WorldWideScience

Sample records for application image quality

  1. Iris Image Quality Assessment for Biometric Application

    Directory of Open Access Journals (Sweden)

    U. M. Chaskar

    2012-05-01

    Full Text Available Image quality assessment plays an important role in the performance of biometric system involving iris images. Data quality assessment is a key issue in order to broaden the applicability of iris biometrics to unconstrained imaging conditions. In this paper, we have proposed the quality factors of individual iris images by assessing their prominent factors by their scores. The work has been carried out for the following databases: CASIA, UBIRIS, UPOL, MMU and our own created COEP Database using HIS 5000 HUVITZ Iris Camera. The comparison is also done with existing databases which in turn will act as a benchmark in increasing the efficiency of further processing.

  2. MATLAB-based Applications for Image Processing and Image Quality Assessment – Part II: Experimental Results

    Directory of Open Access Journals (Sweden)

    L. Krasula

    2012-04-01

    Full Text Available The paper provides an overview of some possible usage of the software described in the Part I. It contains the real examples of image quality improvement, distortion simulations, objective and subjective quality assessment and other ways of image processing that can be obtained by the individual applications.

  3. Image quality transfer and applications in diffusion MRI

    DEFF Research Database (Denmark)

    Alexander, Daniel C; Zikic, Darko; Ghosh, Aurobrata

    2017-01-01

    requires specialised data to reconstruct. In microstructure imaging, IQT shows potential in estimating, from standard "single-shell" data (one non-zero b-value), maps of microstructural parameters that normally require specialised multi-shell data. Further experiments show strong generalisability...

  4. Factors Affecting Image Quality in Near-field Ultra-wideband Radar Imaging for Biomedical Applications

    Science.gov (United States)

    Curtis, Charlotte

    Near-field ultra-wideband radar imaging has potential as a new breast imaging modality. While a number of reconstruction algorithms have been published with the goal of reducing undesired responses or clutter, an in-depth analysis of the dominant sources of clutter has not been conducted. In this thesis, time domain radar image reconstruction is demonstrated to be equivalent to frequency domain synthetic aperture radar. This reveals several assumptions inherent to the reconstruction algorithm related to radial spreading, point source antennas, and the independent summation of point scatterers. Each of these assumptions is examined in turn to determine which has the greatest impact on the resulting image quality and interpretation. In addition, issues related to heterogeneous and dispersive media are addressed. Variations in imaging parameters are tested by observing their influence on the system point spread function. Results are then confirmed by testing on simple and detailed simulation models, followed by data acquired from human volunteers. Recommended parameters are combined into a new imaging operator that is demonstrated to generate results comparable to a more accurate signal model, but with a 50 fold improvement in computational efficiency. Finally, the most significant factor affecting image quality is determined to be the estimate of tissue properties used to form the image.

  5. A review of image quality assessment methods with application to computational photography

    Science.gov (United States)

    Maître, Henri

    2015-12-01

    Image quality assessment has been of major importance for several domains of the industry of image as for instance restoration or communication and coding. New application fields are opening today with the increase of embedded power in the camera and the emergence of computational photography: automatic tuning, image selection, image fusion, image data-base building, etc. We review the literature of image quality evaluation. We pay attention to the very different underlying hypotheses and results of the existing methods to approach the problem. We explain why they differ and for which applications they may be beneficial. We also underline their limits, especially for a possible use in the novel domain of computational photography. Being developed to address different objectives, they propose answers on different aspects, which make them sometimes complementary. However, they all remain limited in their capability to challenge the human expert, the said or unsaid ultimate goal. We consider the methods which are based on retrieving the parameters of a signal, mostly in spectral analysis; then we explore the more global methods to qualify the image quality in terms of noticeable defects or degradation as popular in the compression domain; in a third field the image acquisition process is considered as a channel between the source and the receiver, allowing to use the tools of the information theory and to qualify the system in terms of entropy and information capacity. However, these different approaches hardly attack the most difficult part of the task which is to measure the quality of the photography in terms of aesthetic properties. To help in addressing this problem, in between Philosophy, Biology and Psychology, we propose a brief review of the literature which addresses the problematic of qualifying Beauty, present the attempts to adapt these concepts to visual patterns and initiate a reflection on what could be done in the field of photography.

  6. Applications of hyperspectral imaging in chicken meat safety and quality detection and evaluation: a review.

    Science.gov (United States)

    Xiong, Zhenjie; Xie, Anguo; Sun, Da-Wen; Zeng, Xin-An; Liu, Dan

    2015-01-01

    Currently, the issue of food safety and quality is a great public concern. In order to satisfy the demands of consumers and obtain superior food qualities, non-destructive and fast methods are required for quality evaluation. As one of these methods, hyperspectral imaging (HSI) technique has emerged as a smart and promising analytical tool for quality evaluation purposes and has attracted much interest in non-destructive analysis of different food products. With the main advantage of combining both spectroscopy technique and imaging technique, HSI technique shows a convinced attitude to detect and evaluate chicken meat quality objectively. Moreover, developing a quality evaluation system based on HSI technology would bring economic benefits to the chicken meat industry. Therefore, in recent years, many studies have been conducted on using HSI technology for the safety and quality detection and evaluation of chicken meat. The aim of this review is thus to give a detailed overview about HSI and focus on the recently developed methods exerted in HSI technology developed for microbiological spoilage detection and quality classification of chicken meat. Moreover, the usefulness of HSI technique for detecting fecal contamination and bone fragments of chicken carcasses are presented. Finally, some viewpoints on its future research and applicability in the modern poultry industry are proposed.

  7. Improving imaging quality using least-squares reverse time migration: application to data from Bohai basin

    KAUST Repository

    Zhang, Hao

    2017-07-07

    Least-squares reverse time migration (LSRTM) is a seismic imaging technique based on linear inversion, which usually aims to improve the quality of seismic image through removing the acquisition footprint, suppressing migration artifacts, and enhancing resolution. LSRTM has been shown to produce migration images with better quality than those computed by conventional migration. In this paper, our derivation of LSRTM approximates the near-incident reflection coefficient with the normal-incident reflection coefficient, which shows that the reflectivity term defined is related to the normal-incident reflection coefficient and the background velocity. With reflected data, LSRTM is mainly sensitive to impedance perturbations. According to an approximate relationship between them, we reformulate the perturbation related system into a reflection-coefficient related one. Then, we seek the inverted image through linearized iteration. In the proposed algorithm, we only need the migration velocity for LSRTM considering that the density changes gently when compared with migration velocity. To validate our algorithms, we first apply it to a synthetic case and then a field data set. Both applications illustrate that our imaging results are of good quality.

  8. Line-Scan Hyperspectral Imaging Techniques for Food Safety and Quality Applications

    Directory of Open Access Journals (Sweden)

    Jianwei Qin

    2017-01-01

    Full Text Available Hyperspectral imaging technologies in the food and agricultural area have been evolving rapidly over the past 15 years owing to tremendous interest from both academic and industrial fields. Line-scan hyperspectral imaging is a major method that has been intensively researched and developed using different physical principles (e.g., reflectance, transmittance, fluorescence, Raman, and spatially resolved spectroscopy and wavelength regions (e.g., visible (VIS, near infrared (NIR, and short-wavelength infrared (SWIR. Line-scan hyperspectral imaging systems are mainly developed and used for surface inspection of food and agricultural products using area or line light sources. Some of these systems can also be configured to conduct spatially resolved spectroscopy measurements for internal or subsurface food inspection using point light sources. This paper reviews line-scan hyperspectral imaging techniques, with introduction, demonstration, and summarization of existing and emerging techniques for food and agricultural applications. The main topics include related spectroscopy techniques, line-scan measurement methods, hardware components and systems, system calibration methods, and spectral and image analysis techniques. Applications in food safety and quality are also presented to reveal current practices and future trends of line-scan hyperspectral imaging techniques.

  9. Image Quality Assessment for Fake Biometric Detection: Application to Iris, Fingerprint, and Face Recognition.

    Science.gov (United States)

    Galbally, Javier; Marcel, Sébastien; Fierrez, Julian

    2014-02-01

    To ensure the actual presence of a real legitimate trait in contrast to a fake self-manufactured synthetic or reconstructed sample is a significant problem in biometric authentication, which requires the development of new and efficient protection measures. In this paper, we present a novel software-based fake detection method that can be used in multiple biometric systems to detect different types of fraudulent access attempts. The objective of the proposed system is to enhance the security of biometric recognition frameworks, by adding liveness assessment in a fast, user-friendly, and non-intrusive manner, through the use of image quality assessment. The proposed approach presents a very low degree of complexity, which makes it suitable for real-time applications, using 25 general image quality features extracted from one image (i.e., the same acquired for authentication purposes) to distinguish between legitimate and impostor samples. The experimental results, obtained on publicly available data sets of fingerprint, iris, and 2D face, show that the proposed method is highly competitive compared with other state-of-the-art approaches and that the analysis of the general image quality of real biometric samples reveals highly valuable information that may be very efficiently used to discriminate them from fake traits.

  10. Review of the applications of Multiangle Imaging SpectroRadiometer to air quality research

    Institute of Scientific and Technical Information of China (English)

    LIU Yang; CHEN Dan; Ralph A. KAHN; HE KeBin

    2009-01-01

    The Multiangle Imaging SpectroRadiometer (MISR) launched by NASA in late 1999 has a unique mul tiangle design, which points nine cameras at fixed angles along the satellite flight track and collects reflected solar radiation simultaneously. This design allows the retrieval of a rich dataset of particle abundance, shape and composition over both land and ocean. Some of its capabilities have not been seen by any currently operating satellite aerosol sensors. Since MISR is sensitive to fine particles, it provides a new data source to study the spatial and temporal characteristics of air quality over large geographical regions. We first briefly introduce the MISR instrument, the retrieval and structure of MISR aerosol data, and then review the applications of MISR aerosol data in various aspects of air quality research since its launch. These include the spatial distributions of particle pollution events such as dust storms, wild fires, and urban pollution. Because of the high quality of MISR aerosol data,they can be used as quantitative indicators of particle pollution levels. We review the current modeling studies of surface level particle concentrations. Next, we introduce research results using MISR's ad vanced data such as the plume heights, and particle microphysical properties. In the discussion, we compare MISR research with current MODIS research to the best of our ability as MODIS data have been more extensively explored by the Chinese scientific community. Finally, we summarize the ad vantages and disadvantages of MISR data related to its applications to the air quality research. Given the highly quantitative measurements and comprehensive aerosol information MISR can provide, we believe that it will provide great values to advance our understanding of the particle air pollution in China.

  11. Review of the applications of Multiangle Imaging SpectroRadiometer to air quality research

    Institute of Scientific and Technical Information of China (English)

    Ralph; A.KAHN

    2009-01-01

    The Multiangle Imaging SpectroRadiometer(MISR) launched by NASA in late 1999 has a unique mul-tiangle design,which points nine cameras at fixed angles along the satellite flight track and collects reflected solar radiation simultaneously.This design allows the retrieval of a rich dataset of particle abundance,shape and composition over both land and ocean.Some of its capabilities have not been seen by any currently operating satellite aerosol sensors.Since MISR is sensitive to fine particles,it provides a new data source to study the spatial and temporal characteristics of air quality over large geographical regions.We first briefly introduce the MISR instrument,the retrieval and structure of MISR aerosol data,and then review the applications of MISR aerosol data in various aspects of air quality research since its launch.These include the spatial distributions of particle pollution events such as dust storms,wild fires,and urban pollution.Because of the high quality of MISR aerosol data,they can be used as quantitative indicators of particle pollution levels.We review the current modeling studies of surface level particle concentrations.Next,we introduce research results using MISR’s advanced data such as the plume heights,and particle microphysical properties.In the discussion,we compare MISR research with current MODIS research to the best of our ability as MODIS data have been more extensively explored by the Chinese scientific community.Finally,we summarize the advantages and disadvantages of MISR data related to its applications to the air quality research.Given the highly quantitative measurements and comprehensive aerosol information MISR can provide,we believe that it will provide great values to advance our understanding of the particle air pollution in China.

  12. Application of image quality metamerism to investigate gold color area in cultural property

    Science.gov (United States)

    Miyata, Kimiyoshi; Tsumura, Norimichi

    2013-01-01

    A concept of image quality metamerism as an expansion of conventional metamerism defined in color science is introduced, and it is applied to segment similar color areas in a cultural property. The image quality metamerism can unify different image quality attributes based on an index showing the degree of image quality metamerism proposed. As a basic research step, the index is consisted of color and texture information and examined to investigate a cultural property. The property investigated is a pair of folding screen paintings that depict the thriving city of Kyoto designated as a nationally important cultural property in Japan. Gold-colored areas painted by using high granularity colorants compared with other color areas are evaluated based on the image quality metamerism index locally, then the index is visualized as a map showing the possibility of the image quality metamer to the reference pixel set in the same image. This visualization means a segmentation of areas where color is similar but texture is different. The experimental result showed that the proposed method was effective to show areas of gold color areas in the property.

  13. High-Quality T2-Weighted 4-Dimensional Magnetic Resonance Imaging for Radiation Therapy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dongsu [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Caruthers, Shelton D. [Philips Healthcare, Cleveland, Ohio (United States); Glide-Hurst, Carri [Department of Radiation Oncology, Henry Ford Health System, Detroit, Michigan (United States); Low, Daniel A. [Department of Radiation Oncology, University of California-Los Angeles, Los Angeles, California (United States); Li, H. Harold; Mutic, Sasa [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Hu, Yanle, E-mail: Hu.Yanle@mayo.edu [Department of Radiation Oncology, Washington University School of Medicine, Saint Louis, Missouri (United States); Department of Radiation Oncology, Mayo Clinic in Arizona, Phoenix, Arizona (United States)

    2015-06-01

    Purpose: The purpose of this study was to improve triggering efficiency of the prospective respiratory amplitude-triggered 4-dimensional magnetic resonance imaging (4DMRI) method and to develop a 4DMRI imaging protocol that could offer T2 weighting for better tumor visualization, good spatial coverage and spatial resolution, and respiratory motion sampling within a reasonable amount of time for radiation therapy applications. Methods and Materials: The respiratory state splitting (RSS) and multi-shot acquisition (MSA) methods were analytically compared and validated in a simulation study by using the respiratory signals from 10 healthy human subjects. The RSS method was more effective in improving triggering efficiency. It was implemented in prospective respiratory amplitude-triggered 4DMRI. 4DMRI image datasets were acquired from 5 healthy human subjects. Liver motion was estimated using the acquired 4DMRI image datasets. Results: The simulation study showed the RSS method was more effective for improving triggering efficiency than the MSA method. The average reductions in 4DMRI acquisition times were 36% and 10% for the RSS and MSA methods, respectively. The human subject study showed that T2-weighted 4DMRI with 10 respiratory states, 60 slices at a spatial resolution of 1.5 × 1.5 × 3.0 mm{sup 3} could be acquired in 9 to 18 minutes, depending on the individual's breath pattern. Based on the acquired 4DMRI image datasets, the ranges of peak-to-peak liver displacements among 5 human subjects were 9.0 to 12.9 mm, 2.5 to 3.9 mm, and 0.5 to 2.3 mm in superior-inferior, anterior-posterior, and left-right directions, respectively. Conclusions: We demonstrated that with the RSS method, it was feasible to acquire high-quality T2-weighted 4DMRI within a reasonable amount of time for radiation therapy applications.

  14. Imaging Food Quality

    DEFF Research Database (Denmark)

    Møller, Flemming

    Imaging and spectroscopy have long been established methods for food quality control both in the laboratories and online. An ever increasing number of analytical techniques are being developed into imaging methods and existing imaging methods to contain spectral information. Images and especially...... spectral images contain large amounts of data which should be analysed appropriately by techniques combining structure and spectral information. This dissertation deals with how different types of food quality can be measured by imaging techniques, analysed with appropriate image analysis techniques...... and finally use the image data to predict or visualise food quality. A range of different food quality parameters was addressed, i.e. water distribution in bread throughout storage, time series analysis of chocolate milk stability, yoghurt glossiness, graininess and dullness and finally structure and meat...

  15. Application of imaging and ultrasound to the quality grading of beef

    Science.gov (United States)

    Anselmo, V. J.; Gammell, P. M.

    1980-01-01

    The results of a study conducted to assist the Department of Agriculture in the task of considering innovative methods for the grading of carcass beef for human consumption is presented. The processing of photographic, television and ultrasound images of the longissimus dorsi muscle at the 12/13th rib cut was undertaken. The results showed that a correlation could be developed between the quality grade of the carcass as determined by a professional grader, and the fat to area ratio of the muscle as determined by image processing techniques. In addition, the use of ultrasound shows the potential for grading of an unsliced carcass or a live animal.

  16. Image quality in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Haus, A.G.; Doi, K.; Metz, C.E. Bernstein, J.

    1976-01-01

    In mammography, image quality is a function of the shape, size, and x-ray absorption properties of the anatomic part to be radiographed and of the lesion to be detected; it also depends on geometric unsharpness, and the resolution, characteristic curve and noise properties of the recording system. X-ray energy spectra, modulation transfer functions, Wiener spectra, characteristic and gradient curves, and radiographs of a breast phantom and of a resected breast specimen containing microcalcifications are used in a review of some current considerations of the factors, and the complex relationship among factors, that affect image quality in mammography. Image quality and patient radiation exposure in mammography are interrelated. An approach to the problem of evaluating the trade-off between diagnostic certainty and the cost or risk of performing a breast imaging procedure is discussed.

  17. Construction of realistic liver phantoms from patient images using 3D printer and its application in CT image quality assessment

    Science.gov (United States)

    Leng, Shuai; Yu, Lifeng; Vrieze, Thomas; Kuhlmann, Joel; Chen, Baiyu; McCollough, Cynthia H.

    2015-03-01

    The purpose of this study is to use 3D printing techniques to construct a realistic liver phantom with heterogeneous background and anatomic structures from patient CT images, and to use the phantom to assess image quality with filtered back-projection and iterative reconstruction algorithms. Patient CT images were segmented into liver tissues, contrast-enhanced vessels, and liver lesions using commercial software, based on which stereolithography (STL) files were created and sent to a commercial 3D printer. A 3D liver phantom was printed after assigning different printing materials to each object to simulate appropriate attenuation of each segmented object. As high opacity materials are not available for the printer, we printed hollow vessels and filled them with iodine solutions of adjusted concentration to represent enhance levels in contrast-enhanced liver scans. The printed phantom was then placed in a 35×26 cm oblong-shaped water phantom and scanned repeatedly at 4 dose levels. Images were reconstructed using standard filtered back-projection and an iterative reconstruction algorithm with 3 different strength settings. Heterogeneous liver background were observed from the CT images and the difference in CT numbers between lesions and background were representative for low contrast lesions in liver CT studies. CT numbers in vessels filled with iodine solutions represented the enhancement of liver arteries and veins. Images were run through a Channelized Hotelling model observer with Garbor channels and ROC analysis was performed. The AUC values showed performance improvement using the iterative reconstruction algorithm and the amount of improvement increased with strength setting.

  18. Construction of Realistic Liver Phantoms from Patient Images using 3D Printer and Its Application in CT Image Quality Assessment.

    Science.gov (United States)

    Leng, Shuai; Yu, Lifeng; Vrieze, Thomas; Kuhlmann, Joel; Chen, Baiyu; McCollough, Cynthia H

    2015-01-01

    The purpose of this study is to use 3D printing techniques to construct a realistic liver phantom with heterogeneous background and anatomic structures from patient CT images, and to use the phantom to assess image quality with filtered backprojection and iterative reconstruction algorithms. Patient CT images were segmented into liver tissues, contrast-enhanced vessels, and liver lesions using commercial software, based on which stereolithography (STL) files were created and sent to a commercial 3D printer. A 3D liver phantom was printed after assigning different printing materials to each object to simulate appropriate attenuation of each segmented object. As high opacity materials are not available for the printer, we printed hollow vessels and filled them with iodine solutions of adjusted concentration to represent enhance levels in contrast-enhanced liver scans. The printed phantom was then placed in a 35×26 cm oblong-shaped water phantom and scanned repeatedly at 4 dose levels. Images were reconstructed using standard filtered backprojection and an iterative reconstruction algorithm with 3 different strength settings. Heterogeneous liver background were observed from the CT images and the difference in CT numbers between lesions and background were representative for low contrast lesions in liver CT studies. CT numbers in vessels filled with iodine solutions represented the enhancement of liver arteries and veins. Images were run through a Channelized Hotelling model observer with Garbor channels and ROC analysis was performed. The AUC values showed performance improvement using the iterative reconstruction algorithm and the amount of improvement increased with strength setting.

  19. Application of multispectral imaging to determine quality attributes and ripeness stage in strawberry fruit.

    Directory of Open Access Journals (Sweden)

    Changhong Liu

    Full Text Available Multispectral imaging with 19 wavelengths in the range of 405-970 nm has been evaluated for nondestructive determination of firmness, total soluble solids (TSS content and ripeness stage in strawberry fruit. Several analysis approaches, including partial least squares (PLS, support vector machine (SVM and back propagation neural network (BPNN, were applied to develop theoretical models for predicting the firmness and TSS of intact strawberry fruit. Compared with PLS and SVM, BPNN considerably improved the performance of multispectral imaging for predicting firmness and total soluble solids content with the correlation coefficient (r of 0.94 and 0.83, SEP of 0.375 and 0.573, and bias of 0.035 and 0.056, respectively. Subsequently, the ability of multispectral imaging technology to classify fruit based on ripeness stage was tested using SVM and principal component analysis-back propagation neural network (PCA-BPNN models. The higher classification accuracy of 100% was achieved using SVM model. Moreover, the results of all these models demonstrated that the VIS parts of the spectra were the main contributor to the determination of firmness, TSS content estimation and classification of ripeness stage in strawberry fruit. These results suggest that multispectral imaging, together with suitable analysis model, is a promising technology for rapid estimation of quality attributes and classification of ripeness stage in strawberry fruit.

  20. Radiation exposure and image quality in x-Ray diagnostic radiology physical principles and clinical applications

    CERN Document Server

    Aichinger, Horst; Joite-Barfuß, Sigrid; Säbel, Manfred

    2012-01-01

    The largest contribution to radiation exposure to the population as a whole arises from diagnostic X-rays. Protecting the patient from radiation is a major aim of modern health policy, and an understanding of the relationship between radiation dose and image quality is of pivotal importance in optimising medical diagnostic radiology. In this volume the data provided for exploring these concerns are partly based on X-ray spectra, measured on diagnostic X-ray tube assemblies, and are supplemented by the results of measurements on phantoms and simulation calculations.

  1. Potential applications of near infrared auto-fluorescence spectral polarized imaging for assessment of food quality

    Science.gov (United States)

    Zhou, Kenneth J.; Chen, Jun

    2016-03-01

    The current growing of food industry for low production costs and high efficiency needs for maintenance of high-quality standards and assurance of food safety while avoiding liability issues. Quality and safety of food depend on physical (texture, color, tenderness etc.), chemical (fat content, moisture, protein content, pH, etc.), and biological (total bacterial count etc.) features. There is a need for a rapid (less than a few minutes) and accurate detection system in order to optimize quality and assure safety of food. However, the fluorescence ranges for known fluorophores are limited to ultraviolet emission bands, which are not in the tissue near infrared (NIR) "optical window". Biological tissues excited by far-red or NIR light would exhibit strong emission in spectral range of 650-1,100 nm although no characteristic peaks show the emission from which known fluorophores. The characteristics of the auto-fluorescence emission of different types of tissues were found to be different between different tissue components such as fat, high quality muscle food. In this paper, NIR auto-fluorescence emission from different types of muscle food and fat was measured. The differences of fluorescence intensities of the different types of muscle food and fat emissions were observed. These can be explained by the change of the microscopic structure of physical, chemical, and biological features in meat. The difference of emission intensities of fat and lean meat tissues was applied to monitor food quality and safety using spectral polarized imaging, which can be detect deep depth fat under the muscle food up to several centimeter.

  2. Improved Extreme Learning Machine and Its Application in Image Quality Assessment

    Directory of Open Access Journals (Sweden)

    Li Mao

    2014-01-01

    Full Text Available Extreme learning machine (ELM is a new class of single-hidden layer feedforward neural network (SLFN, which is simple in theory and fast in implementation. Zong et al. propose a weighted extreme learning machine for learning data with imbalanced class distribution, which maintains the advantages from original ELM. However, the current reported ELM and its improved version are only based on the empirical risk minimization principle, which may suffer from overfitting. To solve the overfitting troubles, in this paper, we incorporate the structural risk minimization principle into the (weighted ELM, and propose a modified (weighted extreme learning machine (M-ELM and M-WELM. Experimental results show that our proposed M-WELM outperforms the current reported extreme learning machine algorithm in image quality assessment.

  3. Application of digital image processing techniques and information systems to water quality monitoring of Lake Tahoe

    Science.gov (United States)

    Smith, A. Y.; Blackwell, R. J.

    1981-01-01

    The Tahoe basin occupies over 500 square miles of territory located in a graben straddling the boundary between California and Nevada. Lake Tahoe contains 126 million acre-feet of water. Since the 1950's the basin has experienced an ever increasing demand for land development at the expense of the natural watershed. Discharge of sediment to the lake has greatly increased owing to accelerated human interference, and alterations to the natural drainage patterns are evident in some areas. In connection with an investigation of the utility of a comprehensive system that takes into account the causes as well as the effects of lake eutrophication, it has been attempted to construct an integrated and workable data base, comprised of currently available data sources for the Lake Tahoe region. Attention is given to the image based information system (IBIS), the construction of the Lake Tahoe basin data base, and the application of the IBIS concept to the Lake Tahoe basin.

  4. Application-driven computational imaging

    Science.gov (United States)

    McCloskey, Scott

    2016-05-01

    This paper addresses how the image processing steps involved in computational imaging can be adapted to specific image-based recognition tasks, and how significant reductions in computational complexity can be achieved by leveraging the recognition algorithm's robustness to defocus, poor exposure, and the like. Unlike aesthetic applications of computational imaging, recognition systems need not produce the best possible image quality, but instead need only satisfy certain quality thresholds that allow for reliable recognition. The paper specifically addresses light field processing for barcode scanning, and presents three optimizations which bring light field processing within the complexity limits of low-powered embedded processors.

  5. SU-E-T-208: Comparison of MR Image Quality of Various Brachytherapy Applicators for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, A; Elzibak, A; Fatemi, A; Safigholi, H; Leung, E; Ravi, A; Song, W [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); Han, D [Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada); University of California, San Diego, La Jolla, CA (United States)

    2015-06-15

    Purpose: To compare the quality of Magnetic Resonance (MR) images of a recently-proposed novel direction-modulated brachytherapy (DMBT) tandem applicator against two conventional clinical applicators, using the current MRI clinical protocol. Methods: Three tandem applicators were compared: (1) tungsten-based DMBT applicator, (2) conventional plastic applicator and (3) conventional stainless steel applicator. Physical dimensions were 5.4, 3.8 and 3.2 for tandems (1), (2) and (3), respectively. Each applicator was placed in the same water-phantom and independently scanned using the same parameters and coil settings on a 1.5 T 450w GE scanner. Images were acquired using T2-weighted turbo-spin-echo (TSE) with 8-channel body coil. Acquisition parameters were TR/TE =7000/108 ms; acquisition matrix = 320 x 256; 30 slices with 4 mm thickness and 0.5 gap; pixel bandwidth = 122 Hz and voxel size = 0.5 x 0.625 mm2 and number of excitations (NEX) = 4. Multiple acquisitions were obtained in para-sagittal and para-axial views (with respect to the tandem axis) for each applicator. Diameters of the tandem were measured at multiple angles and multiple locations and compared to the physical dimensions of the corresponding tandems. Results: Minimal susceptibility artifact was observed with the DMBT and the plastic tandems. The stainless steel tandem produced significantly larger artifact than the first two tandems. The average diameter of the DMBT applicator measured 5.94 ± 0.3 mm. The average diameter of the plastic tandem measured 3.9 ± 0.1 mm. The maximum extent of artifact was 1.5 mm and 0.7 mm for DMBT and plastic tandems, respectively. The susceptibility artifact induced by the stainless steel tandem prevented the measurement of its diameter, and the edges of the tandem could not be identified in any acquisition. Conclusion: This work demonstrated that the plastic and the tungsten-based DMBT tandem applicators are both suitable for MRI-guided brachytherapy of cervical cancer.

  6. LANDSAT-4 image data quality analysis for energy related applications. [nuclear power plant sites

    Science.gov (United States)

    Wukelic, G. E. (Principal Investigator)

    1983-01-01

    No useable LANDSAT 4 TM data were obtained for the Hanford site in the Columbia Plateau region, but TM simulator data for a Virginia Electric Company nuclear power plant was used to test image processing algorithms. Principal component analyses of this data set clearly indicated that thermal plumes in surface waters used for reactor cooling would be discrenible. Image processing and analysis programs were successfully testing using the 7 band Arkansas test scene and preliminary analysis of TM data for the Savanah River Plant shows that current interactive, image enhancement, analysis and integration techniques can be effectively used for LANDSAT 4 data. Thermal band data appear adequate for gross estimates of thermal changes occurring near operating nuclear facilities especially in surface water bodies being used for reactor cooling purposes. Additional image processing software was written and tested which provides for more rapid and effective analysis of the 7 band TM data.

  7. Imaging systems and applications.

    Science.gov (United States)

    Catrysse, Peter B; Imai, Francisco H; Linne von Berg, Dale C; Sheridan, John T

    2013-03-01

    Imaging systems have numerous applications in industrial, military, consumer, and medical settings. Assembling a complete imaging system requires the integration of optics, sensing, image processing, and display rendering. This issue features original research ranging from fundamental theories to novel imaging modalities and provides a systems perspective to imaging.

  8. APPLICATION OF IMAGE ANALYSIS METHODS FOR ISOCENTER QUALITY ASSURANCE IN RADIOTHERAPY

    Directory of Open Access Journals (Sweden)

    Michał Niedźwiecki

    2017-03-01

    Full Text Available One of the major procedures for testing the geometrical accuracy of devices used in radiotherapy treatments is the test of the geometrical position of the radiation isocenter. The importance of the test reflects the fact that geometrical position of the radiation isocenter generally affects the tumor targeting. At present the geometric accuracy is assessed with the Winston-Lutz test which checks the position of an image of a ball marker with the respect to the center of the radiation field as projected on a detector plane. Obviously, determination of coordinates of a single marker is not sufficient to fully account for a complicated geometry of a therapeutic device. The purpose of the study was to design a new image analysis tool to better determine the isocenter. The proposed automated procedure for determining isocenter position uses projection data acquired for a special cube phantom. The projection images of a phantom are acquired for various angles of rotation of the gantry. A procedure is proposed to extract some geometric characteristics of a therapeutic device from the projection images.

  9. Quality Control Applications

    CERN Document Server

    Chorafas, Dimitris N

    2013-01-01

    Quality control is a constant priority in electrical, mechanical, aeronautical, and nuclear engineering – as well as in the vast domain of electronics, from home appliances to computers and telecommunications. Quality Control Applications provides guidance and valuable insight into quality control policies; their methods, their implementation, constant observation and associated technical audits. What has previously been a mostly mathematical topic is translated here for engineers concerned with the practical implementation of quality control. Once the fundamentals of quality control are established, Quality Control Applications goes on to develop this knowledge and explain how to apply it in the most effective way. Techniques are described and supported using relevant, real-life, case studies to provide detail and clarity for those without a mathematical background. Among the many practical examples, two case studies dramatize the importance of quality assurance: A shot-by-shot analysis of the errors made ...

  10. Application of a newly developed software program for image quality assessment in cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    De Oliveira, Marcus Vinicius Linhares; Campos, Paulo Sergio Flores [Federal Institute of Bahia, Salvador (Brazil); Paulo, Graciano; Santos, Antonio Carvalho; Santos, Joana [Coimbra Health School, Polytechnic Institute of Coimbra, Coimbra (Portugal)

    2017-06-15

    The purpose of this study was to apply a newly developed free software program, at low cost and with minimal time, to evaluate the quality of dental and maxillofacial cone-beam computed tomography (CBCT) images. A polymethyl methacrylate (PMMA) phantom, CQP-IFBA, was scanned in 3 CBCT units with 7 protocols. A macro program was developed, using the free software ImageJ, to automatically evaluate the image quality parameters. The image quality evaluation was based on 8 parameters: uniformity, the signal-to-noise ratio (SNR), noise, the contrast-to-noise ratio (CNR), spatial resolution, the artifact index, geometric accuracy, and low-contrast resolution. The image uniformity and noise depended on the protocol that was applied. Regarding the CNR, high-density structures were more sensitive to the effect of scanning parameters. There were no significant differences between SNR and CNR in centered and peripheral objects. The geometric accuracy assessment showed that all the distance measurements were lower than the real values. Low-contrast resolution was influenced by the scanning parameters, and the 1-mm rod present in the phantom was not depicted in any of the 3 CBCT units. Smaller voxel sizes presented higher spatial resolution. There were no significant differences among the protocols regarding artifact presence. This software package provided a fast, low-cost, and feasible method for the evaluation of image quality parameters in CBCT.

