloidal plane, retrieving velocity and temperature from Abel inversion. The other, novel setup records spectral lines across another section of the plasma and reconstructs velocity and temperature from 3D vector and 2D scalar tomography techniques. The magnetic field linking both measurement planes is determined from in situ magnetic probe arrays. The ion temperature is then estimated within the volume between the two measurement planes and at the reconnection region. The measurement is followed over several repeatable discharges to follow the heating and acceleration process during the merging reconnection.

  10. Automated tracing of filaments in 3D electron tomography reconstructions using Sculptor and Situs.

    Rusu, Mirabela; Starosolski, Zbigniew; Wahle, Manuel; Rigort, Alexander; Wriggers, Willy

    2012-05-01

    The molecular graphics program Sculptor and the command-line suite Situs are software packages for the integration of biophysical data across spatial resolution scales. Herein, we provide an overview of recently developed tools relevant to cryo-electron tomography (cryo-ET), with an emphasis on functionality supported by Situs 2.7.1 and Sculptor 2.1.1. We describe a work flow for automatically segmenting filaments in cryo-ET maps including denoising, local normalization, feature detection, and tracing. Tomograms of cellular actin networks exhibit both cross-linked and bundled filament densities. Such filamentous regions in cryo-ET data sets can then be segmented using a stochastic template-based search, VolTrac. The approach combines a genetic algorithm and a bidirectional expansion with a tabu search strategy to localize and characterize filamentous regions. The automated filament segmentation by VolTrac compares well to a manual one performed by expert users, and it allows an efficient and reproducible analysis of large data sets. The software is free, open source, and can be used on Linux, Macintosh or Windows computers. PMID:22433493

  11. Virtual 3-D Facial Reconstruction

    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.

  12. 3D reconstruction of tensors and vectors

    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.

  13. The use of 3D computed tomography reconstruction in medico-legal testimony regarding injuries in living victims - Risks and benefits.

    Borowska-Solonynko, Aleksandra; Solonynko, Bohdan

    2015-02-01

    Forensic pathologists are often called upon to determine the mechanism and severity of injuries in living individuals. Such expert testimony is often based solely on hand-written clinical notes. The victims' injuries may also be visualized via three-dimensional (3D) reconstruction of computed tomography (CT) images. This method has certain benefits but is not free from limitations. This paper presents two case reports. The first case is that of a female who was brought to the hospital with a knife thrust into her body. The prosecutor's questions focused on the wound channel. The information obtained from the patient's medical records was very general with many contradictory statements. A re-evaluation of the available CT scan data and a subsequent 3D reconstruction helped determine the exact course of the wound channel. The other case was that of a young male, hospitalized based on CT evidence of bilateral rib fractions, who claimed to have been assaulted by police officers. Court expert witnesses were already in possession of a 3D reconstruction showing symmetrical fractures of the patient's lower ribs with bone fragment displacement. An expert witness in radiology definitively excluded the presence of any actual fractures, and explained their apparent visibility in the three-dimensionally reconstructed image as a motion artifact. These two cases suggest that a professionally conducted 3D CT reconstruction is a very useful tool in providing expert testimony on injuries in living victims. However, the deceptive simplicity of conducting such a reconstruction may encourage inexperienced individuals to undertake it, and thus lead to erroneous conclusions. PMID:25623187

  14. 3D reconstruction of VZV infected cell nuclei and PML nuclear cages by serial section array scanning electron microscopy and electron tomography.

    Mike Reichelt

    Full Text Available Varicella-zoster virus (VZV is a human alphaherpesvirus that causes varicella (chickenpox and herpes zoster (shingles. Like all herpesviruses, the VZV DNA genome is replicated in the nucleus and packaged into nucleocapsids that must egress across the nuclear membrane for incorporation into virus particles in the cytoplasm. Our recent work showed that VZV nucleocapsids are sequestered in nuclear cages formed from promyelocytic leukemia protein (PML in vitro and in human dorsal root ganglia and skin xenografts in vivo. We sought a method to determine the three-dimensional (3D distribution of nucleocapsids in the nuclei of herpesvirus-infected cells as well as the 3D shape, volume and ultrastructure of these unique PML subnuclear domains. Here we report the development of a novel 3D imaging and reconstruction strategy that we term Serial Section Array-Scanning Electron Microscopy (SSA-SEM and its application to the analysis of VZV-infected cells and these nuclear PML cages. We show that SSA-SEM permits large volume imaging and 3D reconstruction at a resolution sufficient to localize, count and distinguish different types of VZV nucleocapsids and to visualize complete PML cages. This method allowed a quantitative determination of how many nucleocapsids can be sequestered within individual PML cages (sequestration capacity, what proportion of nucleocapsids are entrapped in single nuclei (sequestration efficiency and revealed the ultrastructural detail of the PML cages. More than 98% of all nucleocapsids in reconstructed nuclear volumes were contained in PML cages and single PML cages sequestered up to 2,780 nucleocapsids, which were shown by electron tomography to be embedded and cross-linked by an filamentous electron-dense meshwork within these unique subnuclear domains. This SSA-SEM analysis extends our recent characterization of PML cages and provides a proof of concept for this new strategy to investigate events during virion assembly at the

  15. 3D Reconstruction of NMR Images

    Peter Izak; Milan Smetana; Libor Hargas; Miroslav Hrianka; Pavol Spanik

    2007-01-01

    This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.

  16. Extracellular vesicles of calcifying turkey leg tendon characterized by immunocytochemistry and high voltage electron microscopic tomography and 3-D graphic image reconstruction

    Landis, W. J.; Hodgens, K. J.; McKee, M. D.; Nanci, A.; Song, M. J.; Kiyonaga, S.; Arena, J.; McEwen, B.

    1992-01-01

    To gain insight into the structure and possible function of extracellular vesicles in certain calcifying vertebrate tissues, normally mineralizing leg tendons from the domestic turkey, Meleagris gallopavo, have been studied in two separate investigations, one concerning the electron microscopic immunolocalization of the 66 kDa phosphoprotein, osteopontin, and the other detailing the organization and distribution of mineral crystals associated with the vesicles as determined by high voltage microscopic tomography and 3-D graphic image reconstruction. Immunolabeling shows that osteopontin is related to extracellular vesicles of the tendon in the sense that its initial presence appears coincident with the development of mineral associated with the vesicle loci. By high voltage electron microscopy and 3-D imaging techniques, mineral crystals are found to consist of small irregularly shaped particles somewhat randomly oriented throughout individual vesicles sites. Their appearance is different from that found for the mineral observed within calcifying tendon collagen, and their 3-D disposition is not regularly ordered. Possible spatial and temporal relationships of vesicles, osteopontin, mineral, and collagen are being examined further by these approaches.

  17. Forensic 3D Scene Reconstruction

    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

  18. Forensic 3D Scene Reconstruction

    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.

  19. Total Variation-Based Reduction of Streak Artifacts, Ring Artifacts and Noise in 3D Reconstruction from Optical Projection Tomography

    Michálek, Jan

    2015-01-01

    Roč. 21, č. 6 (2015), s. 1602-1615. ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LH13028; GA ČR(CZ) GA13-12412S Institutional support: RVO:67985823 Keywords : optical projection tomography * microscopy * artifacts * total variation * data mismatch Subject RIV: EA - Cell Biology Impact factor: 1.877, year: 2014

  20. 3D Reconstruction of NMR Images

    Peter Izak

    2007-01-01

    Full Text Available This paper introduces experiment of 3D reconstruction NMR images scanned from magnetic resonance device. There are described methods which can be used for 3D reconstruction magnetic resonance images in biomedical application. The main idea is based on marching cubes algorithm. For this task was chosen sophistication method by program Vision Assistant, which is a part of program LabVIEW.

  1. Ordered subsets convex algorithm for 3D terahertz transmission tomography

    Recur, Benoît; Balacey, Hugo; Bou Sleiman, Joyce; Perraud, Jean-Baptiste; Guillet, Jean-Paul; Kingston, Andrew; Mounaix, Patrick

    2014-01-01

    International audience We investigate in this paper a new reconstruction method in order to perform 3D Terahertz (THz) tomography using a continuous wave acquisition setup in transmission mode. This method is based on the Maximum Likelihood for TRansmission tomography (ML-TR) first developed for X-ray imaging. We optimize the Ordered Subsets Convex (OSC) implementation of the ML-TR by including the Gaussian propagation model of THz waves and take into account the intensity distributions of...

  2. Neural Network Based 3D Surface Reconstruction

    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

  3. 3D Reconstruction in Magnetic Resonance Imaging

    Mikulka, J.; Bartušek, Karel

    Cambridge : The Electromagnetics Academy, 2010, s. 1043-1046. ISBN 978-1-934142-14-1. [PIERS 2010 Cambridge. Cambridge (US), 05.07.2010-08.07.2010] R&D Projects: GA ČR GA102/09/0314 Institutional research plan: CEZ:AV0Z20650511 Keywords : 3D reconstruction * magnetic resonance imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

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

    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.

  5. 3-D flame temperature field reconstruction with multiobjective neural network

    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.

  6. 3D imaging of nanomaterials by discrete tomography

    The field of discrete tomography focuses on the reconstruction of samples that consist of only a few different materials. Ideally, a three-dimensional (3D) reconstruction of such a sample should contain only one grey level for each of the compositions in the sample. By exploiting this property in the reconstruction algorithm, either the quality of the reconstruction can be improved significantly, or the number of required projection images can be reduced. The discrete reconstruction typically contains fewer artifacts and does not have to be segmented, as it already contains one grey level for each composition. Recently, a new algorithm, called discrete algebraic reconstruction technique (DART), has been proposed that can be used effectively on experimental electron tomography datasets. In this paper, we propose discrete tomography as a general reconstruction method for electron tomography in materials science. We describe the basic principles of DART and show that it can be applied successfully to three different types of samples, consisting of embedded ErSi2 nanocrystals, a carbon nanotube grown from a catalyst particle and a single gold nanoparticle, respectively.

  7. Fully 3D GPU PET reconstruction

    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.

  8. Fully 3D GPU PET reconstruction

    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.

  9. 3-D Reconstruction From Satellite Images

    Denver, Troelz

    1999-01-01

    The aim of this project has been to implement a software system, that is able to create a 3-D reconstruction from two or more 2-D photographic images made from different positions. The height is determined from the disparity difference of the images. The general purpose of the system is mapping of......, 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....... treated individually. A detailed treatment of various lens distortions is required, in order to correct for these problems. This subject is included in the acquisition part. In the calibration part, the perspective distortion is removed from the images. Most attention has been paid to the matching problem...

  10. Analysis of the of bones through 3D computerized tomography

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-μTC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-μTC is a powerful technique that can be used to analyze bone microstructures. (author)

  11. Software for 3D diagnostic image reconstruction and analysis

    Recent advances in computer technologies have opened new frontiers in medical diagnostics. Interesting possibilities are the use of three-dimensional (3D) imaging and the combination of images from different modalities. Software prepared in our laboratories devoted to 3D image reconstruction and analysis from computed tomography and ultrasonography is presented. In developing our software it was assumed that it should be applicable in standard medical practice, i.e. it should work effectively with a PC. An additional feature is the possibility of combining 3D images from different modalities. The reconstruction and data processing can be conducted using a standard PC, so low investment costs result in the introduction of advanced and useful diagnostic possibilities. The program was tested on a PC using DICOM data from computed tomography and TIFF files obtained from a 3D ultrasound system. The results of the anthropomorphic phantom and patient data were taken into consideration. A new approach was used to achieve spatial correlation of two independently obtained 3D images. The method relies on the use of four pairs of markers within the regions under consideration. The user selects the markers manually and the computer calculates the transformations necessary for coupling the images. The main software feature is the possibility of 3D image reconstruction from a series of two-dimensional (2D) images. The reconstructed 3D image can be: (1) viewed with the most popular methods of 3D image viewing, (2) filtered and processed to improve image quality, (3) analyzed quantitatively (geometrical measurements), and (4) coupled with another, independently acquired 3D image. The reconstructed and processed 3D image can be stored at every stage of image processing. The overall software performance was good considering the relatively low costs of the hardware used and the huge data sets processed. The program can be freely used and tested (source code and program available at

  12. Quantitative nanoscale analysis in 3D using electron tomography

    State-of-the-art electron tomography has been established as a powerful tool to image complex structures with nanometer resolution in 3D. Especially STEM tomography is used extensively in materials science in such diverse areas as catalysis, semiconductor materials, and polymer composites mainly providing qualitative information on morphology, shape and distribution of materials. However, for an increasing number of studies quantitative information, e.g. surface area, fractal dimensions, particle distribution or porosity are needed. A quantitative analysis is typically performed after segmenting the tomographic data, which is one of the main sources of error for the quantification. In addition to noise, systematic errors due to the missing wedge and due to artifacts from the reconstruction algorithm itself are responsible for these segmentation errors and improved algorithms are needed. This presentation will provide an overview of the possibilities and limitations of quantitative nanoscale analysis by electron tomography. Using catalysts and nano composites as applications examples, intensities and intensity variations observed for the 3D volume reconstructed by WBP and SIRT will be quantitatively compared to alternative reconstruction algorithms; implications for quantification of electron (or X-ray) tomographic data will be discussed and illustrated for quantification of particle size distributions, particle correlations, surface area, and fractal dimensions in 3D.

  13. 3D reconstruction methods of coronal structures by radio observations

    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.

  14. 3D diffraction tomography for visualization of contrast media

    Pai, Vinay M.; Stein, Ashley; Kozlowski, Megan; George, Ashvin; Kopace, Rael; Bennett, Eric; Auxier, Julie A.; Wen, Han

    2011-03-01

    In x-ray CT, the ability to selectively isolate a contrast agent signal from the surrounding soft tissue and bone can greatly enhance contrast visibility and enable quantification of contrast concentration. We present here a 3D diffraction tomography implementation for selectively retaining volumetric diffraction signal from contrast agent particles that are within a banded size range while suppressing the background signal from soft tissue and bone. For this purpose, we developed a CT implementation of a single-shot x-ray diffraction imaging technique utilizing gratings. This technique yields both diffraction and absorption images from a single grating-modulated projection image through analysis in the spatial frequency domain. A solution of iron oxide nano-particles, having very different x-ray diffraction properties from tissue, was injected into ex vivo chicken wing and in vivo rat specimens respectively and imaged in a 3D diffraction CT setup. Following parallel beam reconstruction, it is noted that while the soft tissue, bone and contrast media are observed in the absorption volume reconstruction, only the contrast media is observed in the diffraction volume reconstruction. This 3D diffraction tomographic reconstruction permits the visualization and quantification of the contrast agent isolated from the soft tissue and bone background.

  15. 3D SPIRAL COMPUTED TOMOGRAPHY FOR THE DIAGNOSIS OF AN ABDOMINAL TUMOUR

    R.C. Tiutiuca; Iuliana Eva

    2006-01-01

    Patients with digestive illnesses requires a full exploration, cases where imagistic assets support (echographic examination, radiological data, computed tomography, magnetic resonance) are very usefully. Computed tomography, in this process, has a special value. The results from axial images are sustained by the informations supplied from three-dimensional reconstruction processes (3D reconstruction) with relevant importance in establishment of diagnosis and therapeutic plan.

  16. Photogrammetric 3D reconstruction using mobile imaging

    Fritsch, Dieter; Syll, Miguel

    2015-03-01

    In our paper we demonstrate the development of an Android Application (AndroidSfM) for photogrammetric 3D reconstruction that works on smartphones and tablets likewise. The photos are taken with mobile devices, and can thereafter directly be calibrated using standard calibration algorithms of photogrammetry and computer vision, on that device. Due to still limited computing resources on mobile devices, a client-server handshake using Dropbox transfers the photos to the sever to run AndroidSfM for the pose estimation of all photos by Structure-from-Motion and, thereafter, uses the oriented bunch of photos for dense point cloud estimation by dense image matching algorithms. The result is transferred back to the mobile device for visualization and ad-hoc on-screen measurements.

  17. Optimisation and validation of a 3D reconstruction algorithm for single photon emission computed tomography by means of GATE simulation platform

    Although time consuming, Monte-Carlo simulations remain an efficient tool enabling to assess correction methods for degrading physical effects in medical imaging. We have optimized and validated a reconstruction method baptized F3DMC (Fully 3D Monte Carlo) in which the physical effects degrading the image formation process were modelled using Monte-Carlo methods and integrated within the system matrix. We used the Monte-Carlo simulation toolbox GATE. We validated GATE in SPECT by modelling the gamma-camera (Philips AXIS) used in clinical routine. Techniques of threshold, filtering by a principal component analysis and targeted reconstruction (functional regions, hybrid regions) were used in order to improve the precision of the system matrix and to reduce the number of simulated photons as well as the time consumption required. The EGEE Grid infrastructures were used to deploy the GATE simulations in order to reduce their computation time. Results obtained with F3DMC were compared with the reconstruction methods (FBP, ML-EM, MLEMC) for a simulated phantom and with the OSEM-C method for the real phantom. Results have shown that the F3DMC method and its variants improve the restoration of activity ratios and the signal to noise ratio. By the use of the grid EGEE, a significant speed-up factor of about 300 was obtained. These results should be confirmed by performing studies on complex phantoms and patients and open the door to a unified reconstruction method, which could be used in SPECT and also in PET. (author)

  18. 3D/3D registration of coronary CTA and biplane XA reconstructions for improved image guidance

    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.

  19. 3D visualization using pulsed and CW digital holographic tomography techniques (Invited Paper)

    G. Nehmetallah; P. P. Banerjee; D. Ferree; R. Kephart; S. Praharaj

    2011-01-01

    We outline the use of digital holographic tomography to determine the three-dimensional (3D) shapes of falling and static objects, such as lenslets and water droplets. Reconstruction of digitally recorded inline holograms is performed using multiplicative and Radon transform techniques to reveal the exact 3D shapes of the objects.%We outline the use of digital holographic tomography to determine the three-dimensional (3D) shapes of falling and static objects,such as lenslets and water droplets.Reconstruction of digitally recorded inline holograms is performed using multiplicative and Radon transform techniques to reveal the exact 3D shapes of the objects.

  20. Probe Trajectory Interpolation for 3D Reconstruction of Freehand Ultrasound

    Coupé, Pierrick; Hellier, Pierre; Morandi, Xavier; Barillot, Christian

    2007-01-01

    Three-dimensional (3D) Freehand ultrasound uses the acquisition of non parallel B-scans localized in 3D by a tracking system (optic, mechanical or magnetic). Using the positions of the irregularly spaced B-scans, a regular 3D lattice volume can be reconstructed, to which conventional 3D computer vision algorithms (registration and segmentation) can be applied. This paper presents a new 3D reconstruction method which explicitly accounts for the probe trajectory. Experiments were conducted on p...

  1. Digital Reconstruction of 3D Polydisperse Dry Foam

    Chieco, A.; Feitosa, K.; Roth, A. E.; Korda, P. T.; Durian, D. J.

    2012-02-01

    Dry foam is a disordered packing of bubbles that distort into familiar polyhedral shapes. We have implemented a method that uses optical axial tomography to reconstruct the internal structure of a dry foam in three dimensions. The technique consists of taking a series of photographs of the dry foam against a uniformly illuminated background at successive angles. By summing the projections we create images of the foam cross section. Image analysis of the cross sections allows us to locate Plateau borders and vertices. The vertices are then connected according to Plateau's rules to reconstruct the internal structure of the foam. Using this technique we are able to visualize a large number of bubbles of real 3D foams and obtain statistics of faces and edges.

  2. Animal testing using 3D microwave tomography system for breast cancer detection.

    Lee, Jong Moon; Son, Sung Ho; Kim, Hyuk Je; Kim, Bo Ra; Choi, Heyng Do; Jeon, Soon Ik

    2014-01-01

    The three dimensional microwave tomography (3D MT) system of the Electronics and Telecommunications Research Institute (ETRI) comprises an antenna array, transmitting receiving module, switch matrix module and a signal processing component. This system also includes a patient interface bed as well as a 3D reconstruction algorithm. Here, we perform a comparative analysis of image reconstruction results using the assembled system and MRI results, which is used to image the breasts of dogs. Microwave imaging reconstruction results (at 1,500 MHz) obtained using the ETRI 3D MT system are presented. The system provides computationally reliable diagnosis results from the reconstructed MT Image. PMID:25160233

  3. 3D ultrasound computer tomography: update from a clinical study

    Hopp, T.; Zapf, M.; Kretzek, E.; Henrich, J.; Tukalo, A.; Gemmeke, H.; Kaiser, C.; Knaudt, J.; Ruiter, N. V.

    2016-04-01

    Ultrasound Computer Tomography (USCT) is a promising new imaging method for breast cancer diagnosis. We developed a 3D USCT system and tested it in a pilot study with encouraging results: 3D USCT was able to depict two carcinomas, which were present in contrast enhanced MRI volumes serving as ground truth. To overcome severe differences in the breast shape, an image registration was applied. We analyzed the correlation between average sound speed in the breast and the breast density estimated from segmented MRIs and found a positive correlation with R=0.70. Based on the results of the pilot study we now carry out a successive clinical study with 200 patients. For this we integrated our reconstruction methods and image post-processing into a comprehensive workflow. It includes a dedicated DICOM viewer for interactive assessment of fused USCT images. A new preview mode now allows intuitive and faster patient positioning. We updated the USCT system to decrease the data acquisition time by approximately factor two and to increase the penetration depth of the breast into the USCT aperture by 1 cm. Furthermore the compute-intensive reflectivity reconstruction was considerably accelerated, now allowing a sub-millimeter volume reconstruction in approximately 16 minutes. The updates made it possible to successfully image first patients in our ongoing clinical study.

  4. Fully Automatic 3D Reconstruction of Histological Images

    Bagci, Ulas; Bai, Li

    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...

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

    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...

  6. 3D Surface Reconstruction and Automatic Camera Calibration

    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.

  7. 3D Reconstruction in Spiral Multislice CT Scans

    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

  8. 3D Reconstruction by Kinect Sensor:A Brief Review

    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.

  9. Glasses for 3D ultrasound computer tomography: phase compensation

    Zapf, M.; Hopp, T.; Ruiter, N. V.

    2016-03-01

    Ultrasound Computer Tomography (USCT), developed at KIT, is a promising new imaging system for breast cancer diagnosis, and was successfully tested in a pilot study. The 3D USCT II prototype consists of several hundreds of ultrasound (US) transducers on a semi-ellipsoidal aperture. Spherical waves are sequentially emitted by individual transducers and received in parallel by many transducers. Reflectivity volumes are reconstructed by synthetic aperture focusing (SAFT). However, straight forward SAFT imaging leads to blurred images due to system imperfections. We present an extension of a previously proposed approach to enhance the images. This approach includes additional a priori information and system characteristics. Now spatial phase compensation was included. The approach was evaluated with a simulation and clinical data sets. An increase in the image quality was observed and quantitatively measured by SNR and other metrics.

  10. Assessing the Value of 3D Reconstruction in Building Construction

    Murthy, Uma; Boardman, David; Garg, Chirag

    2012-01-01

    3-dimensional (3D) reconstruction is an emerging field in image processing and computer vision that aims to create 3D visualizations/ models of objects/ scenes from image sets. However, its commercial applications and benefits are yet to be fully explored. In this paper, we describe ongoing work towards assessing the value of 3D reconstruction in the building construction domain. We present preliminary results from a user study, where our objective is to understand the use of visual informati...

  11. Analysis of the of bones through 3D computerized tomography; Analise de estrutura ossea atraves de microtomografia computadorizada 3D

    Lima, I.; Lopes, R.T. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Oliveira, L.F. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica; Alves, J.M. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2009-03-15

    This work shows the analysis of the internal structure of the bones samples through 3D micro tomography technique (3D-{mu}TC). The comprehension of the bone structure is particularly important when related to osteoporosis diagnosis because this implies in a deterioration of the trabecular bone architecture, which increases the fragility and the possibility to have bone fractures. Two bone samples (human calcaneous and Wistar rat femur) were used, and the method was a radiographic system in real time with an X Ray microfocus tube. The quantifications parameters are based on stereological principles and they are five: a bone volume fraction, trabecular number, the ratio between surface and bone volume, the trabecular thickness and the trabecular separation. The quantifications were done with a program developed especially for this purpose in Nuclear Instrumentation Laboratory - COPPE/UFRJ. This program uses as input the 3D reconstructions images and generates a table with the quantifications. The results of the human calcaneous quantifications are presented in tables 1 and 2, and the 3D reconstructions are illustrated in Figure 5. The Figure 6 illustrate the 2D reconstructed image and the Figure 7 the 3D visualization respectively of the Wistar femur sample. The obtained results show that the 3D-{mu}TC is a powerful technique that can be used to analyze bone microstructures. (author)

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

    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.

  13. Fast fully 3-D image reconstruction in PET using planograms.

    Brasse, D; Kinahan, P E; Clackdoyle, R; Defrise, M; Comtat, C; Townsend, D W

    2004-04-01

    We present a method of performing fast and accurate three-dimensional (3-D) backprojection using only Fourier transform operations for line-integral data acquired by planar detector arrays in positron emission tomography. This approach is a 3-D extension of the two-dimensional (2-D) linogram technique of Edholm. By using a special choice of parameters to index a line of response (LOR) for a pair of planar detectors, rather than the conventional parameters used to index a LOR for a circular tomograph, all the LORs passing through a point in the field of view (FOV) lie on a 2-D plane in the four-dimensional (4-D) data space. Thus, backprojection of all the LORs passing through a point in the FOV corresponds to integration of a 2-D plane through the 4-D "planogram." The key step is that the integration along a set of parallel 2-D planes through the planogram, that is, backprojection of a plane of points, can be replaced by a 2-D section through the origin of the 4-D Fourier transform of the data. Backprojection can be performed as a sequence of Fourier transform operations, for faster implementation. In addition, we derive the central-section theorem for planogram format data, and also derive a reconstruction filter for both backprojection-filtering and filtered-backprojection reconstruction algorithms. With software-based Fourier transform calculations we provide preliminary comparisons of planogram backprojection to standard 3-D backprojection and demonstrate a reduction in computation time by a factor of approximately 15. PMID:15084067

  14. 3D Equilibrium Reconstructions in DIII-D

    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.

  15. Optimisation and validation of a 3D reconstruction algorithm for single photon emission computed tomography by means of GATE simulation platform; Optimisation et validation d'un algorithme de reconstruction 3D en Tomographie d'Emission Monophotonique a l'aide de la plate forme de simulation GATE

    El Bitar, Ziad [Ecole Doctorale des Sciences Fondamentales, Universite Blaise Pascal, U.F.R de Recherches Scientifiques et Techniques, 34, avenue Carnot - BP 185, 63006 Clermont-Ferrand Cedex (France); Laboratoire de Physique Corpusculaire, CNRS/IN2P3, 63177 Aubiere (France)

    2006-12-15

    Although time consuming, Monte-Carlo simulations remain an efficient tool enabling to assess correction methods for degrading physical effects in medical imaging. We have optimized and validated a reconstruction method baptized F3DMC (Fully 3D Monte Carlo) in which the physical effects degrading the image formation process were modelled using Monte-Carlo methods and integrated within the system matrix. We used the Monte-Carlo simulation toolbox GATE. We validated GATE in SPECT by modelling the gamma-camera (Philips AXIS) used in clinical routine. Techniques of threshold, filtering by a principal component analysis and targeted reconstruction (functional regions, hybrid regions) were used in order to improve the precision of the system matrix and to reduce the number of simulated photons as well as the time consumption required. The EGEE Grid infrastructures were used to deploy the GATE simulations in order to reduce their computation time. Results obtained with F3DMC were compared with the reconstruction methods (FBP, ML-EM, MLEMC) for a simulated phantom and with the OSEM-C method for the real phantom. Results have shown that the F3DMC method and its variants improve the restoration of activity ratios and the signal to noise ratio. By the use of the grid EGEE, a significant speed-up factor of about 300 was obtained. These results should be confirmed by performing studies on complex phantoms and patients and open the door to a unified reconstruction method, which could be used in SPECT and also in PET. (author)

  16. Fully Automatic 3D Reconstruction of Histological Images

    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.

  17. 3D Building Reconstruction Using Dense Photogrammetric Point Cloud

    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.

  18. Three-Dimensional Optical Coherence Tomography (3D OCT) Project

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and dramatically...

  19. Three-Dimensional Optical Coherence Tomography (3D OCT) Project

    National Aeronautics and Space Administration — Applied Science Innovations, Inc. proposes to develop a new tool of 3D optical coherence tomography (OCT) for cellular level imaging at video frame rates and...

  20. 3D Reconstruction in Magnetic Resonance Imaging

    Mikulka, J.; Bartušek, Karel

    2010-01-01

    Roč. 6, č. 7 (2010), s. 617-620. ISSN 1931-7360 R&D Projects: GA ČR GA102/09/0314 Institutional research plan: CEZ:AV0Z20650511 Keywords : reconstruction methods * magnetic resonance imaging Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  1. Array antenna diagnostics with the 3D reconstruction algorithm

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

    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 reconstru......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...

  2. A 3D Model Reconstruction Method Using Slice Images

    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.

  3. Interior Reconstruction Using the 3d Hough Transform

    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.

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

    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.

  5. Stereo Based 3D Face Reconstruction

    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...

  6. Vector spherical harmonics application to 3-D tomography problem

    Balandin, A. L.

    2007-04-01

    A method of series expansion with the aid of vector spherical harmonics intended for inverting line integrated data is proposed to investigate 3-D vector fields in the spherical plasmas. A set of numerical computations demonstrating the 3-D reconstruction of the model vector fields has been performed to assess the inversion method proposed.

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

    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...

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

    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 resul...

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

    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.

  10. Camera Calibration by Registration Stereo Reconstruction to 3D Model

    Klečka, J.

    2015-01-01

    Paper aims at unusual way to camera calibration. The main idea is that by registration of uncalibrated stereo reconstruction to 3D model of the same scene is eliminated ambiguity of the reconstruction. The reason for this is that exact metric scene reconstruction from image pair can be understate as information equivalent to calibration of the source camera pair. Described principles were verified by experiment on real data and results are presented at the end of the paper.

  11. Usefulness of reconstructed 3D-CT for magerl technique

    It is obviously important to determine safe screwing in transarticular atlanto-axial fixation by the Magerl technique by evaluating the morphological features of the screw passing route. In the present study, we investigated the availability of reconstructed 3D-CT to prevent vertebral artery injury in this technique. Thirty patients underwent reconstructed 3D-CT prior to the operation to determine whether safe screw fixation by the Magerl technique, imaging coronal, and sagittal reconstruction CT were possible. As a result, safe screwing was found to be impossible in four cases, of which two therefore underwent Brooks's method and the other two cases O-C2 fusion. Twenty-six cases who were compatible with Magerl's method had no neuro-vascular complications. We concluded that reconstructed 3D-CT is useful for determining safe screw fixation by the Magerl technique. (author)

  12. Light field display and 3D image reconstruction

    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.

  13. [3D Super-resolution Reconstruction and Visualization of Pulmonary Nodules from CT Image].

    Wang, Bing; Fan, Xing; Yang, Ying; Tian, Xuedong; Gu, Lixu

    2015-08-01

    The aim of this study was to propose an algorithm for three-dimensional projection onto convex sets (3D POCS) to achieve super resolution reconstruction of 3D lung computer tomography (CT) images, and to introduce multi-resolution mixed display mode to make 3D visualization of pulmonary nodules. Firstly, we built the low resolution 3D images which have spatial displacement in sub pixel level between each other and generate the reference image. Then, we mapped the low resolution images into the high resolution reference image using 3D motion estimation and revised the reference image based on the consistency constraint convex sets to reconstruct the 3D high resolution images iteratively. Finally, we displayed the different resolution images simultaneously. We then estimated the performance of provided method on 5 image sets and compared them with those of 3 interpolation reconstruction methods. The experiments showed that the performance of 3D POCS algorithm was better than that of 3 interpolation reconstruction methods in two aspects, i.e., subjective and objective aspects, and mixed display mode is suitable to the 3D visualization of high resolution of pulmonary nodules. PMID:26710449

  14. 3D Reconstruction in Spiral Multislice CT Scans

    M. Ghafouri

    2005-01-01

    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 previousl...

  15. Improving automated 3D reconstruction methods via vision metrology

    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. 3D electron tomography of biological photonic crystals

    Butz, Benjamin; Winter, Benjamin; Vieweg, Benito; Knoke, Isabel; Spallek, Stefanie; Spiecker, Erdmann [CENEM, Universitaet Erlangen-Nuernberg (Germany); Schroeder-Turk, Gerd; Mecke, Klaus [Theoretische Physik I, Universitaet Erlangen-Nuernberg (Germany)

    2011-07-01

    Photonic crystals, i.e. periodical nanostructures of materials with different dielectric constants, are highly interesting for applications in optics, optoelectronics, and sensing. By tailoring the geometrical parameters radically different and improved optical properties (e.g., optical band-gap structure, extreme refractive indices, or high anisotropy) can be achieved. Naturally occurring photonic crystals, like butterfly scales, exoskeletons of insects (chitin), or seashells (nacre), can serve as model systems for understanding the relationship between structure and optical properties. Butterfly scales are studied by TEM using a FEI Titan{sup 3} 80-300 instrument. An optimized FIB technique or ultramicrotome sectioning were used to prepare the sensitive specimens with desired thickness. Since the periodical structures have dimensions on the sub-{mu}m scale, HAADF-STEM tomography was employed for obtaining extended tilt series under conditions of atomic-number sensitive imaging. Since the solid crystal consists of chemically homogeneous chitin while the pores are unfilled, the distinct contrast in the images can easily be interpreted in terms of the local projected mass density allowing to reconstruct the chitin distribution within the optical unit cell of the scales with high 3D resolution.

  17. 3D electron tomography of biological photonic crystals

    Photonic crystals, i.e. periodical nanostructures of materials with different dielectric constants, are highly interesting for applications in optics, optoelectronics, and sensing. By tailoring the geometrical parameters radically different and improved optical properties (e.g., optical band-gap structure, extreme refractive indices, or high anisotropy) can be achieved. Naturally occurring photonic crystals, like butterfly scales, exoskeletons of insects (chitin), or seashells (nacre), can serve as model systems for understanding the relationship between structure and optical properties. Butterfly scales are studied by TEM using a FEI Titan3 80-300 instrument. An optimized FIB technique or ultramicrotome sectioning were used to prepare the sensitive specimens with desired thickness. Since the periodical structures have dimensions on the sub-μm scale, HAADF-STEM tomography was employed for obtaining extended tilt series under conditions of atomic-number sensitive imaging. Since the solid crystal consists of chemically homogeneous chitin while the pores are unfilled, the distinct contrast in the images can easily be interpreted in terms of the local projected mass density allowing to reconstruct the chitin distribution within the optical unit cell of the scales with high 3D resolution.

  18. Rapidly 3D Texture Reconstruction Based on Oblique Photography

    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.

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

    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...

  20. 3D surface reconstruction multi-scale hierarchical approaches

    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

  1. 3D reconstruction based on spatial vanishing information

    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.

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

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

    2009-01-01

    external diameter of 0.26mm. A series of measurements were performed to determine the accuracy of 3D reconstructions obtained using stereo-photogrammetry methods, finding a procedure to determine the optimum number of rotations of the object for an acceptable measuring uncertainty. It was determined that...

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

    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. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction.

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-03-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localization because of the large effective volume of the 3D point spread function (PSF). The inability to precisely locate the emitters at a high density causes poor temporal resolution of localization-based superresolution technique and significantly limits its application in 3D live cell imaging. To address this problem, we developed a 3D high-density superresolution imaging platform that allows us to precisely locate the positions of emitters, even when they are significantly overlapped in three dimensional space. Our platform involves a multi-focus system in combination with astigmatic optics and an ℓ 1-Homotopy optimization procedure. To reduce the intrinsic bias introduced by the discrete formulation of compressed sensing, we introduced a debiasing step followed by a 3D weighted centroid procedure, which not only increases the localization accuracy, but also increases the computation speed of image reconstruction. We implemented our algorithms on a graphic processing unit (GPU), which speeds up processing 10 times compared with central processing unit (CPU) implementation. We tested our method with both simulated data and experimental data of fluorescently labeled microtubules and were able to reconstruct a 3D microtubule image with 1000 frames (512×512) acquired within 20 seconds. PMID:25798314

  5. 3D Observation of GEMS by Electron Tomography

    Matsuno, Junya; Miyake, Akira; Tsuchiyama, Akira; Nakamura-Messenger, Keiko; Messenger, Scott

    2014-01-01

    Amorphous silicates in chondritic porous interplanetary dust particles (CP-IDPs) coming from comets are dominated by glass with embedded metal and sulfides (GEMS). GEMS grains are submicron-sized rounded objects (typically 100-500) nm in diameter) with anaometer-sized (10-50 nm) Fe-Ni metal and sulfide grains embedded in an amorphous silicate matrix. Several formation processes for GEMS grains have been proposed so far, but these models are still being debated [2-5]. Bradley et al. proposed that GEMS grains are interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk and that they are amorphiation products of crystalline silicates in the interstellar medium by sputter-deposition of cosmic ray irradiation, similar to space weathering [2,4]. This consideration is based on the observation of nano-sized crystals (approximately 10 nm) called relict grains in GEMS grains and their shapes are pseudomorphs to the host GEMS grains. On the other hand, Keller and Messenger proposed that most GEMS formed in the protoplanetary disk as condensates from high temperature gas [3,5]. This model is based on the fact that most GEMS grains have solar isotopic compositions and have extremely heterogeneous and non-solar elemental compositions. Keller and Messenger (2011) also reported that amorphous silicates in GEMS grains are surrounded by sulfide grains, which formed as sulfidization of metallic iron grains located on the GEMS surface. The previous studies were performed with 2D observation by using transmission electron microscopy (TEM) or scanning TEM (STEM). In order to understand the structure of GEMS grains described above more clearly, we observed 3D structure of GEMS grains by electron tomography using a TEM/STEM (JEM-2100F, JEOL) at Kyoto University. Electron tomography gives not only 3D structures but also gives higher spatial resolution (approximately a few nm) than that in conventional 2D image, which is restricted by

  6. Is 3D true non linear traveltime tomography reasonable ?

    Herrero, A.; Virieux, J.

    2003-04-01

    The data sets requiring 3D analysis tools in the context of seismic exploration (both onshore and offshore experiments) or natural seismicity (micro seismicity surveys or post event measurements) are more and more numerous. Classical linearized tomographies and also earthquake localisation codes need an accurate 3D background velocity model. However, if the medium is complex and a priori information not available, a 1D analysis is not able to provide an adequate background velocity image. Moreover, the design of the acquisition layouts is often intrinsically 3D and renders difficult even 2D approaches, especially in natural seismicity cases. Thus, the solution relies on the use of a 3D true non linear approach, which allows to explore the model space and to identify an optimal velocity image. The problem becomes then practical and its feasibility depends on the available computing resources (memory and time). In this presentation, we show that facing a 3D traveltime tomography problem with an extensive non-linear approach combining fast travel time estimators based on level set methods and optimisation techniques such as multiscale strategy is feasible. Moreover, because management of inhomogeneous inversion parameters is more friendly in a non linear approach, we describe how to perform a jointly non-linear inversion for the seismic velocities and the sources locations.

  7. 3D reconstruction of multiple stained histology images

    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.

  8. 3D reconstruction, a new challenge in industrial radiography

    In a NDT context, industrial radiography enables the detection of defects through their projection on a film. EDF has studied the benefit that may be brought in terms of localisation and orientation of the defects by the mean of 3D reconstruction using a very limited number of radiographs. The reconstruction issue consists of solving an integral equation of the first kind ; in a noisy context, the reconstruction belongs to the so-called ill-posed class of problem. Appropriate solutions may only be found with the help of regularization technique, by the introduction of a priori knowledge concerning the unknown solution and also by the use of a statistical modelization of the physical process which produces radiographs. Another approach simplifies the problem and reconstructs the skeleton of a defect only. All these methods coming from applied mathematical sciences enable a more precise diagnosis in non-destructive testing of thick inhomogeneous material. (authors). 4 refs., 4 figs

  9. Applications of 3-D reconstruction and 3-D image analysis using computer graphics in surgery of the oral and maxillofacial regions

    Using the 2-D data provided by CT-Tomography and MRI-tomography of oral and maxillofacial diseases (cyst, benign tumor, primary tumor and regional lymphnodes of malignant tumor), 3-D images were reconstructed and spatial analysis was attempted. We report the general concepts. The hardware used consisted of the Hewlett-Packard HP-9000/300, which utilizes a 16-bit CPU. A digitizer was used to construct 3-D images from serial CT-tomography and MRI-tomography images. Output was displayed on a color monitor and photographs. The 3 cases on which we used this technique included a 19-year-old male with plunging ranula, a 50-year-old male with maxillary pleomorphic adenoma, and a 58-year-old male with squamous cell carcinoma of the maxillary sinus (T3N3M0). As 3-D reconstruction can be done in any arbitrary direction or cross section, it is possible to spatially determine the position of the disease inside the body, its progression, and its relationship with adjacent organs. Through image analysis, it is possible to better understand the volume and surface area of the disease. 3-D image reconstruction is an effective tool in the determination of diagnosis, therapeutic guidelines, and surgical indications, as well as effectiveness of treatment. (author)

  10. Reconstruction of 3D morphology of polyhedral nanoparticles

    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

  11. Automatic Reconstruction of Personalized Avatars from 3D Face Scans

    Zollhoefer, Michael; Martinek, Michael; Greiner, Guenther; Stamminger, Marc; Suessmuth, Jochen

    2011-01-01

    Abstract We present a simple algorithm for computing a high quality personalized avatar from a single color image and the corresponding depth map which have been captured by Microsoft's Kinect sensor. Due to the low market price of our hardware setup, 3D face scanning becomes feasible for home use. The proposed algorithm combines the advantages of robust non-rigid registration and fitting of a morphable face model. We obtain a high quality reconstruction of the facial geometry and ...

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

    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...

  13. 3DSEM++: Adaptive and intelligent 3D SEM surface reconstruction.

    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

  14. An automated 3D reconstruction method of UAV images

    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.

  15. Projective 3D-reconstruction of Uncalibrated Endoscopic Images

    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.

  16. 3D X-ray microscopy: image formation, tomography and instrumentation

    Selin, Mårten

    2016-01-01

    Tomography in soft X-ray microscopy is an emerging technique for obtaining quantitative 3D structural information about cells. One of its strengths, compared with other techniques, is that it can image intact cells in their near-native state at a few 10 nm’s resolution, without staining. However, the methods for reconstructing 3D-data rely on algorithms that assume projection data, which the images are generally not due to the imaging systems’ limited depth of focus. To bring out the full pot...

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

    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)

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

    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.

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

    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)

  20. Large Scale 3D Image Reconstruction in Optical Interferometry

    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...

  1. 3D Reconstruction of Coronary Artery Vascular Smooth Muscle Cells.

    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.

  2. 3D temperature field reconstruction using ultrasound sensing system

    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.

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

    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.

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

    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

  5. 3D artefact for concurrent scale calibration in Computed Tomography

    Stolfi, Alessandro; De Chiffre, Leonardo

    2016-01-01

    A novel artefact for calibration of the scale in 3D X-ray Computed Tomography (CT) is presented. The artefact comprises a carbon fibre tubular structure on which a number of reference ruby spheres are glued. The artefact is positioned and scanned together with the workpiece inside the CT scanner...... providing a reference system for measurement. The artefact allows a considerable reduction of time by compressing the full process of calibration, scanning, measurement, and re-calibration, into a single process. The method allows a considerable reduction of the amount of data generated from CT scanning. A...

  6. 3D Cone Beam Volumetric Tomography Dedicated to Maxillofacial Radiology

    Masoud Varshosaz

    2009-01-01

      "nThe 3D cone beam volume/computed tomography (CBVT/CBCT) has been designed for imaging the hard tissues of the maxillofacial region, although it has been used in some era of medical imaging for many years. CBVT is capable of providing a sub-millimeter resolution with the short scanning time of mostly less than 20 seconds and radiation dosages reportedly up to 15 times lower than those of spiral CT scans. In less than a decade, CBVT has revolutionized oral and maxillofacial ra...

  7. One-step reconstruction of assembled 3D holographic scenes

    Velez Zea, Alejandro; Barrera-Ramírez, John Fredy; Torroba, Roberto

    2015-12-01

    We present a new experimental approach for reconstructing in one step 3D scenes otherwise not feasible in a single snapshot from standard off-axis digital hologram architecture, due to a lack of illuminating resources or a limited setup size. Consequently, whenever a scene could not be wholly illuminated or the size of the scene surpasses the available setup disposition, this protocol can be implemented to solve these issues. We need neither to alter the original setup in every step nor to cover the whole scene by the illuminating source, thus saving resources. With this technique we multiplex the processed holograms of actual diffuse objects composing a scene using a two-beam off-axis holographic setup in a Fresnel approach. By registering individually the holograms of several objects and applying a spatial filtering technique, the filtered Fresnel holograms can then be added to produce a compound hologram. The simultaneous reconstruction of all objects is performed in one step using the same recovering procedure employed for single holograms. Using this technique, we were able to reconstruct, for the first time to our knowledge, a scene by multiplexing off-axis holograms of the 3D objects without cross talk. This technique is important for quantitative visualization of optically packaged multiple images and is useful for a wide range of applications. We present experimental results to support the method.

  8. 3D reconstruction of porous electrodes and microstructure modelling

    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

  9. 3D Human cartilage surface characterization by optical coherence tomography

    Brill, Nicolai; Riedel, Jörn; Schmitt, Robert; Tingart, Markus; Truhn, Daniel; Pufe, Thomas; Jahr, Holger; Nebelung, Sven

    2015-10-01

    Early diagnosis and treatment of cartilage degeneration is of high clinical interest. Loss of surface integrity is considered one of the earliest and most reliable signs of degeneration, but cannot currently be evaluated objectively. Optical Coherence Tomography (OCT) is an arthroscopically available light-based non-destructive real-time imaging technology that allows imaging at micrometre resolutions to millimetre depths. As OCT-based surface evaluation standards remain to be defined, the present study investigated the diagnostic potential of 3D surface profile parameters in the comprehensive evaluation of cartilage degeneration. To this end, 45 cartilage samples of different degenerative grades were obtained from total knee replacements (2 males, 10 females; mean age 63.8 years), cut to standard size and imaged using a spectral-domain OCT device (Thorlabs, Germany). 3D OCT datasets of 8  ×  8, 4  ×  4 and 1  ×  1 mm (width  ×  length) were obtained and pre-processed (image adjustments, morphological filtering). Subsequent automated surface identification algorithms were used to obtain the 3D primary profiles, which were then filtered and processed using established algorithms employing ISO standards. The 3D surface profile thus obtained was used to calculate a set of 21 3D surface profile parameters, i.e. height (e.g. Sa), functional (e.g. Sk), hybrid (e.g. Sdq) and segmentation-related parameters (e.g. Spd). Samples underwent reference histological assessment according to the Degenerative Joint Disease classification. Statistical analyses included calculation of Spearman’s rho and assessment of inter-group differences using the Kruskal Wallis test. Overall, the majority of 3D surface profile parameters revealed significant degeneration-dependent differences and correlations with the exception of severe end-stage degeneration and were of distinct diagnostic value in the assessment of surface integrity. None of the 3D

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

    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

  11. 3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

    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.

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

    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

  13. Towards automated electron holographic tomography for 3D mapping of electrostatic potentials

    Electron-holographic tomography (EHT), that is, the combination of off-axis electron holography with electron tomography, was successfully applied for the quantitative 3D mapping of electrostatic potentials at the nanoscale. Here we present the first software package (THOMAS) for semi-automated acquisition of holographic tilt series, a prerequisite for efficient data collection. Using THOMAS, the acquisition time for a holographic tilt series, consisting of object and reference holograms, is reduced by a factor of five on average, compared to the previous, completely manual approaches. Moreover, the existing software packages for retrieving amplitude and phase information from electron holograms have been extended, now including a one-step procedure for holographic tilt series reconstruction. Furthermore, a modified SIRT algorithm (WSIRT) was implemented for the quantitative 3D reconstruction of the electrostatic potential from the aligned phase tilt series. Finally, the application of EHT to a polystyrene latex sphere test-specimen and a pn-doped Ge 'needle'-shaped specimen are presented, illustrating the quantitative character of EHT. For both specimens the mean inner potential (MIP) values were accurately determined from the reconstructed 3D potential. For the Ge specimen, additionally the 'built-in' voltage across the pn junction of 0.5 V was obtained.

  14. 3D particle tracking velocimetry using dynamic discrete tomography for plasma physics applications

    Moseev, Dmitry; Alpers, Andreas; Gritzmann, Peter;

    2013-01-01

    3D particle tracking velocimetry (PTV) is a diagnostic technique which is widely used for studying flows, combustion, and plasmas. Current tomographic particle tracking methods are based on the multiplicative algebraic reconstruction technique and used for reconstructing the distribution of multi......-pixel sized particles as greylevel images. Reconstructions obtained by these methods do not necessarily match the experimental data. We propose a new algorithm which can be used for tracking dust particles in tokamaks and stellarators, as well as in low-temperature and complex plasmas. The dynamic discrete...... tomography algorithm is efficient for data from two projection directions and exact. The non-uniqueness can be detected and tracked individually. The algorithm performance is proportional to N3 on average where N is the number of particles in the reconstruction. There is a room for further improvement of the...

  15. 4D image reconstruction for emission tomography

    An overview of the theory of 4D image reconstruction for emission tomography is given along with a review of the current state of the art, covering both positron emission tomography and single photon emission computed tomography (SPECT). By viewing 4D image reconstruction as a matter of either linear or non-linear parameter estimation for a set of spatiotemporal functions chosen to approximately represent the radiotracer distribution, the areas of so-called ‘fully 4D’ image reconstruction and ‘direct kinetic parameter estimation’ are unified within a common framework. Many choices of linear and non-linear parameterization of these functions are considered (including the important case where the parameters have direct biological meaning), along with a review of the algorithms which are able to estimate these often non-linear parameters from emission tomography data. The other crucial components to image reconstruction (the objective function, the system model and the raw data format) are also covered, but in less detail due to the relatively straightforward extension from their corresponding components in conventional 3D image reconstruction. The key unifying concept is that maximum likelihood or maximum a posteriori (MAP) estimation of either linear or non-linear model parameters can be achieved in image space after carrying out a conventional expectation maximization (EM) update of the dynamic image series, using a Kullback-Leibler distance metric (comparing the modeled image values with the EM image values), to optimize the desired parameters. For MAP, an image-space penalty for regularization purposes is required. The benefits of 4D and direct reconstruction reported in the literature are reviewed, and furthermore demonstrated with simple simulation examples. It is clear that the future of reconstructing dynamic or functional emission tomography images, which often exhibit high levels of spatially correlated noise, should ideally exploit these 4D

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

    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.

  17. 3D Coronal Density Reconstruction and Retrieving the Magnetic Field Structure during Solar Minimum

    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...

  18. 3D Reconstruction of virtual colon structures from colonoscopy images.

    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

  19. Digital 3D facial reconstruction of George Washington

    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.

  20. Fast vision-based catheter 3D reconstruction

    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.

  1. 3D Reconstruction of Irregular Buildings and Buddha Statues

    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.

  2. Accuracy assessment of 3D bone reconstructions using CT: an intro comparison.

    Lalone, Emily A; Willing, Ryan T; Shannon, Hannah L; King, Graham J W; Johnson, James A

    2015-08-01

    Computed tomography provides high contrast imaging of the joint anatomy and is used routinely to reconstruct 3D models of the osseous and cartilage geometry (CT arthrography) for use in the design of orthopedic implants, for computer assisted surgeries and computational dynamic and structural analysis. The objective of this study was to assess the accuracy of bone and cartilage surface model reconstructions by comparing reconstructed geometries with bone digitizations obtained using an optical tracking system. Bone surface digitizations obtained in this study determined the ground truth measure for the underlying geometry. We evaluated the use of a commercially available reconstruction technique using clinical CT scanning protocols using the elbow joint as an example of a surface with complex geometry. To assess the accuracies of the reconstructed models (8 fresh frozen cadaveric specimens) against the ground truth bony digitization-as defined by this study-proximity mapping was used to calculate residual error. The overall mean error was less than 0.4 mm in the cortical region and 0.3 mm in the subchondral region of the bone. Similarly creating 3D cartilage surface models from CT scans using air contrast had a mean error of less than 0.3 mm. Results from this study indicate that clinical CT scanning protocols and commonly used and commercially available reconstruction algorithms can create models which accurately represent the true geometry. PMID:26037323

  3. 3D RECONSTRUCTION FROM MULTI-VIEW MEDICAL X-RAY IMAGES – REVIEW AND EVALUATION OF EXISTING METHODS

    S. Hosseinian

    2015-12-01

    Full Text Available The 3D concept is extremely important in clinical studies of human body. Accurate 3D models of bony structures are currently required in clinical routine for diagnosis, patient follow-up, surgical planning, computer assisted surgery and biomechanical applications. However, 3D conventional medical imaging techniques such as computed tomography (CT scan and magnetic resonance imaging (MRI have serious limitations such as using in non-weight-bearing positions, costs and high radiation dose(for CT. Therefore, 3D reconstruction methods from biplanar X-ray images have been taken into consideration as reliable alternative methods in order to achieve accurate 3D models with low dose radiation in weight-bearing positions. Different methods have been offered for 3D reconstruction from X-ray images using photogrammetry which should be assessed. In this paper, after demonstrating the principles of 3D reconstruction from X-ray images, different existing methods of 3D reconstruction of bony structures from radiographs are classified and evaluated with various metrics and their advantages and disadvantages are mentioned. Finally, a comparison has been done on the presented methods with respect to several metrics such as accuracy, reconstruction time and their applications. With regards to the research, each method has several advantages and disadvantages which should be considered for a specific application.

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

    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...

  5. Block matching 3D random noise filtering for absorption optical projection tomography

    Fumene Feruglio, P; Vinegoni, C; Weissleder, R [Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, 185 Cambridge Street, Boston, MA 02114 (United States); Gros, J [Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston MA 02115 (United States); Sbarbati, A, E-mail: cvinegoni@mgh.harvard.ed [Department of Morphological and Biomedical Sciences, University of Verona, Strada Le Grazie 8, 37134 Verona (Italy)

    2010-09-21

    Absorption and emission optical projection tomography (OPT), alternatively referred to as optical computed tomography (optical-CT) and optical-emission computed tomography (optical-ECT), are recently developed three-dimensional imaging techniques with value for developmental biology and ex vivo gene expression studies. The techniques' principles are similar to the ones used for x-ray computed tomography and are based on the approximation of negligible light scattering in optically cleared samples. The optical clearing is achieved by a chemical procedure which aims at substituting the cellular fluids within the sample with a cell membranes' index matching solution. Once cleared the sample presents very low scattering and is then illuminated with a light collimated beam whose intensity is captured in transillumination mode by a CCD camera. Different projection images of the sample are subsequently obtained over a 360{sup 0} full rotation, and a standard backprojection algorithm can be used in a similar fashion as for x-ray tomography in order to obtain absorption maps. Because not all biological samples present significant absorption contrast, it is not always possible to obtain projections with a good signal-to-noise ratio, a condition necessary to achieve high-quality tomographic reconstructions. Such is the case for example, for early stage's embryos. In this work we demonstrate how, through the use of a random noise removal algorithm, the image quality of the reconstructions can be considerably improved even when the noise is strongly present in the acquired projections. Specifically, we implemented a block matching 3D (BM3D) filter applying it separately on each acquired transillumination projection before performing a complete three-dimensional tomographical reconstruction. To test the efficiency of the adopted filtering scheme, a phantom and a real biological sample were processed. In both cases, the BM3D filter led to a signal-to-noise ratio

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

    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

  7. 3-D waveform tomography sensitivity kernels for anisotropic media

    Djebbi, R.

    2014-01-01

    The complications in anisotropic multi-parameter inversion lie in the trade-off between the different anisotropy parameters. We compute the tomographic waveform sensitivity kernels for a VTI acoustic medium perturbation as a tool to investigate this ambiguity between the different parameters. We use dynamic ray tracing to efficiently handle the expensive computational cost for 3-D anisotropic models. Ray tracing provides also the ray direction information necessary for conditioning the sensitivity kernels to handle anisotropy. The NMO velocity and η parameter kernels showed a maximum sensitivity for diving waves which results in a relevant choice of those parameters in wave equation tomography. The δ parameter kernel showed zero sensitivity; therefore it can serve as a secondary parameter to fit the amplitude in the acoustic anisotropic inversion. Considering the limited penetration depth of diving waves, migration velocity analysis based kernels are introduced to fix the depth ambiguity with reflections and compute sensitivity maps in the deeper parts of the model.

  8. New solutions and applications of 3D computer tomography image processing

    Effenberger, Ira; Kroll, Julia; Verl, Alexander

    2008-02-01

    As nowadays the industry aims at fast and high quality product development and manufacturing processes a modern and efficient quality inspection is essential. Compared to conventional measurement technologies, industrial computer tomography (CT) is a non-destructive technology for 3D-image data acquisition which helps to overcome their disadvantages by offering the possibility to scan complex parts with all outer and inner geometric features. In this paper new and optimized methods for 3D image processing, including innovative ways of surface reconstruction and automatic geometric feature detection of complex components, are presented, especially our work of developing smart online data processing and data handling methods, with an integrated intelligent online mesh reduction. Hereby the processing of huge and high resolution data sets is guaranteed. Besides, new approaches for surface reconstruction and segmentation based on statistical methods are demonstrated. On the extracted 3D point cloud or surface triangulation automated and precise algorithms for geometric inspection are deployed. All algorithms are applied to different real data sets generated by computer tomography in order to demonstrate the capabilities of the new tools. Since CT is an emerging technology for non-destructive testing and inspection more and more industrial application fields will use and profit from this new technology.

  9. Test of 3D CT reconstructions by EM + TV algorithm from undersampled data

    Computerized tomography (CT) plays an important role in medical imaging for diagnosis and therapy. However, CT imaging is connected with ionization radiation exposure of patients. Therefore, the dose reduction is an essential issue in CT. In 2011, the Expectation Maximization and Total Variation Based Model for CT Reconstruction (EM+TV) was proposed. This method can reconstruct a better image using less CT projections in comparison with the usual filtered back projection (FBP) technique. Thus, it could significantly reduce the overall dose of radiation in CT. This work reports the results of an independent numerical simulation for cone beam CT geometry with alternative virtual phantoms. As in the original report, the 3D CT images of 128×128×128 virtual phantoms were reconstructed. It was not possible to implement phantoms with lager dimensions because of the slowness of code execution even by the CORE i7 CPU.

  10. Test of 3D CT reconstructions by EM + TV algorithm from undersampled data

    Evseev, Ivan; Ahmann, Francielle; Silva, Hamilton P. da [Universidade Tecnologica Federal do Parana - UTFPR/FB, 85601-970, Caixa Postal 135, Francisco Beltrao - PR (Brazil); Schelin, Hugo R. [Universidade Tecnologica Federal do Parana-UTFPR/FB,85601-970,Caixa Postal 135,Francisco Beltrao-PR (Brazil) and Faculdades Pequeno Principe-FPP, Av. Iguacu, 333, Rebou (Brazil); Yevseyeva, Olga [Universidade Federal de Santa Catarina - UFSC/ARA, 88900-000, Rua Pedro Joao Pereira, 150, Ararangua - SC (Brazil); Klock, Margio C. L. [Universidade Federal do Parana - UFPR Litoral, 80230-901, Rua Jaguaraiva 512, Caioba, Matinhos - PR (Brazil)

    2013-05-06

    Computerized tomography (CT) plays an important role in medical imaging for diagnosis and therapy. However, CT imaging is connected with ionization radiation exposure of patients. Therefore, the dose reduction is an essential issue in CT. In 2011, the Expectation Maximization and Total Variation Based Model for CT Reconstruction (EM+TV) was proposed. This method can reconstruct a better image using less CT projections in comparison with the usual filtered back projection (FBP) technique. Thus, it could significantly reduce the overall dose of radiation in CT. This work reports the results of an independent numerical simulation for cone beam CT geometry with alternative virtual phantoms. As in the original report, the 3D CT images of 128 Multiplication-Sign 128 Multiplication-Sign 128 virtual phantoms were reconstructed. It was not possible to implement phantoms with lager dimensions because of the slowness of code execution even by the CORE i7 CPU.

  11. Applicability of 3D-CT facial reconstruction for forensic individual identification Aplicabilidade da reconstrução facial em 3D-TC para identificação individual forense

    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...