  11. Electrical Inspection Oriented Thermal Image Quality Assessment

    Science.gov (United States)

    Lin, Ying; Wang, Menglin; Gong, Xiaojin; Guo, Zhihong; Geng, Yujie; Bai, Demeng

    2017-01-01

    This paper presents an approach to access the quality of thermal images that are specially used in electrical inspection. In this application, no reference images are given for quality assessment. Therefore, we first analyze the characteristics for these thermal images. Then, four quantitative measurements, which are one-dimensional (1D) entropy, two-dimensional (2D) entropy, centrality, and No-Reference Structural Sharpness (NRSS), are investigated to measure the information content, the centrality for objects of interest, and the sharpness of images. Moreover, in order to provide a more intuitive measure for human operators, we assign each image with a discrete rate based on these quantitative measurements via the k-nearest neighbor (KNN) method. The proposed approach has been validated in a dataset composed of 2,336 images. Experiments show that our quality assessment results are consistent with subjective assessment.

  12. Image quality in context

    NARCIS (Netherlands)

    Besuijen, J.

    2008-01-01

    An analysis of the ergonomic quality of the current standards for the visual display quality leads to a number of recommendations for the development of new international standards: - Separation for different types of users, esp. display designers, purchasers, and end users, -Independence of display

  13. Industrial Applications of Terahertz Imaging

    Science.gov (United States)

    Zeitler, J. Axel; Shen, Yao-Chun

    This chapter gives a concise overview of potential industrial applications for terahertz imaging that have been reported over the past decade with a discussion of the major advantages and limitations of each approach. In the second half of the chapter we discuss in more detail how terahertz imaging can be used to investigate the microstructure of pharmaceutical dosage forms. A particular focus in this context is the nondestructive measurement of the coating thickness of polymer coated tablets, both by means of high resolution offline imaging in research and development as well as for in-line quality control during production.

  14. Physics for Medical Imaging Applications

    CERN Document Server

    Caner, Alesssandra; Rahal, Ghita

    2007-01-01

    The book introduces the fundamental aspects of digital imaging and covers four main themes: Ultrasound techniques and imaging applications; Magnetic resonance and MPJ in hospital; Digital imaging with X-rays; and Emission tomography (PET and SPECT). Each of these topics is developed by analysing the underlying physics principles and their implementation, quality and safety aspects, clinical performance and recent advancements in the field. Some issues specific to the individual techniques are also treated, e.g. choice of radioisotopes or contrast agents, optimisation of data acquisition and st

  15. Industrial Applications of Image Processing

    Science.gov (United States)

    Ciora, Radu Adrian; Simion, Carmen Mihaela

    2014-11-01

    The recent advances in sensors quality and processing power provide us with excellent tools for designing more complex image processing and pattern recognition tasks. In this paper we review the existing applications of image processing and pattern recognition in industrial engineering. First we define the role of vision in an industrial. Then a dissemination of some image processing techniques, feature extraction, object recognition and industrial robotic guidance is presented. Moreover, examples of implementations of such techniques in industry are presented. Such implementations include automated visual inspection, process control, part identification, robots control. Finally, we present some conclusions regarding the investigated topics and directions for future investigation

  16. Field application of moment-based wavefront sensing to in-situ alignment and image quality assessment of astronomical spectrographs: results and analysis of aligning VIRUS unit spectrographs

    Science.gov (United States)

    Lee, Hanshin; Hill, Gary J.; Tuttle, Sarah E.; Noyola, Eva; Peterson, Trent; Vattiat, Brian L.

    2014-07-01

    Teague introduced a phase retrieval method that uses the image shape moments. More recently, an independent study arrived at a similar technique, which was then applied to in-situ full-field image-quality evaluation of spectroscopic systems. This moment-based wavefront sensing (MWFS) method relies on the geometric relation between the image shape moments and the geometric wavefront modal coefficients. The MWFS method allows a non-iterative determination of the modal coefficients from focus-modulated images at arbitrary spatial resolutions. The determination of image moments is a direct extension of routine centroid and image size calculation, making its implementation easy. Previous studies showed that the MWFS works well in capturing large low-order modes, and is quite suitable for in-situ alignment diagnostics. At the Astronomical Instrumentation conference in 2012, we presented initial results of the application of the moment-based wavefront sensing to a fiber-fed astronomical spectrograph, called VIRUS (a set of replicated 150 identical integral-field unit spectrographs contained in 75 unit pairs). This initial result shows that the MWFS can provide accurate full-field image-quality assessment for efficiently aligning these 150 spectrographs. Since then, we have assembled more than 24 unit pairs using this technique. In this paper, we detail the technical update/progress made so far for the moment-based wavefront sensing method and the statistical estimates of the before/after alignment aberrations, image-quality, and various efficiency indicators of the unit spectrograph alignment process.

  17. Image quality (IQ) guided multispectral image compression

    Science.gov (United States)

    Zheng, Yufeng; Chen, Genshe; Wang, Zhonghai; Blasch, Erik

    2016-05-01

    Image compression is necessary for data transportation, which saves both transferring time and storage space. In this paper, we focus on our discussion on lossy compression. There are many standard image formats and corresponding compression algorithms, for examples, JPEG (DCT -- discrete cosine transform), JPEG 2000 (DWT -- discrete wavelet transform), BPG (better portable graphics) and TIFF (LZW -- Lempel-Ziv-Welch). The image quality (IQ) of decompressed image will be measured by numerical metrics such as root mean square error (RMSE), peak signal-to-noise ratio (PSNR), and structural Similarity (SSIM) Index. Given an image and a specified IQ, we will investigate how to select a compression method and its parameters to achieve an expected compression. Our scenario consists of 3 steps. The first step is to compress a set of interested images by varying parameters and compute their IQs for each compression method. The second step is to create several regression models per compression method after analyzing the IQ-measurement versus compression-parameter from a number of compressed images. The third step is to compress the given image with the specified IQ using the selected compression method (JPEG, JPEG2000, BPG, or TIFF) according to the regressed models. The IQ may be specified by a compression ratio (e.g., 100), then we will select the compression method of the highest IQ (SSIM, or PSNR). Or the IQ may be specified by a IQ metric (e.g., SSIM = 0.8, or PSNR = 50), then we will select the compression method of the highest compression ratio. Our experiments tested on thermal (long-wave infrared) images (in gray scales) showed very promising results.

  18. A universal color image quality metric

    NARCIS (Netherlands)

    Toet, A.; Lucassen, M.P.

    2003-01-01

    We extend a recently introduced universal grayscale image quality index to a newly developed perceptually decorrelated color space. The resulting color image quality index quantifies the distortion of a processed color image relative to its original version. We evaluated the new color image quality

  19. Pan Sharpening Quality Investigation of Turkish In-Operation Remote Sensing Satellites: Applications with Rasat and GÖKTÜRK-2 Images

    Science.gov (United States)

    Ozendi, Mustafa; Topan, Hüseyin; Cam, Ali; Bayık, Çağlar

    2016-10-01

    Recently two optical remote sensing satellites, RASAT and GÖKTÜRK-2, launched successfully by the Republic of Turkey. RASAT has 7.5 m panchromatic, and 15 m visible bands whereas GÖKTÜRK-2 has 2.5 m panchromatic and 5 m VNIR (Visible and Near Infrared) bands. These bands with various resolutions can be fused by pan-sharpening methods which is an important application area of optical remote sensing imagery. So that, the high geometric resolution of panchromatic band and the high spectral resolution of VNIR bands can be merged. In the literature there are many pan-sharpening methods. However, there is not a standard framework for quality investigation of pan-sharpened imagery. The aim of this study is to investigate pan-sharpening performance of RASAT and GÖKTÜRK-2 images. For this purpose, pan-sharpened images are generated using most popular pan-sharpening methods IHS, Brovey and PCA at first. This procedure is followed by quantitative evaluation of pan-sharpened images using Correlation Coefficient (CC), Root Mean Square Error (RMSE), Relative Average Spectral Error (RASE), Spectral Angle Mapper (SAM) and Erreur Relative Globale Adimensionnelle de Synthése (ERGAS) metrics. For generation of pan-sharpened images and computation of metrics SharpQ tool is used which is developed with MATLAB computing language. According to metrics, PCA derived pan-sharpened image is the most similar one to multispectral image for RASAT, and Brovey derived pan-sharpened image is the most similar one to multispectral image for GÖKTÜRK-2. Finally, pan-sharpened images are evaluated qualitatively in terms of object availability and completeness for various land covers (such as urban, forest and flat areas) by a group of operators who are experienced in remote sensing imagery.

  20. Potential applications of image-guided radiotherapy for brain metastases and glioblastoma to improve patient quality of life

    Directory of Open Access Journals (Sweden)

    Nam Phong Nguyen

    2013-11-01

    Full Text Available Treatment of glioblastoma multiforme (GBM and brain metastasis remains a challenge because of the poor survival and the potential for brain damage following radiation. Despite concurrent chemotherapy and radiation dose escalation, local recurrence remains the predominant pattern of failure in GBM most likely secondary to repopulation of cancer stem cells. Even though radiotherapy is highly effective for local control of radio-resistant tumors such as melanoma and renal cell cancer, systemic disease progression is the cause of death in most patients with brain metastasis. Preservation of quality of life of cancer survivors is the main issue for patients with brain metastasis. Image-guided radiotherapy (IGRT by virtue of precise radiation dose delivery may reduce treatment time of patients with GBM without excessive toxicity and potentially improve neurocognitive function with preservation of local control in patients with brain metastasis. Future prospective trials for primary brain tumors or brain metastasis should include IGRT to assess its efficacy to improve patient quality of life.

  1. Objective assessment of image quality VI: imaging in radiation therapy

    Science.gov (United States)

    Barrett, Harrison H.; Kupinski, Matthew A.; Müeller, Stefan; Halpern, Howard J.; Morris, John C., III; Dwyer, Roisin

    2013-11-01

    Earlier work on objective assessment of image quality (OAIQ) focused largely on estimation or classification tasks in which the desired outcome of imaging is accurate diagnosis. This paper develops a general framework for assessing imaging quality on the basis of therapeutic outcomes rather than diagnostic performance. By analogy to receiver operating characteristic (ROC) curves and their variants as used in diagnostic OAIQ, the method proposed here utilizes the therapy operating characteristic or TOC curves, which are plots of the probability of tumor control versus the probability of normal-tissue complications as the overall dose level of a radiotherapy treatment is varied. The proposed figure of merit is the area under the TOC curve, denoted AUTOC. This paper reviews an earlier exposition of the theory of TOC and AUTOC, which was specific to the assessment of image-segmentation algorithms, and extends it to other applications of imaging in external-beam radiation treatment as well as in treatment with internal radioactive sources. For each application, a methodology for computing the TOC is presented. A key difference between ROC and TOC is that the latter can be defined for a single patient rather than a population of patients.

  2. Properties of thin film radiation detectors and their application to dosimetry and quality assurance in x-ray imaging

    Science.gov (United States)

    Elshahat, Bassem

    The characteristics of two different types of thin-film radiation detectors are experimentally investigated: organic photovoltaic cells (OPV) and a new self-powered detector that operates based on high-energy secondary electrons (HEC). Although their working principles are substantially different, they both can be used for radiation detection and image formation in medical applications. OPVs with different active layer material thicknesses and aluminum electrode areas were fabricated. The OPV cell consisted of P3HT: PCBM photoactive materials, composed of donor and acceptor semiconducting organic materials, sandwiched between an aluminum electrode as anode and an indium tin oxide (ITO) electrode as a cathode. The detectors were exposed to 60150 kVp x rays, which generated photocurrent in the active layer. The electric charge production in the OPV cells was measured. The net current as function of beam energy (kVp) was proportional to ~1/kVp0.45 when adjusted for x-ray beam output. The best combination of parameters for these cells was 270-nm active layer thicknesses for 0.7cm-2 electrode area. The measured current ranged from about 0.7 to 2.4 nA/cm2 for 60-150 kVp, corresponding to about 0.09 -- 0.06 nA/cm2/mGy, respectively, when adjusted for the output x-ray source flux. The HEC detection concept was recently proposed and experimentally demonstrated by a UML/HMS research group. HEC detection employs direct conversion of high-energy electron current to detector signal without external power and amplification. The potential of using HEC detectors for diagnostic imaging application was investigated by using a heterogeneous phantom consisting of a water cylinder with Al and wax rod inserts.

  3. Quality assessment for online iris images

    CSIR Research Space (South Africa)

    Makinana, S

    2015-01-01

    Full Text Available Iris recognition systems have attracted much attention for their uniqueness, stability and reliability. However, performance of this system depends on quality of iris image. Therefore there is a need to select good quality images before features can...

  4. Optimization of Synthetic Aperture Image Quality

    DEFF Research Database (Denmark)

    Moshavegh, Ramin; Jensen, Jonas; Villagómez Hoyos, Carlos Armando

    2016-01-01

    Synthetic Aperture (SA) imaging produces high-quality images and velocity estimates of both slow and fast flow at high frame rates. However, grating lobe artifacts can appear both in transmission and reception. These affect the image quality and the frame rate. Therefore optimization of parameters...... effecting the image quality of SA is of great importance, and this paper proposes an advanced procedure for optimizing the parameters essential for acquiring an optimal image quality, while generating high resolution SA images. Optimization of the image quality is mainly performed based on measures...... such as F-number, number of emissions and the aperture size. They are considered to be the most contributing acquisition factors in the quality of the high resolution images in SA. Therefore, the performance of image quality is quantified in terms of full-width at half maximum (FWHM) and the cystic...

  5. Perceived image quality assessment for color images on mobile displays

    Science.gov (United States)

    Jang, Hyesung; Kim, Choon-Woo

    2015-01-01

    With increase in size and resolution of mobile displays and advances in embedded processors for image enhancement, perceived quality of images on mobile displays has been drastically improved. This paper presents a quantitative method to evaluate perceived image quality of color images on mobile displays. Three image quality attributes, colorfulness, contrast and brightness, are chosen to represent perceived image quality. Image quality assessment models are constructed based on results of human visual experiments. In this paper, three phase human visual experiments are designed to achieve credible outcomes while reducing time and resources needed for visual experiments. Values of parameters of image quality assessment models are estimated based on results from human visual experiments. Performances of different image quality assessment models are compared.

  6. Image Quality Indicator for Infrared Inspections

    Science.gov (United States)

    Burke, Eric

    2011-01-01

    The quality of images generated during an infrared thermal inspection depends on many system variables, settings, and parameters to include the focal length setting of the IR camera lens. If any relevant parameter is incorrect or sub-optimal, the resulting IR images will usually exhibit inherent unsharpness and lack of resolution. Traditional reference standards and image quality indicators (IQIs) are made of representative hardware samples and contain representative flaws of concern. These standards are used to verify that representative flaws can be detected with the current IR system settings. However, these traditional standards do not enable the operator to quantify the quality limitations of the resulting images, i.e. determine the inherent maximum image sensitivity and image resolution. As a result, the operator does not have the ability to optimize the IR inspection system prior to data acquisition. The innovative IQI described here eliminates this limitation and enables the operator to objectively quantify and optimize the relevant variables of the IR inspection system, resulting in enhanced image quality with consistency and repeatability in the inspection application. The IR IQI consists of various copper foil features of known sizes that are printed on a dielectric non-conductive board. The significant difference in thermal conductivity between the two materials ensures that each appears with a distinct grayscale or brightness in the resulting IR image. Therefore, the IR image of the IQI exhibits high contrast between the copper features and the underlying dielectric board, which is required to detect the edges of the various copper features. The copper features consist of individual elements of various shapes and sizes, or of element-pairs of known shapes and sizes and with known spacing between the elements creating the pair. For example, filled copper circles with various diameters can be used as individual elements to quantify the image sensitivity

  7. Image processing system performance prediction and product quality evaluation

    Science.gov (United States)

    Stein, E. K.; Hammill, H. B. (Principal Investigator)

    1976-01-01

    The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

  8. Terahertz imaging: applications and perspectives.

    Science.gov (United States)

    Jansen, Christian; Wietzke, Steffen; Peters, Ole; Scheller, Maik; Vieweg, Nico; Salhi, Mohammed; Krumbholz, Norman; Jördens, Christian; Hochrein, Thomas; Koch, Martin

    2010-07-01

    Terahertz (THz) spectroscopy, and especially THz imaging, holds large potential in the field of nondestructive, contact-free testing. The ongoing advances in the development of THz systems, as well as the appearance of the first related commercial products, indicate that large-scale market introduction of THz systems is rapidly approaching. We review selected industrial applications for THz systems, comprising inline monitoring of compounding processes, plastic weld joint inspection, birefringence analysis of fiber-reinforced components, water distribution monitoring in polymers and plants, as well as quality inspection of food products employing both continuous wave and pulsed THz systems.

  9. Quality Improvement of Liver Ultrasound Images Using Fuzzy Techniques

    Science.gov (United States)

    Bayani, Azadeh; Langarizadeh, Mostafa; Radmard, Amir Reza; Nejad, Ahmadreza Farzaneh

    2016-01-01

    Background: Liver ultrasound images are so common and are applied so often to diagnose diffuse liver diseases like fatty liver. However, the low quality of such images makes it difficult to analyze them and diagnose diseases. The purpose of this study, therefore, is to improve the contrast and quality of liver ultrasound images. Methods: In this study, a number of image contrast enhancement algorithms which are based on fuzzy logic were applied to liver ultrasound images - in which the view of kidney is observable - using Matlab2013b to improve the image contrast and quality which has a fuzzy definition; just like image contrast improvement algorithms using a fuzzy intensification operator, contrast improvement algorithms applying fuzzy image histogram hyperbolization, and contrast improvement algorithms by fuzzy IF-THEN rules. Results: With the measurement of Mean Squared Error and Peak Signal to Noise Ratio obtained from different images, fuzzy methods provided better results, and their implementation - compared with histogram equalization method - led both to the improvement of contrast and visual quality of images and to the improvement of liver segmentation algorithms results in images. Conclusion: Comparison of the four algorithms revealed the power of fuzzy logic in improving image contrast compared with traditional image processing algorithms. Moreover, contrast improvement algorithm based on a fuzzy intensification operator was selected as the strongest algorithm considering the measured indicators. This method can also be used in future studies on other ultrasound images for quality improvement and other image processing and analysis applications. PMID:28077898

  10. Quality Improvement of Liver Ultrasound Images Using Fuzzy Techniques.

    Science.gov (United States)

    Bayani, Azadeh; Langarizadeh, Mostafa; Radmard, Amir Reza; Nejad, Ahmadreza Farzaneh

    2016-12-01

    Liver ultrasound images are so common and are applied so often to diagnose diffuse liver diseases like fatty liver. However, the low quality of such images makes it difficult to analyze them and diagnose diseases. The purpose of this study, therefore, is to improve the contrast and quality of liver ultrasound images. In this study, a number of image contrast enhancement algorithms which are based on fuzzy logic were applied to liver ultrasound images - in which the view of kidney is observable - using Matlab2013b to improve the image contrast and quality which has a fuzzy definition; just like image contrast improvement algorithms using a fuzzy intensification operator, contrast improvement algorithms applying fuzzy image histogram hyperbolization, and contrast improvement algorithms by fuzzy IF-THEN rules. With the measurement of Mean Squared Error and Peak Signal to Noise Ratio obtained from different images, fuzzy methods provided better results, and their implementation - compared with histogram equalization method - led both to the improvement of contrast and visual quality of images and to the improvement of liver segmentation algorithms results in images. Comparison of the four algorithms revealed the power of fuzzy logic in improving image contrast compared with traditional image processing algorithms. Moreover, contrast improvement algorithm based on a fuzzy intensification operator was selected as the strongest algorithm considering the measured indicators. This method can also be used in future studies on other ultrasound images for quality improvement and other image processing and analysis applications.

  11. Matlab GUI在低质量指纹图像增强中的应用%Application of Matlab GUI in Enhancement of Low-quality Fingerprint Image

    Institute of Scientific and Technical Information of China (English)

    郭依正; 焦蓬蓬

    2013-01-01

    The low quality fingerprint is usually defined as fingerprint which is fuzzy,noisy and low-contrast.Among the fingerprint identification technique which based on the intrinsic physiological property of fingerprint,image enhancement technology is an all-important one.The enhancement will directly affect the recognition effect of low-quality fingerprint image.Based on the introduction of the fingerprint recognition process,focus on the steps of the Matlab GUI design and its realization in the enhancement of the low quality fingerprint image,with Gabor filtering enhancement algorithm-a typical low-quality fingerprint image enhancement algorithm as example.There is certain reference significance for the user developing Matlab GUI application program and using GUI to process image,etc.%低质量指纹通常被定义为模糊、高噪声、低对比度等情况下的指纹.利用人体固有的指纹生理特征来进行个人身份鉴定的指纹识别技术中,图像增强技术是其中一个非常重要的步骤.低质量指纹图像增强效果直接影响低质量指纹图像的识别效果.文中在简介指纹识别过程的基础上,以一种典型的低质量指纹图像增强算法-Gabor滤波增强算法为例,重点阐述了Matlab GUI设计的一般步骤及其在低质量指纹图像增强中的具体实现.对用户开发Matlab GUI应用程序和利用GUI处理图像等相关问题都有一定的借鉴意义.

  12. Dried fruits quality assessment by hyperspectral imaging

    Science.gov (United States)

    Serranti, Silvia; Gargiulo, Aldo; Bonifazi, Giuseppe

    2012-05-01

    Dried fruits products present different market values according to their quality. Such a quality is usually quantified in terms of freshness of the products, as well as presence of contaminants (pieces of shell, husk, and small stones), defects, mould and decays. The combination of these parameters, in terms of relative presence, represent a fundamental set of attributes conditioning dried fruits humans-senses-detectable-attributes (visual appearance, organolectic properties, etc.) and their overall quality in terms of marketable products. Sorting-selection strategies exist but sometimes they fail when a higher degree of detection is required especially if addressed to discriminate between dried fruits of relatively small dimensions and when aiming to perform an "early detection" of pathogen agents responsible of future moulds and decays development. Surface characteristics of dried fruits can be investigated by hyperspectral imaging (HSI). In this paper, specific and "ad hoc" applications addressed to propose quality detection logics, adopting a hyperspectral imaging (HSI) based approach, are described, compared and critically evaluated. Reflectance spectra of selected dried fruits (hazelnuts) of different quality and characterized by the presence of different contaminants and defects have been acquired by a laboratory device equipped with two HSI systems working in two different spectral ranges: visible-near infrared field (400-1000 nm) and near infrared field (1000-1700 nm). The spectra have been processed and results evaluated adopting both a simple and fast wavelength band ratio approach and a more sophisticated classification logic based on principal component (PCA) analysis.

  13. Assessing product image quality for online shopping

    Science.gov (United States)

    Goswami, Anjan; Chung, Sung H.; Chittar, Naren; Islam, Atiq

    2012-01-01

    Assessing product-image quality is important in the context of online shopping. A high quality image that conveys more information about a product can boost the buyer's confidence and can get more attention. However, the notion of image quality for product-images is not the same as that in other domains. The perception of quality of product-images depends not only on various photographic quality features but also on various high level features such as clarity of the foreground or goodness of the background etc. In this paper, we define a notion of product-image quality based on various such features. We conduct a crowd-sourced experiment to collect user judgments on thousands of eBay's images. We formulate a multi-class classification problem for modeling image quality by classifying images into good, fair and poor quality based on the guided perceptual notions from the judges. We also conduct experiments with regression using average crowd-sourced human judgments as target. We compute a pseudo-regression score with expected average of predicted classes and also compute a score from the regression technique. We design many experiments with various sampling and voting schemes with crowd-sourced data and construct various experimental image quality models. Most of our models have reasonable accuracies (greater or equal to 70%) on test data set. We observe that our computed image quality score has a high (0.66) rank correlation with average votes from the crowd sourced human judgments.

  14. Objective and Subjective Assessment of Digital Pathology Image Quality

    Directory of Open Access Journals (Sweden)

    Prarthana Shrestha

    2015-03-01

    Full Text Available The quality of an image produced by the Whole Slide Imaging (WSI scanners is of critical importance for using the image in clinical diagnosis. Therefore, it is very important to monitor and ensure the quality of images. Since subjective image quality assessments by pathologists are very time-consuming, expensive and difficult to reproduce, we propose a method for objective assessment based on clinically relevant and perceptual image parameters: sharpness, contrast, brightness, uniform illumination and color separation; derived from a survey of pathologists. We developed techniques to quantify the parameters based on content-dependent absolute pixel performance and to manipulate the parameters in a predefined range resulting in images with content-independent relative quality measures. The method does not require a prior reference model. A subjective assessment of the image quality is performed involving 69 pathologists and 372 images (including 12 optimal quality images and their distorted versions per parameter at 6 different levels. To address the inter-reader variability, a representative rating is determined as a one-tailed 95% confidence interval of the mean rating. The results of the subjective assessment support the validity of the proposed objective image quality assessment method to model the readers’ perception of image quality. The subjective assessment also provides thresholds for determining the acceptable level of objective quality per parameter. The images for both the subjective and objective quality assessment are based on the HercepTestTM slides scanned by the Philips Ultra Fast Scanners, developed at Philips Digital Pathology Solutions. However, the method is applicable also to other types of slides and scanners.

  15. Automated image analysis with the potential for process quality control applications in stem cell maintenance and differentiation.

    Science.gov (United States)

    Smith, David; Glen, Katie; Thomas, Robert

    2016-01-01

    The translation of laboratory processes into scaled production systems suitable for manufacture is a significant challenge for cell based therapies; in particular there is a lack of analytical methods that are informative and efficient for process control. Here the potential of image analysis as one part of the solution to this issue is explored, using pluripotent stem cell colonies as a valuable and challenging exemplar. The Cell-IQ live cell imaging platform was used to build image libraries of morphological culture attributes such as colony "edge," "core periphery" or "core" cells. Conventional biomarkers, such as Oct3/4, Nanog, and Sox-2, were shown to correspond to specific morphologies using immunostaining and flow cytometry techniques. Quantitative monitoring of these morphological attributes in-process using the reference image libraries showed rapid sensitivity to changes induced by different media exchange regimes or the addition of mesoderm lineage inducing cytokine BMP4. The imaging sample size to precision relationship was defined for each morphological attribute to show that this sensitivity could be achieved with a relatively low imaging sample. Further, the morphological state of single colonies could be correlated to individual colony outcomes; smaller colonies were identified as optimum for homogenous early mesoderm differentiation, while larger colonies maintained a morphologically pluripotent core. Finally, we show the potential of the same image libraries to assess cell number in culture with accuracy comparable to sacrificial digestion and counting. The data supports a potentially powerful role for quantitative image analysis in the setting of in-process specifications, and also for screening the effects of process actions during development, which is highly complementary to current analysis in optimization and manufacture.

  16. The study of surgical image quality evaluation system by subjective quality factor method

    Science.gov (United States)

    Zhang, Jian J.; Xuan, Jason R.; Yang, Xirong; Yu, Honggang; Koullick, Edouard

    2016-03-01

    GreenLightTM procedure is an effective and economical way of treatment of benign prostate hyperplasia (BPH); there are almost a million of patients treated with GreenLightTM worldwide. During the surgical procedure, the surgeon or physician will rely on the monitoring video system to survey and confirm the surgical progress. There are a few obstructions that could greatly affect the image quality of the monitoring video, like laser glare by the tissue and body fluid, air bubbles and debris generated by tissue evaporation, and bleeding, just to name a few. In order to improve the physician's visual experience of a laser surgical procedure, the system performance parameter related to image quality needs to be well defined. However, since image quality is the integrated set of perceptions of the overall degree of excellence of an image, or in other words, image quality is the perceptually weighted combination of significant attributes (contrast, graininess …) of an image when considered in its marketplace or application, there is no standard definition on overall image or video quality especially for the no-reference case (without a standard chart as reference). In this study, Subjective Quality Factor (SQF) and acutance are used for no-reference image quality evaluation. Basic image quality parameters, like sharpness, color accuracy, size of obstruction and transmission of obstruction, are used as subparameter to define the rating scale for image quality evaluation or comparison. Sample image groups were evaluated by human observers according to the rating scale. Surveys of physician groups were also conducted with lab generated sample videos. The study shows that human subjective perception is a trustworthy way of image quality evaluation. More systematic investigation on the relationship between video quality and image quality of each frame will be conducted as a future study.

  17. Process perspective on image quality evaluation

    Science.gov (United States)

    Leisti, Tuomas; Halonen, Raisa; Kokkonen, Anna; Weckman, Hanna; Mettänen, Marja; Lensu, Lasse; Ritala, Risto; Oittinen, Pirkko; Nyman, Göte

    2008-01-01

    The psychological complexity of multivariate image quality evaluation makes it difficult to develop general image quality metrics. Quality evaluation includes several mental processes and ignoring these processes and the use of a few test images can lead to biased results. By using a qualitative/quantitative (Interpretation Based Quality, IBQ) methodology, we examined the process of pair-wise comparison in a setting, where the quality of the images printed by laser printer on different paper grades was evaluated. Test image consisted of a picture of a table covered with several objects. Three other images were also used, photographs of a woman, cityscape and countryside. In addition to the pair-wise comparisons, observers (N=10) were interviewed about the subjective quality attributes they used in making their quality decisions. An examination of the individual pair-wise comparisons revealed serious inconsistencies in observers' evaluations on the test image content, but not on other contexts. The qualitative analysis showed that this inconsistency was due to the observers' focus of attention. The lack of easily recognizable context in the test image may have contributed to this inconsistency. To obtain reliable knowledge of the effect of image context or attention on subjective image quality, a qualitative methodology is needed.

  18. Image quality, compression and segmentation in medicine.

    Science.gov (United States)

    Morgan, Pam; Frankish, Clive

    2002-12-01

    This review considers image quality in the context of the evolving technology of image compression, and the effects image compression has on perceived quality. The concepts of lossless, perceptually lossless, and diagnostically lossless but lossy compression are described, as well as the possibility of segmented images, combining lossy compression with perceptually lossless regions of interest. The different requirements for diagnostic and training images are also discussed. The lack of established methods for image quality evaluation is highlighted and available methods discussed in the light of the information that may be inferred from them. Confounding variables are also identified. Areas requiring further research are illustrated, including differences in perceptual quality requirements for different image modalities, image regions, diagnostic subtleties, and tasks. It is argued that existing tools for measuring image quality need to be refined and new methods developed. The ultimate aim should be the development of standards for image quality evaluation which take into consideration both the task requirements of the images and the acceptability of the images to the users.

  19. PRACTICAL APPLICATION OF QUALITY TOOLS

    Directory of Open Access Journals (Sweden)

    Duško Pavletić

    2008-09-01

    Full Text Available The paper is dealing with one segment of broader research of universality an systematicness in application of seven basic quality tools (7QC tools, which is possible to use in different areas: power plant, process industry, government, health and tourism services. The aim of the paper was to show on practical examples that there is real possibility of application of 7QC tools. Furthermore, the research has to show to what extent are selected tools in usage and what reasons of avoiding their broader application are. The simple example of successful application of the quality tools are shown on selected company in process industry.

  20. Hyperspectral Image Analysis of Food Quality

    DEFF Research Database (Denmark)

    Arngren, Morten

    Assessing the quality of food is a vital step in any food processing line to ensurethe best food quality and maximum profit for the farmer and food manufacturer.Traditional quality evaluation methods are often destructive and labourintensive procedures relying on wet chemistry or subjective human...... inspection.Near-infrared spectroscopy can address these issues by offering a fast and objectiveanalysis of the food quality. A natural extension to these single spectrumNIR systems is to include image information such that each pixel holds a NIRspectrum. This augmented image information offers several...... extensions to the analysis offood quality. This dissertation is concerned with hyperspectral image analysisused to assess the quality of single grain kernels. The focus is to highlight thebenefits and challenges of using hyperspectral imaging for food quality presentedin two research directions. Initially...