  12. The new CORIMP CME catalog & 3D reconstructions

    Byrne, Jason; Morgan, Huw; Gallagher, Peter; Habbal, Shadia; Davies, Jackie

    2015-04-01

    A new coronal mass ejection catalog has been built from a unique set of coronal image processing techniques, called CORIMP, that overcomes many of the limitations of current catalogs in operation. An online database has been produced for the SOHO/LASCO data and event detections therein; providing information on CME onset time, position angle, angular width, speed, acceleration, and mass, along with kinematic plots and observation movies. The high-fidelity and robustness of these methods and derived CME structure and kinematics will lead to an improved understanding of the dynamics of CMEs, and a realtime version of the algorithm has been implemented to provide CME detection alerts to the interested space weather community. Furthermore, STEREO data has been providing the ability to perform 3D reconstructions of CMEs that are observed in multipoint observations. This allows a determination of the 3D kinematics and morphologies of CMEs characterised in STEREO data via the 'elliptical tie-pointing' technique. The associated observations of SOHO, SDO and PROBA2 (and intended use of K-Cor) provide additional measurements and constraints on the CME analyses in order to improve their accuracy.

  13. Inclusion of high resolution MODIS maps on a 3D tropospheric water vapor GPS tomography model

    Benevides, Pedro; Catalao, Joao; Nico, Giovanni; Miranda, Pedro M. A.

    2015-10-01

    Observing the water vapor distribution on the troposphere remains a challenge for the weather forecast. Radiosondes provide precise water vapor profiles of the troposphere, but lack geographical and temporal coverage, while satellite meteorological maps have good spatial resolution but even poorer temporal resolution. GPS has proved its capacity to measure the integrated water vapor in all weather conditions with high temporal sampling frequency. However these measurements lack a vertical water vapor discretization. Reconstruction of the slant path GPS observation to the satellite allows oblique water vapor measurements. Implementation of a 3D grid of voxels along the troposphere over an area where GPS stations are available enables the observation ray tracing. A relation between the water vapor density and the distanced traveled inside the voxels is established, defining GPS tomography. An inverse problem formulation is needed to obtain a water vapor solution. The combination of precipitable water vapor (PWV) maps obtained from MODIS satellite data with the GPS tomography is performed in this work. The MODIS PWV maps can have 1 or 5 km pixel resolution, being obtained 2 times per day in the same location at most. The inclusion of MODIS PWV maps provides an enhanced horizontal resolution for the tomographic solution and benefits the stability of the inversion problem. A 3D tomographic grid was adjusted over a regional area covering Lisbon, Portugal, where a GNSS network of 9 receivers is available. Radiosonde measurements in the area are used to evaluate the 3D water vapor tomography maps.

  14. Neurofunctional systems. 3D reconstructions with correlated neuroimaging

    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

  15. New X-Ray Tomography Method Based on the 3D Radon Transform Compatible with Anisotropic Sources

    Vassholz, M.; Koberstein-Schwarz, B.; Ruhlandt, A.; Krenkel, M.; Salditt, T.

    2016-02-01

    In this work, we propose a novel computed tomography (CT) approach for three-dimensional (3D) object reconstruction, based on a generalized tomographic geometry with two-dimensional angular sampling (two angular degrees of freedom). The reconstruction is based on the 3D radon transform and is compatible with anisotropic beam conditions. This allows isotropic 3D imaging with a source, which can be extended along one direction for increased flux, while high resolution is achieved by a small source size only in the orthogonal direction. This novel scheme for analytical CT is demonstrated by numerical simulations and proof-of-concept experiments. In this way high resolution and coherence along a single direction determines the reconstruction quality of the entire 3D data set, opening up, for example, new opportunities to achieve nanoscale resolution and/or phase contrast with low brilliance sources such as laboratory x-ray or neutron sources.

  16. Gene Electrotransfer in 3D Reconstructed Human Dermal Tissue.

    Madi, Moinecha; Rols, Marie-Pierre; Gibot, Laure

    2016-01-01

    Gene electrotransfer into the skin is of particular interest for the development of medical applications including DNA vaccination, cancer treatment, wound healing or treatment of local skin disorders. However, such clinical applications are currently limited due to poor understanding of the mechanisms governing DNA electrotransfer within human tissue. Nowadays, most studies are carried out in rodent models but rodent skin varies from human skin in terms of cell composition and architecture. We used a tissue-engineering approach to study gene electrotransfer mechanisms in a human tissue context. Primary human dermal fibroblasts were cultured according to the self-assembly method to produce 3D reconstructed human dermal tissue. In this study, we showed that cells of the reconstructed cutaneous tissue were efficiently electropermeabilized by applying millisecond electric pulses, without affecting their viability. A reporter gene was successfully electrotransferred into this human tissue and gene expression was detected for up to 48h. Interestingly, the transfected cells were solely located on the upper surface of the tissue, where they were in close contact with plasmid DNA solution. Furthermore, we report evidences that electrotransfection success depends on plasmid mobility within tissue- rich in collagens, but not on cell proliferation status. In conclusion, in addition to proposing a reliable alternative to animal experiments, tissue engineering produces valid biological tool for the in vitro study of gene electrotransfer mechanisms in human tissue. PMID:27029947

  17. 3D virtual reconstruction of the Pleistocene cheetah skull from the Tangshan, Nanjing, China

    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.

  18. A fast rebinning algorithm for 3D positron emission tomography using John's equation

    Defrise, Michel; Liu, Xuan

    1999-08-01

    Volume imaging in positron emission tomography (PET) requires the inversion of the three-dimensional (3D) x-ray transform. The usual solution to this problem is based on 3D filtered-backprojection (FBP), but is slow. Alternative methods have been proposed which factor the 3D data into independent 2D data sets corresponding to the 2D Radon transforms of a stack of parallel slices. Each slice is then reconstructed using 2D FBP. These so-called rebinning methods are numerically efficient but are approximate. In this paper a new exact rebinning method is derived by exploiting the fact that the 3D x-ray transform of a function is the solution to the second-order partial differential equation first studied by John. The method is proposed for two sampling schemes, one corresponding to a pair of infinite plane detectors and another one corresponding to a cylindrical multi-ring PET scanner. The new FORE-J algorithm has been implemented for this latter geometry and was compared with the approximate Fourier rebinning algorithm FORE and with another exact rebinning algorithm, FOREX. Results with simulated data demonstrate a significant improvement in accuracy compared to FORE, while the reconstruction time is doubled. Compared to FOREX, the FORE-J algorithm is slightly less accurate but more than three times faster.

  19. Advanced reconstruction algorithms for electron tomography: From comparison to combination

    Goris, B. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Roelandts, T. [Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Batenburg, K.J. [Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Centrum Wiskunde and Informatica, Science Park 123, NL-1098XG Amsterdam (Netherlands); Heidari Mezerji, H. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Bals, S., E-mail: sara.bals@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2013-04-15

    In this work, the simultaneous iterative reconstruction technique (SIRT), the total variation minimization (TVM) reconstruction technique and the discrete algebraic reconstruction technique (DART) for electron tomography are compared and the advantages and disadvantages are discussed. Furthermore, we describe how the result of a three dimensional (3D) reconstruction based on TVM can provide objective information that is needed as the input for a DART reconstruction. This approach results in a tomographic reconstruction of which the segmentation is carried out in an objective manner. - Highlights: ► A comparative study between different reconstruction algorithms for tomography is performed. ► Reconstruction algorithms that uses prior knowledge about the specimen have a superior result. ► One reconstruction algorithm can provide the prior knowledge for a second algorithm.

  20. 3-D Reconstruction of Medical Image Using Wavelet Transform and Snake Model

    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.

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

    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.

  2. DIACHRONIC 3D RECONSTRUCTION FOR LOST CULTURAL HERITAGE

    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.

  3. Diachronic 3d Reconstruction for Lost Cultural Heritage

    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.

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

    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.

  5. Validation of the Gate simulation platform in single photon emission computed tomography and application to the development of a complete 3-dimensional reconstruction algorithm; Validation de la plate-forme de simulation GATE en tomographie a emission monophotonique et application au developpement d'un algorithme de reconstruction 3D complete

    Lazaro, D

    2003-10-01

    Monte Carlo simulations are currently considered in nuclear medical imaging as a powerful tool to design and optimize detection systems, and also to assess reconstruction algorithms and correction methods for degrading physical effects. Among the many simulators available, none of them is considered as a standard in nuclear medical imaging: this fact has motivated the development of a new generic Monte Carlo simulation platform (GATE), based on GEANT4 and dedicated to SPECT/PET (single photo emission computed tomography / positron emission tomography) applications. We participated during this thesis to the development of the GATE platform within an international collaboration. GATE was validated in SPECT by modeling two gamma cameras characterized by a different geometry, one dedicated to small animal imaging and the other used in a clinical context (Philips AXIS), and by comparing the results obtained with GATE simulations with experimental data. The simulation results reproduce accurately the measured performances of both gamma cameras. The GATE platform was then used to develop a new 3-dimensional reconstruction method: F3DMC (fully 3-dimension Monte-Carlo) which consists in computing with Monte Carlo simulation the transition matrix used in an iterative reconstruction algorithm (in this case, ML-EM), including within the transition matrix the main physical effects degrading the image formation process. The results obtained with the F3DMC method were compared to the results obtained with three other more conventional methods (FBP, MLEM, MLEMC) for different phantoms. The results of this study show that F3DMC allows to improve the reconstruction efficiency, the spatial resolution and the signal to noise ratio with a satisfactory quantification of the images. These results should be confirmed by performing clinical experiments and open the door to a unified reconstruction method, which could be applied in SPECT but also in PET. (author)

  6. 3D Cone Beam Volumetric Tomography Dedicated to Maxillofacial Radiology

    Masoud Varshosaz

    2009-01-01

    Full Text Available   "nThe 3D cone beam volume/computed tomography (CBVT/CBCT has been designed for imaging the hard tissues of the maxillofacial region, although it has been used in some era of medical imaging for many years. CBVT is capable of providing a sub-millimeter resolution with the short scanning time of mostly less than 20 seconds and radiation dosages reportedly up to 15 times lower than those of spiral CT scans. In less than a decade, CBVT has revolutionized oral and maxillofacial radiology and is known as the “Standard of Care”. Although development was initially directed towards multiplanar viewing for dental implant and orthodontic treatment planning, secondary applications in other areas continue to expand such as maxillo-facial trauma, temporomandibular joint disorders, sinuse pathosis and upper airway evaluation. The intent of this presentation is to provide an overview of CBVT technology, advantages and disadvantages compared to the other modalities such as 2D images and medical CT and examples of justified cases in the oral & maxillofacial region.   

  7. Evaluation of the Possibility of Applying Spatial 3D Imaging Using X-Ray Computed Tomography Reconstruction Methods for Quantitative Analysis of Multiphase Materials / Rentgenowska Analiza Ilościowa Materiałów Wielofazowych Z Wykorzystaniem Przestrzennego Obrazowania (3D Przy Użyciu Metod Rekonstrukcji Tomografii Komputerowej

    Matysik P.

    2015-12-01

    Full Text Available In this paper the possibility of using X-ray computed tomography (CT in quantitative metallographic studies of homogeneous and composite materials is presented. Samples of spheroidal cast iron, Fe-Ti powder mixture compact and epoxy composite reinforced with glass fibers, were subjected to comparative structural tests. Volume fractions of each of the phase structure components were determined by conventional methods with the use of a scanning electron microscopy (SEM and X-ray diffraction (XRD quantitative analysis methods. These results were compared with those obtained by the method of spatial analysis of the reconstructed CT image. Based on the comparative analysis, taking into account the selectivity of data verification methods and the accuracy of the obtained results, the authors conclude that the method of computed tomography is suitable for quantitative analysis of several types of structural materials.

  8. Reconstruction tomography from incomplete projections

    In some instances, reconstruction radionuclide tomography must be carried out from projections that do not include projection values for all portions of the object to be reconstructed. This may occur, for example, when the field of view of the detector is limited, or when an opaque foreign body is present within the object. The effects of such incomplete projections upon reconstructions of computer-simulated phantoms were studied, using iterative and convolution methods. Several methods for reducing the resulting artifacts and inaccuracies are discussed

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

    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

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

    Sturm, Peter; Maybank, Steve

    1999-01-01

    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.

  11. A LabVIEW based user-friendly nano-CT image alignment and 3D reconstruction platform

    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...

  12. 3D mapping of nanoscale electric potentials in semiconductor structures using electron-holographic tomography

    Wolf, Daniel; Lubk, Axel; Prete, Paola; Lovergine, Nico; Lichte, Hannes

    2016-09-01

    Off-axis electron holography (EH) is a powerful method for mapping projected electric potentials, such as built-in potentials in semiconductor devices, in two dimensions (2D) at nanometer resolution. However, not well-defined thickness profiles, surface effects, and composition changes of the sample under investigation complicate the interpretation of the projected potentials. Here, we demonstrate how these problems can be overcome by combining EH with tomographic techniques, that is, electron holographic tomography (EHT), reconstructing electric potentials in 3D. We present EHT reconstructions of an n-type MOSFET including its dopant-related built-in potentials inside the device, as well as of a GaAs/AlGaAs core-multishell nanowire containing a 5 nm thick quantum well tube.

  13. Maxillary sinus 3D segmentation and reconstruction from cone beam CT data sets

    Purpose: Segmentation of the maxillary sinuses for three-dimensional (3D) reconstruction, visualization and volumetry is sought using an automated algorithm applied to cone beam computed tomographic (CBCT) data sets. Materials and methods: Cone beam computed tomography (CBCT) data sets of three subjects aged 9, 17, and 27 were used in 3D segmentation and reconstruction. The maxillary sinuses were obtained by propagation from one start point in the right sinus and one start point in the left sinus to the whole regions of both sinuses. The procedure was based on voxel intensity distributions and common anatomic structures, specifically each middle meatus of the nasal cavity. A program was written in C++ and VTK languages to demonstrate the surface topological shapes of the maxillary sinuses. Results: The developed segmentation algorithm separated maxillary sinuses successfully permitting accurate comparisons. It was robust and efficient. 3D morphological features of the maxillary sinuses were observed from three human subjects. Conclusions: Automated segmentation of maxillary sinuses from CBCT data sets is feasible using the proposed method. This tool might be useful for visualization, pathological diagnosis, and treatment planning of maxillary sinus disorders. (orig.)

  14. Reconstructing 3-D skin surface motion for the DIET breast cancer screening system.

    Botterill, Tom; Lotz, Thomas; Kashif, Amer; Chase, J Geoffrey

    2014-05-01

    Digital image-based elasto-tomography (DIET) is a prototype system for breast cancer screening. A breast is imaged while being vibrated, and the observed surface motion is used to infer the internal stiffness of the breast, hence identifying tumors. This paper describes a computer vision system for accurately measuring 3-D surface motion. A model-based segmentation is used to identify the profile of the breast in each image, and the 3-D surface is reconstructed by fitting a model to the profiles. The surface motion is measured using a modern optical flow implementation customized to the application, then trajectories of points on the 3-D surface are given by fusing the optical flow with the reconstructed surfaces. On data from human trials, the system is shown to exceed the performance of an earlier marker-based system at tracking skin surface motion. We demonstrate that the system can detect a 10 mm tumor in a silicone phantom breast. PMID:24770915

  15. An evaluation of exact and approximate 3-D reconstruction algorithms for a high-resolution small-animal PET scanner

    MicroPET is a low-cost, high-resolution positron emission tomography (PET) scanner designed for imaging small animals. MicroPET operates exclusively without septa, acquiring fully three-dimensional (3-D) data sets. The performance of the projection-reprojection (3DRP), variable axial rebinning (VARB), single slice rebinning (SSRB), and Fourier rebinning (FORE) methods for reconstruction of microPET data were evaluated. The algorithms were compared with respect to resolution, noise variance, and reconstruction time. Results suggested that the 3DRP algorithm gives the best combination of resolution and noise performance in 9 min of reconstruction time on a Sun UltraSparc I workstation. The FORE algorithm provided the most acceptable accelerated method of reconstruction, giving similar resolution performance with a 10%--20% degradation in noise variance in under 2 min. Significant degradation in the axial resolution was measured with the VARB and SSRB methods, offsetting the decrease in reconstruction time achieved with those methods. In-plane angular mashing of the 3-D data before reconstruct ion led to a 50% reduction in reconstruction time but also introduced unacceptable tangential blurring artifacts. This thorough evaluation of analytical 3-D reconstruction techniques allowed for optimal selection of a reconstruction method for the diverse range of microPET applications

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

    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.

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

    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® 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

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

    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

  19. Contribution of 3-D electrical resistivity tomography for landmines detection

    M. Metwaly

    2008-12-01

    Full Text Available Landmines are a type of inexpensive weapons widely used in the pre-conflicted areas in many countries worldwide. The two main types are the metallic and non-metallic (mostly plastic landmines. They are most commonly investigated by magnetic, ground penetrating radar (GPR, and metal detector (MD techniques. These geophysical techniques however have significant limitations in resolving the non-metallic landmines and wherever the host materials are conductive. In this work, the 3-D electric resistivity tomography (ERT technique is evaluated as an alternative and/or confirmation detection system for both landmine types, which are buried in different soil conditions and at different depths. This can be achieved using the capacitive resistivity imaging system, which does not need direct contact with the ground surface. Synthetic models for each case have been introduced using metallic and non-metallic bodies buried in wet and dry environments. The inversion results using the L1 norm least-squares optimization method tend to produce robust blocky models of the landmine body. The dipole axial and the dipole equatorial arrays tend to have the most favorable geometry by applying dynamic capacitive electrode and they show significant signal strength for data sets with up to 5% noise. Increasing the burial depth relative to the electrode spacing as well as the noise percentage in the resistivity data is crucial in resolving the landmines at different environments. The landmine with dimension and burial depth of one electrode separation unit is over estimated while the spatial resolutions decrease as the burial depth and noise percentage increase.

  20. Three-dimensional surface reconstruction for industrial computed tomography

    Modern high resolution medical computed tomography (CT) scanners can produce geometrically accurate sectional images of many types of industrial objects. Computer software has been developed to convert serial CT scans into a 3-D surface form, suitable for display on the scanner itself. This software, originally developed for imaging the skull, has been adapted for application to industrial CT scanning, where serial CT scans through an object of interest may be reconstructed to demonstrate spatial relationships in three dimensions that cannot be easily understood using the original slices. The methods of 3-D reconstruction and solid modeling are reviewed, and reconstruction in three dimensions from CT scans through familiar objects is demonstrated

  1. 3-D reconstruction for mass lesions in the head and neck

    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.)

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

    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....

  3. Direct fourier methods in 3D-reconstruction from cone-beam data

    The problem of 3D-reconstruction is encountered in both medical and industrial applications of X-ray tomography. A method able to utilize a complete set of projections complying with Tuys condition was proposed by Grangeat. His method is mathematically exact and consists of two distinct phases. In phase 1 cone-beam projection data are used to produce the derivative of the radon transform. In phase 2, after interpolation, the radon transform data are used to reconstruct the three-dimensional object function. To a large extent our method is an extension of the Grangeat method. Our aim is to reduce the computational complexity, i.e. to produce a faster method. The most taxing procedure during phase 1 is computation of line-integrals in the detector plane. By applying the direct Fourier method in reverse for this computation, we reduce the complexity of phase 1 from O(N4) to O(N3logN). Phase 2 can be performed either as a straight 3D-reconstruction or as a sequence of two 2D-reconstructions in vertical and horizontal planes, respectively. Direct Fourier methods can be applied for the 2D- and for the 3D-reconstruction, which reduces the complexity of phase 2 from O(N4) to O(N3logN) as well. In both cases, linogram techniques are applied. For 3D-reconstruction the inversion formula contains the second derivative filter instead of the well-known ramp-filter employed in the 2D-case. The derivative filter is more well-behaved than the 2D ramp-filter. This implies that less zeropadding is necessary which brings about a further reduction of the computational efforts. The method has been verified by experiments on simulated data. The image quality is satisfactory and independent of cone-beam angles. For a 5123 volume we estimate that our method is ten times faster than Grangeats method

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

    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

  5. Performance Evaluating of some Methods in 3D Depth Reconstruction from a Single Image

    Wen, Wei

    2009-01-01

    We studied the problem of 3D reconstruction from a single image. The 3D reconstruction is one of the basic problems in Computer Vision. The 3D reconstruction is usually achieved by using two or multiple images of a scene. However recent researches in Computer Vision field have enabled us to recover the 3D information even from only one single image. The methods used in such reconstructions are based on depth information, projection geometry, image content, human psychology and so on. Each met...

  6. Full 3D Microwave Tomography enhanced GPR surveys: a case study

    Catapano, Ilaria; Soldovieri, Francesco; Affinito, Antonio; Hugenschmidt, Johannes

    2014-05-01

    Ground Penetrating Radar (GPR) systems are well assessed non-invasive diagnostic tools capable of providing high resolution images of the inner structure of the probed spatial region. Owing to this capability, GPR systems are nowadays more and more considered in the frame of civil engineering surveys since they may give information on constructive details as well as on the aging and risk factors affecting the healthiness of an infrastructure. In this frame, accurate, reliable and easily interpretable images of the probed scenarios are mandatory in order to support the management of maintenance works and assure the safety of structures. Such a requirement motivates the use of different and sophisticated data processing approaches in order to compare more than one image of the same scene, thus improving the reliability and objectiveness of the GPR survey results. Among GPR data processing procedures, Microwave Tomography approaches based on the Born approximation face the imaging as the solution of a linear inverse problem, which is solved by using the Truncated Singular Value Decomposition as a regularized inversion scheme [1]. So far, an approach exploiting a 2D scalar model of the scattering phenomenon have been adopted to process GPR data gathered along a single scan. In this case, 3D images are obtained by interpolating 2D reconstructions (this is referred commonly as pseudo 3D imaging). Such an imaging approach have provided valuable results in several real cases dealing with not only surveys for civil engineering but also archeological prospection, subservice monitoring, security surveys and so on [1-4]. These encouraging results have motivated the development of a full 3D Microwave Tomography approach capable of accounting for the vectorial nature of the wave propagation. The reconstruction capabilities of this novel approach have been assessed mainly against experimental data collected in laboratory controlled conditions. The obtained results corroborate

  7. ROC analysis for assessment of lesion detection performance in 3D PET: Influence of reconstruction algorithms

    Image quality in positron emission tomography (PET) can be assessed with physical parameters, as spatial resolution and signal-to-noise ratio, or using psychophysical approaches, which include the observer performance and the considered task (ROC analysis). For PET in oncology, such a task is the detection of hot lesions. The aim of the present study was to assess the lesion detection performance due to adequate modeling of the scanner and the measurement process in the image reconstruction process. We compared the standard OSEM software of the manufacturer with a sophisticated fully 3D iterative reconstruction technique (USC MAP). A rectangular phantom with 6 oblique line sources in a homogeneous background (2.6 kBq/ml 18F) was imaged dynamically with an ECAT EXACT HR+ scanner in 3D mode. Reconstructed activity contrasts varied between 15 and 0, as the line sources were filled with 11C (3.2 MBq/ml). Measured attenuation and standard randoms, dead time, and scatter corrections of the manufacturer were employed. For the ROC analysis, a software tool presented a cut-out of the phantom (15x15 pixels) to two observers. These cut-outs were rated (5 classes) and the area Az under the ROC curve was determined as a measure of detection performance. The improvement for Az with USC MAP compared to the OSEM reconstructions ranged between 0.02 and 0.23 for signal-to-noise ratios of the background between 2.8 and 3.1 and lesion contrast between 2.1 and 4.2. This study demonstrates that adequate modeling of the measurement process in the reconstruction algorithm improves the detection of small hot lesions markedly

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

    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.

  9. Automatic Reconstruction of Spacecraft 3D Shape from Imagery

    Poelman, C.; Radtke, R.; Voorhees, H.

    We describe a system that computes the three-dimensional (3D) shape of a spacecraft from a sequence of uncalibrated, two-dimensional images. While the mathematics of multi-view geometry is well understood, building a system that accurately recovers 3D shape from real imagery remains an art. A novel aspect of our approach is the combination of algorithms from computer vision, photogrammetry, and computer graphics. We demonstrate our system by computing spacecraft models from imagery taken by the Air Force Research Laboratory's XSS-10 satellite and DARPA's Orbital Express satellite. Using feature tie points (each identified in two or more images), we compute the relative motion of each frame and the 3D location of each feature using iterative linear factorization followed by non-linear bundle adjustment. The "point cloud" that results from this traditional shape-from-motion approach is typically too sparse to generate a detailed 3D model. Therefore, we use the computed motion solution as input to a volumetric silhouette-carving algorithm, which constructs a solid 3D model based on viewpoint consistency with the image frames. The resulting voxel model is then converted to a facet-based surface representation and is texture-mapped, yielding realistic images from arbitrary viewpoints. We also illustrate other applications of the algorithm, including 3D mensuration and stereoscopic 3D movie generation.

  10. 3D multifocus astigmatism and compressed sensing (3D MACS) based superresolution reconstruction

    Huang, Jiaqing; Sun, Mingzhai; Gumpper, Kristyn; Chi, Yuejie; Ma, Jianjie

    2015-01-01

    Single molecule based superresolution techniques (STORM/PALM) achieve nanometer spatial resolution by integrating the temporal information of the switching dynamics of fluorophores (emitters). When emitter density is low for each frame, they are located to the nanometer resolution. However, when the emitter density rises, causing significant overlapping, it becomes increasingly difficult to accurately locate individual emitters. This is particularly apparent in three dimensional (3D) localiza...

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

    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.

  12. Electron tomography based on a total variation minimization reconstruction technique

    Goris, B., E-mail: bart.goris@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van den Broek, W. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Batenburg, K.J. [Centrum Wiskunde and Informatica, Science Park 123, NL-1098XG Amsterdam (Netherlands); Vision Lab, University of Antwerp, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Heidari Mezerji, H.; Bals, S. [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2012-02-15

    The 3D reconstruction of a tilt series for electron tomography is mostly carried out using the weighted backprojection (WBP) algorithm or using one of the iterative algorithms such as the simultaneous iterative reconstruction technique (SIRT). However, it is known that these reconstruction algorithms cannot compensate for the missing wedge. Here, we apply a new reconstruction algorithm for electron tomography, which is based on compressive sensing. This is a field in image processing specialized in finding a sparse solution or a solution with a sparse gradient to a set of ill-posed linear equations. Therefore, it can be applied to electron tomography where the reconstructed objects often have a sparse gradient at the nanoscale. Using a combination of different simulated and experimental datasets, it is shown that missing wedge artefacts are reduced in the final reconstruction. Moreover, it seems that the reconstructed datasets have a higher fidelity and are easier to segment in comparison to reconstructions obtained by more conventional iterative algorithms. -- Highlights: Black-Right-Pointing-Pointer A reconstruction algorithm for electron tomography is investigated based on total variation minimization. Black-Right-Pointing-Pointer Missing wedge artefacts are reduced by this algorithm. Black-Right-Pointing-Pointer The reconstruction is easier to segment. Black-Right-Pointing-Pointer More reliable quantitative information can be obtained.

  13. Coronary computed tomography angiography with 320-row detector and using the AIDR-3D: initial experience

    Coronary computed tomography angiography (coronary CTA) is a powerful non-invasive imaging method to evaluate coronary artery disease. Nowadays, coronary CTA estimated effective radiation dose can be dramatically reduced using state-of-the-art scanners, such as 320-row detector CT (320-CT), without changing coronary CTA diagnostic accuracy. To optimize and further reduce the radiation dose, new iterative reconstruction algorithms were released recently by several CT manufacturers, and now they are used routinely in coronary CTA. This paper presents our first experience using coronary CTA with 320-CT and the Adaptive Iterative Dose Reduction 3D (AIDR-3D). In addition, we describe the current indications for coronary CTA in our practice as well as the acquisition standard protocols and protocols related to CT application for radiation dose reduction. In conclusion, coronary CTA radiation dose can be dramatically reduced following the 'as low as reasonable achievable' principle by combination of exam indication and well-documented technics for radiation dose reduction, such as beta blockers, low-kV, and also the newest iterative dose reduction software as AIDR-3D. (author)

  14. Regional application of multi-layer artificial neural networks in 3-D ionosphere tomography

    Ghaffari Razin, Mir Reza; Voosoghi, Behzad

    2016-08-01

    Tomography is a very cost-effective method to study physical properties of the ionosphere. In this paper, residual minimization training neural network (RMTNN) is used in voxel-based tomography to reconstruct of 3-D ionosphere electron density with high spatial resolution. For numerical experiments, observations collected at 37 GPS stations from Iranian permanent GPS network (IPGN) are used. A smoothed TEC approach was used for absolute STEC recovery. To improve the vertical resolution, empirical orthogonal functions (EOFs) obtained from international reference ionosphere 2012 (IRI-2012) used as object function in training neural network. Ionosonde observations is used for validate reliability of the proposed method. Minimum relative error for RMTNN is 1.64% and maximum relative error is 15.61%. Also root mean square error (RMSE) of 0.17 × 1011 (electrons/m3) is computed for RMTNN which is less than RMSE of IRI2012. The results show that RMTNN has higher accuracy and compiles speed than other ionosphere reconstruction methods.

  15. 3D optical phase reconstruction within PMMA samples using a spectral OCT system

    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.

  16. 3D neutron computed tomography. Requirements and applications

    Other than X-rays, neutrons can penetrate most metals easily while delivering a high contrast for many light-weight elements. Especially their high sensitivity for hydrogen makes them a valuable tool for the detection of organic materials like lubricants, plastics or sealants within metal housings. Neutron radiography and tomography complement the application of X-ray for the inspection of complex and critical components like in automotive and aerospace applications. An overview about the technical and mathematical differences between neutron and X-ray tomography is given and the imperfections and limitations of a neutron setup are shown. Several examples of technical neutron computed tomography are given. (author)

  17. 3D Maize Plant Reconstruction Based on Georeferenced Overlapping LiDAR Point Clouds

    Miguel Garrido; Dimitris S. Paraforos; David Reiser; Manuel Vázquez Arellano; Griepentrog, Hans W; Constantino Valero

    2015-01-01

    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 LiD...

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

    Arathi T

    2014-12-01

    Full Text Available 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 angles. This 2D stack of images is used to get a 3D view of the organ of interest, to aid doctors in easier diagnosis. Existing 3D reconstruction techniques are voxel based techniques, which tries to reconstruct the 3D view based on the intensity value stored at each voxel location. These techniques don’t make use of the shape/depth information available in the 2D image stack. In this work, a 3D reconstruction technique for MRI/CT 2D image stack, based on Shapelets has been proposed. Here, the shape/depth information available in each 2D image in the image stack is manipulated to get a 3D reconstruction, which gives a more accurate 3D view of the organ of interest. Experimental results exhibit the efficiency of this proposed technique.

  19. 3-D Virtual and Physical Reconstruction of Bendego Iron

    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.

  20. Online reconstruction of 3D magnetic particle imaging data.

    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. PMID:27182668

  1. Online reconstruction of 3D magnetic particle imaging data

    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.

  2. Reconstruction of Building Facades in 3D for Remote Inspection Using a Multicopter

    Ottemo, Torjus Sveier

    2014-01-01

    This thesis' focus is on how computer vision can be used to reconstruct building facades in 3D based on images taken by an unmanned aerial vehicle for the purpose of inspection. It explores and presents different algorithms needed for 3D reconstruction of facades and how this can be used to improve facade inspection both in terms of user friendliness for the operator and increased efficiency. The thesis resulted in a reconstruction application with an interactive graphical user interface...

  3. Autonomous Planetary 3-D Reconstruction From Satellite Images

    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...

  4. 3-D Reconstruction From 2-D Radiographic Images and Its Application to Clinical Veterinary Medicine

    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.

  5. 3D reconstruction of worn parts for flexible remanufacture based on robotic arc welding

    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.

  6. Single view-based 3D face reconstruction robust to self-occlusion

    Lee, Youn Joo; Lee, Sung Joo; Park, Kang Ryoung; Jo, Jaeik; Kim, Jaihie

    2012-12-01

    State-of-the-art 3D morphable model (3DMM) is used widely for 3D face reconstruction based on a single image. However, this method has a high computational cost, and hence, a simplified 3D morphable model (S3DMM) was proposed as an alternative. Unlike the original 3DMM, S3DMM uses only a sparse 3D facial shape, and therefore, it incurs a lower computational cost. However, this method is vulnerable to self-occlusion due to head rotation. Therefore, we propose a solution to the self-occlusion problem in S3DMM-based 3D face reconstruction. This research is novel compared with previous works, in the following three respects. First, self-occlusion of the input face is detected automatically by estimating the head pose using a cylindrical head model. Second, a 3D model fitting scheme is designed based on selected visible facial feature points, which facilitates 3D face reconstruction without any effect from self-occlusion. Third, the reconstruction performance is enhanced by using the estimated pose as the initial pose parameter during the 3D model fitting process. The experimental results showed that the self-occlusion detection had high accuracy and our proposed method delivered a noticeable improvement in the 3D face reconstruction performance compared with previous methods.

  7. 3D planning in the reconstruction of maxillofacial defects

    Schepers, Rutger Hendrik

    2016-01-01

    Resection of a tumor in the upper- or lower jaw often results in a large defect, because with the tumor resection also an adjacent part of the jaw is resected. The most favorable treatment for large defects is the combination of a bony free vascularized graft to reconstruct the defect with implants to retain prosthetic constructions. The Free vascularized Fibula Flap (FFF) is a versatile flap that commonly is used to reconstruct such bony and soft tissue defects. It is shown that oral rehabil...

  8. Analytic 3D image reconstruction using all detected events

    We present the results of testing a previously presented algorithm for three-dimensional image reconstruction that uses all gamma-ray coincidence events detected by a PET volume-imaging scanner. By using two iterations of an analytic filter-backprojection method, the algorithm is not constrained by the requirement of a spatially invariant detector point spread function, which limits normal analytic techniques. Removing this constraint allows the incorporation of all detected events, regardless of orientation, which improves the statistical quality of the final reconstructed image

  9. 3D RBI-EM reconstruction with spherically-symmetric basis function for SPECT rotating slat collimator

    A single photon emission computed tomography (SPECT) rotating slat collimator with strip detector acquires distance-weighted plane integral data, along with the attenuation factor and distance-dependent detector response. In order to image a 3D object, the slat collimator device has first to spin around its axis and then rotate around the object to produce 3D projection measurements. Compared to the slice-by-slice 2D reconstruction for the parallel-hole collimator and line integral data, a more complex 3D reconstruction is needed for the slat collimator and plane integral data. In this paper, we propose a 3D RBI-EM reconstruction algorithm with spherically-symmetric basis function, also called 'blobs', for the slat collimator. It has a closed and spherically symmetric analytical expression for the 3D Radon transform, which makes it easier to compute the plane integral than the voxel. It is completely localized in the spatial domain and nearly band-limited in the frequency domain. Its size and shape can be controlled by several parameters to have desired reconstructed image quality. A mathematical lesion phantom study has demonstrated that the blob reconstruction can achieve better contrast-noise trade-offs than the voxel reconstruction without greatly degrading the image resolution. A real lesion phantom study further confirmed this and showed that a slat collimator with CZT detector has better image quality than the conventional parallel-hole collimator with NaI detector. The improvement might be due to both the slat collimation and the better energy resolution of the CZT detector

  10. 3D RBI-EM reconstruction with spherically-symmetric basis function for SPECT rotating slat collimator

    Wang Wenli; Hawkins, William; Gagnon, Daniel [Philips Medical Systems, Inc., 595 Miner Road, Cleveland, OH 44143-2175 (United States)

    2004-06-07

    A single photon emission computed tomography (SPECT) rotating slat collimator with strip detector acquires distance-weighted plane integral data, along with the attenuation factor and distance-dependent detector response. In order to image a 3D object, the slat collimator device has first to spin around its axis and then rotate around the object to produce 3D projection measurements. Compared to the slice-by-slice 2D reconstruction for the parallel-hole collimator and line integral data, a more complex 3D reconstruction is needed for the slat collimator and plane integral data. In this paper, we propose a 3D RBI-EM reconstruction algorithm with spherically-symmetric basis function, also called 'blobs', for the slat collimator. It has a closed and spherically symmetric analytical expression for the 3D Radon transform, which makes it easier to compute the plane integral than the voxel. It is completely localized in the spatial domain and nearly band-limited in the frequency domain. Its size and shape can be controlled by several parameters to have desired reconstructed image quality. A mathematical lesion phantom study has demonstrated that the blob reconstruction can achieve better contrast-noise trade-offs than the voxel reconstruction without greatly degrading the image resolution. A real lesion phantom study further confirmed this and showed that a slat collimator with CZT detector has better image quality than the conventional parallel-hole collimator with NaI detector. The improvement might be due to both the slat collimation and the better energy resolution of the CZT detector.

  11. 3D RBI-EM reconstruction with spherically-symmetric basis function for SPECT rotating slat collimator

    Wang, Wenli; Hawkins, William; Gagnon, Daniel

    2004-06-01

    A single photon emission computed tomography (SPECT) rotating slat collimator with strip detector acquires distance-weighted plane integral data, along with the attenuation factor and distance-dependent detector response. In order to image a 3D object, the slat collimator device has first to spin around its axis and then rotate around the object to produce 3D projection measurements. Compared to the slice-by-slice 2D reconstruction for the parallel-hole collimator and line integral data, a more complex 3D reconstruction is needed for the slat collimator and plane integral data. In this paper, we propose a 3D RBI-EM reconstruction algorithm with spherically-symmetric basis function, also called 'blobs', for the slat collimator. It has a closed and spherically symmetric analytical expression for the 3D Radon transform, which makes it easier to compute the plane integral than the voxel. It is completely localized in the spatial domain and nearly band-limited in the frequency domain. Its size and shape can be controlled by several parameters to have desired reconstructed image quality. A mathematical lesion phantom study has demonstrated that the blob reconstruction can achieve better contrast-noise trade-offs than the voxel reconstruction without greatly degrading the image resolution. A real lesion phantom study further confirmed this and showed that a slat collimator with CZT detector has better image quality than the conventional parallel-hole collimator with NaI detector. The improvement might be due to both the slat collimation and the better energy resolution of the CZT detector.

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

    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

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

    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.

  14. Effects of point configuration on the accuracy in 3D reconstruction from biplane images

    Dmochowski, Jacek; Hoffmann, Kenneth R.; Singh, Vikas; Xu, Jinhui; Nazareth, Daryl P.

    2005-01-01

    Two or more angiograms are being used frequently in medical imaging to reconstruct locations in three-dimensional (3D) space, e.g., for reconstruction of 3D vascular trees, implanted electrodes, or patient positioning. A number of techniques have been proposed for this task. In this simulation study, we investigate the effect of the shape of the configuration of the points in 3D (the “cloud” of points) on reconstruction errors for one of these techniques developed in our laboratory. Five type...

  15. 3D model tools for architecture and archaeology reconstruction

    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.

  16. 3D Image Reconstruction from Compton camera data

    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).

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

    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

  18. Track reconstruction by GPU in 3D particle tracking detectors

    Bozza, Cristiano, E-mail: kryss@sa.infn.it [Department of Physics of the University of Salerno and INFN Gruppo Collegato di Salerno, via Giovanni Paolo II 132, Fisciano, SA 84084 (Italy); De Sio, Chiara [Department of Physics of the University of Salerno and INFN Gruppo Collegato di Salerno, via Giovanni Paolo II 132, Fisciano, SA 84084 (Italy); Kose, Umut [CERN, Geneva (Switzerland); Stellacci, Simona Maria [Department of Physics of the University of Salerno and INFN Gruppo Collegato di Salerno, via Giovanni Paolo II 132, Fisciano, SA 84084 (Italy)

    2015-09-11

    3D detectors for high-energy physics have always needed large computing power. Its availability has sometimes determined the statistics and performance of experiments. The increasing specific computing power of GPUs in recent years offers new opportunities for this field of application that should not be missed. The paper shows a novel algorithm that supports, as a by-product of speed, wider angular acceptance with respect to established techniques based on CPUs. While the algorithm has been developed in the environment of nuclear emulsions, it has been conceived from the very beginning as a tool for general tracking in 3D detectors. The overall logic can apply to many operational contexts in which tracking occurs in high combinatorial background. The performances of the algorithm are evaluated from different points of view, describing the details of the computing technique that are common to tracking problems and discussing measurements and data from a test-beam exposure. Computing speed has been evaluated on a broad variety of hardware, investigating an approximated scaling formula.

  19. Track reconstruction by GPU in 3D particle tracking detectors

    3D detectors for high-energy physics have always needed large computing power. Its availability has sometimes determined the statistics and performance of experiments. The increasing specific computing power of GPUs in recent years offers new opportunities for this field of application that should not be missed. The paper shows a novel algorithm that supports, as a by-product of speed, wider angular acceptance with respect to established techniques based on CPUs. While the algorithm has been developed in the environment of nuclear emulsions, it has been conceived from the very beginning as a tool for general tracking in 3D detectors. The overall logic can apply to many operational contexts in which tracking occurs in high combinatorial background. The performances of the algorithm are evaluated from different points of view, describing the details of the computing technique that are common to tracking problems and discussing measurements and data from a test-beam exposure. Computing speed has been evaluated on a broad variety of hardware, investigating an approximated scaling formula

  20. 3D reconstruction software comparison for short sequences

    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.

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

    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.

  2. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats

    Tang, Jianbo; Jason E. Coleman; DAI, XIANJIN; Jiang, Huabei

    2016-01-01

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments rev...

  3. Experimental Investigation of Material Flows Within FSWs Using 3D Tomography

    Charles R. Tolle; Timothy A. White; Karen S. Miller; Denis E. Clark; Herschel B. Smartt

    2008-06-01

    There exists significant prior work using tracers or pre-placed hardened markers within friction stir welding (FSWing) to experimentally explore material flow within the FSW process. Our experiments replaced markers with a thin sheet of copper foil placed between the 6061 aluminum lap and butt joints that were then welded. The absorption characteristics of x-rays for copper and aluminum are significantly different allowing for non-destructive evaluation (NDE) methods such as x-ray computed tomography (CT) to be used to demonstrate the material movement within the weldment on a much larger scale than previously shown. 3D CT reconstruction of the copper components of the weldment allows for a unique view into the final turbulent state of the welding process as process parameters are varied. The x-ray CT data of a section of the weld region was collected using a cone-beam x-ray imaging system developed at the INL. Six-hundred projections were collected over 360-degrees using a 160-kVp Bremsstrahlung x-ray generator (25-micrometer focal spot) and amorphoussilicon x-ray detector. The region of the object that was imaged was about 3cm tall and 1.5cm x 1cm in cross section, and was imaged at a magnification of about 3.6x. The data were reconstructed on a 0.5x0.5x0.5 mm3 voxel grid. After reconstruction, the aluminum and copper could be easily discriminated using a gray level threshold allowing visualization of the copper components. Fractal analysis of the tomographic reconstructed material topology is investigated as a means to quantify macro level material flow based on process parameters. The results of multi-pass FSWs show increased refinement of the copper trace material. Implications of these techniques for quantifying process flow are discussed.

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

    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.

  5. Auto-masked 2D/3D image registration and its validation with clinical cone-beam computed tomography

    Image-guided alignment procedures in radiotherapy aim at minimizing discrepancies between the planned and the real patient setup. For that purpose, we developed a 2D/3D approach which rigidly registers a computed tomography (CT) with two x-rays by maximizing the agreement in pixel intensity between the x-rays and the corresponding reconstructed radiographs from the CT. Moreover, the algorithm selects regions of interest (masks) in the x-rays based on 3D segmentations from the pre-planning stage. For validation, orthogonal x-ray pairs from different viewing directions of 80 pelvic cone-beam CT (CBCT) raw data sets were used. The 2D/3D results were compared to corresponding standard 3D/3D CBCT-to-CT alignments. Outcome over 8400 2D/3D experiments showed that parametric errors in root mean square were <0.18° (rotations) and <0.73 mm (translations), respectively, using rank correlation as intensity metric. This corresponds to a mean target registration error, related to the voxels of the lesser pelvis, of <2 mm in 94.1% of the cases. From the results we conclude that 2D/3D registration based on sequentially acquired orthogonal x-rays of the pelvis is a viable alternative to CBCT-based approaches if rigid alignment on bony anatomy is sufficient, no volumetric intra-interventional data set is required and the expected error range fits the individual treatment prescription. (paper)

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

    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.

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

    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.

  8. Positron Emission Tomography with Three-Dimensional Reconstruction

    The development of two different low-cost scanners for positron emission tomography (PET) based on 3D acquisition are presented. The first scanner consists of two rotating scintillation cameras, and produces quantitative images, which have shown to be clinically useful. The second one is a system with two opposed sets of detectors, based on the limited angle tomography principle, dedicated for mammographic studies. The development of low-cost PET scanners can increase the clinical impact of PET, which is an expensive modality, only available at a few centres world-wide and mainly used as a research tool. A 3D reconstruction method was developed that utilizes all the available data. The size of the data-sets is considerably reduced, using the single-slice rebinning approximation. The 3D reconstruction is divided into 1D axial deconvolution and 2D transaxial reconstruction, which makes it relatively fast. This method was developed for the rotating scanner, but was also implemented for multi-ring scanners with and without inter plane septa. An iterative 3D reconstruction method was developed for the limited angle scanner, based on the new concept of 'mobile pixels', which reduces the finite pixel errors and leads to an improved signal to noise ratio. 100 refs

  9. Large area 3-D optical coherence tomography imaging of lumpectomy specimens for radiation treatment planning

    Wang, Cuihuan; Kim, Leonard; Barnard, Nicola; Khan, Atif; Pierce, Mark C.

    2016-02-01

    Our long term goal is to develop a high-resolution imaging method for comprehensive assessment of tissue removed during lumpectomy procedures. By identifying regions of high-grade disease within the excised specimen, we aim to develop patient-specific post-operative radiation treatment regimens. We have assembled a benchtop spectral-domain optical coherence tomography (SD-OCT) system with 1320 nm center wavelength. Automated beam scanning enables "sub-volumes" spanning 5 mm x 5 mm x 2 mm (500 A-lines x 500 B-scans x 2 mm in depth) to be collected in under 15 seconds. A motorized sample positioning stage enables multiple sub-volumes to be acquired across an entire tissue specimen. Sub-volumes are rendered from individual B-scans in 3D Slicer software and en face (XY) images are extracted at specific depths. These images are then tiled together using MosaicJ software to produce a large area en face view (up to 40 mm x 25 mm). After OCT imaging, specimens were sectioned and stained with HE, allowing comparison between OCT image features and disease markers on histopathology. This manuscript describes the technical aspects of image acquisition and reconstruction, and reports initial qualitative comparison between large area en face OCT images and HE stained tissue sections. Future goals include developing image reconstruction algorithms for mapping an entire sample, and registering OCT image volumes with clinical CT and MRI images for post-operative treatment planning.

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

    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.

  11. Bayesian 3D velocity field reconstruction with VIRBIUS

    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.

  12. Bayesian 3d velocity field reconstruction with VIRBIuS

    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...

  13. Efficient and robust 3D CT image reconstruction based on total generalized variation regularization using the alternating direction method.

    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. PMID:26756406

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

    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

    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. Identification and classification in le fort type fractures by using 2D and 3D computed tomography

    CHEN We-jian; YANG Yun-jun; FANG Yi-ming; XU Fang-hong; ZHANG Lin; CAO Guo-quan

    2006-01-01

    Objective:To evaluate the usefulness of twodimensional (2D) and three-dimensional (3D) computed tomography (CT) in the identification and classification of Le Fort type fractures.Methods: Sixty-two patients with different types of Le Fort fractures underwent CT scanning and 3D-CT reconstruction. The data were analyzed by multiplanar reconstruction (MPR), surface shaded display (SSD) and volume rendering (VR) respectively.Results: The patients with Le Fort Ⅰ , Le Fort Ⅱfracture and Le Fort Ⅲ fracture accounted for 16.1%,14.5 % and 12.9 % respectively. The compound fractures were the most common type and accounted for 56.5 % ( n =35, 18 cases with Le Fort Ⅰ + Ⅱ fracture, 10 cases with Le Fort Ⅱ + Ⅲ fracture and 7 cases with Le Fort Ⅰ + Ⅱ + Ⅲfracture). Fifty-five cases coexisted with other fractures in maxillofacial region. 2D-CT could be used to define the tiny fractures and the deep-structure fractures more accurately compared with 3D-CT, but the real impression of Le Fort type fractures could not be correctly evaluated on 2D-CT.3D-CT could clearly demonstrate the whole shape of Le Fort type fractures and identify the classification of Le Fort fractures.Conclusions: 3D-CT is the best imaging method for the diagnosis of Le Fort type fractures and can provide valuable information of space relationship, especially for the design of treatment plan before operation.

  17. 3-D Adaptive Sparsity Based Image Compression With Applications to Optical Coherence Tomography.

    Fang, Leyuan; Li, Shutao; Kang, Xudong; Izatt, Joseph A; Farsiu, Sina

    2015-06-01

    We present a novel general-purpose compression method for tomographic images, termed 3D adaptive sparse representation based compression (3D-ASRC). In this paper, we focus on applications of 3D-ASRC for the compression of ophthalmic 3D optical coherence tomography (OCT) images. The 3D-ASRC algorithm exploits correlations among adjacent OCT images to improve compression performance, yet is sensitive to preserving their differences. Due to the inherent denoising mechanism of the sparsity based 3D-ASRC, the quality of the compressed images are often better than the raw images they are based on. Experiments on clinical-grade retinal OCT images demonstrate the superiority of the proposed 3D-ASRC over other well-known compression methods. PMID:25561591

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

    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.

  19. "High-precision, reconstructed 3D model" of skull scanned by conebeam CT: Reproducibility verified using CAD/CAM data.

    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

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

    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...

  1. 3D Reconstruction of a Rotating Erupting Prominence

    Thompson, W. T.; Kliem, B.; Toeroek, T.

    2011-01-01

    A bright prominence associated with a coronal mass ejection (CME) was seen erupting from the Sun on 9 April 2008. This prominence was tracked by both the Solar Terrestrial Relations Observatory (STEREO) EUVI and COR1 telescopes, and was seen to rotate about the line of sight a it erupted; therefore, the event has been nicknamed the "Cartwheel CME." The threads of the prominence in the core of the CME quite clearly indicate the structure of a weakly to moderately twisted flux rope throughout the field of view, up to heliocentric heights of 4 solar radii. Although the STEREO separation was 48 deg, it was possible to match some sharp features in the later part of the eruption as seen in the 304 A line in EUVI and in the H-alpha-sensitive bandpass of COR I by both STEREO Ahead and Behind. These features could then be traced out in three-dimensional space, and reprojected into a view in which the eruption is directed toward the observer. The reconstructed view shows that the alignment of the prominence to the vertical axis rotates as it rises up to a leading-edge height of approximately equal to 2.5 solar radii, and then remains approximately constant. The alignment at 2.5 solar radii differs by about 115 deg from the original filament orientation inferred from H-alpha and EUV data, and the height profile of the rotation, obtained here for the first time, shows that two thirds of the total rotation are reached within approximately equal to 0.5 solar radii above the photosphere. These features are well reproduced by numerical simulations of an unstable moderately twisted flux rope embedded in external flux with a relatively strong shear field component.

  2. On reliability of 3D reconstructions of thermal plasma jet radiation by inverse Radon transform

    Sekerešová, Zuzana; Hlína, Jan

    2011-01-01

    Roč. 56, č. 2 (2011), s. 171-183. ISSN 0001-7043 Institutional research plan: CEZ:AV0Z20570509 Keywords : thermal plasma jet * tomography * image reconstruction Subject RIV: BL - Plasma and Gas Discharge Physics

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

    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.

  4. 3D Ultrastructural organization of whole Chlamydomonas reinhardtii cells studied by nanoscale soft x-ray tomography.

    Eric Hummel

    Full Text Available The complex architecture of their structural elements and compartments is a hallmark of eukaryotic cells. The creation of high resolution models of whole cells has been limited by the relatively low resolution of conventional light microscopes and the requirement for ultrathin sections in transmission electron microscopy. We used soft x-ray tomography to study the 3D ultrastructural organization of whole cells of the unicellular green alga Chlamydomonas reinhardtii at unprecedented spatial resolution. Intact frozen hydrated cells were imaged using the natural x-ray absorption contrast of the sample without any staining. We applied different fiducial-based and fiducial-less alignment procedures for the 3D reconstructions. The reconstructed 3D volumes of the cells show features down to 30 nm in size. The whole cell tomograms reveal ultrastructural details such as nuclear envelope membranes, thylakoids, basal apparatus, and flagellar microtubule doublets. In addition, the x-ray tomograms provide quantitative data from the cell architecture. Therefore, nanoscale soft x-ray tomography is a new valuable tool for numerous qualitative and quantitative applications in plant cell biology.

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

    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.)

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

    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. 

  7. 3-D reconstruction of neurons from multichannel confocal laser scanning image series.

    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

  8. A user-friendly nano-CT image alignment and 3D reconstruction platform based on LabVIEW

    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.

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

    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...

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

    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;

  11. Data acquisition electronics and reconstruction software for real time 3D track reconstruction within the MIMAC project

    Bourrion, O; Grignon, C; Bouly, J L; Richer, J P; Guillaudin, O; Mayet, F; Billard, J; Santos, D

    2011-01-01

    Directional detection of non-baryonic Dark Matter requires 3D reconstruction of low energy nuclear recoils tracks. A gaseous micro-TPC matrix, filled with either 3He, CF4 or C4H10 has been developed within the MIMAC project. A dedicated acquisition electronics and a real time track reconstruction software have been developed to monitor a 512 channel prototype. This autotriggered electronic uses embedded processing to reduce the data transfer to its useful part only, i.e. decoded coordinates of hit tracks and corresponding energy measurements. An acquisition software with on-line monitoring and 3D track reconstruction is also presented.

  12. Data acquisition electronics and reconstruction software for real time 3D track reconstruction within the MIMAC project

    Directional detection of non-baryonic Dark Matter requires 3D reconstruction of low energy nuclear recoils tracks. A gaseous micro-TPC matrix, filled with either 3He, CF4 or C4H10 has been developed within the MIMAC project. A dedicated acquisition electronics and a real time track reconstruction software have been developed to monitor a 512 channel prototype. This auto-triggered electronic uses embedded processing to reduce the data transfer to its useful part only, i.e. decoded coordinates of hit tracks and corresponding energy measurements. An acquisition software with on-line monitoring and 3D track reconstruction is also presented.

  13. Understanding Plasticity and Fracture in Aluminum Alloys and their Composites by 3D X-ray Synchrotron Tomography and Microdiffraction

    Hruby, Peter

    Aluminum alloys and their composites are attractive materials for applications requiring high strength-to-weight ratios and reasonable cost. Many of these applications, such as those in the aerospace industry, undergo fatigue loading. An understanding of the microstructural damage that occurs in these materials is critical in assessing their fatigue resistance. Two distinct experimental studies were performed to further the understanding of fatigue damage mechanisms in aluminum alloys and their composites, specifically fracture and plasticity. Fatigue resistance of metal matrix composites (MMCs) depends on many aspects of composite microstructure. Fatigue crack growth behavior is particularly dependent on the reinforcement characteristics and matrix microstructure. The goal of this work was to obtain a fundamental understanding of fatigue crack growth behavior in SiC particle-reinforced 2080 Al alloy composites. In situ X-ray synchrotron tomography was performed on two samples at low (R=0.1) and at high (R=0.6) R-ratios. The resulting reconstructed images were used to obtain three-dimensional (3D) rendering of the particles and fatigue crack. Behaviors of the particles and crack, as well as their interaction, were analyzed and quantified. Four-dimensional (4D) visual representations were constructed to aid in the overall understanding of damage evolution. During fatigue crack growth in ductile materials, a plastic zone is created in the region surrounding the crack tip. Knowledge of the plastic zone is important for the understanding of fatigue crack formation as well as subsequent growth behavior. The goal of this work was to quantify the 3D size and shape of the plastic zone in 7075 Al alloys. X-ray synchrotron tomography and Laue microdiffraction were used to non-destructively characterize the volume surrounding a fatigue crack tip. The precise 3D crack profile was segmented from the reconstructed tomography data. Depth-resolved Laue patterns were obtained using

  14. Multislice computed tomography angiography in the diagnosis of cardiovascular disease: 3D visualizations

    Zhonghua Sun

    2011-01-01

    Multislice computed tomography (CT) has been widely used in clinical practice for the diagnosis of cardiovascular disease due to its reduced invasiveness and high spatial and temporal resolution.As a reliable alternative to conventional angiography,multislice CT angiography has been recognized as the method of choice for detecting and diagnosing head and neck vascular disease,abdominal aortic aneurysm,aortic dissection,and pulmonary embolism.In patients with suspected coronary artery disease,although invasive coronary angiography still remains as the gold standard technique,multislice CT angiography demonstrates high diagnostic accuracy; in selected patients,it is considered as the first-line technique.The imaging diagnosis of cardiovascular disease is based on a combination of two-dimensional (2D) and three-dimensional (3D) visualization tools to enhance the diagnostic value.This is facilitated by reconstructed visualizations which provide additional information about the extent of the disease,an accurate assessment of the spatial relationship between normal structures and pathological changes,and pre-operative planning and post-procedure follow-up.The aim of the present article is to present an overview of the diagnostic performance of various 2D and 3D CT visualizations in cardiovascular disease,including multiplanar reformation,maximum intensity projection,volume rendering,and virtual intravascular endoscopy.The recognition of the potential value of these visualizations will assist clinicians in efficiently using the muitislice CT imaging modality for the diagnostic management of patients with cardiovascular disease.

  15. Real-time 3D Fourier-domain optical coherence tomography guided microvascular anastomosis

    Huang, Yong; Ibrahim, Zuhaib; Lee, W. P. A.; Brandacher, Gerald; Kang, Jin U.

    2013-03-01

    Vascular and microvascular anastomosis is considered to be the foundation of plastic and reconstructive surgery, hand surgery, transplant surgery, vascular surgery and cardiac surgery. In the last two decades innovative techniques, such as vascular coupling devices, thermo-reversible poloxamers and suture-less cuff have been introduced. Intra-operative surgical guidance using a surgical imaging modality that provides in-depth view and 3D imaging can improve outcome following both conventional and innovative anastomosis techniques. Optical coherence tomography (OCT) is a noninvasive high-resolution (micron level), high-speed, 3D imaging modality that has been adopted widely in biomedical and clinical applications. In this work we performed a proof-of-concept evaluation study of OCT as an assisted intraoperative and post-operative imaging modality for microvascular anastomosis of rodent femoral vessels. The OCT imaging modality provided lateral resolution of 12 μm and 3.0 μm axial resolution in air and 0.27 volume/s imaging speed, which could provide the surgeon with clearly visualized vessel lumen wall and suture needle position relative to the vessel during intraoperative imaging. Graphics processing unit (GPU) accelerated phase-resolved Doppler OCT (PRDOCT) imaging of the surgical site was performed as a post-operative evaluation of the anastomosed vessels and to visualize the blood flow and thrombus formation. This information could help surgeons improve surgical precision in this highly challenging anastomosis of rodent vessels with diameter less than 0.5 mm. Our imaging modality could not only detect accidental suture through the back wall of lumen but also promptly diagnose and predict thrombosis immediately after reperfusion. Hence, real-time OCT can assist in decision-making process intra-operatively and avoid post-operative complications.

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

    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.

  17. AX-PET A novel PET detector concept with full 3D reconstruction

    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...

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

    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.

  19. Automated reconstruction algorithm for identification of 3D architectures of cribriform ductal carcinoma in situ.

    Kerri-Ann Norton

    Full Text Available Ductal carcinoma in situ (DCIS is a pre-invasive carcinoma of the breast that exhibits several distinct morphologies but the link between morphology and patient outcome is not clear. We hypothesize that different mechanisms of growth may still result in similar 2D morphologies, which may look different in 3D. To elucidate the connection between growth and 3D morphology, we reconstruct the 3D architecture of cribriform DCIS from resected patient material. We produce a fully automated algorithm that aligns, segments, and reconstructs 3D architectures from microscopy images of 2D serial sections from human specimens. The alignment algorithm is based on normalized cross correlation, the segmentation algorithm uses histogram equilization, Otsu's thresholding, and morphology techniques to segment the duct and cribra. The reconstruction method combines these images in 3D. We show that two distinct 3D architectures are indeed found in samples whose 2D histological sections are similarly identified as cribriform DCIS. These differences in architecture support the hypothesis that luminal spaces may form due to different mechanisms, either isolated cell death or merging fronds, leading to the different architectures. We find that out of 15 samples, 6 were found to have 'bubble-like' cribra, 6 were found to have 'tube-like' criba and 3 were 'unknown.' We propose that the 3D architectures found, 'bubbles' and 'tubes', account for some of the heterogeneity of the disease and may be prognostic indicators of different patient outcomes.