  1. WFC3 IR Image Quality

    Science.gov (United States)

    Dressel, Linda

    2009-07-01

    The IR imaging performance over the detector will be assessed periodically {every 4 months} in two passbands to check for image stability. The field around star 58 in the open cluster NGC188 is the chosen target because it is sufficiently dense to provide good sampling over the FOV while providing enough isolated stars to permit accurate PSF {point spread function} measurement. It is available year-round and used previously for ACS image quality assessment. The field is astrometric, and astrometric guide stars will be used, so that the plate scale and image orientation may also be determined if necessary {as in SMOV proposals 11437 and 11443}. Full frame images will be obtained at each of 4 POSTARG offset positions designed to improve sampling over the detector in F098M, F105W, and F160W. The PSFs will be sampled at 4 positions with subpixel shifts in filters F164N and F127M.This proposal is a periodic repeat {once every 4 months} of the visits in SMOV proposal 11437 {activity ID WFC3-24}. The data will be analyzed using the code and techniques described in ISR WFC3 2008-41 {Hartig}. Profiles of encircled energy will be monitored and presented in an ISR. If an update to the SIAF is needed, {V2,V3} locations of stars will be obtained from the Flight Ops Sensors and Calibrations group at GSFC, the {V2,V3} of the reference pixel and the orientation of the detector will be determined by the WFC3 group, and the Telescopes group will update and deliver the SIAF to the PRDB branch.The specific PSF metrics to be examined are encircled energy for aperture diameter 0.25, 0.37, and 0.60 arcsec, FWHM, and sharpness. {See ISR WFC3 2008-41 tables 2 and 3 and preceding text.} 20 stars distributed over the detector will be measured in each exposure for each filter. The mean, rms, and rms of the mean will be determined for each metric. The values determined from each of the 4 exposures per filter within a visit will be compared to each other to see to what extent they are affected

  2. WFC3 UVIS Image Quality

    Science.gov (United States)

    Dressel, Linda

    2009-07-01

    The UVIS imaging performance over the detector will be assessed periodically {every 4 months} in two passbands {F275W and F621M} to check for image stability. The field around star 58 in the open cluster NGC188 is the chosen target because it is sufficiently dense to provide good sampling over the FOV while providing enough isolated stars to permit accurate PSF {point spread function} measurement. It is available year-round and used previously for ACS image quality assessment. The field is astrometric, and astrometric guide stars will be used, so that the plate scale and image orientation may also be determined if necessary {as in SMOV proposals 11436 and 11442}. Full frame images will be obtained at each of 4 POSTARG offset positions designed to improve sampling over the detector.This proposal is a periodic repeat {once every 4 months} of visits similar to those in SMOV proposal 11436 {activity ID WFC3-23}. The data will be analyzed using the code and techniques described in ISR WFC3 2008-40 {Hartig}. Profiles of encircled energy will be monitored and presented in an ISR. If an update to the SIAF is needed, {V2,V3} locations of stars will be obtained from the Flight Ops Sensors and Calibrations group at GSFC, the {V2,V3} of the reference pixel and the orientation of the detector will be determined by the WFC3 group, and the Telescopes group will update and deliver the SIAF to the PRDB branch.The specific PSF metrics to be examined are encircled energy for aperture diameter 0.15, 0.20, 0.25, and 0.35 arcsec, FWHM, and sharpness. {See ISR WFC3 2008-40 tables 2 and 3 and preceding text.} about 20 stars distributed over the detector will be measured in each exposure for each filter. The mean, rms, and rms of the mean will be determined for each metric. The values determined from each of the 4 exposures per filter within a visit will be compared to each other to see to what extent they are affected by "breathing". Values will be compared from visit to visit, starting

  3. Image Signature Based Mean Square Error for Image Quality Assessment

    Institute of Scientific and Technical Information of China (English)

    CUI Ziguan; GAN Zongliang; TANG Guijin; LIU Feng; ZHU Xiuchang

    2015-01-01

    Motivated by the importance of Human visual system (HVS) in image processing, we propose a novel Image signature based mean square error (ISMSE) metric for full reference Image quality assessment (IQA). Efficient image signature based describer is used to predict visual saliency map of the reference image. The saliency map is incorporated into luminance diff erence between the reference and distorted images to obtain image quality score. The eff ect of luminance diff erence on visual quality with larger saliency value which is usually corresponding to foreground objects is highlighted. Experimental results on LIVE database release 2 show that by integrating the eff ects of image signature based saliency on luminance dif-ference, the proposed ISMSE metric outperforms several state-of-the-art HVS-based IQA metrics but with lower complexity.

  4. Standardizing Quality Assessment of Fused Remotely Sensed Images

    Science.gov (United States)

    Pohl, C.; Moellmann, J.; Fries, K.

    2017-09-01

    The multitude of available operational remote sensing satellites led to the development of many image fusion techniques to provide high spatial, spectral and temporal resolution images. The comparison of different techniques is necessary to obtain an optimized image for the different applications of remote sensing. There are two approaches in assessing image quality: 1. Quantitatively by visual interpretation and 2. Quantitatively using image quality indices. However an objective comparison is difficult due to the fact that a visual assessment is always subject and a quantitative assessment is done by different criteria. Depending on the criteria and indices the result varies. Therefore it is necessary to standardize both processes (qualitative and quantitative assessment) in order to allow an objective image fusion quality evaluation. Various studies have been conducted at the University of Osnabrueck (UOS) to establish a standardized process to objectively compare fused image quality. First established image fusion quality assessment protocols, i.e. Quality with No Reference (QNR) and Khan's protocol, were compared on varies fusion experiments. Second the process of visual quality assessment was structured and standardized with the aim to provide an evaluation protocol. This manuscript reports on the results of the comparison and provides recommendations for future research.

  5. IMAGE QUALITY FORECASTING FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2013-05-01

    Full Text Available The article deals with an approach to quality predicting of the space objects images, which can be used to plan optoelectronic systems of remote sensing satellites work programs. The proposed approach is based on evaluation of the optoelectronic equipment transfer properties and calculation of indexes images quality considering the influence of the orbital shooting conditions.

  6. Sparse microwave imaging: Principles and applications

    Institute of Scientific and Technical Information of China (English)

    ZHANG BingChen; HONG Wen; WU YiRong

    2012-01-01

    This paper provides principles and applications of the sparse microwave imaging theory and technology.Synthetic aperture radar (SAR) is an important method of modern remote sensing.During decades microwave imaging technology has achieved remarkable progress in the system performance of microwave imaging technology,and at the same time encountered increasing complexity in system implementation.The sparse microwave imaging introduces the sparse signal processing theory to radar imaging to obtain new theory,new system and new methodology of microwave imaging.Based on classical SAR imaging model and fundamental theories of sparse signal processing,we can derive the model of sparse microwave imaging,which is a sparse measurement and recovery problem and can be solved with various algorithms.There exist several fundamental points that must be considered in the efforts of applying sparse signal processing to radar imaging,including sparse representation,measurement matrix construction,unambiguity reconstruction and performance evaluation.Based on these considerations,the sparse signal processing could be successfully applied to radar imaging,and achieve benefits in several aspects,including improvement of image quality,reduction of data amount for sparse scene and enhancement of system performance.The sparse signal processing has also been applied in several specific radar imaging applications.

  7. Digital image quality measurements by objective and subjective methods from series of parametrically degraded images

    Science.gov (United States)

    Tachó, Aura; Mitjà, Carles; Martínez, Bea; Escofet, Jaume; Ralló, Miquel

    2013-11-01

    Many digital image applications like digitization of cultural heritage for preservation purposes operate with compressed files in one or more image observing steps. For this kind of applications JPEG compression is one of the most widely used. Compression level, final file size and quality loss are parameters that must be managed optimally. Although this loss can be monitored by means of objective image quality measurements, the real challenge is to know how it can be related with the perceived image quality by observers. A pictorial image has been degraded by two different procedures. The first, applying different levels of low pass filtering by convolving the image with progressively broad Gauss kernels. The second, saving the original file to a series of JPEG compression levels. In both cases, the objective image quality measurement is done by analysis of the image power spectrum. In order to obtain a measure of the perceived image quality, both series of degraded images are displayed on a computer screen organized in random pairs. The observers are compelled to choose the best image of each pair. Finally, a ranking is established applying Thurstone scaling method. Results obtained by both measurements are compared between them and with other objective measurement method as the Slanted Edge Test.

  8. Total Variation Based Perceptual Image Quality Assessment Modeling

    Directory of Open Access Journals (Sweden)

    Yadong Wu

    2014-01-01

    Full Text Available Visual quality measure is one of the fundamental and important issues to numerous applications of image and video processing. In this paper, based on the assumption that human visual system is sensitive to image structures (edges and image local luminance (light stimulation, we propose a new perceptual image quality assessment (PIQA measure based on total variation (TV model (TVPIQA in spatial domain. The proposed measure compares TVs between a distorted image and its reference image to represent the loss of image structural information. Because of the good performance of TV model in describing edges, the proposed TVPIQA measure can illustrate image structure information very well. In addition, the energy of enclosed regions in a difference image between the reference image and its distorted image is used to measure the missing luminance information which is sensitive to human visual system. Finally, we validate the performance of TVPIQA measure with Cornell-A57, IVC, TID2008, and CSIQ databases and show that TVPIQA measure outperforms recent state-of-the-art image quality assessment measures.

  9. CMOS Image Sensors for High Speed Applications

    Directory of Open Access Journals (Sweden)

    M. Jamal Deen

    2009-01-01

    Full Text Available Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4~5 μm due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps.

  10. CMOS Image Sensors for High Speed Applications.

    Science.gov (United States)

    El-Desouki, Munir; Deen, M Jamal; Fang, Qiyin; Liu, Louis; Tse, Frances; Armstrong, David

    2009-01-01

    Recent advances in deep submicron CMOS technologies and improved pixel designs have enabled CMOS-based imagers to surpass charge-coupled devices (CCD) imaging technology for mainstream applications. The parallel outputs that CMOS imagers can offer, in addition to complete camera-on-a-chip solutions due to being fabricated in standard CMOS technologies, result in compelling advantages in speed and system throughput. Since there is a practical limit on the minimum pixel size (4∼5 μm) due to limitations in the optics, CMOS technology scaling can allow for an increased number of transistors to be integrated into the pixel to improve both detection and signal processing. Such smart pixels truly show the potential of CMOS technology for imaging applications allowing CMOS imagers to achieve the image quality and global shuttering performance necessary to meet the demands of ultrahigh-speed applications. In this paper, a review of CMOS-based high-speed imager design is presented and the various implementations that target ultrahigh-speed imaging are described. This work also discusses the design, layout and simulation results of an ultrahigh acquisition rate CMOS active-pixel sensor imager that can take 8 frames at a rate of more than a billion frames per second (fps).

  11. Digital radiography image quality: image processing and display.

    Science.gov (United States)

    Krupinski, Elizabeth A; Williams, Mark B; Andriole, Katherine; Strauss, Keith J; Applegate, Kimberly; Wyatt, Margaret; Bjork, Sandra; Seibert, J Anthony

    2007-06-01

    This article on digital radiography image processing and display is the second of two articles written as part of an intersociety effort to establish image quality standards for digital and computed radiography. The topic of the other paper is digital radiography image acquisition. The articles were developed collaboratively by the ACR, the American Association of Physicists in Medicine, and the Society for Imaging Informatics in Medicine. Increasingly, medical imaging and patient information are being managed using digital data during acquisition, transmission, storage, display, interpretation, and consultation. The management of data during each of these operations may have an impact on the quality of patient care. These articles describe what is known to improve image quality for digital and computed radiography and to make recommendations on optimal acquisition, processing, and display. The practice of digital radiography is a rapidly evolving technology that will require timely revision of any guidelines and standards.

  12. Image Quality Modeling and Optimization for Non-Conventional Aperture Imaging Systems

    Science.gov (United States)

    Salvaggio, Philip S.

    The majority of image quality studies have been performed on systems with conventional aperture functions. These systems have straightforward aperture designs and well-understood behavior. Image quality for these systems can be predicted by the General Image Quality Equation (GIQE). However, in order to continue pushing the boundaries of imaging, more control over the point spread function of an imaging system may be necessary. This requires modifications in the pupil plane of a system, causing a departure from the realm of most image quality studies. Examples include sparse apertures, synthetic apertures, coded apertures and phase elements. This work will focus on sparse aperture telescopes and the image quality issues associated with them, however, the methods presented will be applicable to other non-conventional aperture systems. In this research, an approach for modeling the image quality of non-conventional aperture systems will be introduced. While the modeling approach is based in previous work, a novel validation study will be performed, which accounts for the effects of both broadband illumination and wavefront error. One of the key image quality challenges for sparse apertures is post-processing ringing artifacts. These artifacts have been observed in modeled data, but a validation study will be performed to observe them in measured data and to compare them to model predictions. Once validated, the modeling approach will be used to perform a small set of design studies for sparse aperture systems, including spectral bandpass selection and aperture layout optimization.

  13. Molecular imaging. Fundamentals and applications

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Jie (ed.) [Chinese Academy of Sciences, Beijing (China). Intelligent Medical Research Center

    2013-07-01

    Covers a wide range of new theory, new techniques and new applications. Contributed by many experts in China. The editor has obtained the National Science and Technology Progress Award twice. ''Molecular Imaging: Fundamentals and Applications'' is a comprehensive monograph which describes not only the theory of the underlying algorithms and key technologies but also introduces a prototype system and its applications, bringing together theory, technology and applications. By explaining the basic concepts and principles of molecular imaging, imaging techniques, as well as research and applications in detail, the book provides both detailed theoretical background information and technical methods for researchers working in medical imaging and the life sciences. Clinical doctors and graduate students will also benefit from this book.

  14. Assessment of CT image quality using a Bayesian approach

    Science.gov (United States)

    Reginatto, M.; Anton, M.; Elster, C.

    2017-08-01

    One of the most promising approaches for evaluating CT image quality is task-specific quality assessment. This involves a simplified version of a clinical task, e.g. deciding whether an image belongs to the class of images that contain the signature of a lesion or not. Task-specific quality assessment can be done by model observers, which are mathematical procedures that carry out the classification task. The most widely used figure of merit for CT image quality is the area under the ROC curve (AUC), a quantity which characterizes the performance of a given model observer. In order to estimate AUC from a finite sample of images, different approaches from classical statistics have been suggested. The goal of this paper is to introduce task-specific quality assessment of CT images to metrology and to propose a novel Bayesian estimation of AUC for the channelized Hotelling observer (CHO) applied to the task of detecting a lesion at a known image location. It is assumed that signal-present and signal-absent images follow multivariate normal distributions with the same covariance matrix. The Bayesian approach results in a posterior distribution for the AUC of the CHO which provides in addition a complete characterization of the uncertainty of this figure of merit. The approach is illustrated by its application to both simulated and experimental data.

  15. Evaluating Picture Quality of Image Plates in Digital CR Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Byung Joon [Dept. of Radiological Tecnology, Choonhae College of Health Science, Ulsan (Korea, Republic of); Ji Tae Jeong [Dept. of Radiological Science, Kaya University, Kimhae (Korea, Republic of)

    2011-12-15

    Lab effectively supplemented the effects of outside radiation on image plates in the process of image acquisition of CR (computed radiography) systems and conducted for effective utilization in the case of clinical application. For this, Lab classified the storage places and time periods of image plates and compared and analyzed the differences between small dark spots. Lab also assessed the concentration distribution within the boundaries of images. Lab compared and measured the number of dark spots in a light room and a dark room depending on the storage places of image plates and found that dark spots slightly increased in an image plate when stored in a light room on the first and second days. Dark spots increased in proportion to the length of time stored. In the case of the image plate stored in a dark room, the number of dark spots remarkably decreased. With regard to picture quality as related to the location of image plates, the damage to picture quality could be reduced by locating regions of interest in the center. With regard to differences in sharpness following changes in the thickness of subjects, fewer scatter rays occurred and sharpness improved by reducing the thickness of subjects as much as possible. To get medical images of excellent quality, image plates should be managed effectively and it is desirable to keep images plates in dark iron plate boxes and not to expose them to outside radiation for a long time.

  16. Hyperspectral imaging and its applications

    Science.gov (United States)

    Serranti, S.; Bonifazi, G.

    2016-04-01

    Hyperspectral imaging (HSI) is an emerging technique that combines the imaging properties of a digital camera with the spectroscopic properties of a spectrometer able to detect the spectral attributes of each pixel in an image. For these characteristics, HSI allows to qualitatively and quantitatively evaluate the effects of the interactions of light with organic and/or inorganic materials. The results of this interaction are usually displayed as a spectral signature characterized by a sequence of energy values, in a pre-defined wavelength interval, for each of the investigated/collected wavelength. Following this approach, it is thus possible to collect, in a fast and reliable way, spectral information that are strictly linked to chemical-physical characteristics of the investigated materials and/or products. Considering that in an hyperspectral image the spectrum of each pixel can be analyzed, HSI can be considered as one of the best nondestructive technology allowing to perform the most accurate and detailed information extraction. HSI can be applied in different wavelength fields, the most common are the visible (VIS: 400-700 nm), the near infrared (NIR: 1000-1700 nm) and the short wave infrared (SWIR: 1000-2500 nm). It can be applied for inspections from micro- to macro-scale, up to remote sensing. HSI produces a large amount of information due to the great number of continuous collected spectral bands. Such an approach, when successful, is quite challenging being usually reliable, robust and characterized by lower costs, if compared with those usually associated to commonly applied analytical off-line and/or on-line analytical approaches. More and more applications have been thus developed and tested, in these last years, especially in food inspection, with a large range of investigated products, such as fruits and vegetables, meat, fish, eggs and cereals, but also in medicine and pharmaceutical sector, in cultural heritage, in material characterization and in

  17. Food quality assessment by NIR hyperspectral imaging

    Science.gov (United States)

    Whitworth, Martin B.; Millar, Samuel J.; Chau, Astor

    2010-04-01

    Near infrared reflectance (NIR) spectroscopy is well established in the food industry for rapid compositional analysis of bulk samples. NIR hyperspectral imaging provides new opportunities to measure the spatial distribution of components such as moisture and fat, and to identify and measure specific regions of composite samples. An NIR hyperspectral imaging system has been constructed for food research applications, incorporating a SWIR camera with a cooled 14 bit HgCdTe detector and N25E spectrograph (Specim Ltd, Finland). Samples are scanned in a pushbroom mode using a motorised stage. The system has a spectral resolution of 256 pixels covering a range of 970-2500 nm and a spatial resolution of 320 pixels covering a swathe adjustable from 8 to 300 mm. Images are acquired at a rate of up to 100 lines s-1, enabling samples to be scanned within a few seconds. Data are captured using SpectralCube software (Specim) and analysed using ENVI and IDL (ITT Visual Information Solutions). Several food applications are presented. The strength of individual absorbance bands enables the distribution of particular components to be assessed. Examples are shown for detection of added gluten in wheat flour and to study the effect of processing conditions on fat distribution in chips/French fries. More detailed quantitative calibrations have been developed to study evolution of the moisture distribution in baguettes during storage at different humidities, to assess freshness of fish using measurements of whole cod and fillets, and for prediction of beef quality by identification and separate measurement of lean and fat regions.

  18. Image quality dependence on image processing software in computed radiography

    Directory of Open Access Journals (Sweden)

    Lourens Jochemus Strauss

    2012-06-01

    Full Text Available Background. Image post-processing gives computed radiography (CR a considerable advantage over film-screen systems. After digitisation of information from CR plates, data are routinely processed using manufacturer-specific software. Agfa CR readers use MUSICA software, and an upgrade with significantly different image appearance was recently released: MUSICA2. Aim. This study quantitatively compares the image quality of images acquired without post-processing (flatfield with images processed using these two software packages. Methods. Four aspects of image quality were evaluated. An aluminium step-wedge was imaged using constant mA at tube voltages varying from 40 to 117kV. Signal-to-noise ratios (SNRs and contrast-to-noise Ratios (CNRs were calculated from all steps. Contrast variation with object size was evaluated with visual assessment of images of a Perspex contrast-detail phantom, and an image quality figure (IQF was calculated. Resolution was assessed using modulation transfer functions (MTFs. Results. SNRs for MUSICA2 were generally higher than the other two methods. The CNRs were comparable between the two software versions, although MUSICA2 had slightly higher values at lower kV. The flatfield CNR values were better than those for the processed images. All images showed a decrease in CNRs with tube voltage. The contrast-detail measurements showed that both MUSICA programmes improved the contrast of smaller objects. MUSICA2 was found to give the lowest (best IQF; MTF measurements confirmed this, with values at 3.5 lp/mm of 10% for MUSICA2, 8% for MUSICA and 5% for flatfield. Conclusion. Both MUSICA software packages produced images with better contrast resolution than unprocessed images. MUSICA2 has slightly improved image quality than MUSICA.

  19. Image Quality Meter Using Compression

    Directory of Open Access Journals (Sweden)

    Muhammad Ibrar-Ul-Haque

    2016-01-01

    Full Text Available This paper proposed a new technique to compressed image blockiness/blurriness in frequency domain through edge detection method by applying Fourier transform. In image processing, boundaries are characterized by edges and thus, edges are the problems of fundamental importance. The edges have to be identified and computed thoroughly in order to retrieve the complete illustration of the image. Our novel edge detection scheme for blockiness and blurriness shows improvement of 60 and 100 blocks for high frequency components respectively than any other detection technique.

  20. Image quality improvement for underground radar by block migration method

    Science.gov (United States)

    Ho, Gwangsu; Kawanaka, Akira; Takagi, Mikio

    1993-11-01

    Techniques have been developed which have been imaging optically opaque regions using an electromagnetic wave radar in order to estimate the location of the objects in those regions. One important application of these techniques is the detection of buried pipes and cables. In the case of underground radar, its image quality often becomes low because the nature of the soil is not uniform and an electromagnetic wave is attenuated in soil. Hence, the method which improves the quality of the radar images is required. In this paper, we point out that the quality of underground images can be improved significantly by means of the block migration method. In this method LOT (Lapped Orthogonal Transform) was applied. LOT is a new block transform method in which basis functions overlap in adjacent blocks, and it has a fast computation algorithm. In addition to above, we propose a method of estimating dielectric constant in soil using the processed images. The result of applying the block migration method to the underground radar images are presented. It points out the good capability for the image quality improvement and the application of LOT can improve the influence by blocking and the processing time. Also the dielectric constant in each block can be estimated accurately.

  1. Perceptual Depth Quality in Distorted Stereoscopic Images.

    Science.gov (United States)

    Wang, Jiheng; Wang, Shiqi; Ma, Kede; Wang, Zhou

    2017-03-01

    Subjective and objective measurement of the perceptual quality of depth information in symmetrically and asymmetrically distorted stereoscopic images is a fundamentally important issue in stereoscopic 3D imaging that has not been deeply investigated. Here, we first carry out a subjective test following the traditional absolute category rating protocol widely used in general image quality assessment research. We find this approach problematic, because monocular cues and the spatial quality of images have strong impact on the depth quality scores given by subjects, making it difficult to single out the actual contributions of stereoscopic cues in depth perception. To overcome this problem, we carry out a novel subjective study where depth effect is synthesized at different depth levels before various types and levels of symmetric and asymmetric distortions are applied. Instead of following the traditional approach, we ask subjects to identify and label depth polarizations, and a depth perception difficulty index (DPDI) is developed based on the percentage of correct and incorrect subject judgements. We find this approach highly effective at quantifying depth perception induced by stereo cues and observe a number of interesting effects regarding image content dependency, distortion-type dependence, and the impact of symmetric versus asymmetric distortions. Furthermore, we propose a novel computational model for DPDI prediction. Our results show that the proposed model, without explicitly identifying image distortion types, leads to highly promising DPDI prediction performance. We believe that these are useful steps toward building a comprehensive understanding on 3D quality-of-experience of stereoscopic images.

  2. Perceptual image quality in normalized LOG domain for Adaptive Optics image post-processing

    Science.gov (United States)

    Guo, Shiping; Zhang, Rongzhi; Li, Jisheng; Zou, Jianhua; Liu, Changhai; Gao, Weizhe

    2015-08-01

    Adaptive Optics together with subsequent post-processing techniques obviously improve the resolution of turbulencedegraded images in ground-based space objects detection and identification. The most common method for frame selection and stopping iteration in post-processing has always been subjective viewing of the images due to a lack of widely agreed-upon objective quality metric. Full reference metrics are not applicable for assessing the field data, no-reference metrics tend to perform poor sensitivity for Adaptive Optics images. In the present work, based on the Laplacian of Gaussian (LOG) local contrast feature, a nonlinear normalization is applied to transform the input image into a normalized LOG domain; a quantitative index is then extracted in this domain to assess the perceptual image quality. Experiments show this no-reference quality index is highly consistent with the subjective evaluation of input images for different blur degree and different iteration number.

  3. BIOLUMINESCENCE IMAGING: PROGRESS AND APPLICATIONS

    OpenAIRE

    Badr, Christian E.; Tannous, Bakhos A

    2011-01-01

    Application of bioluminescence imaging has grown tremendously in the past decade and has significantly contributed to the core conceptual advances in biomedical research. This technology provides valuable means for monitoring of different biological processes for immunology, oncology, virology and neuroscience. In this review, we will discuss current trends in bioluminescence and its application in different fields with emphasis on cancer research.

  4. NOVEL IMAGE-DEPENDENT QUALITY ASSESSMENT MEASURES

    OpenAIRE

    Asaad Noori Hashim; Zahir M. Hussain

    2014-01-01

    The image is a 2D signal whose pixels are highly correlated in a 2D manner. Hence, using pixel by pixel error what we called previously Mean-Square Error, (MSE) is not an efficient way to compare two similar images (e.g., an original image and a compressed version of it). Due to this correlation, image comparison needs a correlative quality measure. It is clear that correlation between two signals gives an idea about the relation between samples of the two signals. Generally speaking, correla...

  5. Comprehensive model for predicting perceptual image quality of smart mobile devices.

    Science.gov (United States)

    Gong, Rui; Xu, Haisong; Luo, M R; Li, Haifeng

    2015-01-01

    An image quality model for smart mobile devices was proposed based on visual assessments of several image quality attributes. A series of psychophysical experiments were carried out on two kinds of smart mobile devices, i.e., smart phones and tablet computers, in which naturalness, colorfulness, brightness, contrast, sharpness, clearness, and overall image quality were visually evaluated under three lighting environments via categorical judgment method for various application types of test images. On the basis of Pearson correlation coefficients and factor analysis, the overall image quality could first be predicted by its two constituent attributes with multiple linear regression functions for different types of images, respectively, and then the mathematical expressions were built to link the constituent image quality attributes with the physical parameters of smart mobile devices and image appearance factors. The procedure and algorithms were applicable to various smart mobile devices, different lighting conditions, and multiple types of images, and performance was verified by the visual data.

  6. Application and operating technique for quality control of bone imaging%骨显像的技术操作及应用与质量控制

    Institute of Scientific and Technical Information of China (English)

    陈瑞玲; 冯瑾; 杨芳

    2012-01-01

    目的 探讨通过注意骨显像的技术操作要点及正确使用骨显像的各种方式提高骨显像影像质量的方法.方法 对本科2011年~2012年2543例接受骨显像检查的患者进行分析.显像仪器为GE公司生产的Infinia VC Hawkeye双探头带符合线路SPECT,配低能通用型准直器.全身骨显像、局部骨显像、SPECT/CT骨显像静脉注入显像剂,注射后嘱患者饮水500~1000ml,于3~4h后开始检查;三时相骨显像采用“弹丸”式静脉注射显像剂,于即刻、10min、3~4h分别采集血流相、血池相和延迟相.结果 2543例接受骨显像检查的患者,行全身骨显像2543例(100%),行三时相骨显像366(14.4%),行局部骨显像168例(6.6%),行SPECT/CT骨显像81例(3.2%).结论 技师可通过熟练掌握不同方式骨显像的操作技术及其适应症,并充分利用核医学全身显像、局部显像等各种显像方式的优势来提高骨显像影像质量.%Objective To investigate methods for improving the quality of bone scan imaging through operational technical points and proper pattern of bone Imaging. Methods Bone scans of 2 543 patients during 2011 ~ 2012 were reviewed. Imaging instrument was the GE Infinia VC Hawkeye dual-detect coincidence SPECT/CT, with low energy universal colli-mator. Bone Imaging agent was injected intravenously in whole body bone imaging, local bone imaging, and SPECT/CT imaging. Patients were asked to drink 500~1 000 ml water after injection, and accepted examination in 3~4 hours. Pellet injection was used in three-phase bone scan, blood flow imaging, blood pool imaging and late imaging were taken immediately, and 3~4 hours respectively. Results 2 543 patients received bone scan. 2 543 cases were taken whole body bone Imaging (100%), 366 cases were taken three phase bone Imaging (14. 4%), 168 cases were taken local bone Imaging (6. 6%), 81 cases were taken SPECT/CT (3. 2%). Conclusion Technicians can impove the quality of bone scan

  7. Improving the Image Quality of Synthetic Transmit Aperture Ultrasound Images - Achieving Real-Time In-Vivo Imaging

    DEFF Research Database (Denmark)

    Gammelmark, Kim

    2004-01-01

    to increase the SNR, which employs multi-element subapertures and linearly frequency modulated (FM) signals at each emission. The subaperture is applied to emulate a high power spherical wave transmitted by a virtual point source positioned behind the subaperture, and the linear FM signal replaces...... in-vivo experiments, showed, that TMS imaging can increase the SNR by as much as 17 dB compared to the traditional imaging techniques, which improves the in-vivo image quality to a highly competitive level. An in-vivo evaluation of convex array TMS imaging for abdominal imaging applications...

  8. SIMPLE QUALITY ASSESSMENT FOR BINARY IMAGES

    Institute of Scientific and Technical Information of China (English)

    Zhang Chun'e; Qiu Zhengding

    2007-01-01

    Usually image assessment methods could be classified into two categories: subjective assessments and objective ones. The latter are judged by the correlation coefficient with subjective quality measurement MOS (Mean Opinion Score). This paper presents an objective quality assessment algorithm special for binary images. In the algorithm, noise energy is measured by Euclidean distance between noises and signals and the structural effects caused by noise are described by Euler number change. The assessment on image quality is calculated quantitatively in terms of PSNR (Peak Signal to Noise Ratio). Our experiments show that the results of the algorithm are highly correlative with subjective MOS and the algorithm is more simple and computational saving than traditional objective assessment methods.

  9. An approach for quantitative image quality analysis for CT

    Science.gov (United States)

    Rahimi, Amir; Cochran, Joe; Mooney, Doug; Regensburger, Joe

    2016-03-01

    An objective and standardized approach to assess image quality of Compute Tomography (CT) systems is required in a wide variety of imaging processes to identify CT systems appropriate for a given application. We present an overview of the framework we have developed to help standardize and to objectively assess CT image quality for different models of CT scanners used for security applications. Within this framework, we have developed methods to quantitatively measure metrics that should correlate with feature identification, detection accuracy and precision, and image registration capabilities of CT machines and to identify strengths and weaknesses in different CT imaging technologies in transportation security. To that end we have designed, developed and constructed phantoms that allow for systematic and repeatable measurements of roughly 88 image quality metrics, representing modulation transfer function, noise equivalent quanta, noise power spectra, slice sensitivity profiles, streak artifacts, CT number uniformity, CT number consistency, object length accuracy, CT number path length consistency, and object registration. Furthermore, we have developed a sophisticated MATLAB based image analysis tool kit to analyze CT generated images of phantoms and report these metrics in a format that is standardized across the considered models of CT scanners, allowing for comparative image quality analysis within a CT model or between different CT models. In addition, we have developed a modified sparse principal component analysis (SPCA) method to generate a modified set of PCA components as compared to the standard principal component analysis (PCA) with sparse loadings in conjunction with Hotelling T2 statistical analysis method to compare, qualify, and detect faults in the tested systems.

  10. [Application possibilities of chemical imaging in pharmaceutical technology].