  20. Composite laminate impact damage assessment by high resolution 3D X-ray tomography and laminography

    Bull, D. J.; Sinclair, I.; Spearing, S.M.; Helfen, L.

    2011-01-01

    Improvements to toughening mechanisms in composite materials have hitherto relied on visual inspection techniques that can be rather limited, especially since the inherent damage behaviour is three-dimensional (3D) requiring high resolution to capture micro-cracks and similar damage. To achieve a better understanding of impact damage behaviour, synchrotron radiation computed laminography (SRCL) and computed tomography (SRCT) techniques were used to capture 3D damage mechanisms with voxel size...

  1. Computed Tomography 3-D Imaging of the Metal Deformation Flow Path in Friction Stir Welding

    Schneider, Judy; Beshears, Ronald; Nunes, Arthur C., Jr.

    2005-01-01

    In friction stir welding (FSW), a rotating threaded pin tool is inserted into a weld seam and literally stirs the edges of the seam together. To determine optimal processing parameters for producing a defect free weld, a better understanding of the resulting metal deformation flow path is required. Marker studies are the principal method of studying the metal deformation flow path around the FSW pin tool. In our study, we have used computed tomography (CT) scans to reveal the flow pattern of a lead wire embedded in a FSW weld seam. At the welding temperature of aluminum, the lead becomes molten and is carried with the macro-flow of the weld metal. By using CT images, a 3-dimensional (3D) image of the lead flow pattern can be reconstructed. CT imaging was found to be a convenient and comprehensive way of collecting and displaying tracer data. It marks an advance over previous more tedious and ambiguous radiographic/metallographic data collection methods.

  2. 3D Tomography of MHD Fluctuations in the H-1NF Heliac

    Haskey, S R; Seiwald, B; Howard, J

    2014-01-01

    A 3D tomographic reconstruction technique which does not rely on a set of radial basis functions is described for inversion of a set of limited-angle high-resolution 2D visible light emission projections (extended in the vertical and toroidal directions) of global MHD eigenmodes in the H-1NF heliac. This paper deals with some of the features and challenges that will arise in the application of tomographic imaging systems to fusion reactors, especially the strong shaping of optimised stellarator/heliotron configurations, and limited access in all types. The fluctuations are represented as a finite sum of Fourier modes characterised by toroidal and poloidal mode numbers having fixed amplitude and phase in a set of nested cylindrical flux volumes in Boozer space. The amplitudes and phases are calculated using iterative tomographic inversion techniques such as ART, SIRT and standard linear least-squares methods. The tomography is applied to synchronous camera images of singly charged carbon impurity ion emission ...

  3. Effects of point configuration on the accuracy in 3D reconstruction from biplane images

    Two or more angiograms are being used frequently in medical imaging to reconstruct locations in three-dimensional (3D) space, e.g., for reconstruction of 3D vascular trees, implanted electrodes, or patient positioning. A number of techniques have been proposed for this task. In this simulation study, we investigate the effect of the shape of the configuration of the points in 3D (the 'cloud' of points) on reconstruction errors for one of these techniques developed in our laboratory. Five types of configurations (a ball, an elongated ellipsoid (cigar), flattened ball (pancake), flattened cigar, and a flattened ball with a single distant point) are used in the evaluations. For each shape, 100 random configurations were generated, with point coordinates chosen from Gaussian distributions having a covariance matrix corresponding to the desired shape. The 3D data were projected into the image planes using a known imaging geometry. Gaussian distributed errors were introduced in the x and y coordinates of these projected points. Gaussian distributed errors were also introduced into the gantry information used to calculate the initial imaging geometry. The imaging geometries and 3D positions were iteratively refined using the enhanced-Metz-Fencil technique. The image data were also used to evaluate the feasible R-t solution volume. The 3D errors between the calculated and true positions were determined. The effects of the shape of the configuration, the number of points, the initial geometry error, and the input image error were evaluated. The results for the number of points, initial geometry error, and image error are in agreement with previously reported results, i.e., increasing the number of points and reducing initial geometry and/or image error, improves the accuracy of the reconstructed data. The shape of the 3D configuration of points also affects the error of reconstructed 3D configuration; specifically, errors decrease as the 'volume' of the 3D configuration

  4. Conceptual detector development and Monte Carlo simulation of a novel 3D breast computed tomography system

    Ziegle, Jens; Müller, Bernhard H.; Neumann, Bernd; Hoeschen, Christoph

    2016-03-01

    A new 3D breast computed tomography (CT) system is under development enabling imaging of microcalcifications in a fully uncompressed breast including posterior chest wall tissue. The system setup uses a steered electron beam impinging on small tungsten targets surrounding the breast to emit X-rays. A realization of the corresponding detector concept is presented in this work and it is modeled through Monte Carlo simulations in order to quantify first characteristics of transmission and secondary photons. The modeled system comprises a vertical alignment of linear detectors hold by a case that also hosts the breast. Detectors are separated by gaps to allow the passage of X-rays towards the breast volume. The detectors located directly on the opposite side of the gaps detect incident X-rays. Mechanically moving parts in an imaging system increase the duration of image acquisition and thus can cause motion artifacts. So, a major advantage of the presented system design is the combination of the fixed detectors and the fast steering electron beam which enable a greatly reduced scan time. Thereby potential motion artifacts are reduced so that the visualization of small structures such as microcalcifications is improved. The result of the simulation of a single projection shows high attenuation by parts of the detector electronics causing low count levels at the opposing detectors which would require a flat field correction, but it also shows a secondary to transmission ratio of all counted X-rays of less than 1 percent. Additionally, a single slice with details of various sizes was reconstructed using filtered backprojection. The smallest detail which was still visible in the reconstructed image has a size of 0.2mm.

  5. 3D visualisation of the middle ear and adjacent structures using reconstructed multi-slice CT datasets, correlating 3D images and virtual endoscopy to the 2D cross-sectional images

    The 3D imaging of the middle ear facilitates better understanding of the patient's anatomy. Cross-sectional slices, however, often allow a more accurate evaluation of anatomical structures, as some detail may be lost through post-processing. In order to demonstrate the advantages of combining both approaches, we performed computed tomography (CT) imaging in two normal and 15 different pathological cases, and the 3D models were correlated to the cross-sectional CT slices. Reconstructed CT datasets were acquired by multi-slice CT. Post-processing was performed using the in-house software ''3D Slicer'', applying thresholding and manual segmentation. 3D models of the individual anatomical structures were generated and displayed in different colours. The display of relevant anatomical and pathological structures was evaluated in the greyscale 2D slices, 3D images, and the 2D slices showing the segmented 2D anatomy in different colours for each structure. Correlating 2D slices to the 3D models and virtual endoscopy helps to combine the advantages of each method. As generating 3D models can be extremely time-consuming, this approach can be a clinically applicable way of gaining a 3D understanding of the patient's anatomy by using models as a reference. Furthermore, it can help radiologists and otolaryngologists evaluating the 2D slices by adding the correct 3D information that would otherwise have to be mentally integrated. The method can be applied to radiological diagnosis, surgical planning, and especially, to teaching. (orig.)

  6. 3D reconstruction and digitalization of an archeological site, Itanos, Crete

    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.

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

    T. Partovi; H. Arefi; T. Krauß; P. Reinartz

    2013-01-01

    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 ...

  8. 3D RECONSTRUCTION OF BUILDINGS WITH GABLED AND HIPPED STRUCTURES USING LIDAR DATA

    Amini, H; P. Pahlavani; R. Karimi

    2014-01-01

    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 Ma...

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

    T. Partovi; H. Arefi; T. Krauß; P. Reinartz

    2013-01-01

    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 st...

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

    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....

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

    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.

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

    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)

  13. 3D Reconstruction and Restoration Monitoring of Sculptural Artworks by a Multi-Sensor Framework

    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.

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

    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

  15. Tomography Reconstruction with Noisy Projection Data

    LI Xide

    2000-01-01

    Computerized tomography (CT) based on the convolution back projection method has been regarded as an important reconstruction method, but it is not suitable to noisy conditions. In this paper, techniques of filtering, resampling and frequency shifting have been introduced to enhance the quality of CT reconstruction and improved results have been obtained.

  16. Digital 3D Facial Reconstruction Based on Computed Tomography

    Andersson, Björn; Valfridsson, Martin

    2005-01-01

    Despite the introduction of DNA-analysis for identification of human remains (1997-2000) several cases exist where the deceased remain unidentified. Approximately ten percent of unknown deceased persons can not be identified by dental status or other present methods. During the year 2003 alone, seven individuals, in Sweden, remain unidentified. Increase in travel in Europe will lead to more discoveries of foreign human remains in Sweden. In these cases, dental and medical records are often u...

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

    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...

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

    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.

  19. 3-D reconstruction of coastal bathymetry from AIRSAR/POLSAR data

    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.

  20. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator’s identification of landmarks to establish the image synchronization

  1. A new method for real-time co-registration of 3D coronary angiography and intravascular ultrasound or optical coherence tomography

    Carlier, Stéphane, E-mail: sgcarlier@hotmail.com [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Didday, Rich [INDEC Medical Systems Inc., Santa Clara, CA (United States); Slots, Tristan [Pie Medical Imaging BV, Maastricht (Netherlands); Kayaert, Peter; Sonck, Jeroen [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium); El-Mourad, Mike; Preumont, Nicolas [Department of Cardiology, Erasme University Hospital, Université Libre de Bruxelles (ULB), Brussels (Belgium); Schoors, Dany; Van Camp, Guy [Department of Cardiology, Universitair Ziekenhuis - UZ Brussel, Brussels (Belgium)

    2014-06-15

    We present a new clinically practical method for online co-registration of 3D quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS) or optical coherence tomography (OCT). The workflow is based on two modified commercially available software packages. Reconstruction steps are explained and compared to previously available methods. The feasibility for different clinical scenarios is illustrated. The co-registration appears accurate, robust and induced a minimal delay on the normal cath lab activities. This new method is based on the 3D angiographic reconstruction of the catheter path and does not require operator’s identification of landmarks to establish the image synchronization.

  2. Blurring contact maps of thousands of proteins: what we can learn by reconstructing 3D structure

    Vassura Marco

    2011-01-01

    Full Text Available Abstract Background The present knowledge of protein structures at atomic level derives from some 60,000 molecules. Yet the exponential ever growing set of hypothetical protein sequences comprises some 10 million chains and this makes the problem of protein structure prediction one of the challenging goals of bioinformatics. In this context, the protein representation with contact maps is an intermediate step of fold recognition and constitutes the input of contact map predictors. However contact map representations require fast and reliable methods to reconstruct the specific folding of the protein backbone. Methods In this paper, by adopting a GRID technology, our algorithm for 3D reconstruction FT-COMAR is benchmarked on a huge set of non redundant proteins (1716 taking random noise into consideration and this makes our computation the largest ever performed for the task at hand. Results We can observe the effects of introducing random noise on 3D reconstruction and derive some considerations useful for future implementations. The dimension of the protein set allows also statistical considerations after grouping per SCOP structural classes. Conclusions All together our data indicate that the quality of 3D reconstruction is unaffected by deleting up to an average 75% of the real contacts while only few percentage of randomly generated contacts in place of non-contacts are sufficient to hamper 3D reconstruction.

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

    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.

  4. Analyzing 3D xylem networks in Vitis vinifera using High Resolution Computed Tomography (HRCT)

    Recent developments in High Resolution Computed Tomography (HRCT) have made it possible to visualize three dimensional (3D) xylem networks without time consuming, labor intensive physical sectioning. Here we describe a new method to visualize complex vessel networks in plants and produce a quantitat...

  5. Detection of screw threads in computed tomography 3D density fields

    Kosarevsky, Sergey

    2013-01-01

    In this paper, a new method is proposed to automatically detect screw threads in 3D density fields obtained from computed tomography measurement devices. The described method can be used to automate many operations during screw thread inspection process and drastically reduce operator's influence on the measurement process resulting in lower measurement times and increased repeatability.

  6. Capacitance Measurement with a Sigma Delta Converter for 3D Electrical Capacitance Tomography

    Nurge, Mark

    2005-01-01

    This paper will explore suitability of a newly available capacitance to digital converter for use in a 3D Electrical Capacitance Tomography system. A switch design is presented along with circuitry needed to extend the range of the capacitance to digital converter. Results are then discussed for a 15+ hour drift and noise test.

  7. Element-specific X-ray phase tomography of 3D structures at the nanoscale.

    Donnelly, Claire; Guizar-Sicairos, Manuel; Scagnoli, Valerio; Holler, Mirko; Huthwelker, Thomas; Menzel, Andreas; Vartiainen, Ismo; Müller, Elisabeth; Kirk, Eugenie; Gliga, Sebastian; Raabe, Jörg; Heyderman, Laura J

    2015-03-20

    Recent advances in fabrication techniques to create mesoscopic 3D structures have led to significant developments in a variety of fields including biology, photonics, and magnetism. Further progress in these areas benefits from their full quantitative and structural characterization. We present resonant ptychographic tomography, combining quantitative hard x-ray phase imaging and resonant elastic scattering to achieve ab initio element-specific 3D characterization of a cobalt-coated artificial buckyball polymer scaffold at the nanoscale. By performing ptychographic x-ray tomography at and far from the Co K edge, we are able to locate and quantify the Co layer in our sample to a 3D spatial resolution of 25 nm. With a quantitative determination of the electron density we can determine that the Co layer is oxidized, which is confirmed with microfluorescence experiments. PMID:25839287

  8. 3-D reconstruction of a human fetus with combined holoprosencephaly and cyclopia

    Meiselbach Veronika; Arnold Wolfgang H

    2009-01-01

    Abstract Background The purpose of this study was to examine a human fetus with combined holoprosencephaly and cyclopia by means of histology and 3-D reconstruction to determine the internal structure and extent of the malformation. Methods The head from a human fetus at 20 weeks gestation and a diagnosis of holoprosencephaly and cyclopia was investigated histologically and three-dimensionally reconstructed with CAD techniques. The cranial bones, blood vessels, nerves, eye and brain anlagen w...

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

    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.

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

    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

  11. 3D Reconstruction from X-ray Fluoroscopy for Clinical Veterinary Medicine using Differential Volume Rendering

    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.

  12. 3D reconstruction of complex geological bodies: Examples from the Alps

    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.

  13. 3D reconstruction from X-ray fluoroscopy for clinical veterinary medicine using differential volume rendering

    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 technique 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. (author)

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

    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.

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

    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.

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

    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.

  17. Breast mass detection using slice conspicuity in 3D reconstructed digital breast volumes

    In digital breast tomosynthesis, the three dimensional (3D) reconstructed volumes only provide quasi-3D structure information with limited resolution along the depth direction due to insufficient sampling in depth direction and the limited angular range. The limitation could seriously hamper the conventional 3D image analysis techniques for detecting masses because the limited number of projection views causes blurring in the out-of-focus planes. In this paper, we propose a novel mass detection approach using slice conspicuity in the 3D reconstructed digital breast volumes to overcome the above limitation. First, to overcome the limited resolution along the depth direction, we detect regions of interest (ROIs) on each reconstructed slice and separately utilize the depth directional information to combine the ROIs effectively. Furthermore, we measure the blurriness of each slice for resolving the degradation of performance caused by the blur in the out-of-focus plane. Finally, mass features are extracted from the selected in focus slices and analyzed by a support vector machine classifier to reduce the false positives. Comparative experiments have been conducted on a clinical data set. Experimental results demonstrate that the proposed approach outperforms the conventional 3D approach by achieving a high sensitivity with a small number of false positives. (paper)

  18. Investigation of iterative image reconstruction in three-dimensional optoacoustic tomography

    wang, Kun; Oraevsky, Alexander A; Anastasio, Mark A

    2012-01-01

    Iterative image reconstruction algorithms for optoacoustic tomography (OAT), also known as photoacoustic tomography, have the ability to improve image quality over analytic algorithms due to their ability to incorporate accurate models of the imaging physics, instrument response, and measurement noise. However, to date, there have been few reported attempts to employ advanced iterative image reconstruction algorithms for improving image quality in three-dimensional (3D) OAT. In this work, we implement and investigate two iterative image reconstruction methods for use with a 3D OAT small animal imager: namely, a penalized least-squares (PLS) method employing a quadratic smoothness penalty and a PLS method employing a total variation norm penalty. The reconstruction algorithms employ accurate models of the ultrasonic transducer impulse responses. Experimental data sets are employed to compare the performances of the iterative reconstruction algorithms to that of a 3D filtered backprojection (FBP) algorithm. By ...

  19. Sampling of finite elements for sparse recovery in large scale 3D electrical impedance tomography

    This study proposes a method to improve performance of sparse recovery inverse solvers in 3D electrical impedance tomography (3D EIT), especially when the volume under study contains small-sized inclusions, e.g. 3D imaging of breast tumours. Initially, a quadratic regularized inverse solver is applied in a fast manner with a stopping threshold much greater than the optimum. Based on assuming a fixed level of sparsity for the conductivity field, finite elements are then sampled via applying a compressive sensing (CS) algorithm to the rough blurred estimation previously made by the quadratic solver. Finally, a sparse inverse solver is applied solely to the sampled finite elements, with the solution to the CS as its initial guess. The results show the great potential of the proposed CS-based sparse recovery in improving accuracy of sparse solution to the large-size 3D EIT. (paper)

  20. A Smartphone Interface for a Wireless EEG Headset with Real-Time 3D Reconstruction

    Stopczynski, Arkadiusz; Larsen, Jakob Eg; Stahlhut, Carsten; Petersen, Michael Kai; Hansen, Lars Kai

    2011-01-01

    We demonstrate a fully functional handheld brain scanner consisting of a low-cost 14-channel EEG headset with a wireless connec- tion to a smartphone, enabling minimally invasive EEG monitoring in naturalistic settings. The smartphone provides a touch-based interface with real-time brain state decoding and 3D reconstruction.

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

    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.

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

    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

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

    Ghina El Natour

    2015-10-01

    Full Text Available 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.

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

    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

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

    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

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

    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...

  7. Virtual 3D reconstruction of embryonic head structures from physical sections

    Janáček, Jiří; Kundrát, M.

    2004-01-01

    Roč. 260, č. 3 (2004), s. 302. ISSN 0362-2525 R&D Projects: GA AV ČR(CZ) KJB6111301 Institutional research plan: CEZ:AV0Z5011922 Keywords : embryonic heads * 3D reconstruction Subject RIV: EA - Cell Biology Impact factor: 1.528, year: 2004

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

    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

  9. 3D High Resolution l1-SPIRiT Reconstruction on Gadgetron based Cloud

    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...

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

    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.

  11. Reconstruction of 3D Shapes of Opaque Cumulus Clouds from Airborne Multiangle Imaging: A Proof-of-Concept

    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

  12. Degradation study by 3D reconstruction of a nickel-yttria stabilized zirconia cathode after high temperature steam electrolysis operation

    Lay-Grindler, E.; Laurencin, J.; Villanova, J.; Cloetens, P.; Bleuet, P.; Mansuy, A.; Mougin, J.; Delette, G.

    2014-12-01

    Microstructural evolution of a Solid Oxide Electrolyser Cell (SOEC) Ni-YSZ cermet cathode is investigated using three dimensional electrode characterisations. 3D reconstructions are obtained on a reference and two long-term tested cells, which were maintained at -0.5 and -0.8 A cm-2 for 1000 h at 800 °C. During the long term tests, air was fed at the anode and a mixture of 10% H2-90% H2O was fed at the cathode. In this framework, reconstructions have been obtained from synchrotron X-ray nano-tomography technique. Microstructural properties extracted from the 3D reconstructions exhibit an evolution during the tests. Triple Phase Boundary length is decreasing from 10.49 ± 1.18 μm-2 for the reference cell to 6.18 ± 0.6 μm-2 for the long term tested cell at -0.8 A cm-2. Evolutions of morphological parameters were introduced in an in-house multi-scale model to evaluate their impacts on the electrode degradation, and hence, on the global SOEC performance.

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

    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.)

  14. 3D Surface Reconstruction of Plant Seeds by Volume Carving: Performance and Accuracies

    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

  15. X-ray scattering in the elastic regime as source for 3D imaging reconstruction technique

    Kocifaj, Miroslav; Mego, Michal

    2015-11-01

    X-ray beams propagate across a target object before they are projected onto a regularly spaced array of detectors to produce a routine X-ray image. A 3D attenuation coefficient distribution is obtained by tomographic reconstruction where scattering is usually regarded as a source of parasitic signals which increase the level of electromagnetic noise that is difficult to eliminate. However, the elastically scattered radiation could be a valuable source of information, because it can provide a 3D topology of electron densities and thus contribute significantly to the optical characterization of the scanned object. The scattering and attenuation data form a complementary base for concurrent retrieval of both electron density and attenuation coefficient distributions. In this paper we developed the 3D reconstruction method that combines both data inputs and produces better image resolution compared to traditional technology.

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

    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.

  17. Automatic alignment and reconstruction of images for soft x-ray tomography

    Parkinson, Dilworth Y.; Knoechel, Christian; Yang, Chao; Larabell, Carolyn A.; Le Gros, Mark A.

    2011-01-01

    Soft x-ray tomography (SXT) is a powerful imaging technique that generates quantitative, 3D images of the structural organization of whole cells in a near-native state. SXT is also a high-throughput imaging technique. At the National Center for X-ray Tomography (NCXT), specimen preparation and image collection for tomographic reconstruction of a whole cell require only minutes. Aligning and reconstructing the data, however, take significantly longer. Here we describe a new component of the hi...

  18. A Skeleton-Based 3D Shape Reconstruction of Free-Form Objects with Stereo Vision

    Saini, Deepika; Kumar, Sanjeev

    2015-12-01

    In this paper, an efficient approach is proposed for recovering the 3D shape of a free-form object from its arbitrary pair of stereo images. In particular, the reconstruction problem is treated as the reconstruction of the skeleton and the external boundary of the object. The reconstructed skeleton is termed as the line-like representation or curve-skeleton of the 3D object. The proposed solution for object reconstruction is based on this evolved curve-skeleton. It is used as a seed for recovering shape of the 3D object, and the extracted boundary is used for terminating the growing process of the object. NURBS-skeleton is used to extract the skeleton of both views. Affine invariant property of the convex hulls is used to establish the correspondence between the skeletons and boundaries in the stereo images. In the growing process, a distance field is defined for each skeleton point as the smallest distance from that point to the boundary of the object. A sphere centered at a skeleton point of radius equal to the minimum distance to the boundary is tangential to the boundary. Filling in the spheres centered at each skeleton point reconstructs the object. Several results are presented in order to check the applicability and validity of the proposed algorithm.

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

    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.

  20. Weak lensing reconstructions in 2D & 3D: implications for cluster studies

    Leonard, Adrienne; Starck, Jean-Luc

    2015-01-01

    We compare the efficiency with which 2D and 3D weak lensing mass mapping techniques are able to detect clusters of galaxies using two state-of-the-art mass reconstruction techniques: MRLens in 2D and GLIMPSE in 3D. We simulate otherwise-empty cluster fields for 96 different virial mass-redshift combinations spanning the ranges $3\\times10^{13}h^{-1}M_\\odot \\le M_{vir}\\le 10^{15}h^{-1}M_\\odot$ and $0.05 \\le z_{\\rm cl} \\le 0.75$, and for each generate 1000 realisations of noisy shear data in 2D and 3D. For each field, we then compute the cluster (false) detection rate as the mean number of cluster (false) detections per reconstruction over the sample of 1000 reconstructions. We show that both MRLens and GLIMPSE are effective tools for the detection of clusters from weak lensing measurements, and provide comparable quality reconstructions at low redshift. At high redshift, GLIMPSE reconstructions offer increased sensitivity in the detection of clusters, yielding cluster detection rates up to a factor of $\\sim 10\\...

  1. A new cone-beam computed tomography system for dental applications with innovative 3D software

    Pasini, Alessandro; Bianconi, D.; Rossi, A. [University of Bologna, Department of Physics, Bologna (Italy); NECTAR Imaging srl Imola (Italy); Casali, F. [University of Bologna, Department of Physics, Bologna (Italy); Bontempi, M. [CEFLA Dental Group Imola (Italy)

    2007-02-15

    Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70-100 kVp and 1-4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4'' and 6'') and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10-15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1-1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market. (orig.)

  2. A new cone-beam computed tomography system for dental applications with innovative 3D software

    Objective Cone beam computed tomography (CBCT) is an important image technique for oral surgery (dentoalveolar surgery and dental implantology) and maxillofacial applications. This technique requires compact sized scanners with a relatively low radiation dosage, which makes them suitable for imaging of the craniofacial region. This article aims to present the concept and the preliminary findings obtained with the prototype of a new CBCT scanner with dedicated 3D software, specifically designed for dental imaging. Methods The prototype implements an X-ray tube with a nominal focal spot of 0.5 mm operating at 70-100 kVp and 1-4 mA. The detector is a 6 in. image intensifier coupled with a digital CCD camera. Dosimetry was performed on a RANDO anthropomorphic phantom using Beryllium Oxide thermo-luminescent dosimeters positioned in the phantom in the following site: eyes, thyroid, skin (lips, cheeks, back of the neck), brain, mandible, maxilla and parotid glands. Doses were measured using four configurations, changing the field-of-view (4'' and 6'') and acquisition time (10 and 20 s) of the CBCT. Acquisitions were performed with different parameters regarding the x-ray tube, pixel size and acquisition geometries to evaluate image quality in relation to modulation transfer function (MTF), noise and geometric accuracy. Results The prototype was able to acquire a complete maxillofacial scan in 10-15 s. The CT reconstruction algorithm delivered images that were judged to have high quality, allowing for precise volume rendering. The radiation dose was determined to be 1-1.5 times that of the dose applied during conventional dental panoramic studies. Conclusion Preliminary studies using the CBCT prototype indicate that this device provides images with acceptable diagnostic content at a relatively low radiation dosage, if compared to systems currently available on the market. (orig.)

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

    Babu, S; Liao, P; Shin, M C; Tsap, L V

    2004-04-28

    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. Chromosome analysis is significant in the detection of deceases and in monitoring environmental gene mutations. The algorithm 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.

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

    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

    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. Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water

    Glaser, Adam K., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu; Andreozzi, Jacqueline M. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Zhang, Rongxiao [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Pogue, Brian W., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu [Thayer School of Engineering and Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Gladstone, David J. [Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States)

    2015-07-15

    Purpose: To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). Methods: An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp–Davis–Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. Results: 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm{sup 3} volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%–99% pass fraction depending on the chosen threshold dose. Conclusions: The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water.

  7. Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water

    Purpose: To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). Methods: An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp–Davis–Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. Results: 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm3 volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%–99% pass fraction depending on the chosen threshold dose. Conclusions: The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water

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

    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.

  9. External force back-projective composition and globally deformable optimization for 3-D coronary artery reconstruction

    The clinical value of the 3D reconstruction of a coronary artery is important for the diagnosis and intervention of cardiovascular diseases. This work proposes a method based on a deformable model for reconstructing coronary arteries from two monoplane angiographic images acquired from different angles. First, an external force back-projective composition model is developed to determine the external force, for which the force distributions in different views are back-projected to the 3D space and composited in the same coordinate system based on the perspective projection principle of x-ray imaging. The elasticity and bending forces are composited as an internal force to maintain the smoothness of the deformable curve. Second, the deformable curve evolves rapidly toward the true vascular centerlines in 3D space and angiographic images under the combination of internal and external forces. Third, densely matched correspondence among vessel centerlines is constructed using a curve alignment method. The bundle adjustment method is then utilized for the global optimization of the projection parameters and the 3D structures. The proposed method is validated on phantom data and routine angiographic images with consideration for space and re-projection image errors. Experimental results demonstrate the effectiveness and robustness of the proposed method for the reconstruction of coronary arteries from two monoplane angiographic images. The proposed method can achieve a mean space error of 0.564 mm and a mean re-projection error of 0.349 mm. (paper)

  10. 3D Maize Plant Reconstruction Based on Georeferenced Overlapping LiDAR Point Clouds

    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.

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

    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

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

    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)

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

    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.

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

    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.

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

    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)

  16. Use of 3D MR reconstructions in the evaluation of glenoid bone loss: a clinical study

    To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss. (orig.)

  17. Use of 3D MR reconstructions in the evaluation of glenoid bone loss: a clinical study

    Gyftopoulos, Soterios; Beltran, Luis S.; Yemin, Avner; Recht, Michael P. [NYU Langone Medical Center, Department of Radiology, New York, NY (United States); Strauss, Eric; Meislin, Robert; Jazrawi, Laith [NYU Langone Medical Center, Center for Musculoskeletal Care, Department of Orthopaedic Surgery, New York, NY (United States)

    2014-02-15

    To assess the ability of 3D MR shoulder reconstructions to accurately quantify glenoid bone loss in the clinical setting using findings at the time of arthroscopy as the gold standard. Retrospective review of patients with MR shoulder studies that included 3D MR reconstructions (3D MR) produced using an axial Dixon 3D-T1W-FLASH sequence at our institution was conducted with the following inclusion criteria: history of anterior shoulder dislocation, arthroscopy (OR) performed within 6 months of the MRI, and an estimate of glenoid bone loss made in the OR using the bare-spot method. Two musculoskeletal radiologists produced estimates of bone loss along the glenoid width, measured in mm and %, on 3D MR using the best-fit circle method, which were then compared to the OR measurements. There were a total of 15 patients (13 men, two women; mean age, 28, range, 19-51 years). There was no significant difference, on average, between the MRI (mean 3.4 mm/12.6 %; range, 0-30 %) and OR (mean, 12.7 %; range, 0-30 %) measurements of glenoid bone loss (p = 0.767). A 95 % confidence interval for the mean absolute error extended from 0.45-2.21 %, implying that, when averaged over all patients, the true mean absolute error of the MRI measurements relative to the OR measurements is expected to be less than 2.21 %. Inter-reader agreement between the two readers had an IC of 0.92 and CC of 0.90 in terms of percentage of bone loss. 3D MR reconstructions of the shoulder can be used to accurately measure glenoid bone loss. (orig.)

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

    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. Minimizing camera-eye optical aberrations during the 3D reconstruction of retinal structures

    Aldana-Iuit, Javier; Martinez-Perez, M. Elena; Espinosa-Romero, Arturo; Diaz-Uribe, Rufino

    2010-05-01

    3D reconstruction of blood vessels is a powerful visualization tool for physicians, since it allows them to refer to qualitative representation of their subject of study. In this paper we propose a 3D reconstruction method of retinal vessels from fundus images. The reconstruction method propose herein uses images of the same retinal structure in epipolar geometry. Images are preprocessed by RISA system for segmenting blood vessels and obtaining feature points for correspondences. The correspondence points process is solved using correlation. The LMedS analysis and Graph Transformation Matching algorithm are used for outliers suppression. Camera projection matrices are computed with the normalized eight point algorithm. Finally, we retrieve 3D position of the retinal tree points by linear triangulation. In order to increase the power of visualization, 3D tree skeletons are represented by surfaces via generalized cylinders whose radius correspond to morphological measurements obtained by RISA. In this paper the complete calibration process including the fundus camera and the optical properties of the eye, the so called camera-eye system is proposed. On one hand, the internal parameters of the fundus camera are obtained by classical algorithms using a reference pattern. On the other hand, we minimize the undesirable efects of the aberrations induced by the eyeball optical system assuming that contact enlarging lens corrects astigmatism, spherical and coma aberrations are reduced changing the aperture size and eye refractive errors are suppressed adjusting camera focus during image acquisition. Evaluation of two self-calibration proposals and results of 3D blood vessel surface reconstruction are presented.

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

    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.

  1. Submicron STIM tomography reconstruction techniques

    One-dimensional projections of ion energy loss have been converted to areal density using tabulated stopping powers in a scanning transmission ion microscopy (STIM) reconstruction of a test object, displaying a spatial resolution of 0.37 μm. Location and registration of the centre of areal mass density in each projection provides a means of overcoming (a) the misalignment of the specimen rotation axis with the centre of the scan path and (b) deviations of the specimen from its precession around the axis of rotation. Multiplicative algebraic reconstruction technique (ART), filtered backprojection and maximum-entropy algorithms for the reconstruction of the object are considered. Maximum entropy is shown to produce an image with the least number of artifacts. However, when time considerations are taken into account, it is found that filtered backprojection is the preferred algorithm for a tomographic reconstruction. (orig.)

  2. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats.

    Tang, Jianbo; Coleman, Jason E; Dai, Xianjin; Jiang, Huabei

    2016-01-01

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents. PMID:27146026

  3. Reconstructions in ultrasound modulated optical tomography

    Allmaras, Moritz

    2011-01-01

    We introduce a mathematical model for ultrasound modulated optical tomography and present a simple reconstruction scheme for recovering the spatially varying optical absorption coefficient from scanning measurements with narrowly focused ultrasound signals. Computational results for this model show that the reconstruction of sharp features of the absorption coefficient is possible. A formal linearization of the model leads to an equation with a Fredholm operator, which explains the stability observed in our numerical experiments. © de Gruyter 2011.

  4. Reconstruction of axisymmetric strain distributions via neutron strain tomography

    Predicting the behaviour of structural components under a particular set of loading conditions requires knowledge of the residual elastic strain distribution throughout the bulk of these components. Characterising the 3D strain state at any particular point involves the measurement of six independent components which make up the second order strain tensor. Mapping the complete strain distribution throughout large volumes thus presents significant practical challenges. One possible solution to this problem is to reconstruct the 3D variation of strain components using tomographic techniques. The basic principle underpinning this idea is that the multi-component strain tensor can be reconstructed from a redundant set of lower order projection data. Here we demonstrate this fundamental concept for two samples: a shrink fit ‘ring-and-plug’ sample, and a spray-quenched circular cylinder, both possessing axially symmetric internal strain distribution. We present and contrast different approaches to the strain tomography problem. The methods described here can also be readily applied to high-energy X-ray diffraction measurements and represent an important step toward developing the tomographic reconstruction framework for strain tensor distributions of arbitrary complexity. The major benefit of neutron strain tomography is that the incident beam flux is utilised more fully, greatly reducing the data collection times. Using micro-channel plate (MCP) neutron detectors, a spatial resolution of the order of 0.1 mm can be achieved .

  5. Computed Tomography and its Application for the 3D Characterization of Coarse Grained Meteorites

    Gillies, Donald C.; Engel, H. P.; Carpenter, P. K.

    2004-01-01

    With judicious selection of parameters, computed tomography can provide high precision density data. Such data can lead to a non-destructive determination of the phases and phase distribution within large solid objects. Of particular interest is the structure of the Mundrabilla meteorite, which has 25 volumes, percent of a sulfide within a metallic meteorite. 3D digital imaging has enabled a quantitative evaluation of the distribution and contiguity of the phases to be determined.

  6. Preoperative evaluation of the saphenous vein by 3-D contrastless computed tomography

    Maruyama, Yuji; Imura, Hajime; Shirakawa, Makoto; Ochi, Masami

    2013-01-01

    Volume-rendering computed tomography (CT) without contrast medium has clearly demonstrated the 3-D mapping of the saphenous vein (SV). Contrastless volume-rendering CT was used to preoperatively evaluate the SV anatomy before coronary artery bypass grafting (CABG). This technique was useful for atypical anatomical variations, such as partial duplication of SV (Case 1) or varicose veins (Case 2). Volume-rendering CT may also help with redo CABG (to determine remaining SV) or during endoscopic ...

  7. Design and evaluation of a laboratory prototype system for 3D photoacoustic full breast tomography

    Xia, W; Piras, D; Singh, M. K. A.; van Hespen, J. C. G.; Van Leeuwen, T. G.; Steenbergen, W Van; Manohar, S.

    2013-01-01

    Photoacoustic imaging can visualize vascularization-driven optical absorption contrast with great potential for breast cancer detection and diagnosis. State-of-the-art photoacoustic breast imaging systems are promising but are limited either by only a 2D imaging capability or by an insufficient imaging field-of-view (FOV). We present a laboratory prototype system designed for 3D photoacoustic full breast tomography, and comprehensively characterize it and evaluate its performance in imaging p...

  8. 3-D Multiphase Segmentation of X-Ray Micro Computed Tomography Data of Geologic Materials

    Tuller, M.; Kulkarni, R.; Fink, W.

    2011-12-01

    Advancements of noninvasive imaging methods such as X-Ray Computed Tomography (CT) led to a recent surge of applications in Geoscience. While substantial efforts and resources have been devoted to advance CT technology and micro-scale analysis, the development of a stable 3-D multiphase image segmentation method applicable to large datasets is lacking. To eliminate the need for wet/dry or dual energy scans, image alignment, and subtraction analysis, commonly applied in synchrotron X-Ray micro CT, a segmentation method based on a Bayesian Markov Random Field (MRF) framework amenable to true 3-D multiphase processing was developed and evaluated. Furthermore, several heuristic and deterministic combinatorial optimization schemes required to solve the labeling problem of the MRF image model were implemented and tested for computational efficiency and their impact on segmentation results. Test results for natural and artificial porous media datasets demonstrate great potential of the MRF image model for 3-D multiphase segmentation.

  9. Automated Reconstruction of Walls from Airborne LIDAR Data for Complete 3d Building Modelling

    He, Y.; Zhang, C.; Awrangjeb, M.; Fraser, C. S.

    2012-07-01

    Automated 3D building model generation continues to attract research interests in photogrammetry and computer vision. Airborne Light Detection and Ranging (LIDAR) data with increasing point density and accuracy has been recognized as a valuable source for automated 3D building reconstruction. While considerable achievements have been made in roof extraction, limited research has been carried out in modelling and reconstruction of walls, which constitute important components of a full building model. Low point density and irregular point distribution of LIDAR observations on vertical walls render this task complex. This paper develops a novel approach for wall reconstruction from airborne LIDAR data. The developed method commences with point cloud segmentation using a region growing approach. Seed points for planar segments are selected through principle component analysis, and points in the neighbourhood are collected and examined to form planar segments. Afterwards, segment-based classification is performed to identify roofs, walls and planar ground surfaces. For walls with sparse LIDAR observations, a search is conducted in the neighbourhood of each individual roof segment to collect wall points, and the walls are then reconstructed using geometrical and topological constraints. Finally, walls which were not illuminated by the LIDAR sensor are determined via both reconstructed roof data and neighbouring walls. This leads to the generation of topologically consistent and geometrically accurate and complete 3D building models. Experiments have been conducted in two test sites in the Netherlands and Australia to evaluate the performance of the proposed method. Results show that planar segments can be reliably extracted in the two reported test sites, which have different point density, and the building walls can be correctly reconstructed if the walls are illuminated by the LIDAR sensor.

  10. Development and Implementation of a Web-Enabled 3D Consultation Tool for Breast Augmentation Surgery Based on 3D-Image Reconstruction of 2D Pictures

    de Heras Ciechomski, Pablo; Constantinescu, Mihai; Garcia, Jaime; Olariu, Radu; Dindoyal, Irving; Le Huu, Serge; Reyes, Mauricio

    2012-01-01

    Background Producing a rich, personalized Web-based consultation tool for plastic surgeons and patients is challenging. Objective (1) To develop a computer tool that allows individual reconstruction and simulation of 3-dimensional (3D) soft tissue from ordinary digital photos of breasts, (2) to implement a Web-based, worldwide-accessible preoperative surgical planning platform for plastic surgeons, and (3) to validate this tool through a quality control analysis by comparing 3D laser scans of...

  11. Py3DFreeHandUS: A PURE PYTHON LIBRARY FOR 3D VOXEL-ARRAY RECONSTRUCTION BY USING 3D FREEHAND ULTRASOUND

    Monari, Davide; Cenni, Francesco; Aertbeliën, Erwin; Desloovere, Kaat

    2014-01-01

    INTRODUCTION and AIM 3D Freehand ultrasound (3DUS) is a technique that combines ultrasound images and position + orientation sensors (POS) with the aim to reconstruct large 3D anatomical parts. However, the few existing applications for applying this technique have at least one of the following disadvantages: i) not open-source; ii) only supporting data streams from a limited number of ultrasound or POS devices; iii) they are written in low-level languages such as C++, making rapid develop...

  12. 3D reconstruction of carbon nanotube networks from neutron scattering experiments

    Mahdavi, Mostafa; Baniassadi, Majid; Baghani, Mostafa; Dadmun, Mark; Tehrani, Mehran

    2015-09-01

    Structure reconstruction from statistical descriptors, such as scattering data obtained using x-rays or neutrons, is essential in understanding various properties of nanocomposites. Scattering based reconstruction can provide a realistic model, over various length scales, that can be used for numerical simulations. In this study, 3D reconstruction of a highly loaded carbon nanotube (CNT)-conducting polymer system based on small and ultra-small angle neutron scattering (SANS and USANS, respectively) data was performed. These light-weight and flexible materials have recently shown great promise for high-performance thermoelectric energy conversion, and their further improvement requires a thorough understanding of their structure-property relationships. The first step in achieving such understanding is to generate models that contain the hierarchy of CNT networks over nano and micron scales. The studied system is a single walled carbon nanotube (SWCNT)/poly (3,4-ethylenedioxythiophene):poly (styrene sulfonate) (PEDOT:PSS). SANS and USANS patterns of the different samples containing 10, 30, and 50 wt% SWCNTs were measured. These curves were then utilized to calculate statistical two-point correlation functions of the nanostructure. These functions along with the geometrical information extracted from SANS data and scanning electron microscopy images were used to reconstruct a representative volume element (RVE) nanostructure. Generated RVEs can be used for simulations of various mechanical and physical properties. This work, therefore, introduces a framework for the reconstruction of 3D RVEs of high volume faction nanocomposites containing high aspect ratio fillers from scattering experiments.

  13. 3D tomographic reconstruction of coronary arteries using a precomputed 4D motion field

    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

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

    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.)

  15. 3D RECONSTRUCTION AND ANALYSIS OF THE FRAGMENTED GRAINS IN A COMPOSITE MATERIAL

    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.

  16. Utility of reconstructed image from 3-D MRI in the region of oral cavity

    Murakami, Shumei; Kakimoto, Naoya; Nakatani, Atsutoshi; Furuya, Shigeo; Furukawa, Shouhei; Fuchihata, Hajime [Osaka Univ., Suita (Japan). School of Dentistry

    1998-12-01

    The 3-D MRI with short TR was performed in the region of oral cavity, jaw and face, and utility of the reconstructed image was examined. Subjects were 8 healthy volunteers and 12 patients. The 3-D MRI was performed using SPGR with the following parameters; TR: 8 or 9 msec, TE: 2 or 3 msec, and FA: 20-30 degrees. Imaging direction was vertical to body axis. The matrix number was 256 x 192, slice thickness was 1 mm, slice interval was 0 and slice number was 128. The obtained image was reconstructed using software Reformat``. Detectability of temporomandibular joint disc was not enough in 8 of 20 cases. Detectability of mandibular canal was clear in 18 of 20 cases. In panorama MRI, soft tissue such as submandibular gland was detected. But, in hard tissue such as teeth or maxilla, there was a more little information in panorama MRI than in panorama X-ray photography. (K.H.)

  17. Hybrid fluorescence tomography/x-ray tomography improves reconstruction quality

    Schulz, R. B.; Ale, A.; Sarantopoulos, A.; Freyer, M.; Söhngen, R.; Zientkowska, M.; Ntziachristos, V.

    2009-07-01

    A novel hybrid imaging system for simultaneous X-ray and Fluorescence Tomography is presented, capitalizing on 360°-projection free-space fluorescence tomography. The system is implemented within a commercial micro-CT scanner allowing reconstructions with a resolution of 95μm. Acquired data sets are intrinsically coregistered in the same coordinate system and can be used to correctly localize reconstructed fluorescence distributions with morphological features. More importantly, the micro-CT data, automatically segmented into different organ and tissue segments can be used to guide the fluorescence reconstruction algorithm and reduce the ill coditioning of the inverse problem. We showcase the use of the system and the improvements in image quality for lesions in brain and lung.

  18. Sparse Image Reconstruction in Computed Tomography

    Jørgensen, Jakob Sauer

    In recent years, increased focus on the potentially harmful effects of x-ray computed tomography (CT) scans, such as radiation-induced cancer, has motivated research on new low-dose imaging techniques. Sparse image reconstruction methods, as studied for instance in the field of compressed sensing...

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

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

    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.

  1. Automatic urban 3D building reconstruction from multi-ray photogrammetry

    A. P. McClune; Miller, P E; J. P. Mills; Holland, D

    2014-01-01

    Over the last 20 years the use of, and demand for, three dimensional (3D) building models has meant there has been a vast amount of research conducted in automating the extraction and reconstruction of these models from airborne sensors. Whilst many different approaches have been suggested, full automation is yet to be achieved and research has suggested that the combination of data from multiple sources is required in order to achieve this. Developments in digital photogrammetry hav...

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

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

    2016-01-01

    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....

  3. 3D reconstruction of the developing dentition in the incisor region of the pig

    Kopečný, Michal; Witter, K.; Míšek, Ivan

    York : York, 2004, s. 84-84. [8th Meeting - Tooth Morphogenesis and Differentiation. York (GB), 21.07.2004-25.07.2004] R&D Projects: GA ČR(CZ) GP206/04/P197; GA MŠk OC B23.001 Institutional research plan: CEZ:AV0Z5045916 Keywords : incisor region * pig * 3D reconstruction Subject RIV: ED - Physiology

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

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

    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 ca...

  5. Automated Algorithm for Carotid Lumen Segmentation and 3D Reconstruction in B-mode images

    Jorge M. S. Pereira; João Manuel R. S. Tavares

    2011-01-01

    The B-mode image system is one of the most popular systems used in the medical area; however it imposes several difficulties in the image segmentation process due to low contrast and noise. Although these difficulties, this image mode is often used in the study and diagnosis of the carotid artery diseases.In this paper, it is described the a novel automated algorithm for carotid lumen segmentation and 3-D reconstruction in B- mode images.

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

    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...

  7. 3D RECONSTRUCTION OF AN UNDERWATER ARCHAELOGICAL SITE: COMPARISON BETWEEN LOW COST CAMERAS

    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.

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

    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.

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

    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.

  10. Bayesian image reconstruction: Application to emission tomography

    Nunez, J.; Llacer, J.

    1989-02-01

    In this paper we propose a Maximum a Posteriori (MAP) method of image reconstruction in the Bayesian framework for the Poisson noise case. We use entropy to define the prior probability and likelihood to define the conditional probability. The method uses sharpness parameters which can be theoretically computed or adjusted, allowing us to obtain MAP reconstructions without the problem of the grey'' reconstructions associated with the pre Bayesian reconstructions. We have developed several ways to solve the reconstruction problem and propose a new iterative algorithm which is stable, maintains positivity and converges to feasible images faster than the Maximum Likelihood Estimate method. We have successfully applied the new method to the case of Emission Tomography, both with simulated and real data. 41 refs., 4 figs., 1 tab.

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

    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.

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

    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

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

    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.

  14. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    Liang Xin, E-mail: Xin.Liang@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); College of Stomatology, Dalian Medical University (China); Lambrichts, Ivo, E-mail: Ivo.Lambrichts@uhasselt.b [Department of Basic Medical Sciences, Histology and Electron Microscopy, Faculty of Medicine, University of Hasselt, Diepenbeek (Belgium); Sun Yi, E-mail: Sunyihello@hotmail.co [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Denis, Kathleen, E-mail: kathleen.denis@groept.b [Department of Industrial Sciences and Techology-Engineering (IWT), XIOS Hogeschool Limburg, Hasselt (Belgium); Hassan, Bassam, E-mail: b.hassan@acta.n [Department of Oral Radiology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam (Netherlands); Li Limin, E-mail: Limin.Li@uz.kuleuven.b [Department of Paediatric Dentistry and Special Dental Care, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Pauwels, Ruben, E-mail: Ruben.Pauwels@med.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium); Jacobs, Reinhilde, E-mail: Reinhilde.Jacobs@uz.kuleuven.b [Oral Imaging Centre, School of Dentistry, Oral Pathology and Maxillofacial Surgery, Faculty of Medicine, Catholic University of Leuven (Belgium)

    2010-08-15

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G, Accuitomo 3D, i-CAT, Galileos, Scanora 3D) and one MSCT scanner (Somatom Sensation 16). A 3D surface bone model was created from the six systems. The reference (gold standard) 3D model was obtained with a high resolution laser surface scanner. The 3D models from the five systems were compared with the gold standard using a point-based rigid registration algorithm. Results: The mean deviation from the gold standard for MSCT was 0.137 mm and for CBCT were 0.282, 0.225, 0.165, 0.386 and 0.206 mm for the i-CAT, Accuitomo, NewTom, Scanora and Galileos, respectively. Conclusion: The results show that the accuracy of CBCT 3D surface model reconstructions is somewhat lower but acceptable comparing to MSCT from the gold standard.

  15. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G, Accuitomo 3D, i-CAT, Galileos, Scanora 3D) and one MSCT scanner (Somatom Sensation 16). A 3D surface bone model was created from the six systems. The reference (gold standard) 3D model was obtained with a high resolution laser surface scanner. The 3D models from the five systems were compared with the gold standard using a point-based rigid registration algorithm. Results: The mean deviation from the gold standard for MSCT was 0.137 mm and for CBCT were 0.282, 0.225, 0.165, 0.386 and 0.206 mm for the i-CAT, Accuitomo, NewTom, Scanora and Galileos, respectively. Conclusion: The results show that the accuracy of CBCT 3D surface model reconstructions is somewhat lower but acceptable comparing to MSCT from the gold standard.

  16. Imaging the 3D structure of secondary osteons in human cortical bone using phase-retrieval tomography

    Arhatari, B D; Peele, A G [Department of Physics, La Trobe University, Victoria 3086 (Australia); Cooper, D M L [Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon (Canada); Thomas, C D L; Clement, J G [Melbourne Dental School, University of Melbourne, Victoria 3010 (Australia)

    2011-08-21

    By applying a phase-retrieval step before carrying out standard filtered back-projection reconstructions in tomographic imaging, we were able to resolve structures with small differences in density within a densely absorbing sample. This phase-retrieval tomography is particularly suited for the three-dimensional segmentation of secondary osteons (roughly cylindrical structures) which are superimposed upon an existing cortical bone structure through the process of turnover known as remodelling. The resulting images make possible the analysis of the secondary osteon structure and the relationship between an osteon and the surrounding tissue. Our observations have revealed many different and complex 3D structures of osteons that could not be studied using previous methods. This work was carried out using a laboratory-based x-ray source, which makes obtaining these sorts of images readily accessible.

  17. Dynamic reconstruction for atom probe tomography

    Gault, Baptiste, E-mail: baptiste.gault@sydney.edu.au [Australian Centre for Microscopy and Microanalysis, Madsen Building F09, The University of Sydney, NSW 2006 (Australia); Institute of Materials and Engineering Science, Australian Nuclear Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234 (Australia); Loi, Shyeh Tjing; Araullo-Peters, Vicente J.; Stephenson, Leigh T.; Moody, Michael P.; Shrestha, Sachin L.; Marceau, Ross K.W.; Yao, Lan; Cairney, Julie M.; Ringer, Simon P. [Australian Centre for Microscopy and Microanalysis, Madsen Building F09, The University of Sydney, NSW 2006 (Australia)

    2011-11-15

    Progress in the reconstruction for atom probe tomography has been limited since the first implementation of the protocol proposed by Bas et al. in 1995. This approach and those subsequently developed assume that the geometric parameters used to build the three-dimensional atom map are constant over the course of an analysis. Here, we test this assumption within the analyses of low-alloyed materials. By building upon methods recently proposed to measure the tomographic reconstruction parameters, we demonstrate that this assumption can introduce significant limitations in the accuracy of the analysis. Moreover, we propose a strategy to alleviate this problem through the implementation of a new reconstruction algorithm that dynamically accommodates variations in the tomographic reconstruction parameters. -- Highlights: Black-Right-Pointing-Pointer Variation of main reconstruction parameters, namely image compression and field factors, quantified. Black-Right-Pointing-Pointer A new protocol to build the tomographic reconstruction is proposed where reconstruction parameters are dynamically adjusted. Black-Right-Pointing-Pointer Integrity of reconstructions obtained from the standard and dynamic reconstruction protocols compared.

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

    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.

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

    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...... identification is highly desirable for planning sustainable fisheries. Main hurdles in analysing acoustic images are the presence of speckle noise and the vast amount of acoustic data. This paper presents a level set formulation for simultaneous fish reconstruction and noise suppression from raw acoustic images....... Despite the presence of speckle noise blobs, actual fish intensity values can be distinguished by extremely high values, varying exponentially from the background. Edge detection generally gives excessive false edges that are not reliable. Our approach to reconstruction is based on level set evolution...

  20. 3D nanostructure reconstruction based on the SEM imaging principle, and applications

    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)

  1. Development of a 3D muon disappearance algorithm for muon scattering tomography

    Upon passing through a material, muons lose energy, scatter off nuclei and atomic electrons, and can stop in the material. Muons will more readily lose energy in higher density materials. Therefore multiple muon disappearances within a localized volume may signal the presence of high-density materials. We have developed a new technique that improves the sensitivity of standard muon scattering tomography. This technique exploits these muon disappearances to perform non-destructive assay of an inspected volume. Muons that disappear have their track evaluated using a 3D line extrapolation algorithm, which is in turn used to construct a 3D tomographic image of the inspected volume. Results of Monte Carlo simulations that measure muon disappearance in different types of target materials are presented. The ability to differentiate between different density materials using the 3D line extrapolation algorithm is established. Finally the capability of this new muon disappearance technique to enhance muon scattering tomography techniques in detecting shielded HEU in cargo containers has been demonstrated

  2. Model-based adaptive 3D sonar reconstruction in reverberating environments.

    Saucan, Augustin-Alexandru; Sintes, Christophe; Chonavel, Thierry; Caillec, Jean-Marc Le

    2015-10-01

    In this paper, we propose a novel model-based approach for 3D underwater scene reconstruction, i.e., bathymetry, for side scan sonar arrays in complex and highly reverberating environments like shallow water areas. The presence of multipath echoes and volume reverberation generates false depth estimates. To improve the resulting bathymetry, this paper proposes and develops an adaptive filter, based on several original geometrical models. This multimodel approach makes it possible to track and separate the direction of arrival trajectories of multiple echoes impinging the array. Echo tracking is perceived as a model-based processing stage, incorporating prior information on the temporal evolution of echoes in order to reject cluttered observations generated by interfering echoes. The results of the proposed filter on simulated and real sonar data showcase the clutter-free and regularized bathymetric reconstruction. Model validation is carried out with goodness of fit tests, and demonstrates the importance of model-based processing for bathymetry reconstruction. PMID:25974936

  3. Application of high magnification to 3D x-ray computed tomography

    A system was previously described for direct three-dimensional x-ray computed tomography which embodies both a means of performing reconstruction from cone-beam projection data and a means of acquiring such data. After replacing the microfocus source the system resolution under standard conditions is now determined primarily by the spatial resolution of the x-ray image intensifier which serves as the two dimensional detector. To more fully exploit the potential of the x-ray source and to bypass the limits of the detection system the use of high geometric magnification was explored. Initial findings are presented for both a conventional full-field configuration and a configuration in which only a limited volume of a sample can be reconstructed. The results indicate the utility of combining aspects of microradiography with those of computed tomography

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

    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.

  5. 3D RECONSTRUCTION OF BUILDINGS WITH GABLED AND HIPPED STRUCTURES USING LIDAR DATA

    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.

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

    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.

  7. 3D imaging and characterisation of strengthening particles in inconel 718 using FIB tomography

    Kruk, Adam; Gruszczynski, Adam; Czyrska-Filemonowicz, Aleksandra [AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow (Poland)

    2011-07-01

    The Inconel 718 is a commercial nickel-base superalloy, widely used for critical pieces in turbine engines. Its microstructure consists of the {gamma} matrix and strengthening coherent nanoparticles {gamma}' and {gamma}''. In the present work FIB tomography technique was used for imaging and characterisation of strengthening particles. FIB tomography is based on a serial sectioning procedure using a FIB/SEM dual beam workstation. Repeated removal of layers as thin as several nm for some hundred times allows to investigate at total a volume of some {mu}m3 with a voxel size as 2.5 nm x 2.5 nm x 2.5 nm. 3D mapping of nanoparticles with high Z-resolution by serial FIB slicing (in a distance of about 2.5 nm) and SEM imaging was performed. Ga ion beam at 30 kV was used to perform a precise in-situ milling. The SEM images at accelerating voltage 1.5 kV were taken with using ESB detector. The real 3D-data of precipitates obtained by FIB tomography, open a new possibility for microstructure analysis of materials for industrial applications.

  8. 3D MRI findings of anterior cruciate ligament reconstruction at follow-up

    Objective: To investigate the postoperative 3D MRI appearances and their evolvement patterns of ACL grafts and bone tunnels at follow-up. Methods: There were 2,6 double bundles ACL reconstructions and 16 single bundle ACL reconstructions, and a total of 56 follow-up 3D MR Imaging. MR images were reconstructed with MPR technique to evaluate grafts, bone tunnels, fixers and associated complications. Proportions of grafts with hypointensity or hyperintensity and occurrence rates of marrow edema around bone tunnels were calculated respectively among groups of different periods after operation. Results: There were 2, 4 grafts of hypointensity and 32 grafts of hyperintensity. Grafts of 2 cases were suspended with cross pins within femoral tunnels, graft of 1 case was suspended with an endobutton within the femoral tunnel, and grafts of other sites were fixed with interference screws. In the three periods as 3 months, 6 to 9 months and over 12 months after cruciate ligament reconstruction, proportions of hypointensive grafts were 20/25, 0/14 and 4/10 respectively, while proportions of hyperintensive grafts were 5/25, 14/14 and 6/10 respectively, occurrence proportions of marrow edema around bone tunnels were 54/54, 10/32 and 4/26 respectively. There was 1 tear graft, 4 tibial tunnels placed anteriorly with ACL graft impingement on the intercondylar roof, 3 femoral tunnels placed anteriorly, and 2 bone tunnels with mismatching interference screws. Conclusion: 3D MRI can accurately demonstrate the state of ACL grafts, bone tunnels, fixers and associated complications. Intensity of grafts presented a rise and reduce pattern after operation. (authors)

  9. Belief-propagation reconstruction for discrete tomography

    We consider the reconstruction of a two-dimensional discrete image from a set of tomographic measurements corresponding to the Radon projection. Assuming that the image has a structure where neighbouring pixels have a larger probability of taking the same value, we follow a Bayesian approach and introduce a fast message-passing reconstruction algorithm based on belief propagation. For numerical results, we specialize to the case of binary tomography. We test the algorithm on binary synthetic images with different length scales and compare our results against a more usual convex optimization approach. We investigate the reconstruction error as a function of the number of tomographic measurements, corresponding to the number of projection angles. The belief-propagation algorithm turns out to be more efficient than the convex-optimization algorithm, both in terms of recovery bounds for noise-free projections and reconstruction quality when moderate Gaussian noise is added to the projections. (paper)

  10. Frequency and types of fractures in maxillofacial traumas. Assessment using MDCT with multiplanar and 3D reconstructions

    Introduction: Maxillofacial trauma (MFT) is a common reason for attendance at Emergency Departments. The complex anatomy of the facial bones requires multiplanar imaging techniques for a proper evaluation. Objectives. To describe frequency and types of fractures in a series of patients with MFT evaluated by multi-slice computed tomography (MDCT) with multiplanar and 3D reconstructions. Materials and Methods: Facial bone CTs ordered for MFT by the Emergency Department from June 2008 to December 2009 were retrospectively reviewed. The following data were obtained: age, gender, cause of trauma, presence and type of fractures. Patients were evaluated with an 8-channel MDCT. Multiplanar reconstructions were performed in all cases using high resolution bone window and soft tissue window, as well as 3D reconstructions. Results: One-hundred and thirty-seven CTs were performed for MFT: 78 (57%) showed 131 fractures. Of these 78 patients, 52 (66%) were males and 26 (34%) were females; mean age 33 years old (range: 14-90 yrs.). Causes: 58 % were injuries from traffic accidents; 24% were injuries from fights; 13% were sport injuries; and 7% were due to miscellaneous etiologies. Type and frequency of fractures: 18.3% were orbital floor fractures, 16% were maxillary sinus fractures, 15.3% were nasal fractures, 13% were jaw fractures, 9.2% were orbital fractures, and 12.3% were fractures of the zygomatic-malar complex; two cases of Le Fort II-III fractures were also observed. Conclusions: Fractures were more common in males, in the age range from 15 to 35 years old. Most fractures, and the most complex ones, were caused by traffic accidents. The most common fracture, either isolated or associated with other fractures, was the orbital floor fracture. (authors)

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

    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.