    Science.gov (United States)

    Vajna, Balázs; Nagy, Zsombor; Patyi, Gergo; Zsigmond, Zsolt; Antal, István; Marosi, György

    2009-01-01

    Chemical imaging is a novel analytical method that simultaneously delivers spatial, chemical, structural, and functional information on the dosage forms. Both infrared and Raman spectroscopic imaging may serve as useful nondestructive analytical techniques in the pharmaceutical product development and quality control. Most important application possibilities are reviewed and some studies demonstrate the advantages of the structure exploration. Raman imaging is suitable to understand and control the quality attributes of different dosage forms.

  11. Subjective matters: from image quality to image psychology

    Science.gov (United States)

    Fedorovskaya, Elena A.; De Ridder, Huib

    2013-03-01

    From the advent of digital imaging through several decades of studies, the human vision research community systematically focused on perceived image quality and digital artifacts due to resolution, compression, gamma, dynamic range, capture and reproduction noise, blur, etc., to help overcome existing technological challenges and shortcomings. Technological advances made digital images and digital multimedia nearly flawless in quality, and ubiquitous and pervasive in usage, provide us with the exciting but at the same time demanding possibility to turn to the domain of human experience including higher psychological functions, such as cognition, emotion, awareness, social interaction, consciousness and Self. In this paper we will outline the evolution of human centered multidisciplinary studies related to imaging and propose steps and potential foci of future research.

  12. Biomedical Imaging Principles and Applications

    CERN Document Server

    Salzer, Reiner

    2012-01-01

    This book presents and describes imaging technologies that can be used to study chemical processes and structural interactions in dynamic systems, principally in biomedical systems. The imaging technologies, largely biomedical imaging technologies such as MRT, Fluorescence mapping, raman mapping, nanoESCA, and CARS microscopy, have been selected according to their application range and to the chemical information content of their data. These technologies allow for the analysis and evaluation of delicate biological samples, which must not be disturbed during the profess. Ultimately, this may me

  13. Medical imaging technology and applications

    CERN Document Server

    Iniewski, Krzysztof

    2014-01-01

    The book has two intentions. First, it assembles the latest research in the field of medical imaging technology in one place. Detailed descriptions of current state-of-the-art medical imaging systems (comprised of x-ray CT, MRI, ultrasound, and nuclear medicine) and data processing techniques are discussed. Information is provided that will give interested engineers and scientists a solid foundation from which to build with additional resources. Secondly, it exposes the reader to myriad applications that medical imaging technology has enabled.

  14. Comparison-based Image Quality Assessment for Selecting Image Restoration Parameters.

    Science.gov (United States)

    Liang, Haoyi; Weller, Daniel

    2016-08-19

    Image quality assessment (IQA) is traditionally classified into full-reference (FR) IQA, reduced-reference (RR) IQA, and no-reference (NR) IQA according to the amount of information required from the original image. Although NRIQA and RR-IQA are widely used in practical applications, room for improvement still remains because of the lack of the reference image. Inspired by the fact that in many applications, such as parameter selection for image restoration algorithms, a series of distorted images are available, the authors propose a novel comparison-based image quality assessment (C-IQA) framework. The new comparison-based framework parallels FRIQA by requiring two input images, and resembles NR-IQA by not using the original image. As a result, the new comparisonbased approach has more application scenarios than FR-IQA does, and takes greater advantage of the accessible information than the traditional single-input NR-IQA does. Further, C-IQA is compared with other state-of-the-art NR-IQA methods and another RR-IQA method on two widely used IQA databases. Experimental results show that C-IQA outperforms the other methods for parameter selection, and the parameter trimming framework combined with C-IQA saves the computation of iterative image reconstruction up to 80%.

  15. Quantification of image quality using information theory.

    Science.gov (United States)

    Niimi, Takanaga; Maeda, Hisatoshi; Ikeda, Mitsuru; Imai, Kuniharu

    2011-12-01

    Aims of present study were to examine usefulness of information theory in visual assessment of image quality. We applied first order approximation of the Shannon's information theory to compute information losses (IL). Images of a contrast-detail mammography (CDMAM) phantom were acquired with computed radiographies for various radiation doses. Information content was defined as the entropy Σp( i )log(1/p ( i )), in which detection probabilities p ( i ) were calculated from distribution of detection rate of the CDMAM. IL was defined as the difference between information content and information obtained. IL decreased with increases in the disk diameters (P information losses (TIL), were closely correlated with the image quality figures (r = 0.985). TIL was dependent on the distribution of image reading ability of each examinee, even when average reading ratio was the same in the group. TIL was shown to be sensitive to the observers' distribution of image readings and was expected to improve the evaluation of image quality.

  16. QUALITY PARAMETERS IN NANOTECHNOLOGIC APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ayşegül Akdoğan Eker

    2013-06-01

    Full Text Available Nanotechnology concept which has added a new dimension to our lives in recent years, is finding a place in every sector day by day. The combined effect of nanotechnology is almost equal to the industrial revolution of last 200 years and have is able to fill all developments in a few years. However this development should be taken under control. Otherwise unstoppable new structures will not ease life but will be a problem for humanity. For this purpose, the main parameters (from the start up stage of nano-technologic applications to the obtained product should be checked. These parameters are actually not different than the adaptation of the classical quality indicators for nanotechnology applications. Especially it plays an important role in obtaining a uniform distribution and regarding the features of the end product in nano-technological ceramic and etc. applications. The most important problem faced in particles of that size is the accumulation they create. Another problem is the increasing friction force as size gets smaller. The friction force of asubstance increases proportionally with the cube of its surface area. Another problem is surface tension. The increasing surface tension due to increasing surface area will cause the particles to attract and stick to each other. The structures aimed to be obtained are mostly complex and especially in upwards approach, it is thermodynamically very hard for the atoms to get into that order. Therefore in this announcement, we stated the quality parameters that will be taken into consideration in nano-technological applications and the methods for obtaining those parameters. The aim is to explain these parameters with all dimensions so that they will lead the way to the future nano-technological applications.

  17. REQUIREMENTS FOR IMAGE QUALITY OF EMERGENCY SPACECRAFTS

    Directory of Open Access Journals (Sweden)

    A. I. Altukhov

    2015-05-01

    Full Text Available The paper deals with the method for formation of quality requirements to the images of emergency spacecrafts. The images are obtained by means of remote sensing of near-earth space orbital deployment in the visible range. of electromagnetic radiation. The method is based on a joint taking into account conditions of space survey, characteristics of surveillance equipment, main design features of the observed spacecrafts and orbital inspection tasks. Method. Quality score is the predicted linear resolution image that gives the possibility to create a complete view of pictorial properties of the space image obtained by electro-optical system from the observing satellite. Formulation of requirements to the numerical value of this indicator is proposed to perform based on the properties of remote sensing system, forming images in the conditions of outer space, and the properties of the observed emergency spacecraft: dimensions, platform construction of the satellite, on-board equipment placement. For method implementation the authors have developed a predictive model of requirements to a linear resolution for images of emergency spacecrafts, making it possible to select the intervals of space shooting and get the satellite images required for quality interpretation. Main results. To verify the proposed model functionality we have carried out calculations of the numerical values for the linear resolution of the image, ensuring the successful task of determining the gross structural damage of the spacecrafts and identifying changes in their spatial orientation. As input data were used with dimensions and geometric primitives corresponding to the shape of deemed inspected spacecrafts: Resurs-P", "Canopus-B", "Electro-L". Numerical values of the linear resolution images have been obtained, ensuring the successful task solution for determining the gross structural damage of spacecrafts.

  18. Web applications for total quality management.

    Science.gov (United States)

    Golaz, O; Hochstrasser, D

    1999-05-01

    Total quality management involves the consideration of many quality subjects as part of the management, such as quality processes, quality education, quality assurance, quality planning, quality results and quality document management. But crucial quality elements are also communication, data management and information sharing. Web applications and other associated computer communication applications such as E-mail and newsgroups, for example, offer to the laboratory environment the best tools to achieve proper communication and data management/sharing. These applications, enabling the set-up of Internet and Intranet sites, are used to share the information in the form of simple text pages or of completely interactive pages, which could comprise audio and video files, web page formulae and web data management applications. These applications are being associated to several applications and also being integrated into the laboratory information system (LIS).

  19. Color Image Quality in Presentation Software

    Directory of Open Access Journals (Sweden)

    María S. Millán

    2008-11-01

    Full Text Available The color image quality of presentation programs is evaluated and measured using S-CIELAB and CIEDE2000 color difference formulae. A color digital image in its original format is compared with the same image already imported by the program and introduced as a part of a slide. Two widely used presentation programs—Microsoft PowerPoint 2004 for Mac and Apple's Keynote 3.0.2—are evaluated in this work.

  20. X-ray image quality in radiography

    Energy Technology Data Exchange (ETDEWEB)

    Borcke, E.

    1987-01-01

    A proposal is worked out to express X-ray image quality by means of a meaningful and practically useful numerical system. Attenuations have been selected in such a manner that whole numbers of quality value figures ranging from -10 to +60 result in meaningful associations with radiological indications. Individual parameters are incorporated into the resulting values. A test body for determining information sensitivity figures is described that is practical easy built and inexpensive; its most important feature, however, is that it is reproducible and permits international comparisons. This test body provides a direct linking with the quality value figures.

  1. Image quality in digital radiographic systems

    Directory of Open Access Journals (Sweden)

    Almeida Solange Maria de

    2003-01-01

    Full Text Available The aim of the present study was to evaluate the image quality of four direct digital radiographic systems. Radiographs were made of the maxillary central incisor and mandibular left molar regions of a dry skull, and an aluminum step-wedge. The X-ray generator operated at 10 mA, 60 and 70 kVp, and images were acquired with 3, 5, 8, 12, 24 and 48 exposure pulses. Six well-trained observers classified the images by means of scores from 1 to 3. Collected data were submitted to nonparametric statistical analysis using Fisher's exact test. Statistical analysis showed significant differences (p<0.01 in image quality with the four systems. Based on the results, it was possible to conclude that: 1 all of the digital systems presented good performance in producing acceptable images for diagnosis, if the exposures of the step-wedge and the maxillary central incisor region were made at 5 pulses, as well as at 8 pulses for the mandibular left molar region, selecting 60 or 70kVp; 2 higher percentages of acceptable images were obtained with the administration of lower radiation doses in CCD-sensors (charge-coupled device; 3 the Storage Phosphor systems produced acceptable images at a large range of exposure settings, that included low, intermediate and high radiation doses.

  2. Does resolution really increase image quality?

    Science.gov (United States)

    Tisse, Christel-Loïc; Guichard, Frédéric; Cao, Frédéric

    2008-02-01

    A general trend in the CMOS image sensor market is for increasing resolution (by having a larger number of pixels) while keeping a small form factor by shrinking photosite size. This article discusses the impact of this trend on some of the main attributes of image quality. The first example is image sharpness. A smaller pitch theoretically allows a larger limiting resolution which is derived from the Modulation Transfer Function (MTF). But recent sensor technologies (1.75μm, and soon 1.45μm) with typical aperture f/2.8 are clearly reaching the size of the diffraction blur spot. A second example is the impact on pixel light sensitivity and image sensor noise. For photonic noise, the Signal-to-Noise-Ratio (SNR) is typically a decreasing function of the resolution. To evaluate whether shrinking pixel size could be beneficial to the image quality, the tradeoff between spatial resolution and light sensitivity is examined by comparing the image information capacity of sensors with varying pixel size. A theoretical analysis that takes into consideration measured and predictive models of pixel performance degradation and improvement associated with CMOS imager technology scaling, is presented. This analysis is completed by a benchmarking of recent commercial sensors with different pixel technologies.

  3. Registration accuracy and quality of real-life images.

    Directory of Open Access Journals (Sweden)

    Wei-Yen Hsu

    Full Text Available BACKGROUND: A common registration problem for the application of consumer device is to align all the acquired image sequences into a complete scene. Image alignment requires a registration algorithm that will compensate as much as possible for geometric variability among images. However, images captured views from a real scene usually produce different distortions. Some are derived from the optic characteristics of image sensors, and others are caused by the specific scenes and objects. METHODOLOGY/PRINCIPAL FINDINGS: An image registration algorithm considering the perspective projection is proposed for the application of consumer devices in this study. It exploits a multiresolution wavelet-based method to extract significant features. An analytic differential approach is then proposed to achieve fast convergence of point matching. Finally, the registration accuracy is further refined to obtain subpixel precision by a feature-based modified Levenberg-Marquardt method. Due to its feature-based and nonlinear characteristic, it converges considerably faster than most other methods. In addition, vignette compensation and color difference adjustment are also performed to further improve the quality of registration results. CONCLUSIONS/SIGNIFICANCE: The performance of the proposed method is evaluated by testing the synthetic and real images acquired by a hand-held digital still camera and in comparison with two registration techniques in terms of the squared sum of intensity differences (SSD and correlation coefficient (CC. The results indicate that the proposed method is promising in registration accuracy and quality, which are statistically significantly better than other two approaches.

  4. Siderophores for molecular imaging applications.

    Science.gov (United States)

    Petrik, Milos; Zhai, Chuangyan; Haas, Hubertus; Decristoforo, Clemens

    2017-01-01

    This review covers publications on siderophores applied for molecular imaging applications, mainly for radionuclide-based imaging. Siderophores are low molecular weight chelators produced by bacteria and fungi to scavenge essential iron. Research on these molecules has a continuing history over the past 50 years. Many biomedical applications have been developed, most prominently the use of the siderophore desferrioxamine (DFO) to tackle iron overload related diseases. Recent research described the upregulation of siderophore production and transport systems during infection. Replacing iron in siderophores by radionuclides, the most prominent Ga-68 for PET, opens approaches for targeted imaging of infection; the proof of principle has been reported for fungal infections using (68)Ga-triacetylfusarinine C (TAFC). Additionally, fluorescent siderophores and therapeutic conjugates have been described and may be translated to optical imaging and theranostic applications. Siderophores have also been applied as bifunctional chelators, initially DFO as chelator for Ga-67 and more recently for Zr-89 where it has become the standard chelator in Immuno-PET. Improved DFO constructs and bifunctional chelators based on cyclic siderophores have recently been developed for Ga-68 and Zr-89 and show promising properties for radiopharmaceutical development in PET. A huge potential from basic biomedical research on siderophores still awaits to be utilized for clinical and translational imaging.

  5. Ultrasound Image Quality Assessment: A framework for evaluation of clinical image quality

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Pedersen, Mads Møller; Nikolov, Svetoslav Ivanov

    2010-01-01

    Improvement of ultrasound images should be guided by their diagnostic value. Evaluation of clinical image quality is generally performed subjectively, because objective criteria have not yet been fully developed and accepted for the evaluation of clinical image quality. Based on recommendation 500...... from the International Telecommunication Union - Radiocommunication (ITU-R) for such subjective quality assessment, this work presents equipment and a methodology for clinical image quality evaluation for guiding the development of new and improved imaging. The system is based on a BK-Medical 2202 Pro......Focus scanner equipped with a UA2227 research interface, connected to a PC through X64-CL Express camera link. Data acquisition features subject data recording, loading/saving of exact scanner settings (for later experiment reproducibility), free access to all system parameters for beamformation...

  6. Simulation of High Quality Ultrasound Imaging

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Kortbek, Jacob; Nikolov, Svetoslav Ivanov

    2010-01-01

    This paper investigates if the influence on image quality using physical transducers can be simulated with an sufficient accuracy to reveal system performance. The influence is investigated in a comparative study between Synthetic Aperture Sequential Beamformation (SASB) and Dynamic Receive Focus...

  7. Detection of image quality metamers based on the metric for unified image quality

    Science.gov (United States)

    Miyata, Kimiyoshi; Tsumura, Norimichi

    2012-01-01

    In this paper, we introduce a concept of the image quality metamerism as an expanded version of the metamerism defined in the color science. The concept is used to unify different image quality attributes, and applied to introduce a metric showing the degree of image quality metamerism to analyze a cultural property. Our global goal is to build a metric to evaluate total quality of images acquired by different imaging systems and observed under different viewing conditions. As the basic step to the global goal, the metric is consisted of color, spectral and texture information in this research, and applied to detect image quality metamers to investigate the cultural property. The property investigated is the oldest extant version of folding screen paintings that depict the thriving city of Kyoto designated as a nationally important cultural property in Japan. Gold colored areas painted by using high granularity colorants compared with other color areas in the property are evaluated based on the metric, then the metric is visualized as a map showing the possibility of the image quality metamer to the reference pixel.

  8. Biomedical Optical Imaging Technologies Design and Applications

    CERN Document Server

    2013-01-01

    This book provides an introduction to design of biomedical optical imaging technologies and their applications. The main topics include: fluorescence imaging, confocal imaging, micro-endoscope, polarization imaging, hyperspectral imaging, OCT imaging, multimodal imaging and spectroscopic systems. Each chapter is written by the world leaders of the respective fields, and will cover: principles and limitations of optical imaging technology, system design and practical implementation for one or two specific applications, including design guidelines, system configuration, optical design, component requirements and selection, system optimization and design examples, recent advances and applications in biomedical researches and clinical imaging. This book serves as a reference for students and researchers in optics and biomedical engineering.

  9. Raman Imaging Techniques and Applications

    CERN Document Server

    2012-01-01

    Raman imaging has long been used to probe the chemical nature of a sample, providing information on molecular orientation, symmetry and structure with sub-micron spatial resolution. Recent technical developments have pushed the limits of micro-Raman microscopy, enabling the acquisition of Raman spectra with unprecedented speed, and opening a pathway to fast chemical imaging for many applications from material science and semiconductors to pharmaceutical drug development and cell biology, and even art and forensic science. The promise of tip-enhanced raman spectroscopy (TERS) and near-field techniques is pushing the envelope even further by breaking the limit of diffraction and enabling nano-Raman microscopy.

  10. Blind image quality assessment via deep learning.

    Science.gov (United States)

    Hou, Weilong; Gao, Xinbo; Tao, Dacheng; Li, Xuelong

    2015-06-01

    This paper investigates how to blindly evaluate the visual quality of an image by learning rules from linguistic descriptions. Extensive psychological evidence shows that humans prefer to conduct evaluations qualitatively rather than numerically. The qualitative evaluations are then converted into the numerical scores to fairly benchmark objective image quality assessment (IQA) metrics. Recently, lots of learning-based IQA models are proposed by analyzing the mapping from the images to numerical ratings. However, the learnt mapping can hardly be accurate enough because some information has been lost in such an irreversible conversion from the linguistic descriptions to numerical scores. In this paper, we propose a blind IQA model, which learns qualitative evaluations directly and outputs numerical scores for general utilization and fair comparison. Images are represented by natural scene statistics features. A discriminative deep model is trained to classify the features into five grades, corresponding to five explicit mental concepts, i.e., excellent, good, fair, poor, and bad. A newly designed quality pooling is then applied to convert the qualitative labels into scores. The classification framework is not only much more natural than the regression-based models, but also robust to the small sample size problem. Thorough experiments are conducted on popular databases to verify the model's effectiveness, efficiency, and robustness.

  11. Image quality assessment metrics by using directional projection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective image quality mcasure, which is a fundamental and challenging job in image processing, evaluates the image quality consistently with human perception automatically. On the assumption that any image distortion could be modeled as the difference between the directional projection-based maps of reference and distortion images, wc propose a new objective quality assessment method based on directional projection for full reference model. Experimental results show that the proposed metrics are well consistent with the subjective quality score.

  12. Image quality evaluation of light field photography

    Science.gov (United States)

    Fu, Qiang; Zhou, Zhiliang; Yuan, Yan; Xiangli, Bin

    2011-01-01

    Light field photography captures 4D radiance information of a scene. Digital refocusing and digital correction of aberrations could be done after the photograph is taken. However, capturing 4D light field is costly and tradeoffs between different image quality metrics should be made and evaluated. This paper explores the effects of light field photography on image quality by quantitatively evaluating some basic criteria for an imaging system. A simulation approach was first developed by ray-tracing a designed light field camera. A standard testing chart followed by ISO 12233 was provided as the input scene. A sequence of light field raw images were acquired and processed by light field rendering methods afterwards. Through-focus visual resolution and MTF were calculated and analyzed. As a comparison, the same tests were taken for the same main lens system as the results of conventional photography. An experimental light field system was built up and its performance was tested. This work helps better understanding the pros and cons of light field photography in contrast with conventional imaging methods and perceiving the way to optimize the joint digital-optical design of the system.

  13. Automated Quality Assurance Applied to Mammographic Imaging

    Directory of Open Access Journals (Sweden)

    Anne Davis

    2002-07-01

    Full Text Available Quality control in mammography is based upon subjective interpretation of the image quality of a test phantom. In order to suppress subjectivity due to the human observer, automated computer analysis of the Leeds TOR(MAM test phantom is investigated. Texture analysis via grey-level co-occurrence matrices is used to detect structures in the test object. Scoring of the substructures in the phantom is based on grey-level differences between regions and information from grey-level co-occurrence matrices. The results from scoring groups of particles within the phantom are presented.

  14. Analysis and Comparison of Objective Methods for Image Quality Assessment

    Directory of Open Access Journals (Sweden)

    P. S. Babkin

    2014-01-01

    Full Text Available The purpose of this work is research and modification of the reference objective methods for image quality assessment. The ultimate goal is to obtain a modification of formal assessments that more closely corresponds to the subjective expert estimates (MOS.In considering the formal reference objective methods for image quality assessment we used the results of other authors, which offer results and comparative analyzes of the most effective algorithms. Based on these investigations we have chosen two of the most successful algorithm for which was made a further analysis in the MATLAB 7.8 R 2009 a (PQS and MSSSIM. The publication focuses on the features of the algorithms, which have great importance in practical implementation, but are insufficiently covered in the publications by other authors.In the implemented modification of the algorithm PQS boundary detector Kirsch was replaced by the boundary detector Canny. Further experiments were carried out according to the method of the ITU-R VT.500-13 (01/2012 using monochrome images treated with different types of filters (should be emphasized that an objective assessment of image quality PQS is applicable only to monochrome images. Images were obtained with a thermal imaging surveillance system. The experimental results proved the effectiveness of this modification.In the specialized literature in the field of formal to evaluation methods pictures, this type of modification was not mentioned.The method described in the publication can be applied to various practical implementations of digital image processing.Advisability and effectiveness of using the modified method of PQS to assess the structural differences between the images are shown in the article and this will be used in solving the problems of identification and automatic control.

  15. Image fusion theories, techniques and applications

    CERN Document Server

    Mitchell, HB

    2010-01-01

    This text provides a comprehensive introduction to the theories, techniques and applications of image fusion. It examines in detail many real-life examples of image fusion, including panchromatic sharpening and ensemble color image segmentation.

  16. Factors that affect print quality in thermal dye transfer imaging

    Science.gov (United States)

    Harrison, Daniel J. P.; McInerney, Elizabeth

    1995-04-01

    Thermal dye transfer (TDT) imaging has established itself as the state- of-the-art process for high quality, continuous tone, nonimpact printing. Imaging quality from this process rivals conventional silver halide photography and exceeds other nonimpact printing technologies. Because this output appears to be virtually indistinguishable from photographic prints, there has been an expectation that all the quality attributes of silver halide photography are embodied in a TDT print. However, there are many significant differences that affect output quality between these two technologies. These differences are primarily in color gamut, print artifacts, Dmin, grain/sharpness, and image stability. The range of colors reproducible by a color, hard copy device, known as its color gamut, is dictated primarily by the image- forming dyes used by the device. The size and shape of a device's gamut is controlled by the spectral density distributions of these image forming dyes, the Dmin of the receiver base, the Dmax of each dye, the amount of light scatter, and the spectral distribution of the viewing illuminant. The spectral density distributions of dyes also have an impact on illuminant sensitivity, which is a predictor of how much the color balance of a print will change with a change in illuminant. By determining and then using characteristic curves for various image- forming dyes, we have been able to calculate and compare the color gamuts and illuminant sensitivity of TDT imaging with other technologies (color monitor and silver halide photography, for example). The differences we have found can have a significant impact on output quality, depending upon the application. Compared to conventional photography, thermal dye transfer prints have traditionally had inferior light stability and resistance to damage from fingerprints. In addition, thermal dye transfer prints have been aggressively attacked by plasticized polyvinyl chloride sheets and folders commonly found in

  17. Vibration factors impact analysis on aerial film camera imaging quality

    Science.gov (United States)

    Xie, Jun; Han, Wei; Xu, Zhonglin; Tan, Haifeng; Yang, Mingquan

    2017-08-01

    Aerial film camera can acquire ground target image information advantageous, but meanwhile the change of aircraft attitude, the film features and the work of camera inside system could result in a vibration which could depress the image quality greatly. This paper presented a design basis of vibration mitigation stabilized platform based on the vibration characteristic of the aerial film camera and indicated the application analysis that stabilized platform could support aerial camera to realize the shoot demand of multi-angle and large scale. According to the technique characteristics of stabilized platform, the development direction are high precision, more agility, miniaturization and low power.

  18. Biomedical image understanding methods and applications

    CERN Document Server

    Lim, Joo-Hwee; Xiong, Wei

    2015-01-01

    A comprehensive guide to understanding and interpreting digital images in medical and functional applications Biomedical Image Understanding focuses on image understanding and semantic interpretation, with clear introductions to related concepts, in-depth theoretical analysis, and detailed descriptions of important biomedical applications. It covers image processing, image filtering, enhancement, de-noising, restoration, and reconstruction; image segmentation and feature extraction; registration; clustering, pattern classification, and data fusion. With contributions from ex

  19. ImageJ软件在大型医疗设备质量检测中的应用%Application of the ImageJ in large medical equipment quality test

    Institute of Scientific and Technical Information of China (English)

    徐桓; 段新安

    2011-01-01

    Objective:To clarify the methods, advantages and value of ImageJ for large medical equipment quality test. Methods:The testing of MRI thickness, DSA subtract function was taken for an example to make an argument, and it was compared with the traditional methods. Results:Compared with traditional methods, the measurement results using ImageJ were consistent. The use of ImageJ can improve test efficiency. Conclusion:ImageJ is powerful in image analysis and processing. The use of ImageJ in the large medical equipment quality test has advantages of accurate and effect test data and simple and feasible methods. Therefore, it can meet the needs of analysis and processing test image.%目的:将计算机技术引入大型医疗设备质量检测工作之中是今后质量检测技术的发展方向,阐述ImageJ软件用于大型医疗设备质量检测中的方法、优势及意义。方法:以使用ImageJ软件测量MRI层厚、DSA减影功能为例,进行具体论证,并与传统的测量方法进行比较。结果:使用ImageJ软件测量与传统测量方法相比较,其测量结果具有一致性,并且前者提高了质量检测效率。结论:ImageJ软件在质量检测图像分析处理方面功能强大,用于大型医疗设备质量检测中,测量数据准确有效、测量方法简单易行,能够满足质量检测图像分析处理的需求。

  20. Calculations and surface quality measurements of high-asymmetry angle x-ray crystal monochromators for advanced x-ray imaging and metrological applications

    Science.gov (United States)

    Zápražný, Zdenko; Korytár, Dušan; Jergel, Matej; Šiffalovič, Peter; Dobročka, Edmund; Vagovič, Patrik; Ferrari, Claudio; Mikulík, Petr; Demydenko, Maksym; Mikloška, Marek

    2015-03-01

    We present the numerical optimization and the technological development progress of x-ray optics based on asymmetric germanium crystals. We show the results of several basic calculations of diffraction properties of germanium x-ray crystal monochromators and of an analyzer-based imaging method for various asymmetry factors using an x-ray energy range from 8 to 20 keV. The important parameter of highly asymmetric monochromators as image magnifiers or compressors is the crystal surface quality. We have applied several crystal surface finishing methods, including advanced nanomachining using single-point diamond turning (SPDT), conventional mechanical lapping, chemical polishing, and chemomechanical polishing, and we have evaluated these methods by means of atomic force microscopy, diffractometry, reciprocal space mapping, and others. Our goal is to exclude the chemical etching methods as the final processing technique because it causes surface undulations. The aim is to implement very precise deterministic methods with a control of surface roughness down to 0.1 nm. The smallest roughness (˜0.3 nm), best planarity, and absence of the subsurface damage were observed for the sample which was machined using an SPDT with a feed rate of 1 mm/min and was consequently polished using a fine polishing 15-min process with a solution containing SiO2 nanoparticles (20 nm).

  1. The application of automatic tube current modulation (ATCM) on image quality and radiation dose at abdominal computed tomography (CT): A phantom study.

    Science.gov (United States)

    Wang, Qian; Zhao, Xinming; Song, Junfeng; Guo, Ning; Zhu, Ying; Liu, Jianxin; Qi, Weiwei; Wu, Jing; Liang, Yuan; Feng, Shichao; Hu, Mancang; Zhou, Chunwu; Wang, Xiaoying; Hong, Nan

    2013-01-01

    Multi-phase spiral Computed tomography (CT) of abdomen has been widely used as an effective imaging modality to diagnose variety of diseases. As a result, the accumulated radiation exposure on the abdomen is substantially higher than other human organ regions. According to ALARA (as low as reasonably achievable) principle, how to control radiation dose without compromising imaging quality becomes a research topic of high interest. However, how to achieve dose optimization of the abdomen CT examinations in Chinese patients have not been fully investigated in previous studies. In this study, we develop an abdomen-equivalent tissue model made by well-known CTP579 auxiliary testing model and the real CT data acquired from 68 Chinese male subjects. Combining with catphan600, we simulated the visibility of low and high contrast objects at adult abdomen under variety of x-ray dose levels. Using the automatic tube current modulation (ATCM) technique, we reduced the total radiation dose and identified a proper noise index (NI) for Chinese patients to maintain low or high contrast detectability of abdominal CT image. Our numerical experiments showed that in the phantom study for Chinese patients, when a NI was set at 10, the radiation dose reduced by 34.3% with low contrast objects detectable, while setting NI at 14 the dose level decreased by 65.1% without change the detectability of high contrast targets. The subjective ratings from three radiologists also yielded high consistence with Kappa > 0.75. This study demonstrated the feasibility of performing the CT dose optimization studies through a unique phantom with the ATCM method.

  2. Improvement of material decomposition and image quality in dual-energy radiography by reducing image noise

    Science.gov (United States)

    Lee, D.; Kim, Y.-s.; Choi, S.; Lee, H.; Choi, S.; Jo, B. D.; Jeon, P.-H.; Kim, H.; Kim, D.; Kim, H.; Kim, H.-J.

    2016-08-01

    Although digital radiography has been widely used for screening human anatomical structures in clinical situations, it has several limitations due to anatomical overlapping. To resolve this problem, dual-energy imaging techniques, which provide a method for decomposing overlying anatomical structures, have been suggested as alternative imaging techniques. Previous studies have reported several dual-energy techniques, each resulting in different image qualities. In this study, we compared three dual-energy techniques: simple log subtraction (SLS), simple smoothing of a high-energy image (SSH), and anti-correlated noise reduction (ACNR) with respect to material thickness quantification and image quality. To evaluate dual-energy radiography, we conducted Monte Carlo simulation and experimental phantom studies. The Geant 4 Application for Tomographic Emission (GATE) v 6.0 and tungsten anode spectral model using interpolation polynomials (TASMIP) codes were used for simulation studies and digital radiography, and human chest phantoms were used for experimental studies. The results of the simulation study showed improved image contrast-to-noise ratio (CNR) and coefficient of variation (COV) values and bone thickness estimation accuracy by applying the ACNR and SSH methods. Furthermore, the chest phantom images showed better image quality with the SSH and ACNR methods compared to the SLS method. In particular, the bone texture characteristics were well-described by applying the SSH and ACNR methods. In conclusion, the SSH and ACNR methods improved the accuracy of material quantification and image quality in dual-energy radiography compared to SLS. Our results can contribute to better diagnostic capabilities of dual-energy images and accurate material quantification in various clinical situations.

  3. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Sensakovic, William F.; O' Dell, M.C.; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura [Florida Hospital, Imaging Administration, Orlando, FL (United States)

    2016-10-15

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA{sup 2} by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image

  4. Low Quality Image Retrieval System For Generic Databases

    Directory of Open Access Journals (Sweden)

    W.A.D.N. Wijesekera

    2015-08-01

    Full Text Available Abstract Content Based Image Retrieval CBIR systems have become the trend in image retrieval technologies as the index or notation based image retrieval algorithms give less efficient results in high usage of images. These CBIR systems are mostly developed considering the availability of high or normal quality images. High availability of low quality images in databases due to usage of different quality equipment to capture images and different environmental conditions the photos are being captured has opened up a new path in image retrieval research area. The algorithms which are developed for low quality image based image retrieval are only a few and have been performed only for specific domains. Low quality image based image retrieval algorithm on a generic database with a considerable accuracy level for different industries is an area which remains unsolved. Through this study an algorithm has been developed to achieve above mentioned gaps. By using images with inappropriate brightness and compressed images as low quality images the proposed algorithm is tested on a generic database which includes many categories of data instead of using a specific domain. The new algorithm developed gives better precision and recall values when they are clustered into the most appropriate number of clusters which changes according to the level of quality of the image. As the quality of the image decreases the accuracy of the algorithm also tends to be reduced a space for further improvement.