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

    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

  13. 3D INDOOR BUILDING ENVIRONMENT RECONSTRUCTION USING CALIBRATION OF RANGEFINDER DATA

    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.

  14. A parallel algorithm for 3D particle tracking and Lagrangian trajectory reconstruction

    Particle-tracking methods are widely used in fluid mechanics and multi-target tracking research because of their unique ability to reconstruct long trajectories with high spatial and temporal resolution. Researchers have recently demonstrated 3D tracking of several objects in real time, but as the number of objects is increased, real-time tracking becomes impossible due to data transfer and processing bottlenecks. This problem may be solved by using parallel processing. In this paper, a parallel-processing framework has been developed based on frame decomposition and is programmed using the asynchronous object-oriented Charm++ paradigm. This framework can be a key step in achieving a scalable Lagrangian measurement system for particle-tracking velocimetry and may lead to real-time measurement capabilities. The parallel tracking algorithm was evaluated with three data sets including the particle image velocimetry standard 3D images data set #352, a uniform data set for optimal parallel performance and a computational-fluid-dynamics-generated non-uniform data set to test trajectory reconstruction accuracy, consistency with the sequential version and scalability to more than 500 processors. The algorithm showed strong scaling up to 512 processors and no inherent limits of scalability were seen. Ultimately, up to a 200-fold speedup is observed compared to the serial algorithm when 256 processors were used. The parallel algorithm is adaptable and could be easily modified to use any sequential tracking algorithm, which inputs frames of 3D particle location data and outputs particle trajectories

  15. Modeling the Coast Mountains Batholith, British Columbia, Canada with 3D Seismic Tomography

    Quinonez, S. M.; Olaya, J. C.; Miller, K. C.; Romero, R.; Velasco, A. A.; Harder, S. H.; Cerda, I.

    2011-12-01

    The Coast Mountains Batholith on the west coast of British Columbia, Canada comprises a series of granitic to tonalitic plutons; where felsic continental crust is generated from the subduction of mafic oceanic crust by partial melting and fractionation, leaving ultra-mafic roots. In July of 2009, a large controlled-source experiment was conducted along a 400km east - west transect from Bella Bella into central British Columbia. Student volunteers from multiple universities deployed 1,800 one-component and 200 three-component geophones plus 2400 Texan data recorders with 200-m spacing intervals and shot spacing at 30-km. The 18-point sources ranged from 160 to 1,000 kg of high explosive. The geoscience component of the NSF-funded Cyber-ShARE project at UTEP focuses on fusing models developed from different data sets to develop 3-D Earth models. Created in 2007, the Cyber-ShARE Center brings together experts in computer science, computational mathematics, education, earth science, and environmental science. We leverage the Cyber-ShARE work to implement an enhanced 3-D finite difference tomography approach for P-wave delays times (Hole, 1992) with a graphical user interface and visualization framework. In particular, to account for model sensitivity to picked P-wave arrival times, we use a model fusion approach (Ochoa et al., 2010) to generate a model with the lowest RMS residual that a combination of a set of Monte Carlo sample models. In order to make the seismic tomography process more interactive at many points, visualizations of model perturbation at each iteration will help to troubleshoot when a model is not converging to highlight where the RMS residual values are the highest to pinpoint where changes need to be made to achieve model convergence. Finally, a model of the upper mantle using 3-D P-wave tomography will be made to determine the location of these ultra-mafic roots.

  16. Custom Anatomical 3D Spacer for Temporomandibular Joint Resection and Reconstruction.

    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

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

    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.

  18. Monitoring CO2 migration in a shallow sand aquifer using 3D crosshole electrical resistivity tomography

    Yang, Xianjin; Lassen, Rune Nørbæk; Jensen, Karsten Høgh; Zibar, Majken Caroline Looms

    2015-01-01

    Three-dimensional (3D) crosshole electrical resistivity tomography (ERT) was used to monitor a pilot CO2 injection experiment at Vrøgum, western Denmark. The purpose was to evaluate the effectiveness of the ERT method for detection of small electrical conductivity (EC) changes during the first 2 days of CO2 injection in a shallow siliciclastic aquifer and to study the early-time behavior of a controlled small gaseous CO2 release. 45 kg of CO2 was injected over a 50-h period at 9.85 m depth. E...

  19. Phase-retrieved optical projection tomography for 3D imaging through scattering layers

    Ancora, Daniele; Di Battista, Diego; Giasafaki, Georgia; Psycharakis, Stylianos; Liapis, Evangelos; Zacharopoulos, Athanasios; Zacharakis, Giannis

    2016-03-01

    Recently great progress has been made in biological and biomedical imaging by combining non-invasive optical methods, novel adaptive light manipulation and computational techniques for intensity-based phase recovery and three dimensional image reconstruction. In particular and in relation to the work presented here, Optical Projection Tomography (OPT) is a well-established technique for imaging mostly transparent absorbing biological models such as C. Elegans and Danio Rerio. On the contrary, scattering layers like the cocoon surrounding the Drosophila during the pupae stage constitutes a challenge for three dimensional imaging through such a complex structure. However, recent studies enabled image reconstruction through scattering curtains up to few transport mean free paths via phase retrieval iterative algorithms allowing to uncover objects hidden behind complex layers. By combining these two techniques we explore the possibility to perform a three dimensional image reconstruction of fluorescent objects embedded between scattering layers without compromising its structural integrity. Dynamical cross correlation registration was implemented for the registration process due to translational and flipping ambiguity of the phase retrieval problem, in order to provide the correct aligned set of data to perform the back-projection reconstruction. We have thus managed to reconstruct a hidden complex object between static scattering curtains and compared with the effective reconstruction to fully understand the process before the in-vivo biological implementation.

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

    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

  1. 3D reconstruction in PET cameras with irregular sampling and depth of interaction

    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

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

    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.

  3. Object-shape recognition and 3D reconstruction from tactile sensor images.

    Khasnobish, Anwesha; Singh, Garima; Jati, Arindam; Konar, Amit; Tibarewala, D N

    2014-04-01

    This article presents a novel approach of edged and edgeless object-shape recognition and 3D reconstruction from gradient-based analysis of tactile images. We recognize an object's shape by visualizing a surface topology in our mind while grasping the object in our palm and also taking help from our past experience of exploring similar kind of objects. The proposed hybrid recognition strategy works in similar way in two stages. In the first stage, conventional object-shape recognition using linear support vector machine classifier is performed where regional descriptors features have been extracted from the tactile image. A 3D shape reconstruction is also performed depending upon the edged or edgeless objects classified from the tactile images. In the second stage, the hybrid recognition scheme utilizes the feature set comprising both the previously obtained regional descriptors features and some gradient-related information from the reconstructed object-shape image for the final recognition in corresponding four classes of objects viz. planar, one-edged object, two-edged object and cylindrical objects. The hybrid strategy achieves 97.62 % classification accuracy, while the conventional recognition scheme reaches only to 92.60 %. Moreover, the proposed algorithm has been proved to be less noise prone and more statistically robust. PMID:24469960

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

    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.

  5. Algebraic Reconstruction Algorithm of Vapor Tomography

    HE Lin

    2015-01-01

    Full Text Available While applying algebraic reconstruction algorithm in vapor tomography, problems have to be solved with respect to constructing the constraint condition, selecting the initial value, calculating optimal relaxation factor and deciding the iteration termination condition. Golden section search method and NCP termination rule are given to solve the latter two problems, respectively. Eight algebraic reconstruction algorithms, including Kaczmarz, Randkaczmarz, Symkaczmarz, SART, Landweber, Cimmino, CAV and DROP algorithm, are comparatively analyzed and tested by the data from SatRef station in Hong Kong. The results show that all the eight algorithms can satisfy the requirements of vapor tomography and the iteration termination condition is more important than the relaxation condition. While the golden section method and NCP method are used, the CAV algorithm performs best, and then the Cimmino algorithm.

  6. 3D reconstruction in laparoscopy with close-range photometric stereo.

    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

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

    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.

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

    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.

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

    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.

  10. 3D tracking the Brownian motion of colloidal particles using digital holographic microscopy and joint reconstruction

    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.

  11. Reconstruction of 3D Scenes by Camera Self-Calibration and Using Genetic Algorithms

    El Akkad, Nabil; El Hazzat, Soulaiman; Saaidi, Abderrahim; Satori, Khalid

    2016-03-01

    In this paper, we address a problem of reconstruction of three-dimensional scenes from images taken by cameras, with varying parameters, from different views. This method is based on the projection of 3D points in the image planes. The relationships between the matches and the camera parameters are used to formulate a nonlinear equation system. This system is transformed into an objective function, which is minimized by a genetic algorithm to estimate the intrinsic and extrinsic camera parameters. Finally, the coordinates of 3D points of the scene are obtained by solving a linear equation system. The experiments on synthetic and real data show the quality of this work and the good obtained results.

  12. Fully 3D PET image reconstruction using a fourier preconditioned conjugate-gradient algorithm

    Since the data sizes in fully 3D PET imaging are very large, iterative image reconstruction algorithms must converge in very few iterations to be useful. One can improve the convergence rate of the conjugate-gradient (CG) algorithm by incorporating preconditioning operators that approximate the inverse of the Hessian of the objective function. If the 3D cylindrical PET geometry were not truncated at the ends, then the Hessian of the penalized least-squares objective function would be approximately shift-invariant, i.e. G'G would be nearly block-circulant, where G is the system matrix. We propose a Fourier preconditioner based on this shift-invariant approximation to the Hessian. Results show that this preconditioner significantly accelerates the convergence of the CG algorithm with only a small increase in computation

  13. 3D reconstruction of hollow parts analyzing images acquired by a fiberscope

    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)

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

    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. PMID:26306866

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

    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.

  16. Geometric reconstruction methods for electron tomography

    Alpers, Andreas, E-mail: alpers@ma.tum.de [Zentrum Mathematik, Technische Universität München, D-85747 Garching bei München (Germany); Gardner, Richard J., E-mail: Richard.Gardner@wwu.edu [Department of Mathematics, Western Washington University, Bellingham, WA 98225-9063 (United States); König, Stefan, E-mail: koenig@ma.tum.de [Zentrum Mathematik, Technische Universität München, D-85747 Garching bei München (Germany); Pennington, Robert S., E-mail: robert.pennington@uni-ulm.de [Center for Electron Nanoscopy, Technical University of Denmark, DK-2800 Kongens Lyngby (Denmark); Boothroyd, Chris B., E-mail: ChrisBoothroyd@cantab.net [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Houben, Lothar, E-mail: l.houben@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Dunin-Borkowski, Rafal E., E-mail: rdb@fz-juelich.de [Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons and Peter Grünberg Institute, Forschungszentrum Jülich, D-52425 Jülich (Germany); Joost Batenburg, Kees, E-mail: Joost.Batenburg@cwi.nl [Centrum Wiskunde and Informatica, NL-1098XG, Amsterdam, The Netherlands and Vision Lab, Department of Physics, University of Antwerp, B-2610 Wilrijk (Belgium)

    2013-05-15

    Electron tomography is becoming an increasingly important tool in materials science for studying the three-dimensional morphologies and chemical compositions of nanostructures. The image quality obtained by many current algorithms is seriously affected by the problems of missing wedge artefacts and non-linear projection intensities due to diffraction effects. The former refers to the fact that data cannot be acquired over the full 180° tilt range; the latter implies that for some orientations, crystalline structures can show strong contrast changes. To overcome these problems we introduce and discuss several algorithms from the mathematical fields of geometric and discrete tomography. The algorithms incorporate geometric prior knowledge (mainly convexity and homogeneity), which also in principle considerably reduces the number of tilt angles required. Results are discussed for the reconstruction of an InAs nanowire. - Highlights: ► Four algorithms for electron tomography are introduced that utilize prior knowledge. ► Objects are assumed to be homogeneous; convexity and regularity is also discussed. ► We are able to reconstruct slices of a nanowire from as few as four projections. ► Algorithms should be selected based on the specific reconstruction task at hand.

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

    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...

  18. Portable and accurate 3D scanner for breast implant design and reconstructive plastic surgery

    Rigotti, Camilla; Borghese, Nunzio A.; Ferrari, Stefano; Baroni, Guido; Ferrigno, Giancarlo

    1998-06-01

    In order to evaluate the proper breast implant, the surgeon relies on a standard set of measurements manually taken on the subject. This approach does not allow to obtain an accurate reconstruction of the breast shape and asymmetries can easily arise after surgery. The purpose of this work is to present a method which can help the surgeon in the choice of the shape and dimensions of a prosthesis allowing for a perfect symmetry between the prosthesis and the controlateral breast and can be used as a 3D visual feedback in plastic surgery.

  19. Compensation and evaluation of errors of 3D reconstructions from confocal microscopic images

    Čapek, Martin; Brůža, Petr; Kocandová, L.; Janáček, Jiří; Kubínová, Lucie; Vagnerová, R.

    Vol. 1. Berlin : Springer, 2008 - (Luysberg, M.; Tillman, K.; Weirich, T.), s. 781-782 ISBN 978-3-540-85154-7. [European Microscopy Congress EMC 2008 /14./. Aachen (DE), 01.09.2008-05.09.2008] R&D Projects: GA MŠk(CZ) LC06063; GA AV ČR(CZ) IAA100110502; GA AV ČR(CZ) IAA500200510; GA ČR(CZ) GA102/08/0691 Institutional research plan: CEZ:AV0Z50110509 Keywords : 3D reconstruction * confocal microscopy * error Subject RIV: JD - Computer Applications, Robotics

  20. 3D CAD model reconstruction of a human femur from MRI images

    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.

  1. Development of a system for 3D reconstruction of objects using passive computer vision methods

    Gec, Sandi

    2015-01-01

    The main goal of the master thesis is to develop a system for reconstruction of 3D objects from colour images. The main focus is on passive computer vision methods from which we select two, i.e., Stereo vision and Space carving. Both methods require information about camera poses. The camera pose for a given image is estimated from the information obtained by detecting a reference object, i.e., a standard A4 paper sheet. We develop an Android based mobile application to guide a user during im...

  2. Numerical modeling of 3-D Position Reconstruction from 3-Axial Planar Spiral Coil Sensor Sensitivity

    Sanjaya, Edi; Viridi, Sparisoma

    2011-01-01

    A sensitivity profile of a planar spiral coil sensor (PSCS) is proposed and use to generate the relation of 3-D position of object observed using three (PSCS)-s, one in each x, y, and z axis to the sensors response. A numerical procedure using self consistent field-like method to reconstruct the real position of observed object from sensor sensitivity is presented and the results are discussed. Unfortunately, the procedure fails to approach the desired results due to the existence of quadratic terms.

  3. Strategies to improve 3D whole-body PET image reconstruction

    An algorithm is described for three-dimensional whole-body (3DWB) image reconstruction in positron emission tomography. For whole-body applications, improvements to the popular fixed-axial-acceptance-angle technique are achieved by combining axially adjacent projection data available with a long-axis data set. Time-consuming reprojection of unmeasured oblique lines of response is reduced or eliminated by axial overlap of bed positions, while pixel variance and reconstructed axial resolution are made more uniform by the overlap. Improvements in noise and resolution uniformity are accompanied by gains in reconstruction efficiency, and may be optimized against increased acquisition time due to overlapping acquisition segments and reduced axial coverage. An 11-detector-ring overlap improves axial uniformity in coronal images of a long, uniform cylinder from 23% to 8% with uniform axial resolution. Associated with a 37% improvement in reconstruction time is a 34% reduction in axial coverage for four bed positions. A smaller degree of overlap is found to provide the best trade-off between image uniformity, total scan duration, and reconstruction time because of a proportionally greater reduction in reprojected lines of response. Using a sample optimization scheme, we find a three-ring overlap is best for a 60 cm axial field of view and a five-ring overlap for an 80 cm axial field of view. (author)

  4. Multiple Baseline SAR Tomography's Performance Analysis in Forest 3-D Structure Mapping with long term ALOS L band repeat pass InSAR data

    Lin, Q.; Zebker, H. A.

    2013-12-01

    Acquiring accurate measurement of three-dimensional structure of forest globally , is key to improve quantitative understanding of the state and dynamics of ecosystems, particularly global carbon cycle. Moreover, forest contains a large portion of Earth's renewable natural resources. All these require an accurate, timely and cost-effective global forest vertical structure mapping. Synthetic Aperture Radar Interferometry (InSAR) remote sensing is widely acknowledged as a powerful tool to accomplish this task. Within the last decade, a number of experimental demonstrations of 3-D InSAR techniques have suggested the possibility of remotely sensing global 3-D vegetation structure. Among all the 3-D InSAR techniques, Multiple Baseline SAR Tomography( MB Tomo-SAR) is a very promising one. Multiple baseline SAR tomography exploits InSAR images acquired from different baselines and form a synthetic aperture in the vertical direction in order to retrieval vertical structure. Though theoretical predictions and several laboratory experiments show great reconstruction results, applying the method in real world condition still face a lot of challenges, including low acquisition number, irregular sample distribution, atmospheric phase noise and time decorrelation effect. In this article, we use L band ALOS spaceborne SAR data in Hawaii area to test the performance of MB TomoSAR . In the process, advanced Fourier beamforming method, atmospheric phase screen removal algorithm and time decorrelation effect are all applied. In addition, we also utilize the Landsat vegetation index and the result with other 3-D reconstruction methods as comparison to validate its performance.

  5. Pragmatic reconstruction methods in atom probe tomography

    Data collected in atom probe tomography have to be carefully analysed in order to give reliable composition data accurately and precisely positioned in the probed volume. Indeed, the large analysed surfaces of recent instruments require reconstruction methods taking into account not only the tip geometry but also accurate knowledge of geometrical projection parameters. This is particularly crucial in the analysis of multilayers materials or planar interfaces. The current work presents a simulation model that enables extraction of the two main projection features as a function of the tip and atom probe instrumentation geometries. Conversely to standard assumptions, the image compression factor and the field factor vary significantly during the analysis. An improved reconstruction method taking into account the intrinsic shape of a sample containing planar features is proposed to overcome this shortcoming. -- Highlights: → Tomographic reconstructions in atom probe tomography. → Model of field evaporation in a 2D non-regular geometry with cylindrical symmetry. → Calculation of the field factor and of the image compression factor. → New algorithm of reconstruction for specimen composed of flat layer structures.

  6. Comparative evaluation of scatter correction techniques in 3D positron emission tomography

    Zaidi, H

    2000-01-01

    Much research and development has been concentrated on the scatter compensation required for quantitative 3D PET. Increasingly sophisticated scatter correction procedures are under investigation, particularly those based on accurate scatter models, and iterative reconstruction-based scatter compensation approaches. The main difference among the correction methods is the way in which the scatter component in the selected energy window is estimated. Monte Carlo methods give further insight and might in themselves offer a possible correction procedure. Methods: Five scatter correction methods are compared in this paper where applicable. The dual-energy window (DEW) technique, the convolution-subtraction (CVS) method, two variants of the Monte Carlo-based scatter correction technique (MCBSC1 and MCBSC2) and our newly developed statistical reconstruction-based scatter correction (SRBSC) method. These scatter correction techniques are evaluated using Monte Carlo simulation studies, experimental phantom measurements...

  7. Bone histomorphometric quantification by X-ray phase contrast and transmission 3D SR microcomputed tomography

    Full text: Conventional histomorphometry is an important method for quantitative evaluation of bone microstructure. X-ray computed tomography is a noninvasive technique, which can be used to evaluate histomorphometric indices. In this technique, the output 3D images are used to quantify the whole sample, differently from the conventional one, in which the quantification is performed in 2D slices and extrapolated for 3D case. Looking for better resolutions and visualization of soft tissues, X-ray phase contrast imaging technique was developed. The objective of this work was to perform histomorphometric quantification of human cancellous bone using 3D synchrotron X ray computed microtomography, using two distinct techniques: transmission and phase contrast, in order to compare the results and evaluate the viability of applying the same methodology of quantification for both technique. All experiments were performed at the ELETTRA Synchrotron Light Laboratory in Trieste (Italy). MicroCT data sets were collected using the CT set-up on the SYRMEP (Synchrotron Radiation for Medical Physics) beamline. Results showed that there is a better correlation between histomorphometric parameters of both techniques when morphological filters had been used. However, using these filters, some important information given by phase contrast are lost and they shall be explored by new techniques of quantification

  8. Regularization Designs for Uniform Spatial Resolution and Noise Properties in Statistical Image Reconstruction for 3D X-ray CT

    Cho, Jang Hwan; Fessler, Jeffrey A.

    2014-01-01

    Statistical image reconstruction methods for X-ray computed tomography (CT) provide improved spatial resolution and noise properties over conventional filtered back-projection (FBP) reconstruction, along with other potential advantages such as reduced patient dose and artifacts. Conventional regularized image reconstruction leads to spatially variant spatial resolution and noise characteristics because of interactions between the system models and the regularization. Previous regularization d...

  9. 3-D analysis of dictyosomes and multivesicular bodies in the green alga Micrasterias denticulata by FIB/SEM tomography.

    Wanner, Gerhard; Schäfer, Tillman; Lütz-Meindl, Ursula

    2013-11-01

    In the present study we employ FIB/SEM tomography for analyzing 3-D architecture of dictyosomes and formation of multivesicular bodies (MVB) in high pressure frozen and cryo-substituted interphase cells of the green algal model system Micrasterias denticulata. The ability of FIB/SEM of milling very thin 'slices' (5-10 nm), viewing the block face and of capturing cytoplasmic volumes of several hundred μm(3) provides new insight into the close spatial connection of the ER-Golgi machinery in an algal cell particularly in z-direction, complementary to informations obtained by TEM serial sectioning or electron tomography. Our FIB/SEM series and 3-D reconstructions show that interphase dictyosomes of Micrasterias are not only closely associated to an ER system at their cis-side which is common in various plant cells, but are surrounded by a huge "trans-ER" sheath leading to an almost complete enwrapping of dictyosomes by the ER. This is particularly interesting as the presence of a trans-dictyosomal ER system is well known from mammalian secretory cells but not from cells of higher plants to which the alga Micrasterias is closely related. In contrast to findings in plant storage tissue indicating that MVBs originate from the trans-Golgi network or its derivatives our investigations show that MVBs in Micrasterias are in direct spatial contact with both, trans-Golgi cisternae and the trans-ER sheath which provides evidence that both endomembrane compartments are involved in their formation. PMID:24135121

  10. 3D reconstruction of the optic nerve head using stereo fundus images for computer-aided diagnosis of glaucoma

    Tang, Li; Kwon, Young H.; Alward, Wallace L. M.; Greenlee, Emily C.; Lee, Kyungmoo; Garvin, Mona K.; Abràmoff, Michael D.

    2010-03-01

    The shape of the optic nerve head (ONH) is reconstructed automatically using stereo fundus color images by a robust stereo matching algorithm, which is needed for a quantitative estimate of the amount of nerve fiber loss for patients with glaucoma. Compared to natural scene stereo, fundus images are noisy because of the limits on illumination conditions and imperfections of the optics of the eye, posing challenges to conventional stereo matching approaches. In this paper, multi scale pixel feature vectors which are robust to noise are formulated using a combination of both pixel intensity and gradient features in scale space. Feature vectors associated with potential correspondences are compared with a disparity based matching score. The deep structures of the optic disc are reconstructed with a stack of disparity estimates in scale space. Optical coherence tomography (OCT) data was collected at the same time, and depth information from 3D segmentation was registered with the stereo fundus images to provide the ground truth for performance evaluation. In experiments, the proposed algorithm produces estimates for the shape of the ONH that are close to the OCT based shape, and it shows great potential to help computer-aided diagnosis of glaucoma and other related retinal diseases.

  11. Accelerating Image Reconstruction in Three-Dimensional Optoacoustic Tomography on Graphics Processing Units

    Wang, Kun; Kao, Yu-Jiun; Chou, Cheng-Ying; Oraevsky, Alexander A; Anastasio, Mark A; 10.1118/1.4774361

    2013-01-01

    Purpose: Optoacoustic tomography (OAT) is inherently a three-dimensional (3D) inverse problem. However, most studies of OAT image reconstruction still employ two-dimensional (2D) imaging models. One important reason is because 3D image reconstruction is computationally burdensome. The aim of this work is to accelerate existing image reconstruction algorithms for 3D OAT by use of parallel programming techniques. Methods: Parallelization strategies are proposed to accelerate a filtered backprojection (FBP) algorithm and two different pairs of projection/backprojection operations that correspond to two different numerical imaging models. The algorithms are designed to fully exploit the parallel computing power of graphic processing units (GPUs). In order to evaluate the parallelization strategies for the projection/backprojection pairs, an iterative image reconstruction algorithm is implemented. Computer-simulation and experimental studies are conducted to investigate the computational efficiency and numerical a...

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

    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.

  13. Moving beyond flat earth: dense 3D scene reconstruction from a single FL-LWIR camera

    Stone, K.; Keller, J. M.; Anderson, D. T.

    2013-06-01

    In previous work an automatic detection system for locating buried explosive hazards in forward-looking longwave infrared (FL-LWIR) and forward-looking ground penetrating radar (FL-GPR) data was presented. This system consists of an ensemble of trainable size-contrast filters prescreener coupled with a secondary classification step which extracts cell-structured image space features, such as local binary patterns (LBP), histogram of oriented gradients (HOG), and edge histogram descriptors (EHD), from multiple looks and classifies the resulting feature vectors using a support vector machine. Previously, this system performed image space to UTM coordinate mapping under a flat earth assumption. This limited its applicability to flat terrain and short standoff distances. This paper demonstrates a technique for dense 3D scene reconstruction from a single vehicle mounted FL-LWIR camera. This technique utilizes multiple views and standard stereo vision algorithms such as polar rectification and optimal correction. Results for the detection algorithm using this 3D scene reconstruction approach on data from recent collections at an arid US Army test site are presented. These results are compared to those obtained under the flat earth assumption, with special focus on rougher terrain and longer standoff distance than in previous experiments. The most recent collection also allowed comparison between uncooled and cooled FL-LWIR cameras for buried explosive hazard detection.

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

    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

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

    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)

  16. Monitoring 3D dose distributions in proton therapy by reconstruction using an iterative method.

    Kim, Young-Hak; Yoon, Changyeon; Lee, Wonho

    2016-08-01

    The Bragg peak of protons can be determined by measuring prompt γ-rays. In this study, prompt γ-rays detected by single-photon emission computed tomography with a geometrically optimized collimation system were reconstructed by an iterative method. The falloff position by iterative method (52.48mm) was most similar to the Bragg peak (52mm) of an 80MeV proton compared with those of back-projection (54.11mm) and filtered back-projection (54.91mm) methods. Iterative method also showed better image performance than other methods. PMID:27179145

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

    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.

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

    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.

  19. 3-D-CT reconstructions in fractures of the skull base and facial skeleton

    3-D reconstructions of the skull base, temporal bone, and skull fractures were compared to 2-D CT to evaluate the diagnostic value in traumatized patients. 38 patients with 22 fractures of the facial skeleton (orbita, zygomatic, Le Fort), 12 temporal bone, and 4 skull fractures were investigated. Subjective grading was perfomed by two physicians (ENT/RAD) in respect of quality diagnostic validity and estimated clinical impact. The average image validity and quality were graded good. In the temporal bone the average information supplied by 3-D was of inferior value; here, the lack of information regarding the inner ear structures was responsible for the lack of clinical impact. In fractures of the facial skeleton and the skull base of good to very good image quality was seen and clinical relevance was high. 3-D CT is capable of demonstrating fractures, which is of little value in the temporal bone, but of high value in the skull base and the facial skeleton, especially if surfaces are involved or fragments are displaced. (orig.)

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

    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.

  1. Spatial decomposition of molecular ions within 3D atom probe reconstructions.

    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

  2. Detecting and visualizing internal 3D oleoresin in agarwood by means of micro-computed tomography

    Detection and analysis of oleoresin is particularly significant since the commercial value of agarwood is related to the quantity of oleoresins that are present. A modern technique of non-destructive may reach the interior region of the wood. Currently, tomographic image data in particular is most commonly visualized in three dimensions using volume rendering. The aim of this paper is to explore the potential of high resolution non-destructive 3D visualization technique, X-ray micro-computed tomography, as imaging tools to visualize micro-structure oleoresin in agarwood. Investigations involving desktop X-ray micro-tomography system on high grade agarwood sample, performed at the Centre of Tomography in Nuclear Malaysia, demonstrate the applicability of the method. Prior to experiments, a reference test was conducted to stimulate the attenuation of oleoresin in agarwood. Based on the experiment results, micro-CT imaging with voxel size 7.0 μm is capable to of detecting oleoresin and pores in agarwood. This imaging technique, although sophisticated can be used for standard development especially in grading of agarwood for commercial activities. (author)

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

    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.

  4. Automatic Model Selection for 3d Reconstruction of Buildings from Satellite Imagary

    Partovi, T.; Arefi, H.; Krauß, T.; Reinartz, P.

    2013-09-01

    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.

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

    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.

  6. A Unified Approach to Diffusion Direction Sensitive Slice Registration and 3-D DTI Reconstruction From Moving Fetal Brain Anatomy

    Fogtmann, Mads; Seshamani, Sharmishtaa; Kroenke, Christopher; Cheng, Xi; Chapman, Teresa; Wilm, Jakob; Rousseau, François; Studholme, Colin

    2013-01-01

    This paper presents an approach to 3-D diffusion tensor image (DTI) reconstruction from multi-slice diffusion weighted (DW) magnetic resonance imaging acquisitions of the moving fetal brain. Motion scatters the slice measurements in the spatial and spherical diffusion domain with respect to the underlying anatomy. Previous image registration techniques have been described to estimate the between slice fetal head motion, allowing the reconstruction of 3-D a diffusion estimate on a regular grid...