  5. Imaging technologies in oilfield applications

    Institute of Scientific and Technical Information of China (English)

    XIE C.G.; NORTH R.; WILT M.; ZHANG P.; DENACLARA H.; LEVESQUE C.

    2005-01-01

    In this paper, we describe some recent imaging technologies developed by Schlumberger for oilfield downhole multiphase flow production logging (PL) and cross-well electromagnetic (EM) survey applications. FloScan Imager (FSITM) has been introduced as a 3-phase oil/gas/water flow PL tool for deviated and horizontal wells. FSI sensors can map fluid velocity and holdup profiles along a vertical diameter of the wellbore at every survey depth, enabling a robust estimate of the individual phase flow rates in complex flow regimes. The cross-well EM survey is based on cross-borehole induction logging technique and provides resistivity distribution at a reservoir scale. It is a useful tool for reservoir management and is most effective in dynamic fields where fluid saturations are variable in time and space. The tool can be used to identify (water or steam) flooded and bypassed regions. By monitoring changes in the resistivity spatial distribution with time, cross-well EM survey is very effective at mapping inter-well temperature and structure. Some field examples are shown for both FloScan Imager PL tool and cross-well resistivity imaging survey.

  6. Factors Influencing the Quality of Mobile Applications

    Directory of Open Access Journals (Sweden)

    Alin ZAMFIROIU

    2014-01-01

    Full Text Available Mobile applications are becoming increasingly used. Mobile devices are becoming indispensable for the user. In the material are claiming the sales of mobile devices internationally and the use of mobile applications compared to traditional internet use on desktop systems for the United States. Are presented influences the quality of mobile applications and based on these influencing factors built a model of choice for optimal application of mobile applications and traditional desktop application. At the end of the material presented methods to increase quality by tracking the influence factors during the development of mobile applications.

  7. Multimodal imaging of bone metastases: From preclinical to clinical applications

    Directory of Open Access Journals (Sweden)

    Stephan Ellmann

    2015-10-01

    Full Text Available Metastases to the skeletal system are commonly observed in cancer patients, highly affecting the patients' quality of life. Imaging plays a major role in detection, follow-up, and molecular characterisation of metastatic disease. Thus, imaging techniques have been optimised and combined in a multimodal and multiparametric manner for assessment of complementary aspects in osseous metastases. This review summarises both application of the most relevant imaging techniques for bone metastasis in preclinical models and the clinical setting.

  8. Color imaging fundamentals and applications

    CERN Document Server

    Reinhard, Erik; Oguz Akyuz, Ahmet; Johnson, Garrett

    2008-01-01

    This book provides the reader with an understanding of what color is, where color comes from, and how color can be used correctly in many different applications. The authors first treat the physics of light and its interaction with matter at the atomic level, so that the origins of color can be appreciated. The intimate relationship between energy levels, orbital states, and electromagnetic waves helps to explain why diamonds shimmer, rubies are red, and the feathers of the Blue Jay are blue. Then, color theory is explained from its origin to the current state of the art, including image captu

  9. Programmable resolution imager for imaging applications

    Science.gov (United States)

    Roca, Elisenda; Soriano, German; Espejo, Servando; Dominguez-Castro, Rafael; Linan, Gustavo; Rodriguez-Vazquez, Angel

    2000-05-01

    In this paper a programmable imager with averaging capabilities will be described which is intended for averaging of different groups or sets of pixels formed by n X n kernels, n X m kernels or any group of randomly- selected pixels across the array. This imager is a 64 X 64 array which uses passive pixels with electronic shutter and anti-blooming structure that can be randomly accessed. The read-out stage includes a sole charge amplifier with programmable gain, a sample-and-hold structure and an analog buffer. This read-out structure is different from other existing imagers with variable resolution since it uses a sole charge amplifier, whereas the conventional structure employs an opamp per column plus another global opamp. this architecture allows a reduction of the fixed-pattern noise observed in standard imagers. The prototype also includes an analog to digital converter which provides the digital output of the images.

  10. Image analysis for dental bone quality assessment using CBCT imaging

    Science.gov (United States)

    Suprijanto; Epsilawati, L.; Hajarini, M. S.; Juliastuti, E.; Susanti, H.

    2016-03-01

    Cone beam computerized tomography (CBCT) is one of X-ray imaging modalities that are applied in dentistry. Its modality can visualize the oral region in 3D and in a high resolution. CBCT jaw image has potential information for the assessment of bone quality that often used for pre-operative implant planning. We propose comparison method based on normalized histogram (NH) on the region of inter-dental septum and premolar teeth. Furthermore, the NH characteristic from normal and abnormal bone condition are compared and analyzed. Four test parameters are proposed, i.e. the difference between teeth and bone average intensity (s), the ratio between bone and teeth average intensity (n) of NH, the difference between teeth and bone peak value (Δp) of NH, and the ratio between teeth and bone of NH range (r). The results showed that n, s, and Δp have potential to be the classification parameters of dental calcium density.

  11. Image Quality Stability of Whole-body Diffusion Weighted Imaging

    Institute of Scientific and Technical Information of China (English)

    Yun-bin Chen; Chun-miao Hu; Jing Zhong; Fei Sun

    2009-01-01

    To assess the reproducibility of whole-body diffusion weighted imaging (WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression. Methods WB-DWI was performed on 32 healthy volunteers twice within two-week period using short TI inversion-recovery diffusion-weighted echo-planar imaging sequence and built-in body coil. The volunteers were scanned across six stations continuously covering the entire body from the head to the feet under normal breathing. The bone apparent diffusion coefficient (ADC) and exponential ADC (eADC) of regions of interest (ROIs) were measured. We analyzed correlation of the results using paired-t-test to assess the reproducibility of the WB-DWl technique.Results We were successful in collecting and analyzing data of 64 WB-DWI images. There was no significant difference in bone ADC and eADC of 824 ROIs between the paired observers and paired scans (P>0.05). Most of the images from all stations were of diagnostic quality.Conclusion The measurements of bone ADC and eADC have good reproducibility. WB-DWI technique under normal breathing with background body signal suppression is adequate.

  12. Towards Improving the NIST Fingerprint Image Quality (NFIQ) Algorithm (Extended Version)

    CERN Document Server

    Merkle, Johannes; Bausinger, Oliver; Breitenstein, Marco; Elwart, Kristina; Nuppeney, Markus

    2010-01-01

    The NIST Fingerprint Image Quality (NFIQ) algorithm has become a standard method to assess fingerprint image quality. However, in many applications a more accurate and reliable assessment is desirable. In this publication, we report on our efforts to optimize the NFIQ algorithm by a re-training of the underlying neural network based on a large fingerprint image database. Although we only achieved a marginal improvement, our work has revealed several areas for potential optimization.

  13. Finger vein image quality evaluation using support vector machines

    Science.gov (United States)

    Yang, Lu; Yang, Gongping; Yin, Yilong; Xiao, Rongyang

    2013-02-01

    In an automatic finger-vein recognition system, finger-vein image quality is significant for segmentation, enhancement, and matching processes. In this paper, we propose a finger-vein image quality evaluation method using support vector machines (SVMs). We extract three features including the gradient, image contrast, and information capacity from the input image. An SVM model is built on the training images with annotated quality labels (i.e., high/low) and then applied to unseen images for quality evaluation. To resolve the class-imbalance problem in the training data, we perform oversampling for the minority class with random-synthetic minority oversampling technique. Cross-validation is also employed to verify the reliability and stability of the learned model. Our experimental results show the effectiveness of our method in evaluating the quality of finger-vein images, and by discarding low-quality images detected by our method, the overall finger-vein recognition performance is considerably improved.

  14. Crowdsourcing quality control for Dark Energy Survey images

    CERN Document Server

    Melchior, P; Drlica-Wagner, A; Rykoff, E S; Abbott, T M C; Abdalla, F B; Allam, S; Benoit-Levy, A; Brooks, D; Buckley-Geer, E; Rosell, A Carnero; Kind, M Carrasco; Carretero, J; Crocce, M; D'Andrea, C B; da Costa, L N; Desai, S; Doel, P; Evrard, A E; Finley, D A; Flaugher, B; Frieman, J; Gaztanaga, E; Gerdes, D W; Gruen, D; Gruendl, R A; Honscheid, K; James, D J; Jarvis, M; Kuehn, K; Li, T S; Maia, M A G; March, M; Marshall, J L; Nord, B; Ogando, R; Plazas, A A; Romer, A K; Sanchez, E; Scarpine, V; Sevilla-Noarbe, I; Smith, R C; Soares-Santos, M; Suchyta, E; Swanson, M E C; Tarle, G; Vikram, V; Walker, A R; Wester, W; Zhang, Y

    2015-01-01

    We have developed a crowdsourcing web application for image quality control employed by the Dark Energy Survey. Dubbed the "DES exposure checker", it renders science-grade images directly to a web browser and allows users to mark problematic features from a set of predefined classes. Users can also generate custom labels and thus help identify previously unknown problem classes. User reports are fed back to hardware and software experts to help mitigate and eliminate recognized issues. We report on the implementation of the application and our experience with its over 100 users, the majority of which are professional or prospective astronomers but not data management experts. We discuss aspects of user training and engagement, and demonstrate how problem reports have been pivotal to rapidly correct artifacts which would likely have been too subtle or infrequent to be recognized otherwise. We conclude with a number of important lessons learned, suggest possible improvements, and recommend this collective explo...

  15. Quality Information Management and Application of AWS

    Institute of Scientific and Technical Information of China (English)

    Yan WANG; Feng GAO; Chao SUN; Yu YU; Yiming LIU

    2016-01-01

    This paper has designed a unified storage model of Automatic Weather Station Quality Information Inquiries and Feedback( AWSQIF),and has developed an AWSQIF automatic management system,which implements the storage of AWSQIF automatically in national quality information two-way feedback process. Based on the unified storage,AWSQIF data have important application in real-time data management,data quality assessment and quality control effect analysis. The results show that the data quality has been improved significantly,and the data assessment has achieved online operating. In addition,AWSQIF can assist the improvement of the quality control effect.

  16. Fingerprint matching algorithm for poor quality images

    Directory of Open Access Journals (Sweden)

    Vedpal Singh

    2015-04-01

    Full Text Available The main aim of this study is to establish an efficient platform for fingerprint matching for low-quality images. Generally, fingerprint matching approaches use the minutiae points for authentication. However, it is not such a reliable authentication method for low-quality images. To overcome this problem, the current study proposes a fingerprint matching methodology based on normalised cross-correlation, which would improve the performance and reduce the miscalculations during authentication. It would decrease the computational complexities. The error rate of the proposed method is 5.4%, which is less than the two-dimensional (2D dynamic programming (DP error rate of 5.6%, while Lee's method produces 5.9% and the combined method has 6.1% error rate. Genuine accept rate at 1% false accept rate is 89.3% but at 0.1% value it is 96.7%, which is higher. The outcome of this study suggests that the proposed methodology has a low error rate with minimum computational effort as compared with existing methods such as Lee's method and 2D DP and the combined method.

  17. [The quality of the roentgen image--a recommendation for quantifying image quality].

    Science.gov (United States)

    Borcke, E

    1987-01-01

    A proposal is worked out to express x-ray image quality by means of a meaningful and practically useful numerical system. Attennations have been selected in such a manner that whole numbers of Quality Value figures ranging from -10 to +60 result in meaningful associations with radiological indications. Individual parameters are incorporated into the resulting values. A test body for determining Information Sensitivity figures is described that is practical easy built and inexpensive; its most important feature, however, is that it is reproducible and permits international comparisons. This test body provides a direct linking with the Quality Value figures.

  18. Neutron imaging and applications a reference for the imaging community

    CERN Document Server

    McGreevy, Robert L; Bilheux, Hassina Z

    2009-01-01

    Offers an introduction to the basics of neutron beam production in addition to the wide scope of techniques that enhance imaging application capabilities. This title features a section that describes imaging single grains in polycrystalline materials, neutron imaging of geological materials and other materials science and engineering areas.

  19. Content based no-reference image quality metrics

    OpenAIRE

    Marini,, A.C.

    2012-01-01

    Images are playing a more and more important role in sharing, expressing, mining and exchanging information in our daily lives. Now we can all easily capture and share images anywhere and anytime. Since digital images are subject to a wide variety of distortions during acquisition, processing, compression, storage, transmission and reproduction; it becomes necessary to assess the Image Quality. In this thesis, starting from an organized overview of available Image Quality Assessment methods, ...

  20. Systematic infrared image quality improvement using deep learning based techniques

    Science.gov (United States)

    Zhang, Huaizhong; Casaseca-de-la-Higuera, Pablo; Luo, Chunbo; Wang, Qi; Kitchin, Matthew; Parmley, Andrew; Monge-Alvarez, Jesus

    2016-10-01

    Infrared thermography (IRT, or thermal video) uses thermographic cameras to detect and record radiation in the longwavelength infrared range of the electromagnetic spectrum. It allows sensing environments beyond the visual perception limitations, and thus has been widely used in many civilian and military applications. Even though current thermal cameras are able to provide high resolution and bit-depth images, there are significant challenges to be addressed in specific applications such as poor contrast, low target signature resolution, etc. This paper addresses quality improvement in IRT images for object recognition. A systematic approach based on image bias correction and deep learning is proposed to increase target signature resolution and optimise the baseline quality of inputs for object recognition. Our main objective is to maximise the useful information on the object to be detected even when the number of pixels on target is adversely small. The experimental results show that our approach can significantly improve target resolution and thus helps making object recognition more efficient in automatic target detection/recognition systems (ATD/R).

  1. IR image quality assessment and real-time optimum seeking method based on dynamic visual characteristics

    Science.gov (United States)

    Li, Bin; Liu, Gang; Gao, Yongmin; Lei, Hao; Wu, Haiying; Wang, Yu; Rong, Xiaolong

    2016-10-01

    Image quality is an important factor that influences the dynamic target information perception; it is the key factor of real-time target state analysis and judgment. In order to solve the multi-observation station comparison and video optimum seeking problem in the process of target information perception and recognition, an image quality assessment method based on visual characteristics is proposed for infrared target tracking. First, it analyses the basic infrared target image characteristics and application requirements, analyses the status and problems of the multi station optimum seeking technology. According to the expected research results, the processing flow of image processing is established. Then, the image quality objective assessment index is established, which reflects the basic characteristics of the target image, and the assessment index is integrated into the normalized assessment function. According to the quality assessment function, the infrared image quality assessment based on infrared target recognition and image analysis processing is realized, which is mainly characterized by the region of interest and dynamic visual characteristics. And on the basis of this technology, the real-time optimum seeking of multi station infrared target tracking image is completed. In order to verify the effectiveness of the method and the practical application effect, it designs the quality assessment and comparison of different station infrared images. Example shows that the method proposed in this paper can realize multi-observation station infrared image assessment comparison, image quality sorting, the optimum seeking of the infrared image based on the quality assessment. The results accord with the characteristics of infrared target image and dynamic visual characteristics.

  2. Luminescence imaging using radionuclides: a potential application in molecular imaging

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Chan [Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Il An, Gwang [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Park, Se-Il [Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Oh, Jungmin [Korea Basic Science Institute Chuncheon Center, Gangwon-do 200-701 (Korea, Republic of); Kim, Hong Joo [Department of Physics and Energy Science, Kyungpook National University, Daegu 702-710 (Korea, Republic of); Su Ha, Yeong; Wang, Eun Kyung [Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Min Kim, Kyeong; Kim, Jung Young [Molecular Imaging Research Center, Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of); Lee, Jaetae [Department of Nuclear Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of); Welch, Michael J. [Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 (United States); Yoo, Jeongsoo, E-mail: yooj@knu.ac.k [Department of Molecular Medicine, School of Medicine, Kyungpook National University, Daegu 700-422 (Korea, Republic of)

    2011-04-15

    Introduction: Nuclear and optical imaging are complementary in many aspects and there would be many advantages when optical imaging probes are prepared using radionuclides rather than classic fluorophores, and when nuclear and optical dual images are obtained using single imaging probe. Methods: The luminescence intensities of various radionuclides having different decay modes have been assayed using luminescence imaging and in vitro luminometer. Radioiodinated Herceptin was injected into a tumor-bearing mouse, and luminescence and microPET images were obtained. The plant dipped in [{sup 32}P]phosphate solution was scanned in luminescence mode. Radio-TLC plate was also imaged in the same imaging mode. Results: Radionuclides emitting high energy {beta}{sup +}/{beta}{sup -} particles showed higher luminescence signals. NIH3T6.7 tumors were detected in both optical and nuclear imaging. The uptake of [{sup 32}P]phosphate in plant was easily followed by luminescence imaging. Radio-TLC plate was visualized and radiochemical purity was quantified using luminescence imaging. Conclusion: Many radionuclides with high energetic {beta}{sup +} or {beta}{sup -} particles during decay were found to be imaged in luminescence mode due mainly to Cerenkov radiation. 'Cerenkov imaging' provides a new optical imaging platform and an invaluable bridge between optical and nuclear imaging. New optical imaging probes could be easily prepared using well-established radioiodination methods. Cerenkov imaging will have more applications in the research field of plant science and autoradiography.

  3. Color Image Quality Assessment Based on CIEDE2000

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2012-01-01

    Full Text Available Combining the color difference formula of CIEDE2000 and the printing industry standard for visual verification, we present an objective color image quality assessment method correlated with subjective vision perception. An objective score conformed to subjective perception (OSCSP Q was proposed to directly reflect the subjective visual perception. In addition, we present a general method to calibrate correction factors of color difference formula under real experimental conditions. Our experiment results show that the present DE2000-based metric can be consistent with human visual system in general application environment.

  4. Assessment of image quality in x-ray radiography imaging using a small plasma focus device

    Science.gov (United States)

    Kanani, A.; Shirani, B.; Jabbari, I.; Mokhtari, J.

    2014-08-01

    This paper offers a comprehensive investigation of image quality parameters for a small plasma focus as a pulsed hard x-ray source for radiography applications. A set of images were captured from some metal objects and electronic circuits using a low energy plasma focus at different voltages of capacitor bank and different pressures of argon gas. The x-ray source focal spot of this device was obtained to be about 0.6 mm using the penumbra imaging method. The image quality was studied by several parameters such as image contrast, line spread function (LSF) and modulation transfer function (MTF). Results showed that the contrast changes by variations in gas pressure. The best contrast was obtained at a pressure of 0.5 mbar and 3.75 kJ stored energy. The results of x-ray dose from the device showed that about 0.6 mGy is sufficient to obtain acceptable images on the film. The measurements of LSF and MTF parameters were carried out by means of a thin stainless steel wire 0.8 mm in diameter and the cut-off frequency was obtained to be about 1.5 cycles/mm.

  5. PAN SHARPENING QUALITY INVESTIGATION OF TURKISH IN-OPERATION REMOTE SENSING SATELLITES: APPLICATIONS WITH RASAT AND GÖKTÜRK-2 IMAGES

    Directory of Open Access Journals (Sweden)

    M. Ozendi

    2016-10-01

    The aim of this study is to investigate pan-sharpening performance of RASAT and GÖKTÜRK-2 images. For this purpose, pan-sharpened images are generated using most popular pan-sharpening methods IHS, Brovey and PCA at first. This procedure is followed by quantitative evaluation of pan-sharpened images using Correlation Coefficient (CC, Root Mean Square Error (RMSE, Relative Average Spectral Error (RASE, Spectral Angle Mapper (SAM and Erreur Relative Globale Adimensionnelle de Synthése (ERGAS metrics. For generation of pan-sharpened images and computation of metrics SharpQ tool is used which is developed with MATLAB computing language. According to metrics, PCA derived pan-sharpened image is the most similar one to multispectral image for RASAT, and Brovey derived pan-sharpened image is the most similar one to multispectral image for GÖKTÜRK-2. Finally, pan-sharpened images are evaluated qualitatively in terms of object availability and completeness for various land covers (such as urban, forest and flat areas by a group of operators who are experienced in remote sensing imagery.

  6. Image feature detectors and descriptors foundations and applications

    CERN Document Server

    Hassaballah, Mahmoud

    2016-01-01

    This book provides readers with a selection of high-quality chapters that cover both theoretical concepts and practical applications of image feature detectors and descriptors. It serves as reference for researchers and practitioners by featuring survey chapters and research contributions on image feature detectors and descriptors. Additionally, it emphasizes several keywords in both theoretical and practical aspects of image feature extraction. The keywords include acceleration of feature detection and extraction, hardware implantations, image segmentation, evolutionary algorithm, ordinal measures, as well as visual speech recognition. .

  7. Image and video compression fundamentals, techniques, and applications

    CERN Document Server

    Joshi, Madhuri A; Dandawate, Yogesh H; Joshi, Kalyani R; Metkar, Shilpa P

    2014-01-01

    Image and video signals require large transmission bandwidth and storage, leading to high costs. The data must be compressed without a loss or with a small loss of quality. Thus, efficient image and video compression algorithms play a significant role in the storage and transmission of data.Image and Video Compression: Fundamentals, Techniques, and Applications explains the major techniques for image and video compression and demonstrates their practical implementation using MATLAB® programs. Designed for students, researchers, and practicing engineers, the book presents both basic principles

  8. Quality Prediction of Asymmetrically Distorted Stereoscopic 3D Images.

    Science.gov (United States)

    Wang, Jiheng; Rehman, Abdul; Zeng, Kai; Wang, Shiqi; Wang, Zhou

    2015-11-01

    Objective quality assessment of distorted stereoscopic images is a challenging problem, especially when the distortions in the left and right views are asymmetric. Existing studies suggest that simply averaging the quality of the left and right views well predicts the quality of symmetrically distorted stereoscopic images, but generates substantial prediction bias when applied to asymmetrically distorted stereoscopic images. In this paper, we first build a database that contains both single-view and symmetrically and asymmetrically distorted stereoscopic images. We then carry out a subjective test, where we find that the quality prediction bias of the asymmetrically distorted images could lean toward opposite directions (overestimate or underestimate), depending on the distortion types and levels. Our subjective test also suggests that eye dominance effect does not have strong impact on the visual quality decisions of stereoscopic images. Furthermore, we develop an information content and divisive normalization-based pooling scheme that improves upon structural similarity in estimating the quality of single-view images. Finally, we propose a binocular rivalry-inspired multi-scale model to predict the quality of stereoscopic images from that of the single-view images. Our results show that the proposed model, without explicitly identifying image distortion types, successfully eliminates the prediction bias, leading to significantly improved quality prediction of the stereoscopic images.

  9. Using short-wave infrared imaging for fruit quality evaluation

    Science.gov (United States)

    Zhang, Dong; Lee, Dah-Jye; Desai, Alok

    2013-12-01

    Quality evaluation of agricultural and food products is important for processing, inventory control, and marketing. Fruit size and surface quality are two important quality factors for high-quality fruit such as Medjool dates. Fruit size is usually measured by length that can be done easily by simple image processing techniques. Surface quality evaluation on the other hand requires more complicated design, both in image acquisition and image processing. Skin delamination is considered a major factor that affects fruit quality and its value. This paper presents an efficient histogram analysis and image processing technique that is designed specifically for real-time surface quality evaluation of Medjool dates. This approach, based on short-wave infrared imaging, provides excellent image contrast between the fruit surface and delaminated skin, which allows significant simplification of image processing algorithm and reduction of computational power requirements. The proposed quality grading method requires very simple training procedure to obtain a gray scale image histogram for each quality level. Using histogram comparison, each date is assigned to one of the four quality levels and an optimal threshold is calculated for segmenting skin delamination areas from the fruit surface. The percentage of the fruit surface that has skin delamination can then be calculated for quality evaluation. This method has been implemented and used for commercial production and proven to be efficient and accurate.

  10. Practical guidelines for radiographers to improve computed radiography image quality.

    Science.gov (United States)

    Pongnapang, N

    2005-10-01

    Computed Radiography (CR) has become a major digital imaging modality in a modern radiological department. CR system changes workflow from the conventional way of using film/screen by employing photostimulable phosphor plate technology. This results in the changing perspectives of technical, artefacts and quality control issues in radiology departments. Guidelines for better image quality in digital medical enterprise include professional guidelines for users and the quality control programme specifically designed to serve the best quality of clinical images. Radiographers who understand technological shift of the CR from conventional method can employ optimization of CR images. Proper anatomic collimation and exposure techniques for each radiographic projection are crucial steps in producing quality digital images. Matching image processing with specific anatomy is also important factor that radiographers should realise. Successful shift from conventional to fully digitised radiology department requires skilful radiographers who utilise the technology and a successful quality control program from teamwork in the department.

  11. Learning to rank for blind image quality assessment.

    Science.gov (United States)

    Gao, Fei; Tao, Dacheng; Gao, Xinbo; Li, Xuelong

    2015-10-01

    Blind image quality assessment (BIQA) aims to predict perceptual image quality scores without access to reference images. State-of-the-art BIQA methods typically require subjects to score a large number of images to train a robust model. However, subjective quality scores are imprecise, biased, and inconsistent, and it is challenging to obtain a large-scale database, or to extend existing databases, because of the inconvenience of collecting images, training the subjects, conducting subjective experiments, and realigning human quality evaluations. To combat these limitations, this paper explores and exploits preference image pairs (PIPs) such as the quality of image Ia is better than that of image Ib for training a robust BIQA model. The preference label, representing the relative quality of two images, is generally precise and consistent, and is not sensitive to image content, distortion type, or subject identity; such PIPs can be generated at a very low cost. The proposed BIQA method is one of learning to rank. We first formulate the problem of learning the mapping from the image features to the preference label as one of classification. In particular, we investigate the utilization of a multiple kernel learning algorithm based on group lasso to provide a solution. A simple but effective strategy to estimate perceptual image quality scores is then presented. Experiments show that the proposed BIQA method is highly effective and achieves a performance comparable with that of state-of-the-art BIQA algorithms. Moreover, the proposed method can be easily extended to new distortion categories.

  12. Application of Total Quality Management in Education

    Science.gov (United States)

    Farooq, M. S.; Akhtar, M. S.; Ullah, S. Zia; Memon, R. A.

    2007-01-01

    The purpose of the paper is to analyzing thoughts of the modern management paradigm "Total Quality Management" (TQM), and its application in the field of education. The basic theme of TQM is participatory approach to address the question(s) of quality in business aswell as in the field of education. Reviewing fresh literature from the internet …

  13. Spatial data quality: from description to application

    NARCIS (Netherlands)

    Oort, van P.A.J.

    2006-01-01

    The growing availability of spatial data along with growing ease to use the spatial data (thanks to wide-scale adoption of GIS) have made it possible to use spatial data in applications inappropriate considering the quality of the data. As a result, concerns about spatial data quality have

  14. Image quality of a cone beam O-arm 3D imaging system

    Science.gov (United States)

    Zhang, Jie; Weir, Victor; Lin, Jingying; Hsiung, Hsiang; Ritenour, E. Russell

    2009-02-01

    The O-arm is a cone beam imaging system designed primarily to support orthopedic surgery and is also used for image-guided and vascular surgery. Using a gantry that can be opened or closed, the O-arm can function as a 2-dimensional (2D) fluoroscopy device or collect 3-dimensional (3D) volumetric imaging data like a CT system. Clinical applications of the O-arm in spine surgical procedures, assessment of pedicle screw position, and kyphoplasty procedures show that the O-arm 3D mode provides enhanced imaging information compared to radiographs or fluoroscopy alone. In this study, the image quality of an O-arm system was quantitatively evaluated. A 20 cm diameter CATPHAN 424 phantom was scanned using the pre-programmed head protocols: small/medium (120 kVp, 100 mAs), large (120 kVp, 128 mAs), and extra-large (120 kVp, 160 mAs) in 3D mode. High resolution reconstruction mode (512×512×0.83 mm) was used to reconstruct images for the analysis of low and high contrast resolution, and noise power spectrum. MTF was measured using the point spread function. The results show that the O-arm image is uniform but with a noise pattern which cannot be removed by simply increasing the mAs. The high contrast resolution of the O-arm system was approximately 9 lp/cm. The system has a 10% MTF at 0.45 mm. The low-contrast resolution cannot be decided due to the noise pattern. For surgery where locations of a structure are emphasized over a survey of all image details, the image quality of the O-arm is well accepted clinically.

  15. An image quality analysis of ANVIS-6 night vision goggles

    OpenAIRE

    Abel, Derek H.

    1994-01-01

    This study was undertaken in an effort to relate ANVIS-6 Night Vision Goggle image quality to user performance. The purpose was to determine which of five image quality metrics best related to performance tasks. The image quality metrics examined Modulation Transfer Function Area (MTFA), Integrated Contrast Sensitivity (leS), Square Root Integral (SQRI), Resolution, and Signal-to-Noise Ratio (SNR). The performance tasks were detection and recognition of targets under various le...

  16. Measuring Fingerprint Image Quality Using the Fourier Spectrum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The fingerprint image quality has a significant effect on the performance of automatic fingerprint identification system. A method for measure of fingerprint image quality based on Fourier spectrum is proposed. First the band frequency which corresponds to the global average period of ridge is searched. Then the quality score of the fingerprint image is computed by measuring relative magnitude of the band frequency components. The method is verified to have good performance by experiments.

  17. Reduced-reference image quality assessment using moment method

    Science.gov (United States)

    Yang, Diwei; Shen, Yuantong; Shen, Yongluo; Li, Hongwei

    2016-10-01

    Reduced-reference image quality assessment (RR IQA) aims to evaluate the perceptual quality of a distorted image through partial information of the corresponding reference image. In this paper, a novel RR IQA metric is proposed by using the moment method. We claim that the first and second moments of wavelet coefficients of natural images can have approximate and regular change that are disturbed by different types of distortions, and that this disturbance can be relevant to human perceptions of quality. We measure the difference of these statistical parameters between reference and distorted image to predict the visual quality degradation. The introduced IQA metric is suitable for implementation and has relatively low computational complexity. The experimental results on Laboratory for Image and Video Engineering (LIVE) and Tampere Image Database (TID) image databases indicate that the proposed metric has a good predictive performance.

  18. Molecular imaging applications for immunology.

    Science.gov (United States)

    Hildebrandt, Isabel Junie; Gambhir, Sanjiv Sam

    2004-05-01

    The use of multimodality molecular imaging has recently facilitated the study of molecular and cellular events in living subjects in a noninvasive and repetitive manner to improve the diagnostic capability of traditional assays. The noninvasive imaging modalities utilized for both small animal and human imaging include positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), ultrasound, and computed tomography (CT). Techniques specific to small-animal imaging include bioluminescent imaging (BIm) and fluorescent imaging (FIm). Molecular imaging permits the study of events within cells, the examination of cell trafficking patterns that relate to inflammatory diseases and metastases, and the ability to rapidly screen new drug treatments for distribution and effectiveness. In this paper, we will review the current field of molecular imaging assays (especially those utilizing PET and BIm modalities) and examine how they might impact animal models and human disease in the field of clinical immunology.

  19. Quantitative image quality evaluation for cardiac CT reconstructions

    Science.gov (United States)

    Tseng, Hsin-Wu; Fan, Jiahua; Kupinski, Matthew A.; Balhorn, William; Okerlund, Darin R.

    2016-03-01

    Maintaining image quality in the presence of motion is always desirable and challenging in clinical Cardiac CT imaging. Different image-reconstruction algorithms are available on current commercial CT systems that attempt to achieve this goal. It is widely accepted that image-quality assessment should be task-based and involve specific tasks, observers, and associated figures of merits. In this work, we developed an observer model that performed the task of estimating the percentage of plaque in a vessel from CT images. We compared task performance of Cardiac CT image data reconstructed using a conventional FBP reconstruction algorithm and the SnapShot Freeze (SSF) algorithm, each at default and optimal reconstruction cardiac phases. The purpose of this work is to design an approach for quantitative image-quality evaluation of temporal resolution for Cardiac CT systems. To simulate heart motion, a moving coronary type phantom synchronized with an ECG signal was used. Three different percentage plaques embedded in a 3 mm vessel phantom were imaged multiple times under motion free, 60 bpm, and 80 bpm heart rates. Static (motion free) images of this phantom were taken as reference images for image template generation. Independent ROIs from the 60 bpm and 80 bpm images were generated by vessel tracking. The observer performed estimation tasks using these ROIs. Ensemble mean square error (EMSE) was used as the figure of merit. Results suggest that the quality of SSF images is superior to the quality of FBP images in higher heart-rate scans.

  20. Comparing image compression methods in biomedical applications

    Directory of Open Access Journals (Sweden)

    Libor Hargas

    2004-01-01

    Full Text Available Compression methods suitable for image processing are described in this article in biomedical applications. The compression is often realized by reduction of irrelevance or redundancy. There are described lossless and lossy compression methods which can be use for compress of images in biomedical applications and comparison of these methods based on fidelity criteria.

  1. Fuzzy image processing and applications with Matlab

    CERN Document Server

    Chaira, Tamalika

    2009-01-01

    In contrast to classical image analysis methods that employ ""crisp"" mathematics, fuzzy set techniques provide an elegant foundation and a set of rich methodologies for diverse image-processing tasks. However, a solid understanding of fuzzy processing requires a firm grasp of essential principles and background knowledge.Fuzzy Image Processing and Applications with MATLAB® presents the integral science and essential mathematics behind this exciting and dynamic branch of image processing, which is becoming increasingly important to applications in areas such as remote sensing, medical imaging,

  2. Service quality of cloud-based applications

    CERN Document Server

    Bauer, Eric

    2014-01-01

    This book explains why applications running on cloud might not deliver the same service reliability, availability, latency and overall quality to end users as they do when the applications are running on traditional (non-virtualized, non-cloud) configurations, and explains what can be done to mitigate that risk.

  3. Image quality and dose differences caused by vendor-specific image processing of neonatal radiographs.

    Science.gov (United States)

    Sensakovic, William F; O'Dell, M Cody; Letter, Haley; Kohler, Nathan; Rop, Baiywo; Cook, Jane; Logsdon, Gregory; Varich, Laura

    2016-10-01

    Image processing plays an important role in optimizing image quality and radiation dose in projection radiography. Unfortunately commercial algorithms are black boxes that are often left at or near vendor default settings rather than being optimized. We hypothesize that different commercial image-processing systems, when left at or near default settings, create significant differences in image quality. We further hypothesize that image-quality differences can be exploited to produce images of equivalent quality but lower radiation dose. We used a portable radiography system to acquire images on a neonatal chest phantom and recorded the entrance surface air kerma (ESAK). We applied two image-processing systems (Optima XR220amx, by GE Healthcare, Waukesha, WI; and MUSICA(2) by Agfa HealthCare, Mortsel, Belgium) to the images. Seven observers (attending pediatric radiologists and radiology residents) independently assessed image quality using two methods: rating and matching. Image-quality ratings were independently assessed by each observer on a 10-point scale. Matching consisted of each observer matching GE-processed images and Agfa-processed images with equivalent image quality. A total of 210 rating tasks and 42 matching tasks were performed and effective dose was estimated. Median Agfa-processed image-quality ratings were higher than GE-processed ratings. Non-diagnostic ratings were seen over a wider range of doses for GE-processed images than for Agfa-processed images. During matching tasks, observers matched image quality between GE-processed images and Agfa-processed images acquired at a lower effective dose (11 ± 9 μSv; P < 0.0001). Image-processing methods significantly impact perceived image quality. These image-quality differences can be exploited to alter protocols and produce images of equivalent image quality but lower doses. Those purchasing projection radiography systems or third-party image-processing software should be aware that image

  4. Open source database of images DEIMOS: extension for large-scale subjective image quality assessment

    Science.gov (United States)

    Vítek, Stanislav

    2014-09-01

    DEIMOS (Database of Images: Open Source) is an open-source database of images and video sequences for testing, verification and comparison of various image and/or video processing techniques such as compression, reconstruction and enhancement. This paper deals with extension of the database allowing performing large-scale web-based subjective image quality assessment. Extension implements both administrative and client interface. The proposed system is aimed mainly at mobile communication devices, taking into account advantages of HTML5 technology; it means that participants don't need to install any application and assessment could be performed using web browser. The assessment campaign administrator can select images from the large database and then apply rules defined by various test procedure recommendations. The standard test procedures may be fully customized and saved as a template. Alternatively the administrator can define a custom test, using images from the pool and other components, such as evaluating forms and ongoing questionnaires. Image sequence is delivered to the online client, e.g. smartphone or tablet, as a fully automated assessment sequence or viewer can decide on timing of the assessment if required. Environmental data and viewing conditions (e.g. illumination, vibrations, GPS coordinates, etc.), may be collected and subsequently analyzed.

  5. Image quality simulation and verification of x-ray volume imaging systems

    Science.gov (United States)

    Kroon, Han; Schoumans, Nicole; Snoeren, Ruud

    2006-03-01

    Nowadays, 2D X-ray systems are used more and more for 3-dimensional rotational X-ray imaging (3D-RX) or volume imaging, such as 3D rotational angiography. However, it is not evident that the application of settings for optimal 2D images also guarantee optimal conditions for 3D-RX reconstruction results. In particular the search for a good compromise between patient dose and IQ may lead to different results in case of 3D imaging. For this purpose we developed an additional 3D-RX module for our full-scale image quality & patient dose (IQ&PD) simulation model, with specific calculations of patient dose under rotational conditions, and contrast, sharpness and noise of 3D images. The complete X-ray system from X-ray tube up to and including the display device is modelled in separate blocks for each distinguishable component or process. The model acts as a tool for X-ray system design, image quality optimisation and patient dose reduction. The model supports the decomposition of system level requirements, and takes inherently care of the prerequisite mutual coherence between component requirements. The short calculation times enable comprehensive multi-parameter optimisation studies. The 3D-RX IQ&PD performance is validated by comparing calculation results with actual measurements performed on volume images acquired with a state-of-the-art 3D-RX system. The measurements include RXDI dose index, signal and contrast based on Hounsfield units (H and ΔH), modulation transfer function (MTF), noise variance (σ2) and contrast-to-noise ratio (CNR). Further we developed a new 3D contrast-delta (3D-CΔ) phantom with details of varying size and contrast medium material and concentration. Simulation and measurement results show a significant correlation.

  6. Review of polarization imaging for international military application

    Science.gov (United States)

    Duan, Jin; Fu, Qiang; Mo, Chunhe; Zhu, Yong; Liu, Dan

    2013-08-01

    Polarization is a primary characteristic of electromagnetic wave. Polarization is another field of the light except the intensity, wavelength, and coherence. Polarization can indicate the different attributions that decided by objects, such as surface features, roughness, shading, shape and so on. Polarization Imaging is a useful complement to traditional intensity and spectral imaging methods with great potential in many application fields. In the future war, the advantages of polarization are significant for target detection and recognition in the increasingly complicated battlefield environment. In this paper, the research progress is generally introduced in military application in four fields: 1) target polarization characteristics and simulationenhance contrast, distinguish the target and background; 2) polarization transmission characteristics- observe target through the smoke and fog of War; 3) polarization imaging detection methods- improve the imaging quality, enhance the information available; 4) polarization image processing- improve detection and tracking performance.

  7. Medical imaging technology reviews and computational applications

    CERN Document Server

    Dewi, Dyah

    2015-01-01

    This book presents the latest research findings and reviews in the field of medical imaging technology, covering ultrasound diagnostics approaches for detecting osteoarthritis, breast carcinoma and cardiovascular conditions, image guided biopsy and segmentation techniques for detecting lung cancer, image fusion, and simulating fluid flows for cardiovascular applications. It offers a useful guide for students, lecturers and professional researchers in the fields of biomedical engineering and image processing.

  8. Principles and clinical applications of image analysis.

    Science.gov (United States)

    Kisner, H J

    1988-12-01

    Image processing has traveled to the lunar surface and back, finding its way into the clinical laboratory. Advances in digital computers have improved the technology of image analysis, resulting in a wide variety of medical applications. Offering improvements in turnaround time, standardized systems, increased precision, and walkaway automation, digital image analysis has likely found a permanent home as a diagnostic aid in the interpretation of microscopic as well as macroscopic laboratory images.

  9. Super-resolution convolutional neural network for the improvement of the image quality of magnified images in chest radiographs

    Science.gov (United States)

    Umehara, Kensuke; Ota, Junko; Ishimaru, Naoki; Ohno, Shunsuke; Okamoto, Kentaro; Suzuki, Takanori; Shirai, Naoki; Ishida, Takayuki

    2017-02-01

    Single image super-resolution (SR) method can generate a high-resolution (HR) image from a low-resolution (LR) image by enhancing image resolution. In medical imaging, HR images are expected to have a potential to provide a more accurate diagnosis with the practical application of HR displays. In recent years, the super-resolution convolutional neural network (SRCNN), which is one of the state-of-the-art deep learning based SR methods, has proposed in computer vision. In this study, we applied and evaluated the SRCNN scheme to improve the image quality of magnified images in chest radiographs. For evaluation, a total of 247 chest X-rays were sampled from the JSRT database. The 247 chest X-rays were divided into 93 training cases with non-nodules and 152 test cases with lung nodules. The SRCNN was trained using the training dataset. With the trained SRCNN, the HR image was reconstructed from the LR one. We compared the image quality of the SRCNN and conventional image interpolation methods, nearest neighbor, bilinear and bicubic interpolations. For quantitative evaluation, we measured two image quality metrics, peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). In the SRCNN scheme, PSNR and SSIM were significantly higher than those of three interpolation methods (pmethods without any obvious artifacts. These preliminary results indicate that the SRCNN scheme significantly outperforms conventional interpolation algorithms for enhancing image resolution and that the use of the SRCNN can yield substantial improvement of the image quality of magnified images in chest radiographs.

  10. Quality assurance in digital dental imaging: a systematic review.

    Science.gov (United States)

    Metsälä, Eija; Henner, Anja; Ekholm, Marja

    2014-07-01

    Doses induced by individual dental examinations are low. However, dental radiography accounts for nearly one third of the total number of radiological examinations in the European Union. Therefore, special attention is needed with regard to radiation protection. In order to lower patient doses, the staff performing dental examinations must have competence in imaging as well as in radiation protection issues. This paper presents a systematic review about the core competencies needed by the healthcare staff in performing digital dental radiological imaging quality assurance. The following databases were searched: Pubmed, Cinahl, Pro Quest and IEEXplore digital library. Also volumes of some dental imaging journals and doctoral theses of the Finnish universities educating dentists were searched. The search was performed using both MeSH terms and keywords using the option 'search all text'. The original keywords were: dental imaging, digital, x-ray, panoramic, quality, assurance, competence, competency, skills, knowledge, radiographer, radiologist technician, dentist, oral hygienist, radiation protection and their Finnish synonyms. Core competencies needed by the healthcare staff performing digital dental radiological imaging quality assurance described in the selected studies were: management of dental imaging equipment, competence in image quality and factors associated with it, dose optimization and quality assurance. In the future there will be higher doses in dental imaging due to increasing use of CBCT and digital imaging. The staff performing dental imaging must have competence in dental imaging quality assurance issues found in this review. They also have to practice ethical radiation safety culture in clinical practice.

  11. Digital Watermarking Method Warranting the Lower Limit of Image Quality of Watermarked Images

    Directory of Open Access Journals (Sweden)

    Iwata Motoi

    2010-01-01

    Full Text Available We propose a digital watermarking method warranting the lower limit of the image quality of watermarked images. The proposed method controls the degradation of a watermarked image by using a lower limit image. The lower limit image means the image of the worst quality that users can permit. The proposed method accepts any lower limit image and does not require it at extraction. Therefore lower limit images can be decided flexibly. In this paper, we introduce 2-dimensional human visual MTF model as an example of obtaining lower limit images. Also we use JPEG-compressed images of quality 75% and 50% as lower limit images. We investigate the performance of the proposed method by experiments. Moreover we compare the proposed method using three types of lower limit images with the existing method in view of the tradeoff between PSNR and the robustness against JPEG compression.

  12. DESIGN QUALITY IN MECHANICAL ENGINEERING APPLICATION

    Directory of Open Access Journals (Sweden)

    Ayşegül Akdogan Eker

    2010-09-01

    Full Text Available There is a close relationship between material chose and quality in mechanical engineering application like there is in all the other engineering applications. If this relation is balanced then engineering success increases. Material chose comes to fore in the design process most of the time. The two most important responsibilities of the design engineer in here is to chose suitable material and to know the production processes about design. The chose of material of a design that will fulfill the needs all through its life has great importance. It is needed to limit the material applicants by choosing the most suitable ones among variable material. Choosing materials that were examined before and whose behavior is well known provides the designer to feel confident. However since using highly successful materials would increase the competitive power of the designs; designers should follow the developments in materials and know the features of new materials. The description of these features can be interpreted within quality. Quality from the point of engineer is the total fulfillment of expectations.Engineer today are faced with very important problems such as fast technological innovations, a dynamic socio-economical environment, global rivalry. One of the life buoys they stick while trying to solve these problems is total method of quality control. Total Quality model which can provide higher competitive power compared to classical management model brings success only when applied with its whole components. "Approach toward prevention" and "measurement and statistics" have an important place among these elements. The first step of the approach toward prevention composes of design quality and Quality Function Deployment (QFD, or in other words The House of Quality method that will provide this. In this paper; considering the quality function deployment, how the chose of material are done in mechanical engineering applications will be explained.

  13. Application of image fusion techniques in DSA

    Science.gov (United States)

    Ye, Feng; Wu, Jian; Cui, Zhiming; Xu, Jing

    2007-12-01

    Digital subtraction angiography (DSA) is an important technology in both medical diagnoses and interposal therapy, which can eliminate the interferential background and give prominence to blood vessels by computer processing. After contrast material is injected into an artery or vein, a physician produces fluoroscopic images. Using these digitized images, a computer subtracts the image made with contrast material from a series of post injection images made without background information. By analyzing the characteristics of DSA medical images, this paper provides a solution of image fusion which is in allusion to the application of DSA subtraction. We fuse the images of angiogram and subtraction, in order to obtain the new image which has more data information. The image that fused by wavelet transform can display the blood vessels and background information clearly, and medical experts gave high score on the effect of it.

  14. Terahertz Imaging and Security Applications

    Science.gov (United States)

    Grossman, Erich

    2005-03-01

    Imaging at millimeter-wave and terahertz frequencies could vastly improve the security of personnel checkpoints, because of the penetration through clothing and spatial resolution available in this spectral range. Since 9/11, the social need for improved checkpoint screening has been obvious and great. However, although efforts to develop such imagers had been underway for many years before that, practical low-cost systems, analogous to IR uncooled imagers, still don't exist. An emphasis on purely passive imaging places very stringent sensitivity requirements on such imagers. A number of long-term efforts, which I briefly mention, are underway to improve the sensitivity of such passive imagers. However, most of the emphasis in our program is on active imaging. With this approach, much simpler and lower-cost detectors, such as (uncooled) antenna-coupled microbolometers can be used, at the expense of incorporating slightly more complex optics and illumination components. I discuss several tradeoffs presented in the design of active imaging systems for the 100 to 1000 GHz frequency range, describe how we have addressed them in the design of a scanning, 95 GHz, bolometer-based imager for concealed weapons detection that is nearing completion, and describe how the system architecture can be modified to scale the operating frequency to the 650 GHz atmospheric window. Co-authors: Arttu Luukanen and Aaron Miller

  15. Crowdsourcing quality control for Dark Energy Survey images

    Science.gov (United States)

    Melchior, P.; Sheldon, E.; Drlica-Wagner, A.; Rykoff, E. S.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Brooks, D.; Buckley-Geer, E.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; D'Andrea, C. B.; da Costa, L. N.; Desai, S.; Doel, P.; Evrard, A. E.; Finley, D. A.; Flaugher, B.; Frieman, J.; Gaztanaga, E.; Gerdes, D. W.; Gruen, D.; Gruendl, R. A.; Honscheid, K.; James, D. J.; Jarvis, M.; Kuehn, K.; Li, T. S.; Maia, M. A. G.; March, M.; Marshall, J. L.; Nord, B.; Ogando, R.; Plazas, A. A.; Romer, A. K.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Suchyta, E.; Swanson, M. E. C.; Tarle, G.; Vikram, V.; Walker, A. R.; Wester, W.; Zhang, Y.

    2016-07-01

    We have developed a crowdsourcing web application for image quality control employed by the Dark Energy Survey. Dubbed the "DES exposure checker", it renders science-grade images directly to a web browser and allows users to mark problematic features from a set of predefined classes. Users can also generate custom labels and thus help identify previously unknown problem classes. User reports are fed back to hardware and software experts to help mitigate and eliminate recognized issues. We report on the implementation of the application and our experience with its over 100 users, the majority of which are professional or prospective astronomers but not data management experts. We discuss aspects of user training and engagement, and demonstrate how problem reports have been pivotal to rapidly correct artifacts which would likely have been too subtle or infrequent to be recognized otherwise. We conclude with a number of important lessons learned, suggest possible improvements, and recommend this collective exploratory approach for future astronomical surveys or other extensive data sets with a sufficiently large user base. We also release open-source code of the web application and host an online demo version at http://des-exp-checker.pmelchior.net.

  16. Quality assessment of stereoscopic 3D image compression by binocular integration behaviors.

    Science.gov (United States)

    Lin, Yu-Hsun; Wu, Ja-Ling

    2014-04-01

    The objective approaches of 3D image quality assessment play a key role for the development of compression standards and various 3D multimedia applications. The quality assessment of 3D images faces more new challenges, such as asymmetric stereo compression, depth perception, and virtual view synthesis, than its 2D counterparts. In addition, the widely used 2D image quality metrics (e.g., PSNR and SSIM) cannot be directly applied to deal with these newly introduced challenges. This statement can be verified by the low correlation between the computed objective measures and the subjectively measured mean opinion scores (MOSs), when 3D images are the tested targets. In order to meet these newly introduced challenges, in this paper, besides traditional 2D image metrics, the binocular integration behaviors-the binocular combination and the binocular frequency integration, are utilized as the bases for measuring the quality of stereoscopic 3D images. The effectiveness of the proposed metrics is verified by conducting subjective evaluations on publicly available stereoscopic image databases. Experimental results show that significant consistency could be reached between the measured MOS and the proposed metrics, in which the correlation coefficient between them can go up to 0.88. Furthermore, we found that the proposed metrics can also address the quality assessment of the synthesized color-plus-depth 3D images well. Therefore, it is our belief that the binocular integration behaviors are important factors in the development of objective quality assessment for 3D images.

  17. Image quality influences the assessment of left ventricular function

    DEFF Research Database (Denmark)

    Grossgasteiger, Manuel; Hien, Maximilian D; Graser, Bastian;

    2014-01-01

    divided by the total endocardial border. These ratings were used to generate groups of poor (0%-40%), fair (41%-70%), and good (71%-100%) image quality. The ejection fraction (EF), end-diastolic volume, and end-systolic volume were analyzed by the Simpson method of disks (biplane and monoplane), eyeball......Objectives: Transesophageal echocardiography has become a standard tool for eval uating left ventricular function during cardiac surgery. However, the image quality varies widely between patients and examinations. The aim of this study was to investigate the influence of the image quality on 5...... commonly used 2-dimensional methods. Methods: Transesophageal real-time 3-dimensional echocardiography (3DE) served as a reference. Left ventricular function was evaluated in 63 patients with sufficient real-time 3DE image quality. The image quality was rated using the ratio of the visualized border...

  18. No-Reference Image Quality Assessment for ZY3 Imagery in Urban Areas Using Statistical Model

    Science.gov (United States)

    Zhang, Y.; Cui, W. H.; Yang, F.; Wu, Z. C.

    2016-06-01

    More and more high-spatial resolution satellite images are produced with the improvement of satellite technology. However, the quality of images is not always satisfactory for application. Due to the impact of complicated atmospheric conditions and complex radiation transmission process in imaging process the images often suffer deterioration. In order to assess the quality of remote sensing images over urban areas, we proposed a general purpose image quality assessment methods based on feature extraction and machine learning. We use two types of features in multi scales. One is from the shape of histogram the other is from the natural scene statistics based on Generalized Gaussian distribution (GGD). A 20-D feature vector for each scale is extracted and is assumed to capture the RS image quality degradation characteristics. We use SVM to learn to predict image quality scores from these features. In order to do the evaluation, we construct a median scale dataset for training and testing with subjects taking part in to give the human opinions of degraded images. We use ZY3 satellite images over Wuhan area (a city in China) to conduct experiments. Experimental results show the correlation of the predicted scores and the subjective perceptions.

  19. Image quality assessment for CT used on small animals

    Energy Technology Data Exchange (ETDEWEB)

    Cisneros, Isabela Paredes, E-mail: iparedesc@unal.edu.co; Agulles-Pedrós, Luis, E-mail: lagullesp@unal.edu.co [Universidad Nacional de Colombia, Departamento de Física, Grupo de Física Médica (Colombia)

    2016-07-07

    Image acquisition on a CT scanner is nowadays necessary in almost any kind of medical study. Its purpose, to produce anatomical images with the best achievable quality, implies the highest diagnostic radiation exposure to patients. Image quality can be measured quantitatively based on parameters such as noise, uniformity and resolution. This measure allows the determination of optimal parameters of operation for the scanner in order to get the best diagnostic image. A human Phillips CT scanner is the first one minded for veterinary-use exclusively in Colombia. The aim of this study was to measure the CT image quality parameters using an acrylic phantom and then, using the computational tool MATLAB, determine these parameters as a function of current value and window of visualization, in order to reduce dose delivery by keeping the appropriate image quality.

  20. Image quality assessment for CT used on small animals

    Science.gov (United States)

    Cisneros, Isabela Paredes; Agulles-Pedrós, Luis

    2016-07-01

    Image acquisition on a CT scanner is nowadays necessary in almost any kind of medical study. Its purpose, to produce anatomical images with the best achievable quality, implies the highest diagnostic radiation exposure to patients. Image quality can be measured quantitatively based on parameters such as noise, uniformity and resolution. This measure allows the determination of optimal parameters of operation for the scanner in order to get the best diagnostic image. A human Phillips CT scanner is the first one minded for veterinary-use exclusively in Colombia. The aim of this study was to measure the CT image quality parameters using an acrylic phantom and then, using the computational tool MatLab, determine these parameters as a function of current value and window of visualization, in order to reduce dose delivery by keeping the appropriate image quality.

  1. Practical guidelines for radiographers to improve computed radiography image quality

    OpenAIRE

    Pongnapang, N

    2005-01-01

    Computed Radiography (CR) has become a major digital imaging modality in a modern radiological department. CR system changes workflow from the conventional way of using film/screen by employing photostimulable phosphor plate technology. This results in the changing perspectives of technical, artefacts and quality control issues in radiology departments. Guidelines for better image quality in digital medical enterprise include professional guidelines for users and the quality control programme...

  2. A new assessment method for image fusion quality

    Science.gov (United States)

    Li, Liu; Jiang, Wanying; Li, Jing; Yuchi, Ming; Ding, Mingyue; Zhang, Xuming

    2013-03-01

    Image fusion quality assessment plays a critically important role in the field of medical imaging. To evaluate image fusion quality effectively, a lot of assessment methods have been proposed. Examples include mutual information (MI), root mean square error (RMSE), and universal image quality index (UIQI). These image fusion assessment methods could not reflect the human visual inspection effectively. To address this problem, we have proposed a novel image fusion assessment method which combines the nonsubsampled contourlet transform (NSCT) with the regional mutual information in this paper. In this proposed method, the source medical images are firstly decomposed into different levels by the NSCT. Then the maximum NSCT coefficients of the decomposed directional images at each level are obtained to compute the regional mutual information (RMI). Finally, multi-channel RMI is computed by the weighted sum of the obtained RMI values at the various levels of NSCT. The advantage of the proposed method lies in the fact that the NSCT can represent image information using multidirections and multi-scales and therefore it conforms to the multi-channel characteristic of human visual system, leading to its outstanding image assessment performance. The experimental results using CT and MRI images demonstrate that the proposed assessment method outperforms such assessment methods as MI and UIQI based measure in evaluating image fusion quality and it can provide consistent results with human visual assessment.

  3. Principle and applications of terahertz molecular imaging.

    Science.gov (United States)

    Son, Joo-Hiuk

    2013-05-31

    The principle, characteristics and applications of molecular imaging with terahertz electromagnetic waves are reviewed herein. The terahertz molecular imaging (TMI) technique uses nanoparticle probes to achieve dramatically enhanced sensitivity compared with that of conventional terahertz imaging. Surface plasmons, induced around the nanoparticles, raise the temperature of water in biological cells, and the temperature-dependent changes in the optical properties of water, which are large in the terahertz range, are measured differentially by terahertz waves. TMI has been applied to cancer diagnosis and nanoparticle drug delivery imaging. The technique is also compared with magnetic resonance imaging by using a dual-modality nanoparticle probe.

  4. Specific developed phantoms and software to assess radiological equipment image quality

    Energy Technology Data Exchange (ETDEWEB)

    Verdu, G., E-mail: gverdu@iqn.upv.es [Universidad Politecnica de Valencia (Spain). Dept. de Ingenieria Quimica y Nuclear; Mayo, P., E-mail: p.mayo@titaniast.com [TITANIA Servicios Teconologicos, Valencia (Spain); Rodenas, F., E-mail: frodenas@mat.upv.es [Universidad Politecnica de Valencia (Spain). Dept. de Matematica Aplicada; Campayo, J.M., E-mail: j.campayo@lainsa.com [Logistica y Acondicionamientos Industriales S.A.U (LAINSA), Valencia (Spain)

    2011-07-01

    The use of radiographic phantoms specifically designed to evaluate the operation of the radiographic equipment lets the study of the image quality obtained by this equipment in an objective way. In digital radiographic equipment, the analysis of the image quality can be automatized because the acquisition of the image is possible in different technologies that are, computerized radiography or phosphor plate and direct radiography or detector. In this work we have shown an application to assess automatically the constancy quality image in the image chain of the radiographic equipment. This application is integrated by designed radiographic phantoms which are adapted to conventional, dental equipment and specific developed software for the automatic evaluation of the phantom image quality. The software is based on digital image processing techniques that let the automatic detection of the different phantom tests by edge detector, morphological operators, threshold histogram techniques, etc. The utility developed is enough sensitive to the radiographic equipment of operating conditions of voltage (kV) and charge (mAs). It is a friendly user programme connected with a data base of the hospital or clinic where it has been used. After the phantom image processing the user can obtain an inform with a resume of the imaging system state with accepting and constancy results. (author)

  5. Effect of image quality on calcification detection in digital mammography.

    Science.gov (United States)

    Warren, Lucy M; Mackenzie, Alistair; Cooke, Julie; Given-Wilson, Rosalind M; Wallis, Matthew G; Chakraborty, Dev P; Dance, David R; Bosmans, Hilde; Young, Kenneth C

    2012-06-01

    This study aims to investigate if microcalcification detection varies significantly when mammographic images are acquired using different image qualities, including: different detectors, dose levels, and different image processing algorithms. An additional aim was to determine how the standard European method of measuring image quality using threshold gold thickness measured with a CDMAM phantom and the associated limits in current EU guidelines relate to calcification detection. One hundred and sixty two normal breast images were acquired on an amorphous selenium direct digital (DR) system. Microcalcification clusters extracted from magnified images of slices of mastectomies were electronically inserted into half of the images. The calcification clusters had a subtle appearance. All images were adjusted using a validated mathematical method to simulate the appearance of images from a computed radiography (CR) imaging system at the same dose, from both systems at half this dose, and from the DR system at quarter this dose. The original 162 images were processed with both Hologic and Agfa (Musica-2) image processing. All other image qualities were processed with Agfa (Musica-2) image processing only. Seven experienced observers marked and rated any identified suspicious regions. Free response operating characteristic (FROC) and ROC analyses were performed on the data. The lesion sensitivity at a nonlesion localization fraction (NLF) of 0.1 was also calculated. Images of the CDMAM mammographic test phantom were acquired using the automatic setting on the DR system. These images were modified to the additional image qualities used in the observer study. The images were analyzed using automated software. In order to assess the relationship between threshold gold thickness and calcification detection a power law was fitted to the data. There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC (AFROC) area decreased from

  6. CMOS imager for pointing and tracking applications

    Science.gov (United States)

    Pain, Bedabrata (Inventor); Sun, Chao (Inventor); Yang, Guang (Inventor); Heynssens, Julie B. (Inventor)

    2006-01-01

    Systems and techniques to realize pointing and tracking applications with CMOS imaging devices. In general, in one implementation, the technique includes: sampling multiple rows and multiple columns of an active pixel sensor array into a memory array (e.g., an on-chip memory array), and reading out the multiple rows and multiple columns sampled in the memory array to provide image data with reduced motion artifact. Various operation modes may be provided, including TDS, CDS, CQS, a tracking mode to read out multiple windows, and/or a mode employing a sample-first-read-later readout scheme. The tracking mode can take advantage of a diagonal switch array. The diagonal switch array, the active pixel sensor array and the memory array can be integrated onto a single imager chip with a controller. This imager device can be part of a larger imaging system for both space-based applications and terrestrial applications.

  7. Automated quality assessment in three-dimensional breast ultrasound images.

    Science.gov (United States)

    Schwaab, Julia; Diez, Yago; Oliver, Arnau; Martí, Robert; van Zelst, Jan; Gubern-Mérida, Albert; Mourri, Ahmed Bensouda; Gregori, Johannes; Günther, Matthias

    2016-04-01

    Automated three-dimensional breast ultrasound (ABUS) is a valuable adjunct to x-ray mammography for breast cancer screening of women with dense breasts. High image quality is essential for proper diagnostics and computer-aided detection. We propose an automated image quality assessment system for ABUS images that detects artifacts at the time of acquisition. Therefore, we study three aspects that can corrupt ABUS images: the nipple position relative to the rest of the breast, the shadow caused by the nipple, and the shape of the breast contour on the image. Image processing and machine learning algorithms are combined to detect these artifacts based on 368 clinical ABUS images that have been rated manually by two experienced clinicians. At a specificity of 0.99, 55% of the images that were rated as low quality are detected by the proposed algorithms. The areas under the ROC curves of the single classifiers are 0.99 for the nipple position, 0.84 for the nipple shadow, and 0.89 for the breast contour shape. The proposed algorithms work fast and reliably, which makes them adequate for online evaluation of image quality during acquisition. The presented concept may be extended to further image modalities and quality aspects.

  8. Imaging gaseous detectors and their applications

    CERN Document Server

    Nappi, Eugenio

    2013-01-01

    Covers the detector and imaging technology and their numerous applications in nuclear and high energy physics, astrophysics, medicine and radiation measurements Foreword from G. Charpak, awarded the Nobel Prize in Physics for this invention.

  9. The Influence of Spectral Wavelength on the Quality of Pansharpened Image Simulated Using Hyperspectral Data

    Science.gov (United States)

    Matsuoka, M.