  7. A Novel 3D Reconstruction Approach from Uncalibrated Multiple Views Based on Homography

    Shuai Liu

    2014-07-01

    Full Text Available In this paper, we focus on a kind of 3D object shape reconstruction from images and put forward a metric approach to recover the object based on slicing planes by homography transformation and image consistency between multiple images.  This approach done here eliminates the requirement for camera calibration, the estimation of the fundamental matrix, feature matches and pose estimation. We adopt a set of hypothetical planes to intersect the reconstructed object to obtain every slicing plane of the reconstructed object by homography transformation and recover it to 3D adding vanishing points by the constraints of silhouette and the scene. The experiment shows that the approach is much validated, and something useful is obtained. topological changes of 2D curves, we adopt a physically-based 2D level set model to animate the evolution and propagation of the interface. We build a level set equation to model the evolution of the interface. In addition, to handle the large scale virtual environment correctly in our physically-based level set model, an image-based 2D voxelization method is proposed in the paper. In the voxelization method, the virtual environment will be converted to boundary conditions when solving the level set equation. Finally, the water pollutants diffusion phenomenon is simulated on large scale water surface by merging the interface animation results as well as the large scale virtual environment. Animation results about the algae propagation phenomenon in Taihu Lake show that our method is intuitively to be implemented and very convenient to produce visually interesting results.

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

    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

    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. Nucleocapsid-like structures of Ebola virus reconstructed using electron tomography

    Electron tomography (ET) is a new technique for high resolution, three-dimensional (3D) reconstruction of pleiomocphic mac. n)molecular complexes, such as virus components. By employing this technique, we resolved the 3D structure of Ebola virus nucleocapsid-like (NC-like) structures in the cytoplasm of cells expressing NP, VP24, and VP35: the minimum components required to form these NC-like structures. Reconstruction of these tubular NC-like structures of Ebola virus showed them to be composed of left-handed helices spaced at short intervals, which is structurally consistent with other non-segmented negative-strand RNA viruses

  11. 3D road marking reconstruction from street-level calibrated stereo pairs

    Soheilian, Bahman; Paparoditis, Nicolas; Boldo, Didier

    This paper presents an automatic approach to road marking reconstruction using stereo pairs acquired by a mobile mapping system in a dense urban area. Two types of road markings were studied: zebra crossings (crosswalks) and dashed lines. These two types of road markings consist of strips having known shape and size. These geometric specifications are used to constrain the recognition of strips. In both cases (i.e. zebra crossings and dashed lines), the reconstruction method consists of three main steps. The first step extracts edge points from the left and right images of a stereo pair and computes 3D linked edges using a matching process. The second step comprises a filtering process that uses the known geometric specifications of road marking objects. The goal is to preserve linked edges that can plausibly belong to road markings and to filter others out. The final step uses the remaining linked edges to fit a theoretical model to the data. The method developed has been used for processing a large number of images. Road markings are successfully and precisely reconstructed in dense urban areas under real traffic conditions.

  12. 3D VIRTUAL RECONSTRUCTION OF AN URBAN HISTORICAL SPACE: A CONSIDERATION ON THE METHOD

    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.

  13. RECONSTRUCCIÓN DE OBJETO 3D A PARTIR DE IMÁGENES CALIBRADAS 3D OBJECT RECONSTRUCTION WITH CALIBRATED IMAGES

    Natividad Grandón-Pastén

    2007-08-01

    Full Text Available Este trabajo presenta el desarrollo de un sistema de reconstrucción de objeto 3D, a partir de una colección de vistas. El sistema se compone de dos módulos principales. El primero realiza el procesamiento de imagen, cuyo objetivo es determinar el mapa de profundidad en un par de vistas, donde cada par de vistas sucesivas sigue una secuencia de fases: detección de puntos de interés, correspondencia de puntos y reconstrucción de puntos; en el proceso de reconstrucción se determinan los parámetros que describen el movimiento (matriz de rotación R y el vector de traslación T entre las dos vistas. Esta secuencia de pasos se repite para todos los pares de vista sucesivas del conjunto. El segundo módulo tiene como objetivo crear el modelo 3D del objeto, para lo cual debe determinar el mapa total de todos los puntos 3D generados; en cada iteración del módulo anterior, una vez obtenido el mapa de profundidad total, genera la malla 3D, aplicando el método de triangulación de Delaunay [28]. Los resultados obtenidos del proceso de reconstrucción son modelados en un ambiente virtual VRML para obtener una visualización más realista del objeto.The system is composed of two main modules. The first one, carries out the image prosecution, whose objective is to determine the depth map of a pair of views where each pair of successive views continues a sequence of phases: interest points detection, points correspondence and points reconstruction; in the reconstruction process, is determined the parameters that describe the movement (rotation matrix R and the translation vector T between the two views. This an sequence of steps is repeated for all the peers of successive views of the set. The second module has as objective to create the 3D model of the object, for it should determine the total map of all the 3D points generated, by each iteration of the previous module, once obtained the map of total depth generates the 3D netting, applying the

  14. Development of a noncontact 3-D fluorescence tomography system for small animal in vivo imaging

    Zhang, Xiaofeng; Badea, Cristian; Jacob, Mathews; Johnson, G. Allan

    2009-02-01

    Fluorescence imaging is an important tool for tracking molecular-targeting probes in preclinical studies. It offers high sensitivity, but nonetheless low spatial resolution compared to other leading imaging methods such CT and MRI. We demonstrate our methodological development in small animal in vivo whole-body imaging using fluorescence tomography. We have implemented a noncontact fluid-free fluorescence diffuse optical tomography system that uses a raster-scanned continuous-wave diode laser as the light source and an intensified CCD camera as the photodetector. The specimen is positioned on a motorized rotation stage. Laser scanning, data acquisition, and stage rotation are controlled via LabVIEW applications. The forward problem in the heterogeneous medium is based on a normalized Born method, and the sensitivity function is determined using a Monte Carlo method. The inverse problem (image reconstruction) is performed using a regularized iterative algorithm, in which the cost function is defined as a weighted sum of the L-2 norms of the solution image, the residual error, and the image gradient. The relative weights are adjusted by two independent regularization parameters. Our initial tests of this imaging system were performed with an imaging phantom that consists of a translucent plastic cylinder filled with tissue-simulating liquid and two thin-wall glass tubes containing indocyanine green. The reconstruction is compared to the output of a finite element method-based software package NIRFAST and has produced promising results.

  15. The Availability of Radiological Measurement of Femoral Anteversion Angle: Three-Dimensional Computed Tomography Reconstruction

    Byun, Ha Young; Shin, Heesuk; Lee, Eun Shin; Kong, Min Sik; Lee, Seung Hun; Lee, Chang Hee

    2016-01-01

    Objective To assess the intra-rater and inter-rater reliability for measuring femoral anteversion angle (FAA) by a radiographic method using three-dimensional computed tomography reconstruction (3D-CT). Methods The study included 82 children who presented with intoeing gait. 3D-CT data taken between 2006 and 2014 were retrospectively reviewed. FAA was measured by 3D-CT. FAA is defined as the angle between the long axis of the femur neck and condylar axis of the distal femur. FAA measurement w...

  16. The Availability of Radiological Measurement of Tibial Torsion: Three-Dimensional Computed Tomography Reconstruction

    Shin, Sang-yeop; Yoon, Chul Ho; Lee, Eun Shin; Oh, Min-Kyun; Kim, A Ram; Park, Jong Moon; Shin, Jun-Hwa; Shin, Hee Suk

    2011-01-01

    Objective To assess the intra-rater and inter-rater reliability for measuring tibial torsion measurements by a radiographic method using three-dimensional computed tomography reconstruction (3D-CT) and to compare the physical measures to those of 3D-CT. Method The study included 33 children who presented with intoeing gait. Tibial torsion was measured by 3D-CT. Distal reference point was the bimalleolar axis. Proximal reference points were the transtibial axis and posterior condylar axis. Phy...

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

    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

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

    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

  19. Monitoring CO2 migration in a shallow sand aquifer using 3D crosshole electrical resistivity tomography

    Yang, Xianjin; Lassen, Rune Nørbæk; Jensen, Karsten Høgh;

    2015-01-01

    Three-dimensional (3D) crosshole electrical resistivity tomography (ERT) was used to monitor a pilot CO2 injection experiment at Vrøgum, western Denmark. The purpose was to evaluate the effectiveness of the ERT method for detection of small electrical conductivity (EC) changes during the first 2...... days of CO2 injection in a shallow siliciclastic aquifer and to study the early-time behavior of a controlled small gaseous CO2 release. 45 kg of CO2 was injected over a 50-h period at 9.85 m depth. ERT data were collected using horizontal bipole-bipole (HBB) and vertical bipole-bipole (VBB) arrays....... The combined HBB and VBB data sets were inverted using a difference inversion algorithm for cancellation of coherent noises and enhanced resolution of small changes. ERT detected the small bulk EC changes (<10%) from conductive dissolved CO2 and resistive gaseous CO2. The primary factors that control...

  20. 3D imaging using combined neutron-photon fan-beam tomography: A Monte Carlo study.

    Hartman, J; Yazdanpanah, A Pour; Barzilov, A; Regentova, E

    2016-05-01

    The application of combined neutron-photon tomography for 3D imaging is examined using MCNP5 simulations for objects of simple shapes and different materials. Two-dimensional transmission projections were simulated for fan-beam scans using 2.5MeV deuterium-deuterium and 14MeV deuterium-tritium neutron sources, and high-energy X-ray sources, such as 1MeV, 6MeV and 9MeV. Photons enable assessment of electron density and related mass density, neutrons aid in estimating the product of density and material-specific microscopic cross section- the ratio between the two provides the composition, while CT allows shape evaluation. Using a developed imaging technique, objects and their material compositions have been visualized. PMID:26953978

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

    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

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

    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

  3. Pre-clinical Positron Emission Tomography Reconstruction Algorithm Effect on Cu-64 ATSM Lesion Hypoxia

    Bal Sanghera

    2016-02-01

    Full Text Available Objective: Application of distinct positron emission tomography (PET scan reconstruction algorithms can lead to statistically significant differences in measuring lesion functional properties. We looked at the influence of two-dimensional filtered back projection (2D FBP, two-dimensional ordered subset expectation maximization (2D OSEM, three-dimensional ordered subset expectation maximization (3D OSEM without 3D maximum a posteriori and with (3D OSEM MAP on lesion hypoxia tracer uptake using a pre-clinical PET scanner. Methods: Reconstructed images of a rodent tumor model bearing P22 carcinosarcoma injected with hypoxia tracer Copper- 64-Diacetyl-bis (N4-methylthiosemicarbazone (i.e. Cu-64 ATSM were analyzed at 10 minute intervals till 60 minute post injection. Lesion maximum standardized uptake values (SUVmax and SUVmax/background SUVmean (T/B were recorded and investigated after application of multiple algorithm and reconstruction parameters to assess their influence on Cu-64 ATSM measurements and associated trends over time. Results: SUVmax exhibited convergence for OSEM reconstructions while ANOVA results showed a significant difference in SUVmax or T/B between 2D FBP, 2D OSEM, 3D OSEM and 3D OSEM MAP reconstructions across all time frames. SUVmax and T/B were greatest in magnitude for 2D OSEM followed by 3D OSEM MAP, 3D OSEM and then 2D FBP at all time frames respectively. Similarly SUVmax and T/B standard deviations (SD were lowest for 2D OSEM in comparison with other algorithms. Conclusion: Significantly higher magnitude lesion SUVmax and T/B combined with lower SD were observed using 2D OSEM reconstruction in comparison with 2D FBP, 3D OSEM and 3D OSEM MAP algorithms at all time frames. Results are consistent with other published studies however more specimens are required for full validation.

  4. Adaptive techniques in electrical impedance tomography reconstruction

    We present an adaptive algorithm for solving the inverse problem in electrical impedance tomography. To strike a balance between the accuracy of the reconstructed images and the computational efficiency of the forward and inverse solvers, we propose to combine an adaptive mesh refinement technique with the adaptive Kaczmarz method. The iterative algorithm adaptively generates the optimal current patterns and a locally-refined mesh given the conductivity estimate and solves for the unknown conductivity distribution with the block Kaczmarz update step. Simulation and experimental results with numerical analysis demonstrate the accuracy and the efficiency of the proposed algorithm. (paper)

  5. Simultaneous multiplicative column-normalized method (SMART) for 3-D ionosphere tomography in comparison to other algebraic methods

    Gerzen, T.; Minkwitz, D.

    2016-01-01

    The accuracy and availability of satellite-based applications like GNSS positioning and remote sensing crucially depends on the knowledge of the ionospheric electron density distribution. The tomography of the ionosphere is one of the major tools to provide link specific ionospheric corrections as well as to study and monitor physical processes in the ionosphere. In this paper, we introduce a simultaneous multiplicative column-normalized method (SMART) for electron density reconstruction. Further, SMART+ is developed by combining SMART with a successive correction method. In this way, a balancing between the measurements of intersected and not intersected voxels is realised. The methods are compared with the well-known algebraic reconstruction techniques ART and SART. All the four methods are applied to reconstruct the 3-D electron density distribution by ingestion of ground-based GNSS TEC data into the NeQuick model. The comparative case study is implemented over Europe during two periods of the year 2011 covering quiet to disturbed ionospheric conditions. In particular, the performance of the methods is compared in terms of the convergence behaviour and the capability to reproduce sTEC and electron density profiles. For this purpose, independent sTEC data of four IGS stations and electron density profiles of four ionosonde stations are taken as reference. The results indicate that SMART significantly reduces the number of iterations necessary to achieve a predefined accuracy level. Further, SMART+ decreases the median of the absolute sTEC error up to 15, 22, 46 and 67 % compared to SMART, SART, ART and NeQuick respectively.

  6. X-ray tomography: Biological cells in 3-D at better than 50 nm resolution

    Full text: X-ray microscopy can be used to image whole, hydrated, specimens with a spatial resolution 5-10 times better than that obtained using visible light microscopy. X-ray imaging at photon energies below the K- absorption edge of oxygen, referred to as the water window, exploits the strong natural contrast for organic material embedded in a mostly water matrix. With a transmission X-ray microscope using Fresnel zone plate optics, specimens up to 10 microns thick can be examined. The highest X-ray transmission in hydrated samples is obtained at a wavelength of 2.4 nm but, due to the low numerical aperture of zone plate lenses operated in st order diffraction mode the structures resolved are much larger than the X-ray wavelength. Because of the low NA of X-ray lenses (NA=0.05), combined with the effect of polychromatic illumination and a wavelength dependant focal length, the effective depth of ld is large (6-10 microns). The experiments presented here were performed at the Advanced Light Source using the full ld transmission X-ray microscope, XM-1. This microscope employs a bend magnet X-ray source and zone plate condenser and objective lenses. The condenser zone plate acts as a monochromator and the X-ray images are recorded directly on a cooled, back-thinned 1024x1024 pixel CCD camera. The sample holder was a rotationally symmetric glass tube; the region containing the sample was 10 microns in diameter with a wall thickness of 200 nm. Live yeast cells were loaded into the tube, rapidly frozen by a blast of liquid nitrogen-cooled helium gas, and maintained at 140 deg C by a steady flow of cold helium. The image sequence spanned 180 deg and consisted of 45 images spaced by 4 deg. The images were aligned to a common axis and computed tomographic reconstruction was used to obtain the 3-D X-ray linear absorption coefficient. Volume rendering and animation of reconstructed data was performed using the 3-D program, Amira. Acquisition time for 90 images was 3 min

  7. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    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 screenclose quotes. To confine the scope, this presentation will not discuss such approaches

  8. Post-processing methods of rendering and visualizing 3-D reconstructed tomographic images

    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.

  9. An evaluation of three-dimensional surface-reconstruction CT (3D-CT) in children with craniosynostosis

    In this study, 3D-CT images were reconstructed from axial computed tomographic scans using the new software on 10 children with craniosynostosis. The authors discuss the advantages of the 3D-CT imaging technique in the diagnosis and surgical planning for craniosynostosis. The following conclusions may be drawn: 1) The images obtained from the new 3D-CT software are more accurate and realistic than the images previously reported by Vannier and Marsh. Reconstruction artifacts, known as pseudoforamina, have not appeared in the 3D-CT images reconstructed by the new software, and the top axial view of the 3D-CT reveals precisely anatomical details of the intracranial skull base. 2) The use of this new method provides accurate anatomical data which cannot be obtained by means of conventional radiological techniques in living subjects. 3) This technique of three-dimensional reconstruction from CT scans is most helpful in surgical planning and in the postoperative assessments of surgical results for craniosynostosis. The 3D-CT images allow the surgeon to visualize precisely the abnormalities of the skull to be corrected by the craniofacial surgery. Based on our experience with this study, we would expect that three-dimensional surface reconstruction from CT scans will henceforth be widely used in the planning of craniofacial surgery and in the postoperative follow-up assessment of craniosynostosis or craniofacial anomalies. (J.P.N.)

  10. Adaptive geometric tessellation for 3D reconstruction of anisotropically developing cells in multilayer tissues from sparse volumetric microscopy images.

    Anirban Chakraborty

    Full Text Available The need for quantification of cell growth patterns in a multilayer, multi-cellular tissue necessitates the development of a 3D reconstruction technique that can estimate 3D shapes and sizes of individual cells from Confocal Microscopy (CLSM image slices. However, the current methods of 3D reconstruction using CLSM imaging require large number of image slices per cell. But, in case of Live Cell Imaging of an actively developing tissue, large depth resolution is not feasible in order to avoid damage to cells from prolonged exposure to laser radiation. In the present work, we have proposed an anisotropic Voronoi tessellation based 3D reconstruction framework for a tightly packed multilayer tissue with extreme z-sparsity (2-4 slices/cell and wide range of cell shapes and sizes. The proposed method, named as the 'Adaptive Quadratic Voronoi Tessellation' (AQVT, is capable of handling both the sparsity problem and the non-uniformity in cell shapes by estimating the tessellation parameters for each cell from the sparse data-points on its boundaries. We have tested the proposed 3D reconstruction method on time-lapse CLSM image stacks of the Arabidopsis Shoot Apical Meristem (SAM and have shown that the AQVT based reconstruction method can correctly estimate the 3D shapes of a large number of SAM cells.

  11. Operator-free, film-based 3D seed reconstruction in brachytherapy

    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)

  12. Operator-free, film-based 3D seed reconstruction in brachytherapy.

    Todor, D A; Cohen, G N; Amols, H I; Zaider, M

    2002-06-21

    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 (105 125I and 15 103Pd) 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. PMID:12118599

  13. Operator-free, film-based 3D seed reconstruction in brachytherapy

    Todor, D.A.; Cohen, G.N.; Amols, H.I.; Zaider, M. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2002-06-21

    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 (105{sup 125}I and 15{sup 103}Pd) 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)

  14. Optical diffraction tomography: accuracy of an off-axis reconstruction

    Kostencka, Julianna; Kozacki, Tomasz

    2014-05-01

    Optical diffraction tomography is an increasingly popular method that allows for reconstruction of three-dimensional refractive index distribution of semi-transparent samples using multiple measurements of an optical field transmitted through the sample for various illumination directions. The process of assembly of the angular measurements is usually performed with one of two methods: filtered backprojection (FBPJ) or filtered backpropagation (FBPP) tomographic reconstruction algorithm. The former approach, although conceptually very simple, provides an accurate reconstruction for the object regions located close to the plane of focus. However, since FBPJ ignores diffraction, its use for spatially extended structures is arguable. According to the theory of scattering, more precise restoration of a 3D structure shall be achieved with the FBPP algorithm, which unlike the former approach incorporates diffraction. It is believed that with this method one is allowed to obtain a high accuracy reconstruction in a large measurement volume exceeding depth of focus of an imaging system. However, some studies have suggested that a considerable improvement of the FBPP results can be achieved with prior propagation of the transmitted fields back to the centre of the object. This, supposedly, enables reduction of errors due to approximated diffraction formulas used in FBPP. In our view this finding casts doubt on quality of the FBPP reconstruction in the regions far from the rotation axis. The objective of this paper is to investigate limitation of the FBPP algorithm in terms of an off-axis reconstruction and compare its performance with the FBPJ approach. Moreover, in this work we propose some modifications to the FBPP algorithm that allow for more precise restoration of a sample structure in off-axis locations. The research is based on extensive numerical simulations supported with wave-propagation method.

  15. Modeling, measurement, and 3-D equilibrium reconstruction of the bootstrap current in the Helically Symmetric Experiment

    The bootstrap current for three electron cyclotron resonance heated plasma scenarios in a quasihelically symmetric stellarator (the Helically Symmetric Experiment) are analyzed and compared to a neoclassical transport code PENTA. The three conditions correspond to 50 kW input power with a resonance that is off-axis, 50 kW on-axis heating and 100 kW on-axis heating. When the heating location was moved from off-axis to on-axis with 50 kW heating power, the stored energy and the extrapolated steady-state current were both observed to increase. When the on-axis heating power was increased from 50 kW to 100 kW, the stored energy continued to increase while the bootstrap current slightly decreased. This trend is qualitatively in agreement with the calculations which indicate that a large positive electric field for the 100 kW case was driving the current negative in a small region close to the magnetic axis and accounting for the decrease in the total integrated current. This trend in the calculations is only observed to occur when momentum conservation between particle species is included. Without momentum conservation, the calculated bootstrap current increases monotonically. We show that the magnitude of the bootstrap current as calculated by PENTA agrees better with the experiment when momentum conservation between plasma species is included in the calculation. The total current was observed in all cases to flow in a direction to unwind the transform, unlike in a tokamak in which the bootstrap current adds to the transform. The 3-D inductive response of the plasma is simulated to predict the evolution of the current profile during the discharge. The 3-D equilibrium reconstruction code V3FIT is used to reconstruct profiles of the plasma pressure and current constrained by measurements with a set of magnetic diagnostics. The reconstructed profiles are consistent with the measured plasma pressure profile and the simulated current profile when the

  16. Self-adapting denoising, alignment and reconstruction in electron tomography in materials science.

    Printemps, Tony; Mula, Guido; Sette, Daniele; Bleuet, Pierre; Delaye, Vincent; Bernier, Nicolas; Grenier, Adeline; Audoit, Guillaume; Gambacorti, Narciso; Hervé, Lionel

    2016-01-01

    An automatic procedure for electron tomography is presented. This procedure is adapted for specimens that can be fashioned into a needle-shaped sample and has been evaluated on inorganic samples. It consists of self-adapting denoising, automatic and accurate alignment including detection and correction of tilt axis, and 3D reconstruction. We propose the exploitation of a large amount of information of an electron tomography acquisition to achieve robust and automatic mixed Poisson-Gaussian noise parameter estimation and denoising using undecimated wavelet transforms. The alignment is made by mixing three techniques, namely (i) cross-correlations between neighboring projections, (ii) common line algorithm to get a precise shift correction in the direction of the tilt axis and (iii) intermediate reconstructions to precisely determine the tilt axis and shift correction in the direction perpendicular to that axis. Mixing alignment techniques turns out to be very efficient and fast. Significant improvements are highlighted in both simulations and real data reconstructions of porous silicon in high angle annular dark field mode and agglomerated silver nanoparticles in incoherent bright field mode. 3D reconstructions obtained with minimal user-intervention present fewer artefacts and less noise, which permits easier and more reliable segmentation and quantitative analysis. After careful sample preparation and data acquisition, the denoising procedure, alignment and reconstruction can be achieved within an hour for a 3D volume of about a hundred million voxels, which is a step toward a more routine use of electron tomography. PMID:26413937

  17. Data Management Framework of Drone-Based 3d Model Reconstruction of Disaster Site

    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.

  18. 3D Reconstruction Using Interval Methods on The Kinect Device Coupled With an IMU

    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.

  19. 3D reconstruction of the source and scale of buried young flood channels on Mars.

    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 (Marte Vallis is essential to our assessment of recent 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. PMID:23470730

  20. QUALITY ASSESSMENT OF 3D RECONSTRUCTION USING FISHEYE AND PERSPECTIVE SENSORS

    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.

  1. EFFECT OF DIGITAL FRINGE PROJECTION PARAMETERS ON 3D RECONSTRUCTION ACCURACY

    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.

  2. 3D shape reconstruction of medical images using a perspective shape-from-shading method

    A 3D shape reconstruction approach for medical images using a shape-from-shading (SFS) method was proposed in this paper. A new reflectance map equation of medical images was analyzed with the assumption that the Lambertian reflectance surface was irradiated by a point light source located at the light center and the image was formed under perspective projection. The corresponding static Hamilton–Jacobi (H–J) equation of the reflectance map equation was established. So the shape-from-shading problem turned into solving the viscosity solution of the static H–J equation. Then with the conception of a viscosity vanishing approximation, the Lax–Friedrichs fast sweeping numerical method was used to compute the viscosity solution of the H–J equation and a new iterative SFS algorithm was gained. Finally, experiments on both synthetic images and real medical images were performed to illustrate the efficiency of the proposed SFS method

  3. 3D shape reconstruction of medical images using a perspective shape-from-shading method

    Yang, Lei; Han, Jiu-qiang

    2008-06-01

    A 3D shape reconstruction approach for medical images using a shape-from-shading (SFS) method was proposed in this paper. A new reflectance map equation of medical images was analyzed with the assumption that the Lambertian reflectance surface was irradiated by a point light source located at the light center and the image was formed under perspective projection. The corresponding static Hamilton-Jacobi (H-J) equation of the reflectance map equation was established. So the shape-from-shading problem turned into solving the viscosity solution of the static H-J equation. Then with the conception of a viscosity vanishing approximation, the Lax-Friedrichs fast sweeping numerical method was used to compute the viscosity solution of the H-J equation and a new iterative SFS algorithm was gained. Finally, experiments on both synthetic images and real medical images were performed to illustrate the efficiency of the proposed SFS method.

  4. Comparison of radiographs, axial CT, 2D and 3D reconstruction in unstable operated vertebral lesions

    During a period of 16 months about 70 patients suffering from an unstable spinel injury were operated in the surgical department of our clinic. In 50 of these patients it was possible to correlate the results of preoperative radiography and CT with the operative findings. Several cases of distraction instability in the dorsal column had not been recognised in the preoperative evaluation. Therefore the rationale of this study was the question as to whether modern CT technology can help to avoid such wrong diagnoses. For that purpose radiographs, axial CT-scans of 2 mm thickness or less, sagittal and coronal 2D and (in 35 cases) 3D reconstructions were re-evaluated step by step by a specifically trained radiologist without knowing the operative findings. 15 additional lesions out of 28 were demonstrated and specifically classified as distraction instabilities of the dorsal column using the improved CT technology. (orig.)

  5. 3D reconstruction of wooden member of ancient architecture from point clouds

    Zhang, Ruiju; Wang, Yanmin; Li, Deren; Zhao, Jun; Song, Daixue

    2006-10-01

    This paper presents a 3D reconstruction method to model wooden member of ancient architecture from point clouds based on improved deformable model. Three steps are taken to recover the shape of wooden member. Firstly, Hessian matrix is adopted to compute the axe of wooden member. Secondly, an initial model of wooden member is made by contour orthogonal to its axis. Thirdly, an accurate model is got through the coupling effect between the initial model and the point clouds of the wooden member according to the theory of improved deformable model. Every step and algorithm is studied and described in the paper. Using the point clouds captured from Forbidden City of China, shaft member and beam member are taken as examples to test the method proposed in the paper. Results show the efficiency and robustness of the method addressed in the literature to model the wooden member of ancient architecture.

  6. Morphological and electrochemical cycling effects in MnO2 nanostructures by 3D electron tomography

    Chen, Wei

    2014-02-12

    In this study, MnO2 nanostructures with well-controlled morphology and crystal phase are successfully prepared by chemical synthesis, and characterized by three-dimensional electron tomography for use as supercapacitor electrode materials. The growth process of the various MnO 2 nanostructures is revealed in detail, and correlated to their electrochemical performance as supercapacitor materials. The specific capacitance of MnO2 electrodes is found to be strongly correlated with the inner morphology and crystal phase of the MnO2 nanostructures. Furthermore, it is demonstrated that the increased capacity with electrochemical cycling of the materials is due to the formation of defective regions embedded in the MnO2 nanostructures; these regions form during electrochemical cycling of the electrodes, resulting in increased porosity, surface area, and consequently, increased electrochemical capacity. The preparation, characterization and supercapacitor application of MnO 2 nanostructures by 3D electron tomography are studied. The electrochemical performance of MnO2 is correlated to its surface area, determined by the morphological effect, as well as the cycling effect, determined by the formation of defective regions on the nanostructures during electrochemical cycling tests. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. 3D Power Line Reconstruction from Airborne LiDAR Point Cloud of Overhead Electric Power Transmission Corridors

    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...

  8. REGION-BASED 3D SURFACE RECONSTRUCTION USING IMAGES ACQUIRED BY LOW-COST UNMANNED AERIAL SYSTEMS

    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.

  9. Region-Based 3d Surface Reconstruction Using Images Acquired by Low-Cost Unmanned Aerial Systems

    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.

  10. The Avignon Bridge: a 3d Reconstruction Project Integrating Archaeological, Historical and Gemorphological Issues

    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.

  11. 3D Reconstruction of Human Laryngeal Dynamics Based on Endoscopic High-Speed Recordings.

    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

  12. Reconstructing the Vulcano Island evolution from 3D modeling of magnetic signatures

    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.

  13. GPU accelerated generation of digitally reconstructed radiographs for 2-D/3-D image registration.

    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

  14. 3D Reconstruction of the Vortex in a Human Right Ventricle Model using High Speed PIV

    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.

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

    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...

  16. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    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 (μrecon = − 2.7 × 10−3 mm−1, σrecon = 7.0 × 10−3 mm−1) and (μCT = − 2.5 × 10−3 mm−1, σCT = 5.3 × 10−3 mm−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

  17. A continuous surface reconstruction method on point cloud captured from a 3D surface photogrammetry system

    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.

  18. Interface Orientation Distribution during Grain Growth in Bulk SrTiO3 Measured by Means of 3D X-Ray Diffraction Contrast Tomography

    Syha, Melanie; Rheinheimer, Wolfgang; Bäurer, Michael;

    2012-01-01

    interface normal distribution clearly shows a preference for (100) oriented interfaces in the selected grains when annealed at 1600°C. This observation can be connected to existent interfacial energy estimations resulting from capillarity vector reconstructions. © 2012 Materials Research Society.......3D x-ray diffraction contrast tomography (DCT) is a non-destructive technique for the determination of grain shape and crystallography in polycrystalline bulk materials. Using this technique, a strontium titanate specimen was repeatedly measured between annealing steps.. A systematic analysis of...

  19. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    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)

  20. Processing of MRI images weighted in TOF for blood vessels analysis: 3-D reconstruction

    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)