    2012-07-01

    Preservation of the spectral characteristics in multispectral images is important in the development of pansharpening methods because it affects the accuracy of subsequent applications, such as visual interpretation, land cover classification, and change detection. The combinations of the spectral properties (observation wavelength and width of spectral bands) of multispectral and panchromatic images affect both the spatial and spectral quality of pansharpened images. Therefore, the clarification of the relations between spectral bands and quality of pansharpened image is important for improving our understanding of pansharpening methods, and for developing better schemes for image fusion. This study investigated the influence of the spectral waveband of panchromatic images on the image quality of multispectral (MS) images using simulated images produced from hyperspectral data. Panchromatic images with different spectral band position and multispectral images with degraded spatial resolution were generated from airborne visible/infrared imaging spectrometer (AVIRIS) images and pansharpened using seven methods: additive wavelet intensity, additive wavelet principal component, generalized Laplacian pyramid with spectral distortion minimization, generalized intensity-huesaturation (GIHS) transform, GIHS adaptive, Gram-Schmidt spectral sharpening, and block-based synthetic variable ratio. The pansharpened near-infrared band was visually and statistically compared with the non-degraded image. Wide variation in quality was identified visually within and between methods depending on the spectral wavelengths of the panchromatic images. Quantitative evaluations using three frequently used indices, the correlation coefficient, erreur relative globale adimensionnelle de synthèse (ERGAS), and the Q index, showed the individual behaviors of the pansharpening methods in terms of the spectral similarity in panchromatic and near-infrared, though all methods had similar qualities

  10. Cone beam computed tomography radiation dose and image quality assessments.

    Science.gov (United States)

    Lofthag-Hansen, Sara

    2010-01-01

    Diagnostic radiology has undergone profound changes in the last 30 years. New technologies are available to the dental field, cone beam computed tomography (CBCT) as one of the most important. CBCT is a catch-all term for a technology comprising a variety of machines differing in many respects: patient positioning, volume size (FOV), radiation quality, image capturing and reconstruction, image resolution and radiation dose. When new technology is introduced one must make sure that diagnostic accuracy is better or at least as good as the one it can be expected to replace. The CBCT brand tested was two versions of Accuitomo (Morita, Japan): 3D Accuitomo with an image intensifier as detector, FOV 3 cm x 4 cm and 3D Accuitomo FPD with a flat panel detector, FOVs 4 cm x 4 cm and 6 cm x 6 cm. The 3D Accuitomo was compared with intra-oral radiography for endodontic diagnosis in 35 patients with 46 teeth analyzed, of which 41 were endodontically treated. Three observers assessed the images by consensus. The result showed that CBCT imaging was superior with a higher number of teeth diagnosed with periapical lesions (42 vs 32 teeth). When evaluating 3D Accuitomo examinations in the posterior mandible in 30 patients, visibility of marginal bone crest and mandibular canal, important anatomic structures for implant planning, was high with good observer agreement among seven observers. Radiographic techniques have to be evaluated concerning radiation dose, which requires well-defined and easy-to-use methods. Two methods: CT dose index (CTDI), prevailing method for CT units, and dose-area product (DAP) were evaluated for calculating effective dose (E) for both units. An asymmetric dose distribution was revealed when a clinical situation was simulated. Hence, the CTDI method was not applicable for these units with small FOVs. Based on DAP values from 90 patient examinations effective dose was estimated for three diagnostic tasks: implant planning in posterior mandible and

  11. Quality assessment of video image capture systems

    Science.gov (United States)

    Rowberg, Alan H.; Lian, Jing

    1991-05-01

    As Picture Archiving and Communication System (PACS) technology has matured, video image capture has become a common way of capturing digital images from many modalities. While digital interfaces, such as those which use the ACR/NEMA standard, will become more common in the future, and are preferred because of the accuracy of image transfer, video image capture will be the dominant method in the short term, and may continue to be used for some time because of the low cost and high speed often associated with such devices. A series of digital phantoms has been developed for display on either a CT9800 or Hilite Advantage scanner. The phantom images have been stored on magnetic tape in the standard tape archive format used by General Electric, so that the images may be loaded onto the scanner at any time. These images are then captured using a commercial video image capture board in a PC/286 computer, where the images are not only to be displayed, but also analyzed with the use of an automated process implemented in a computer program on the same PC. Results of the analyses are saved, together with the data and time of image acquisition, so that the results can be displayed graphically, as trend plots.

  12. Prior image constrained image reconstruction in emerging computed tomography applications

    Science.gov (United States)

    Brunner, Stephen T.

    Advances have been made in computed tomography (CT), especially in the past five years, by incorporating prior images into the image reconstruction process. In this dissertation, we investigate prior image constrained image reconstruction in three emerging CT applications: dual-energy CT, multi-energy photon-counting CT, and cone-beam CT in image-guided radiation therapy. First, we investigate the application of Prior Image Constrained Compressed Sensing (PICCS) in dual-energy CT, which has been called "one of the hottest research areas in CT." Phantom and animal studies are conducted using a state-of-the-art 64-slice GE Discovery 750 HD CT scanner to investigate the extent to which PICCS can enable radiation dose reduction in material density and virtual monochromatic imaging. Second, we extend the application of PICCS from dual-energy CT to multi-energy photon-counting CT, which has been called "one of the 12 topics in CT to be critical in the next decade." Numerical simulations are conducted to generate multiple energy bin images for a photon-counting CT acquisition and to investigate the extent to which PICCS can enable radiation dose efficiency improvement. Third, we investigate the performance of a newly proposed prior image constrained scatter correction technique to correct scatter-induced shading artifacts in cone-beam CT, which, when used in image-guided radiation therapy procedures, can assist in patient localization, and potentially, dose verification and adaptive radiation therapy. Phantom studies are conducted using a Varian 2100 EX system with an on-board imager to investigate the extent to which the prior image constrained scatter correction technique can mitigate scatter-induced shading artifacts in cone-beam CT. Results show that these prior image constrained image reconstruction techniques can reduce radiation dose in dual-energy CT by 50% in phantom and animal studies in material density and virtual monochromatic imaging, can lead to radiation

  13. Second Harmonic Imaging improves Echocardiograph Quality on board the International Space Station

    Science.gov (United States)

    Garcia, Kathleen; Sargsyan, Ashot; Hamilton, Douglas; Martin, David; Ebert, Douglas; Melton, Shannon; Dulchavsky, Scott

    2008-01-01

    Ultrasound (US) capabilities have been part of the Human Research Facility (HRF) on board the International Space Station (ISS) since 2001. The US equipment on board the ISS includes a first-generation Tissue Harmonic Imaging (THI) option. Harmonic imaging (HI) is the second harmonic response of the tissue to the ultrasound beam and produces robust tissue detail and signal. Since this is a first-generation THI, there are inherent limitations in tissue penetration. As a breakthrough technology, HI extensively advanced the field of ultrasound. In cardiac applications, it drastically improves endocardial border detection and has become a common imaging modality. U.S. images were captured and stored as JPEG stills from the ISS video downlink. US images with and without harmonic imaging option were randomized and provided to volunteers without medical education or US skills for identification of endocardial border. The results were processed and analyzed using applicable statistical calculations. The measurements in US images using HI improved measurement consistency and reproducibility among observers when compared to fundamental imaging. HI has been embraced by the imaging community at large as it improves the quality and data validity of US studies, especially in difficult-to-image cases. Even with the limitations of the first generation THI, HI improved the quality and measurability of many of the downlinked images from the ISS and should be an option utilized with cardiac imaging on board the ISS in all future space missions.

  14. Image quality of a mobile display under different illuminations.

    Science.gov (United States)

    Lin, Po-Hung; Kuo, Wen-Hung

    2011-08-01

    This study constructed the image quality models for a small mobile display under different ambient illumination levels using Group Method and Data Handling (GMDH) and described the relationship between perceived image quality and physical measurements. 33 college students took part in this experiment and were asked to evaluate the image quality under 1500 lux (typical indoor office illumination) and 7000 lux (simulated outdoor environment) in Stage One and Stage Two, respectively. In each stage, the participants had to evaluate 21 images. 17 sets of the data as a training set were used to build the model and four sets of the data as a testing set were used to verify the model. The results indicated that the effects of luminance, contrast, correlated color temperature (CCT), and resolution were significant on perceived image quality under 1500 lux. However, color temperature was not a significant physical characteristic, and an interaction between luminance and contrast was found below 7000 lux. From the results of the experiment, it is considered that the outdoor environment (7000 lux) is not suitable for using mobile displays. Finally, once a valid image quality model is built, the subjective image quality can be established when the measurements of significant physical characteristics are provided. The results of subjective ratings can also be provided for mobile display manufacturers to improve the product quality so that their products can meet customers' requirements.

  15. Applications of Quality Management in Language Education

    Science.gov (United States)

    Heyworth, Frank

    2013-01-01

    This review examines applications of quality management (QM) in language education. QM approaches have been adapted from methodologies developed in industrial and commercial settings, and these are briefly described. Key aspects of QM in language education are the definition of purpose, descriptions of principles and practice, including various…

  16. Applications of Quality Management in Language Education

    Science.gov (United States)

    Heyworth, Frank

    2013-01-01

    This review examines applications of quality management (QM) in language education. QM approaches have been adapted from methodologies developed in industrial and commercial settings, and these are briefly described. Key aspects of QM in language education are the definition of purpose, descriptions of principles and practice, including various…

  17. Image and Video Quality Assessment Using Neural Network and SVM

    Institute of Scientific and Technical Information of China (English)

    DING Wenrui; TONG Yubing; ZHANG Qishan; YANG Dongkai

    2008-01-01

    An image and video quality assessment method was developed using neural network and support vector machines (SVM) with the peak signal to noise ratio (PSNR) and the structure similarity indexes used to describe image quality. The neural network was used to obtain the mapping functions between the objec-tive quality assessment indexes and subjective quality assessment. The SVM was used to classify the im-ages into different types which were accessed using different mapping functions. Video quality was as-sessed based on the quality of each frame in the video sequence with various weights to describe motion and scene changes in the video. The number of isolated points in the correlations of the image and video subjective and objective quality assessments was reduced by this method. Simulation results show that the method accurately accesses image quality. The monotonicity of the method for images is 6.94% higher than with the PSNR method, and the root mean square error is at least 35.90% higher than with the PSNR.

  18. Performance comparison of different graylevel image fusion schemes through a universal image quality index

    NARCIS (Netherlands)

    Toet, A.; Hogervorst, M.A.

    2003-01-01

    We applied a recently introduced universal image quality index Q that quantifies the distortion of a processed image relative to its original version, to assess the performance of different graylevel image fusion schemes. The method is as follows. First, we adopt an original test image as the refere

  19. Computer image processing: Geologic applications

    Science.gov (United States)

    Abrams, M. J.

    1978-01-01

    Computer image processing of digital data was performed to support several geological studies. The specific goals were to: (1) relate the mineral content to the spectral reflectance of certain geologic materials, (2) determine the influence of environmental factors, such as atmosphere and vegetation, and (3) improve image processing techniques. For detection of spectral differences related to mineralogy, the technique of band ratioing was found to be the most useful. The influence of atmospheric scattering and methods to correct for the scattering were also studied. Two techniques were used to correct for atmospheric effects: (1) dark object subtraction, (2) normalization of use of ground spectral measurements. Of the two, the first technique proved to be the most successful for removing the effects of atmospheric scattering. A digital mosaic was produced from two side-lapping LANDSAT frames. The advantages were that the same enhancement algorithm can be applied to both frames, and there is no seam where the two images are joined.

  20. Meat quality evaluation by hyperspectral imaging technique: an overview.

    Science.gov (United States)

    Elmasry, Gamal; Barbin, Douglas F; Sun, Da-Wen; Allen, Paul

    2012-01-01

    During the last two decades, a number of methods have been developed to objectively measure meat quality attributes. Hyperspectral imaging technique as one of these methods has been regarded as a smart and promising analytical tool for analyses conducted in research and industries. Recently there has been a renewed interest in using hyperspectral imaging in quality evaluation of different food products. The main inducement for developing the hyperspectral imaging system is to integrate both spectroscopy and imaging techniques in one system to make direct identification of different components and their spatial distribution in the tested product. By combining spatial and spectral details together, hyperspectral imaging has proved to be a promising technology for objective meat quality evaluation. The literature presented in this paper clearly reveals that hyperspectral imaging approaches have a huge potential for gaining rapid information about the chemical structure and related physical properties of all types of meat. In addition to its ability for effectively quantifying and characterizing quality attributes of some important visual features of meat such as color, quality grade, marbling, maturity, and texture, it is able to measure multiple chemical constituents simultaneously without monotonous sample preparation. Although this technology has not yet been sufficiently exploited in meat process and quality assessment, its potential is promising. Developing a quality evaluation system based on hyperspectral imaging technology to assess the meat quality parameters and to ensure its authentication would bring economical benefits to the meat industry by increasing consumer confidence in the quality of the meat products. This paper provides a detailed overview of the recently developed approaches and latest research efforts exerted in hyperspectral imaging technology developed for evaluating the quality of different meat products and the possibility of its widespread

  1. Testing the quality of images for permanent magnet desktop MRI systems using specially designed phantoms.

    Science.gov (United States)

    Qiu, Jianfeng; Wang, Guozhu; Min, Jiao; Wang, Xiaoyan; Wang, Pengcheng

    2013-12-21

    Our aim was to measure the performance of desktop magnetic resonance imaging (MRI) systems using specially designed phantoms, by testing imaging parameters and analysing the imaging quality. We designed multifunction phantoms with diameters of 18 and 60 mm for desktop MRI scanners in accordance with the American Association of Physicists in Medicine (AAPM) report no. 28. We scanned the phantoms with three permanent magnet 0.5 T desktop MRI systems, measured the MRI image parameters, and analysed imaging quality by comparing the data with the AAPM criteria and Chinese national standards. Image parameters included: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, signal-to-noise ratio (SNR), and image uniformity. The image parameters of three desktop MRI machines could be measured using our specially designed phantoms, and most parameters were in line with MRI quality control criterion, including: resonance frequency, high contrast spatial resolution, low contrast object detectability, slice thickness, geometrical distortion, image uniformity and slice position accuracy. However, SNR was significantly lower than in some references. The imaging test and quality control are necessary for desktop MRI systems, and should be performed with the applicable phantom and corresponding standards.

  2. Application of task-based measures of image quality to optimization and evaluation of three-dimensional reconstruction-based compensation methods in myocardial perfusion SPECT.

    Science.gov (United States)

    Frey, Eric C; Gilland, Karen L; Tsui, Benjamin M W

    2002-09-01

    In this paper, we apply the channelized Hotelling observer (CHO) using a defect detection task to the optimization and evaluation of three-dimensional iterative reconstruction-based compensation methods for myocardial perfusion single-photon emission computed tomography (SPECT). We used a population of 24 mathematical cardiac-torso phantoms that realistically model the activity and attenuation distribution in three classes of patients: females, and males with flat diaphragms and raised diaphragms. Projection data were generated and subsequently reconstructed using methods based on the ordered subsets-expectation maximization (OSEM) algorithm. The methods evaluated included compensation for attenuation, detector response blurring, and scatter in various combinations. We applied the CHO to optimize the number of iterations for OSEM and the cutoff frequency and order of a three-dimensional postreconstruction Butterworth filter. Using the optimal parameters, we then compared the compensation methods. The index of comparison in these studies was the area under the receiver operating characteristics curve (AUC) for the CHO. We found that attenuation compensation with either detector response or scatter compensation gave statistically significant increases in the AUC compared to attenuation compensation alone. The greatest increase in the AUC occurred when all three compensations were applied. These results indicate that compensation for detector response and scatter, in addition to attenuation compensation, will improve defect detectability in myocardial SPECT images.

  3. The Development and Application of a Method to Quantify the Quality of Cryoprotectant Conditions Using Standard Area Detector X-Ray Images

    Science.gov (United States)

    McFerrin, Michael; Snell, Edward; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    An X-ray based method for determining cryoprotectant concentrations necessary to protect solutions from crystalline ice formation was developed. X-ray images from a CCD area detector were integrated as powder patterns and quantified by determining the standard deviation of the slope of the normalized intensity curve in the resolution range where ice rings are known to occur. The method was tested determining the concentrations of glycerol, PEG400, ethylene glycol and 1,2-propanediol necessary to form an amorphous glass at 1OOK with each of the 98 crystallization solutions of Crystal Screens I and II (Hampton Research, Laguna Hills, California, USA). For conditions that required glycerol concentrations of 35% or above cryoprotectant conditions using 2,3-butanediol were determined. The method proved to be remarkably accurate. The results build on the work of [Garman and Mitchell] and extend the number, of suitable starting conditions to alternative cryoprotectants. In particular, 1,2-propanediol has emerged as a particularly good additive for glass formation upon flash cooling.

  4. Infrared thermal imaging fundamentals, research and applications

    CERN Document Server

    Vollmer, Michael

    2011-01-01

    This richly illustrated hands-on guide is designed for researchers, teachers and practitioners. The huge selection of examples taken from science, basic teaching of physics, practical applications in industry and a variety of other disciplines spanning the range from medicine to volcano research allows readers to pick those that come closest to their own individual task at hand. Following a look at the fundamentals of IR thermal imaging, properties of the imaging systems, as well as basic and advanced methods, the book goes on to discuss IR imaging applications in teaching, research and indust

  5. Improving image quality in laboratory x-ray phase-contrast imaging

    Science.gov (United States)

    De Marco, F.; Marschner, M.; Birnbacher, L.; Viermetz, M.; Noël, P.; Herzen, J.; Pfeiffer, F.

    2017-03-01

    Grating-based X-ray phase-contrast (gbPC) is known to provide significant benefits for biomedical imaging. To investigate these benefits, a high-sensitivity gbPC micro-CT setup for small (≍ 5 cm) biological samples has been constructed. Unfortunately, high differential-phase sensitivity leads to an increased magnitude of data processing artifacts, limiting the quality of tomographic reconstructions. Most importantly, processing of phase-stepping data with incorrect stepping positions can introduce artifacts resembling Moiré fringes to the projections. Additionally, the focal spot size of the X-ray source limits resolution of tomograms. Here we present a set of algorithms to minimize artifacts, increase resolution and improve visual impression of projections and tomograms from the examined setup. We assessed two algorithms for artifact reduction: Firstly, a correction algorithm exploiting correlations of the artifacts and differential-phase data was developed and tested. Artifacts were reliably removed without compromising image data. Secondly, we implemented a new algorithm for flatfield selection, which was shown to exclude flat-fields with strong artifacts. Both procedures successfully improved image quality of projections and tomograms. Deconvolution of all projections of a CT scan can minimize blurring introduced by the finite size of the X-ray source focal spot. Application of the Richardson-Lucy deconvolution algorithm to gbPC-CT projections resulted in an improved resolution of phase-contrast tomograms. Additionally, we found that nearest-neighbor interpolation of projections can improve the visual impression of very small features in phase-contrast tomograms. In conclusion, we achieved an increase in image resolution and quality for the investigated setup, which may lead to an improved detection of very small sample features, thereby maximizing the setup's utility.

  6. Method and tool for generating and managing image quality allocations through the design and development process

    Science.gov (United States)

    Sparks, Andrew W.; Olson, Craig; Theisen, Michael J.; Addiego, Chris J.; Hutchins, Tiffany G.; Goodman, Timothy D.

    2016-05-01

    Performance models for infrared imaging systems require image quality parameters; optical design engineers need image quality design goals; systems engineers develop image quality allocations to test imaging systems against. It is a challenge to maintain consistency and traceability amongst the various expressions of image quality. We present a method and parametric tool for generating and managing expressions of image quality during the system modeling, requirements specification, design, and testing phases of an imaging system design and development project.

  7. Computational Phase Imaging for Biomedical Applications

    Science.gov (United States)

    Nguyen, Tan Huu

    laser comes at the expense of speckles, which degrades image quality. Therefore, solutions purely based on physical modeling and computations to remove these artifacts, using white-light illumination, are highly desirable. Here, using physical optics, we develop a theoretical model that accurately explains the effects of partial coherence on image information and phase information. The model is further combined with numerical processing to suppress the artifacts, and recover the correct phase information. The third topic is devoted to applying QPI to clinical applications. Traditionally, stained tissues are used in prostate cancer diagnosis instead. The reason is that tissue samples used in diagnosis are nearly transparent under bright field inspection if unstained. Contrast-enhanced microscopy techniques, e.g., phase contrast microscopy (PC) and differential interference contrast microscopy (DIC), can render visibility of the untagged samples with high throughput. However, since these methods are intensity-based, the contrast of acquired images varies significantly from one imaging facility to another, preventing them from being used in diagnosis. Inheriting the merits of PC, SLIM produces phase maps, which measure the refractive index of label-free samples. However, the maps measured by SLIM are not affected by variation in imaging conditions, e.g., illumination, magnification, etc., allowing consistent imaging results when using SLIM across different clinical institutions. Here, we combine SLIM images with machine learning for automatic diagnosis results for prostate cancer. We focus on two diagnosis problems of automatic Gleason grading and cancer vs. non-cancer diagnosis. Finally, we introduce a new imaging modality, named Gradient Light Interference Microscopy (GLIM), which is able to image through optically thick samples using low spatial coherence illumination. The key benefit of GLIM comes from a large numerical aperture of the condenser, which is 0.55 NA

  8. Magnetic imaging and its applications to materials

    CERN Document Server

    De Graef, Marc

    2000-01-01

    Volume 36 provides an extensive introduction to magnetic imaging,including theory and practice, utilizing a wide range of magnetic sensitive imaging methods. It also illustrates the applications of these modern experimental techniques together with imaging calculations to today's advanced magnetic materials. This book is geared towards the upper-level undergraduate students and entry-level graduate students majoring in physics or materials science who are interested in magnetic structure and magnetic imaging. Researchers involved in studying magnetic materials should alsofind the book usef

  9. Clinical applications of choroidal imaging technologies

    Directory of Open Access Journals (Sweden)

    Jay Chhablani

    2015-01-01

    Full Text Available Choroid supplies the major blood supply to the eye, especially the outer retinal structures. Its understanding has significantly improved with the advent of advanced imaging modalities such as enhanced depth imaging technique and the newer swept source optical coherence tomography. Recent literature reports the findings of choroidal changes, quantitative as well as qualitative, in various chorioretinal disorders. This review article describes applications of choroidal imaging in the management of common diseases such as age-related macular degeneration, high myopia, central serous chorioretinopathy, chorioretinal inflammatory diseases, and tumors. This article briefly discusses future directions in choroidal imaging including angiography.

  10. SEGMENTATION AND QUALITY ANALYSIS OF LONG RANGE CAPTURED IRIS IMAGE

    Directory of Open Access Journals (Sweden)

    Anand Deshpande

    2016-05-01

    Full Text Available The iris segmentation plays a major role in an iris recognition system to increase the performance of the system. This paper proposes a novel method for segmentation of iris images to extract the iris part of long range captured eye image and an approach to select best iris frame from the iris polar image sequences by analyzing the quality of iris polar images. The quality of iris image is determined by the frequency components present in the iris polar images. The experiments are carried out on CASIA-long range captured iris image sequences. The proposed segmentation method is compared with Hough transform based segmentation and it has been determined that the proposed method gives higher accuracy for segmentation than Hough transform.

  11. Brain imaging with synthetic MR in children: clinical quality assessment

    Energy Technology Data Exchange (ETDEWEB)

    Betts, Aaron M.; Serai, Suraj [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Leach, James L.; Jones, Blaise V. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); University of Cincinnati College of Medicine, Cincinnati, OH (United States); Zhang, Bin [Cincinnati Children' s Hospital Medical Center, Biostatistics and Epidemiology, Cincinnati, OH (United States)

    2016-10-15

    Synthetic magnetic resonance imaging is a quantitative imaging technique that measures inherent T1-relaxation, T2-relaxation, and proton density. These inherent tissue properties allow synthesis of various imaging sequences from a single acquisition. Clinical use of synthetic MR imaging has been described in adult populations. However, use of synthetic MR imaging has not been previously reported in children. The purpose of this study is to report our assessment of diagnostic image quality using synthetic MR imaging in children. Synthetic MR acquisition was obtained in a sample of children undergoing brain MR imaging. Image quality assessments were performed on conventional and synthetic T1-weighted, T2-weighted, and FLAIR images. Standardized linear measurements were performed on conventional and synthetic T2 images. Estimates of patient age based upon myelination patterns were also performed. Conventional and synthetic MR images were evaluated on 30 children. Using a 4-point assessment scale, conventional imaging performed better than synthetic imaging for T1-weighted, T2-weighted, and FLAIR images. When the assessment was simplified to a dichotomized scale, the conventional and synthetic T1-weighted and T2-weighted images performed similarly. However, the superiority of conventional FLAIR images persisted in the dichotomized assessment. There were no statistically significant differences between linear measurements made on T2-weighted images. Estimates of patient age based upon pattern of myelination were also similar between conventional and synthetic techniques. Synthetic MR imaging may be acceptable for clinical use in children. However, users should be aware of current limitations that could impact clinical utility in the software version used in this study. (orig.)

  12. Improving a DWT-based compression algorithm for high image-quality requirement of satellite images

    Science.gov (United States)

    Thiebaut, Carole; Latry, Christophe; Camarero, Roberto; Cazanave, Grégory

    2011-10-01

    Past and current optical Earth observation systems designed by CNES are using a fixed-rate data compression processing performed at a high-rate in a pushbroom mode (also called scan-based mode). This process generates fixed-length data to the mass memory and data downlink is performed at a fixed rate too. Because of on-board memory limitations and high data rate processing needs, the rate allocation procedure is performed over a small image area called a "segment". For both PLEIADES compression algorithm and CCSDS Image Data Compression recommendation, this rate allocation is realised by truncating to the desired rate a hierarchical bitstream of coded and quantized wavelet coefficients for each segment. Because the quantisation induced by truncation of the bit planes description is the same for the whole segment, some parts of the segment have a poor image quality. These artefacts generally occur in low energy areas within a segment of higher level of energy. In order to locally correct these areas, CNES has studied "exceptional processing" targeted for DWT-based compression algorithms. According to a criteria computed for each part of the segment (called block), the wavelet coefficients can be amplified before bit-plane encoding. As usual Region of Interest handling, these multiplied coefficients will be processed earlier by the encoder than in the nominal case (without exceptional processing). The image quality improvement brought by the exceptional processing has been confirmed by visual image analysis and fidelity criteria. The complexity of the proposed improvement for on-board application has also been analysed.

  13. The Image Quality Translator – A Way to Support Specification of Imaging Requirements

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad; Bech, Mogens

    2015-01-01

    Archives, libraries, and museums run numerous imaging projects to digitize physical works and collections of cultural heritage. This study presents a tool called the 'Image Quality Translator' that is being designed at the Royal Library to support the planning of digitization projects and to make...... the process of specifying and controlling imaging requirements more efficient. The tool seeks to translate between the language used by collection managers and curators to express needs for image quality, and the more technical terms and metrics used by imaging experts and photographers to express...... the requirements for the performance of imaging systems....

  14. Investigation into image quality difference between total variation and nonlinear sparsifying transform based compressed sensing

    Science.gov (United States)

    Dong, Jian; Kudo, Hiroyuki

    2017-03-01

    Compressed sensing (CS) is attracting growing concerns in sparse-view computed tomography (CT) image reconstruction. The most standard approach of CS is total variation (TV) minimization. However, images reconstructed by TV usually suffer from distortions, especially in reconstruction of practical CT images, in forms of patchy artifacts, improper serrate edges and loss of image textures. Most existing CS approaches including TV achieve image quality improvement by applying linear transforms to object image, but linear transforms usually fail to take discontinuities into account, such as edges and image textures, which is considered to be the key reason for image distortions. Actually, discussions on nonlinear filter based image processing has a long history, leading us to clarify that the nonlinear filters yield better results compared to linear filters in image processing task such as denoising. Median root prior was first utilized by Alenius as nonlinear transform in CT image reconstruction, with significant gains obtained. Subsequently, Zhang developed the application of nonlocal means-based CS. A fact is gradually becoming clear that the nonlinear transform based CS has superiority in improving image quality compared with the linear transform based CS. However, it has not been clearly concluded in any previous paper within the scope of our knowledge. In this work, we investigated the image quality differences between the conventional TV minimization and nonlinear sparsifying transform based CS, as well as image quality differences among different nonlinear sparisying transform based CSs in sparse-view CT image reconstruction. Additionally, we accelerated the implementation of nonlinear sparsifying transform based CS algorithm.

  15. Digital radiography: image quality and radiation dose.

    Science.gov (United States)

    Seibert, J Anthony

    2008-11-01

    Digital radiography devices, rapidly replacing analog screen-film detectors, are now common in diagnostic radiological imaging, where implementation has been accelerated by the commodity status of electronic imaging and display systems. The shift from narrow latitude, fixed-speed screen-film detectors to wide latitude, variable-speed digital detectors has created a flexible imaging system that can easily result in overexposures to the patient without the knowledge of the operator, thus potentially increasing the radiation burden of the patient population from radiographic examinations. In addition, image processing can be inappropriately applied causing inconsistent or artifactual appearance of anatomy, which can lead to misdiagnosis. On the other hand, many advantages can be obtained from the variable-speed digital detector, such as an ability to lower dose in many examinations, image post-processing for disease-specific conditions, display flexibility to change the appearance of the image and aid the physician in making a differential diagnosis, and easy access to digital images. An understanding of digital radiography is necessary to minimize the possibility of overexposures and inconsistent results, and to achieve the principle of as low as reasonably achievable (ALARA) for the safe and effective care of all patients. Thus many issues must be considered for optimal implementation of digital radiography, as reviewed in this article.

  16. Rotation Covariant Image Processing for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Henrik Skibbe

    2013-01-01

    Full Text Available With the advent of novel biomedical 3D image acquisition techniques, the efficient and reliable analysis of volumetric images has become more and more important. The amount of data is enormous and demands an automated processing. The applications are manifold, ranging from image enhancement, image reconstruction, and image description to object/feature detection and high-level contextual feature extraction. In most scenarios, it is expected that geometric transformations alter the output in a mathematically well-defined manner. In this paper we emphasis on 3D translations and rotations. Many algorithms rely on intensity or low-order tensorial-like descriptions to fulfill this demand. This paper proposes a general mathematical framework based on mathematical concepts and theories transferred from mathematical physics and harmonic analysis into the domain of image analysis and pattern recognition. Based on two basic operations, spherical tensor differentiation and spherical tensor multiplication, we show how to design a variety of 3D image processing methods in an efficient way. The framework has already been applied to several biomedical applications ranging from feature and object detection tasks to image enhancement and image restoration techniques. In this paper, the proposed methods are applied on a variety of different 3D data modalities stemming from medical and biological sciences.

  17. 40 CFR 227.31 - Applicable marine water quality criteria.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Applicable marine water quality... § 227.31 Applicable marine water quality criteria. Applicable marine water quality criteria means the criteria given for marine waters in the EPA publication “Quality Criteria for Water” as published in 1976...

  18. Using image quality metrics to identify adversarial imagery for deep learning networks

    Science.gov (United States)

    Harguess, Josh; Miclat, Jeremy; Raheema, Julian

    2017-05-01

    Deep learning has continued to gain momentum in applications across many critical areas of research in computer vision and machine learning. In particular, deep learning networks have had much success in image classification, especially when training data are abundantly available, as is the case with the ImageNet project. However, several researchers have exposed potential vulnerabilities of these networks to carefully crafted adversarial imagery. Additionally, researchers have shown the sensitivity of these networks to some types of noise and distortion. In this paper, we investigate the use of no-reference image quality metrics to identify adversarial imagery and images of poor quality that could potentially fool a deep learning network or dramatically reduce its accuracy. Results are shown on several adversarial image databases with comparisons to popular image classification databases.

  19. Perceived no reference image quality measurement for chromatic aberration

    Science.gov (United States)

    Lamb, Anupama B.; Khambete, Madhuri

    2016-03-01

    Today there is need for no reference (NR) objective perceived image quality measurement techniques as conducting subjective experiments and making reference image available is a very difficult task. Very few NR perceived image quality measurement algorithms are available for color distortions like chromatic aberration (CA), color quantization with dither, and color saturation. We proposed NR image quality assessment (NR-IQA) algorithms for images distorted with CA. CA is mostly observed in images taken with digital cameras, having higher sensor resolution with inexpensive lenses. We compared our metric performance with two state-of-the-art NR blur techniques, one full reference IQA technique and three general-purpose NR-IQA techniques, although they are not tailored for CA. We used a CA dataset in the TID-2013 color image database to evaluate performance. Proposed algorithms give comparable performance with state-of-the-art techniques in terms of performance parameters and outperform them in terms of monotonicity and computational complexity. We have also discovered that the proposed CA algorithm best predicts perceived image quality of images distorted with realistic CA.

  20. A method for the evaluation of image quality according to the recognition effectiveness of objects in the optical remote sensing image using machine learning algorithm.

    Directory of Open Access Journals (Sweden)

    Tao Yuan

    Full Text Available Objective and effective image quality assessment (IQA is directly related to the application of optical remote sensing images (ORSI. In this study, a new IQA method of standardizing the target object recognition rate (ORR is presented to reflect quality. First, several quality degradation treatments with high-resolution ORSIs are implemented to model the ORSIs obtained in different imaging conditions; then, a machine learning algorithm is adopted for recognition experiments on a chosen target object to obtain ORRs; finally, a comparison with commonly used IQA indicators was performed to reveal their applicability and limitations. The results showed that the ORR of the original ORSI was calculated to be up to 81.95%, whereas the ORR ratios of the quality-degraded images to the original images were 65.52%, 64.58%, 71.21%, and 73.11%. The results show that these data can more accurately reflect the advantages and disadvantages of different images in object identification and information extraction when compared with conventional digital image assessment indexes. By recognizing the difference in image quality from the application effect perspective, using a machine learning algorithm to extract regional gray scale features of typical objects in the image for analysis, and quantitatively assessing quality of ORSI according to the difference, this method provides a new approach for objective ORSI assessment.

  1. Optimisation of patient protection and image quality in diagnostic ...

    African Journals Online (AJOL)

    Optimisation of patient protection and image quality in diagnostic radiology. ... The study leads to the introduction of the concept of plan- do-check-act on QC results ... (QA) programme and continues to collect data for establishment of DRL's.

  2. Multivariate image analysis for quality inspection in fish feed production

    DEFF Research Database (Denmark)

    Ljungqvist, Martin Georg

    , or synthesised chemically. Common for both types is that they are relatively expensive in comparison to the other feed ingredients. This thesis investigates multi-variate data collection for visual inspection and optimisation of industrial production in the fish feed industry. Quality parameters focused on here...... are: pellet size, type and concentration level of astaxanthin in pellet coating, as well as astaxanthin type detected in salmonid fish. Methods used are three different devices for multi- and hyper-spectral imaging, together with shape analysis and multi-variate statistical analysis. The results...... of the work demonstrate a high potential of image analysis and spectral imaging for assessing the product quality of fish feed pellets, astaxanthin and fish meat. We show how image analysis can be used to inspect the pellet size, and how spectral imaging can be used to inspect the surface quality...

  3. Dosimetry and image quality assessment in a direct radiography system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bruno Beraldo; Paixao, Lucas; Nogueira, Maria do Socorro, E-mail: boliveira.mg@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Marcio Alves de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina. Dept. de Anatomia e Imagem; Teixeira, Maria Helena Araujo [Clinica Dra. Maria Helena Araujo Teixeira, Belo Horizonte, MG (Brazil)

    2014-11-15

    Objective: to evaluate the mean glandular dose with a solid state detector and the image quality in a direct radiography system, utilizing phantoms. Materials and methods: Irradiations were performed with automatic exposure control and polymethyl methacrylate slabs with different thicknesses to calculate glandular dose values. The image quality was evaluated by means of the structures visualized on the images of the phantoms. Results: considering the uncertainty of the measurements, the mean glandular dose results are in agreement with the values provided by the equipment and with internationally adopted reference levels. Results obtained from images of the phantoms were in agreement with the reference values. Conclusion: the present study contributes to verify the equipment conformity as regards dose values and image quality. (author)

  4. Web-based psychometric evaluation of image quality

    Science.gov (United States)

    Sprow, Iris; Baranczuk, Zofia; Stamm, Tobias; Zolliker, Peter

    2009-01-01

    The measurement of image quality requires the judgement by the human visual system. This paper describes a psycho-visual test technique that uses the internet as a test platform to identify image quality in a more time-effective manner, comparing the visual response data with the results from the same test in a lab-based environment and estimate the usefulness of the internet as a platform for scaling studies.

  5. High quality image-pair-based deblurring method using edge mask and improved residual deconvolution

    Science.gov (United States)

    Cui, Guangmang; Zhao, Jufeng; Gao, Xiumin; Feng, Huajun; Chen, Yueting

    2017-04-01

    Image deconvolution problem is a challenging task in the field of image process. Using image pairs could be helpful to provide a better restored image compared with the deblurring method from a single blurred image. In this paper, a high quality image-pair-based deblurring method is presented using the improved RL algorithm and the gain-controlled residual deconvolution technique. The input image pair includes a non-blurred noisy image and a blurred image captured for the same scene. With the estimated blur kernel, an improved RL deblurring method based on edge mask is introduced to obtain the preliminary deblurring result with effective ringing suppression and detail preservation. Then the preliminary deblurring result is served as the basic latent image and the gain-controlled residual deconvolution is utilized to recover the residual image. A saliency weight map is computed as the gain map to further control the ringing effects around the edge areas in the residual deconvolution process. The final deblurring result is obtained by adding the preliminary deblurring result with the recovered residual image. An optical experimental vibration platform is set up to verify the applicability and performance of the proposed algorithm. Experimental results demonstrate that the proposed deblurring framework obtains a superior performance in both subjective and objective assessments and has a wide application in many image deblurring fields.

  6. A Methodology for Anatomic Ultrasound Image Diagnostic Quality Assessment

    DEFF Research Database (Denmark)

    Hemmsen, Martin Christian; Lange, Theis; Brandt, Andreas Hjelm

    2017-01-01

    is valuable in the continuing process of method optimization and guided development of new imaging methods. It includes a three phased study plan covering from initial prototype development to clinical assessment. Recommendations to the clinical assessment protocol, software, and statistical analysis......This paper discusses methods for assessment of ultrasound image quality based on our experiences with evaluating new methods for anatomic imaging. It presents a methodology to ensure a fair assessment between competing imaging methods using clinically relevant evaluations. The methodology...... to properly reveal the clinical value. The paper exemplifies the methodology using recent studies of Synthetic Aperture Sequential Beamforming tissue harmonic imaging....

  7. Quality and reliability management and its applications

    CERN Document Server

    2016-01-01

    Integrating development processes, policies, and reliability predictions from the beginning of the product development lifecycle to ensure high levels of product performance and safety, this book helps companies overcome the challenges posed by increasingly complex systems in today’s competitive marketplace.   Examining both research on and practical aspects of product quality and reliability management with an emphasis on applications, the book features contributions written by active researchers and/or experienced practitioners in the field, so as to effectively bridge the gap between theory and practice and address new research challenges in reliability and quality management in practice.    Postgraduates, researchers and practitioners in the areas of reliability engineering and management, amongst others, will find the book to offer a state-of-the-art survey of quality and reliability management and practices.

  8. ANALYSIS OF THE EFFECTS OF IMAGE QUALITY ON DIGITAL MAP GENERATION FROM SATELLITE IMAGES

    Directory of Open Access Journals (Sweden)

    H. Kim

    2012-07-01

    Full Text Available High resolution satellite images are widely used to produce and update a digital map since they became widely available. It is well known that the accuracy of digital map produced from satellite images is decided largely by the accuracy of geometric modelling. However digital maps are made by a series of photogrammetric workflow. Therefore the accuracy of digital maps are also affected by the quality of satellite images, such as image interpretability. For satellite images, parameters such as Modulation Transfer Function(MTF, Signal to Noise Ratio(SNR and Ground Sampling Distance(GSD are used to present images quality. Our previous research stressed that such quality parameters may not represent the quality of image products such as digital maps and that parameters for image interpretability such as Ground Resolved Distance(GRD and National Imagery Interpretability Rating Scale(NIIRS need to be considered. In this study, we analyzed the effects of the image quality on accuracy of digital maps produced by satellite images. QuickBird, IKONOS and KOMPSAT-2 imagery were used to analyze as they have similar GSDs. We measured various image quality parameters mentioned above from these images. Then we produced digital maps from the images using a digital photogrammetric workstation. We analyzed the accuracy of the digital maps in terms of their location accuracy and their level of details. Then we compared the correlation between various image quality parameters and the accuracy of digital maps. The results of this study showed that GRD and NIIRS were more critical for map production then GSD, MTF or SNR.

  9. Age estimation under changes in image quality: An experimental study

    NARCIS (Netherlands)

    Alnajar, F.; Gevers, T.; Karaoglu, S.

    2015-01-01

    In this paper, we investigate the influence of image quality on the performance of aging features. Age estimation systems used or designed a number of aging features to capture the aging cues from the face such as skin texture and wrinkles. These aging cues are sensitive to small changes in the imag

  10. Chemometrics in multispectral imaging for quality inspection of postharvest products

    NARCIS (Netherlands)

    Noordam, Jan Corstiaan

    2005-01-01

    This thesis describes different novel chemometric techniques applied to multispectral images for quality inspection on agricultural food products. These images do not only have a huge number of spectral bands which makes training set selection a challenging task, they also contain classes with small

  11. Applications of nuclear medicine in genitourinary imaging

    Energy Technology Data Exchange (ETDEWEB)

    Blaufox, M.D.; Kalika, V.; Scharf, S.; Milstein, D.

    1982-01-01

    Major advances in nuclear medicine instrumentation and radiopharmaceuticals for renal studies have occurred during the last decade. Current nuclear medicine methodology can be applied for accurate evaluation of renal function and for renal imaging in a wide variety of clinical situations. Total renal function can be estimated from the plasma clearance of agents excreted by glomerular filtration or tubular secretion, and individual function can be estimated by imaging combined with renography. A major area of radionuclide application is in the evaluation of obstructive uropathy. The introduction of diuretic renography and the use of computer-generated regions of interest offer the clinician added useful data which may aid in diagnosis and management. Imaging is of proven value also in trauma, renovascular hypertension, and acute and chronic renal failure. Methods for the evaluation of residual urine, vesicoureteral reflux, and testicular torsion have achieved increasing clinical use. These many procedures assure a meaningful and useful role for the application of nuclear medicine in genitourinary imaging.

  12. A learning-based approach for automated quality assessment of computer-rendered images

    Science.gov (United States)

    Zhang, Xi; Agam, Gady

    2012-01-01

    Computer generated images are common in numerous computer graphics applications such as games, modeling, and simulation. There is normally a tradeoff between the time allocated to the generation of each image frame and and the quality of the image, where better quality images require more processing time. Specifically, in the rendering of 3D objects, the surfaces of objects may be manipulated by subdividing them into smaller triangular patches and/or smoothing them so as to produce better looking renderings. Since unnecessary subdivision results in increased rendering time and unnecessary smoothing results in reduced details, there is a need to automatically determine the amount of necessary processing for producing good quality rendered images. In this paper we propose a novel supervised learning based methodology for automatically predicting the quality of rendered images of 3D objects. To perform the prediction we train on a data set which is labeled by human observers for quality. We are then able to predict the quality of renderings (not used in the training) with an average prediction error of roughly 20%. The proposed approach is compared to known techniques and is shown to produce better results.

  13. A feature-enriched completely blind image quality evaluator.

    Science.gov (United States)

    Lin Zhang; Lei Zhang; Bovik, Alan C

    2015-08-01

    Existing blind image quality assessment (BIQA) methods are mostly opinion-aware. They learn regression models from training images with associated human subjective scores to predict the perceptual quality of test images. Such opinion-aware methods, however, require a large amount of training samples with associated human subjective scores and of a variety of distortion types. The BIQA models learned by opinion-aware methods often have weak generalization capability, hereby limiting their usability in practice. By comparison, opinion-unaware methods do not need human subjective scores for training, and thus have greater potential for good generalization capability. Unfortunately, thus far no opinion-unaware BIQA method has shown consistently better quality prediction accuracy than the opinion-aware methods. Here, we aim to develop an opinion-unaware BIQA method that can compete with, and perhaps outperform, the existing opinion-aware methods. By integrating the features of natural image statistics derived from multiple cues, we learn a multivariate Gaussian model of image patches from a collection of pristine natural images. Using the learned multivariate Gaussian model, a Bhattacharyya-like distance is used to measure the quality of each image patch, and then an overall quality score is obtained by average pooling. The proposed BIQA method does not need any distorted sample images nor subjective quality scores for training, yet extensive experiments demonstrate its superior quality-prediction performance to the state-of-the-art opinion-aware BIQA methods. The MATLAB source code of our algorithm is publicly available at www.comp.polyu.edu.hk/~cslzhang/IQA/ILNIQE/ILNIQE.htm.

  14. Application of Perona Malik anisotropic diffusion on digital radiographic image

    Energy Technology Data Exchange (ETDEWEB)

    Halim, Suhaila Abd; Razak, Rohayu Abdul; Ibrahim, Arsmah [Center of Mathematics Studies, Faculty of Computer and Mathematical Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Selangor DE (Malaysia); Manurung, Yupiter HP [Advanced Manufacturing Technology Center, Faculty of Mechanical Engineering, Universiti Teknologi MARA, 40450 Shah Alam, Selangor DE (Malaysia)

    2014-07-10

    Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.

  15. Application of DSP in the image transmission system

    Science.gov (United States)

    Gui, Feng; Wei, LinQi

    2006-05-01

    A scheme to realize static image and video code and decode based on TI DSP chip TMS320C6416 was proposed in this paper, and a reliable image transmission system was developed. According to the application demand, the software has six major modules: (1) initialization of DSP chip and other hardware; (2) video acquisition and input control program; (3) serial port communicating program; (4) RAM storage and communicating program that applies and releases the token-ring; (5) video reconstruct and output control; (6) the major parts of the software, encoding and decoding program, in which wavelet was applied first, then run length coding and Huffman coding were carried out, the image or video could had balance resolution and better visual effect by adaptive processing, in the decoding parts, the reverse operation were executed. After the system line up debugging was carried out, a satisfying result was reached: the comparatively high compression rate, preferable image quality and relatively real-time result.

  16. Beef quality parameters estimation using ultrasound and color images

    OpenAIRE

    Nunes, Jose Luis; Piquerez, Martín; Pujadas, Leonardo; Armstrong,Eileen; Alicia FERNÁNDEZ; Lecumberry, Federico

    2015-01-01

    Background Beef quality measurement is a complex task with high economic impact. There is high interest in obtaining an automatic quality parameters estimation in live cattle or post mortem. In this paper we set out to obtain beef quality estimates from the analysis of ultrasound (in vivo) and color images (post mortem), with the measurement of various parameters related to tenderness and amount of meat: rib eye area, percentage of intramuscular fat and backfat thickness or subcutaneous fat. ...

  17. Beef quality parameters estimation using ultrasound and color images

    OpenAIRE

    Nunes, Jose Luis; Piquerez, Mart?n; Pujadas, Leonardo; Armstrong,Eileen; Fern?ndez, Alicia; Lecumberry, Federico

    2015-01-01

    Background Beef quality measurement is a complex task with high economic impact. There is high interest in obtaining an automatic quality parameters estimation in live cattle or post mortem. In this paper we set out to obtain beef quality estimates from the analysis of ultrasound (in vivo) and color images (post mortem), with the measurement of various parameters related to tenderness and amount of meat: rib eye area, percentage of intramuscular fat and backfat thickness or subcutaneous fat. ...

  18. Learning Sparse Representation for Objective Image Retargeting Quality Assessment.

    Science.gov (United States)

    Jiang, Qiuping; Shao, Feng; Lin, Weisi; Jiang, Gangyi

    2017-04-13

    The goal of image retargeting is to adapt source images to target displays with different sizes and aspect ratios. Different retargeting operators create different retargeted images, and a key problem is to evaluate the performance of each retargeting operator. Subjective evaluation is most reliable, but it is cumbersome and labor-consuming, and more importantly, it is hard to be embedded into online optimization systems. This paper focuses on exploring the effectiveness of sparse representation for objective image retargeting quality assessment. The principle idea is to extract distortion sensitive features from one image (e.g., retargeted image) and further investigate how many of these features are preserved or changed in another one (e.g., source image) to measure the perceptual similarity between them. To create a compact and robust feature representation, we learn two overcomplete dictionaries to represent the distortion sensitive features of an image. Features including local geometric structure and global context information are both addressed in the proposed framework. The intrinsic discriminative power of sparse representation is then exploited to measure the similarity between the source and retargeted images. Finally, individual quality scores are fused into an overall quality by a typical regression method. Experimental results on several databases have demonstrated the superiority of the proposed method.

  19. Optimized Plane Wave Imaging for Fast and High-Quality Ultrasound Imaging

    DEFF Research Database (Denmark)

    Jensen, Jonas; Stuart, Matthias Bo; Jensen, Jørgen Arendt

    2016-01-01

    This paper presents a method for optimizing parameters affecting the image quality in plane wave imaging. More specifically, the number of emissions and steering angles is optimized to attain the best images with the highest frame rate possible. The method is applied to a specific problem, where ...

  20. Quality assessment of butter cookies applying multispectral imaging

    DEFF Research Database (Denmark)

    Stenby Andresen, Mette; Dissing, Bjørn Skovlund; Løje, Hanne

    2013-01-01

    A method for characterization of butter cookie quality by assessing the surface browning and water content using multispectral images is presented. Based on evaluations of the browning of butter cookies, cookies were manually divided into groups. From this categorization, reference values were...... in a forced convection electrically heated oven. In addition to the browning score, a model for predicting the average water content based on the same images is presented. This shows how multispectral images of butter cookies may be used for the assessment of different quality parameters. Statistical analysis...

  1. Application of numerical methods to elasticity imaging.

    Science.gov (United States)

    Castaneda, Benjamin; Ormachea, Juvenal; Rodríguez, Paul; Parker, Kevin J

    2013-03-01

    Elasticity imaging can be understood as the intersection of the study of biomechanical properties, imaging sciences, and physics. It was mainly motivated by the fact that pathological tissue presents an increased stiffness when compared to surrounding normal tissue. In the last two decades, research on elasticity imaging has been an international and interdisciplinary pursuit aiming to map the viscoelastic properties of tissue in order to provide clinically useful information. As a result, several modalities of elasticity imaging, mostly based on ultrasound but also on magnetic resonance imaging and optical coherence tomography, have been proposed and applied to a number of clinical applications: cancer diagnosis (prostate, breast, liver), hepatic cirrhosis, renal disease, thyroiditis, arterial plaque evaluation, wall stiffness in arteries, evaluation of thrombosis in veins, and many others. In this context, numerical methods are applied to solve forward and inverse problems implicit in the algorithms in order to estimate viscoelastic linear and nonlinear parameters, especially for quantitative elasticity imaging modalities. In this work, an introduction to elasticity imaging modalities is presented. The working principle of qualitative modalities (sonoelasticity, strain elastography, acoustic radiation force impulse) and quantitative modalities (Crawling Waves Sonoelastography, Spatially Modulated Ultrasound Radiation Force (SMURF), Supersonic Imaging) will be explained. Subsequently, the areas in which numerical methods can be applied to elasticity imaging are highlighted and discussed. Finally, we present a detailed example of applying total variation and AM-FM techniques to the estimation of elasticity.

  2. Rapid Assessment of Tablet Film Coating Quality by Multispectral UV Imaging.

    Science.gov (United States)

    Klukkert, Marten; Wu, Jian X; Rantanen, Jukka; Rehder, Soenke; Carstensen, Jens M; Rades, Thomas; Leopold, Claudia S

    2016-08-01

    Chemical imaging techniques are beneficial for control of tablet coating layer quality as they provide spectral and spatial information and allow characterization of various types of coating defects. The purpose of this study was to assess the applicability of multispectral UV imaging for assessment of the coating layer quality of tablets. UV images were used to detect, characterize, and localize coating layer defects such as chipped parts, inhomogeneities, and cracks, as well as to evaluate the coating surface texture. Acetylsalicylic acid tablets were prepared on a rotary tablet press and coated with a polyvinyl alcohol-polyethylene glycol graft copolymer using a pan coater. It was demonstrated that the coating intactness can be assessed accurately and fast by UV imaging. The different types of coating defects could be differentiated and localized based on multivariate image analysis and Soft Independent Modeling by Class Analogy applied to the UV images. Tablets with inhomogeneous texture of the coating could be identified and distinguished from those with a homogeneous surface texture. Consequently, UV imaging was shown to be well-suited for monitoring of the tablet coating layer quality. UV imaging is a promising technique for fast quality control of the tablet coating because of the high data acquisition speed and its nondestructive analytical nature.

  3. [Image quality from direct radiological magnification (author's transl)].

    Science.gov (United States)

    Franken, T; Borcke, E

    1980-03-01

    An assessment of image quality from a direct radiological magnification method with a microfocus was carried out. It was found that direct magnification has advantages for the magnification of thin objects (5 cm. thickness). Because of the marked radiation scarrer in thick objects an improvement in picture quality is not possible. Scatter, despite the Groedel effect, is too large. Optimum results are obtained with a microfocus tube using universal screens. Comparable image quality is not possible with high intensification screens. High definition screens are not suitable for magnification. Dose measurements revealed unexpectedly low levels, particularly for thin objects. The reasons for this were examined and are described.

  4. Scattered Radiation Emission Imaging: Principles and Applications

    Directory of Open Access Journals (Sweden)

    M. K. Nguyen

    2011-01-01

    Full Text Available Imaging processes built on the Compton scattering effect have been under continuing investigation since it was first suggested in the 50s. However, despite many innovative contributions, there are still formidable theoretical and technical challenges to overcome. In this paper, we review the state-of-the-art principles of the so-called scattered radiation emission imaging. Basically, it consists of using the cleverly collected scattered radiation from a radiating object to reconstruct its inner structure. Image formation is based on the mathematical concept of compounded conical projection. It entails a Radon transform defined on circular cone surfaces in order to express the scattered radiation flux density on a detecting pixel. We discuss in particular invertible cases of such conical Radon transforms which form a mathematical basis for image reconstruction methods. Numerical simulations performed in two and three space dimensions speak in favor of the viability of this imaging principle and its potential applications in various fields.

  5. Image quality and radiation dose in cardiac imaging

    NARCIS (Netherlands)

    Dijk, van Joris David

    2016-01-01

    Coronary artery disease is a major cause of death accounting for 8% of all deaths in the Netherlands. This disease can be detected in an early stage by cardiac imaging. However, this detection comes at the price of a relatively high radiation dose which is potentially harmful for the patient. Despit

  6. Image quality and radiation dose in cardiac imaging

    NARCIS (Netherlands)

    van Dijk, Joris David

    2016-01-01

    Coronary artery disease is a major cause of death accounting for 8% of all deaths in the Netherlands. This disease can be detected in an early stage by cardiac imaging. However, this detection comes at the price of a relatively high radiation dose which is potentially harmful for the patient.

  7. Color Image Watermarking Application for ERTU Cloud

    OpenAIRE

    Salah A. Khamis; Salwa M. Serag Eldin; Prof. Abdel-Aziz Ibrahim Mahmoud HASSANIN; Mohammed A. Alsharqawy

    2013-01-01

    Color image is one of the the Egyptian Radio and Television Union (ERTU)’s content should be saved from any abuse from outside or inside the organization alike. The application of saving color image deploys the watermarking techniques based on Discrete Wavelet Transform (DWT). This application is implemented by software that suits the ERTU’s cloud besides many tests to insure the originality of the photo and if there is any changes applied on. All that provides the essential objectives of the...

  8. Standardization of Image Quality Analysis – ISO 19264

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad; Wüller, Dietmar

    2016-01-01

    There are a variety of image quality analysis tools available for the archiving world, which are based on different test charts and analysis algorithms. ISO has formed a working group in 2012 to harmonize these approaches and create a standard way of analyzing the image quality for archiving...... systems. This has resulted in three documents that have been or are going to be published soon. ISO 19262 defines the terms used in the area of image capture to unify the language. ISO 19263 describes the workflow issues and provides detailed information on how the measurements are done. Last...... but not least ISO 19264 describes the measurements in detail and provides aims and tolerance levels for the different aspects. This paper will present the new ISO 19264 technical specification to analyze image quality based on a single capture of a multi-pattern test chart, and discuss the reasoning behind its...

  9. Standardization of Image Quality Analysis – ISO 19264

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad; Wüller, Dietmar

    2016-01-01

    There are a variety of image quality analysis tools available for the archiving world, which are based on different test charts and analysis algorithms. ISO has formed a working group in 2012 to harmonize these approaches and create a standard way of analyzing the image quality for archiving...... systems. This has resulted in three documents that have been or are going to be published soon. ISO 19262 defines the terms used in the area of image capture to unify the language. ISO 19263 describes the workflow issues and provides detailed information on how the measurements are done. Last...... but not least ISO 19264 describes the measurements in detail and provides aims and tolerance levels for the different aspects. This paper will present the new ISO 19264 technical specification to analyze image quality based on a single capture of a multi-pattern test chart, and discuss the reasoning behind its...

  10. Quantifying Image Quality Improvement Using Elevated Acoustic Output in B-Mode Harmonic Imaging.

    Science.gov (United States)

    Deng, Yufeng; Palmeri, Mark L; Rouze, Ned C; Trahey, Gregg E; Haystead, Clare M; Nightingale, Kathryn R

    2017-10-01

    Tissue harmonic imaging has been widely used in abdominal imaging because of its significant reduction in acoustic noise compared with fundamental imaging. However, tissue harmonic imaging can be limited by both signal-to-noise ratio and penetration depth during clinical imaging, resulting in decreased diagnostic utility. A logical approach would be to increase the source pressure, but the in situ pressures used in diagnostic ultrasound are subject to a de facto upper limit based on the U.S. Food and Drug Administration guideline for the mechanical index (tissues without gas bodies, but would only be justified if there were a concurrent improvement in image quality and diagnostic utility. This work evaluates image quality differences between normal and elevated acoustic output hepatic harmonic imaging using a transmit frequency of 1.8 MHz. The results indicate that harmonic imaging using elevated acoustic output leads to modest improvements (3%-7%) in contrast-to-noise ratio of hypo-echoic hepatic vessels and increases in imaging penetration depth on the order of 4 mm per mechanical index increase of 0.1 for a given focal depth. Difficult-to-image patients who suffer from poor ultrasound image quality exhibited larger improvements than easy-to-image study participants. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  11. Imaging systems and applications: introduction to the feature.

    Science.gov (United States)

    Imai, Francisco H; Linne von Berg, Dale C; Skauli, Torbjørn; Tominaga, Shoji; Zalevsky, Zeev

    2014-05-01

    Imaging systems have numerous applications in industrial, military, consumer, and medical settings. Assembling a complete imaging system requires the integration of optics, sensing, image processing, and display rendering. This issue features original research ranging from design of stimuli for human perception, optics applications, and image enhancement to novel imaging modalities in both color and infrared spectral imaging, gigapixel imaging as well as a systems perspective to imaging.

  12. Characterization of the image quality in neutron radioscopy

    Science.gov (United States)

    Brunner, J.; Engelhardt, M.; Frei, G.; Gildemeister, A.; Lehmann, E.; Hillenbach, A.; Schillinger, B.

    2005-04-01

    Neutron radioscopy, or dynamic neutron radiography, is a non-destructive testing method, which has made big steps in the last years. Depending on the neutron flux, the object and the detector, for single events a time resolution down to a few milliseconds is possible. In the case of repetitive processes the object can be synchronized with the detector and better statistics in the image can be reached by adding radiographies of the same phase with a time resolution down to 100 μs. By stepwise delaying the trigger signal a radiography movie can be composed. Radiography images of a combustion engine and an injection nozzle were evaluated quantitatively by different methods trying to characterize the image quality of an imaging system. The main factors which influence the image quality are listed and discussed.

  13. Automated Selection of Uniform Regions for CT Image Quality Detection

    CERN Document Server

    Naeemi, Maitham D; Roychodhury, Sohini

    2016-01-01

    CT images are widely used in pathology detection and follow-up treatment procedures. Accurate identification of pathological features requires diagnostic quality CT images with minimal noise and artifact variation. In this work, a novel Fourier-transform based metric for image quality (IQ) estimation is presented that correlates to additive CT image noise. In the proposed method, two windowed CT image subset regions are analyzed together to identify the extent of variation in the corresponding Fourier-domain spectrum. The two square windows are chosen such that their center pixels coincide and one window is a subset of the other. The Fourier-domain spectral difference between these two sub-sampled windows is then used to isolate spatial regions-of-interest (ROI) with low signal variation (ROI-LV) and high signal variation (ROI-HV), respectively. Finally, the spatial variance ($var$), standard deviation ($std$), coefficient of variance ($cov$) and the fraction of abdominal ROI pixels in ROI-LV ($\

  14. Image quality in double- and triple-intensity ghost imaging with classical partially polarized light

    CERN Document Server

    Kellock, Henri; Shirai, Tomohiro; Friberg, Ari T

    2012-01-01

    Classical ghost imaging is a correlation-imaging technique in which the image of the object is found through intensity correlations of light. We analyze three different quality parameters, namely the visibility, the signal-to-noise ratio (SNR), and the contrast-to-noise ratio (CNR), to assess the performance of double- and triple-intensity correlation-imaging setups. The source is a random partially polarized beam of light obeying Gaussian statistics and the image quality is evaluated as a function of the degree of polarization (DoP). We show that the visibility improves when the DoP and the order of imaging increase, while the SNR behaves oppositely. The CNR is for the most part independent of DoP and the imaging order. The results are important for the development of new imaging devices using partially polarized light.

  15. Learning Receptive Fields and Quality Lookups for Blind Quality Assessment of Stereoscopic Images.

    Science.gov (United States)

    Shao, Feng; Lin, Weisi; Wang, Shanshan; Jiang, Gangyi; Yu, Mei; Dai, Qionghai

    2016-03-01

    Blind quality assessment of 3D images encounters more new challenges than its 2D counterparts. In this paper, we propose a blind quality assessment for stereoscopic images by learning the characteristics of receptive fields (RFs) from perspective of dictionary learning, and constructing quality lookups to replace human opinion scores without performance loss. The important feature of the proposed method is that we do not need a large set of samples of distorted stereoscopic images and the corresponding human opinion scores to learn a regression model. To be more specific, in the training phase, we learn local RFs (LRFs) and global RFs (GRFs) from the reference and distorted stereoscopic images, respectively, and construct their corresponding local quality lookups (LQLs) and global quality lookups (GQLs). In the testing phase, blind quality pooling can be easily achieved by searching optimal GRF and LRF indexes from the learnt LQLs and GQLs, and the quality score is obtained by combining the LRF and GRF indexes together. Experimental results on three publicly 3D image quality assessment databases demonstrate that in comparison with the existing methods, the devised algorithm achieves high consistent alignment with subjective assessment.

  16. Toward the development of an image quality tool for active millimeter wave imaging systems

    Science.gov (United States)

    Barber, Jeffrey; Weatherall, James C.; Greca, Joseph; Smith, Barry T.

    2015-05-01

    Preliminary design considerations for an image quality tool to complement millimeter wave imaging systems are presented. The tool is planned for use in confirming operating parameters; confirmation of continuity for imaging component design changes, and analysis of new components and detection algorithms. Potential embodiments of an image quality tool may contain materials that mimic human skin in order to provide a realistic signal return for testing, which may also help reduce or eliminate the need for mock passengers for developmental testing. Two candidate materials, a dielectric liquid and an iron-loaded epoxy, have been identified and reflection measurements have been performed using laboratory systems in the range 18 - 40 GHz. Results show good agreement with both laboratory and literature data on human skin, particularly in the range of operation of two commercially available millimeter wave imaging systems. Issues related to the practical use of liquids and magnetic materials for image quality tools are discussed.

  17. Curve Matching with Applications in Medical Imaging

    DEFF Research Database (Denmark)

    Bauer, Martin; Bruveris, Martins; Harms, Philipp

    2015-01-01

    In the recent years, Riemannian shape analysis of curves and surfaces has found several applications in medical image analysis. In this paper we present a numerical discretization of second order Sobolev metrics on the space of regular curves in Euclidean space. This class of metrics has several...

  18. Fundus autofluorescence applications in retinal imaging

    Directory of Open Access Journals (Sweden)

    Andrea Gabai

    2015-01-01

    Full Text Available Fundus autofluorescence (FAF is a relatively new imaging technique that can be used to study retinal diseases. It provides information on retinal metabolism and health. Several different pathologies can be detected. Peculiar AF alterations can help the clinician to monitor disease progression and to better understand its pathogenesis. In the present article, we review FAF principles and clinical applications.

  19. Image Processing and its Military Applications

    Directory of Open Access Journals (Sweden)

    V. V.D. Shah

    1987-10-01

    Full Text Available One of the important breakthroughs, image processing is the stand alone, non-human image understanding system (IUS. The task of understanding images becomes monumental as one tries to define what understanding really is. Both pattern recognition and artificial intelligence are used in addition to traditional signal processing. Scene analysis procedures using edge and texture segmentation can be considered as the early stages of image understanding process. Symbolic representation and relationship grammers come at subsequent stages. Thus it is not reasonable to put a man into a loop of signal processing at certain sensors such as remotely piloted vehicles, satellites and spacecrafts. Consequently smart sensors and semi-automatic processes are being developed. Land remote sensing has been another important application of the image processing. With the introduction of programmes like Star Wars this particular application has gained a special importance from the Military's point of view. This paper provides an overview of digital image processing and explores the scope of the technology of remote sensing and IUSs from the Military's point of view. An example of the autonomous vehicle project now under progress in the US is described in detail to elucidate the impact of IUSs.

  20. Novel hemispheric image formation: concepts and applications

    Science.gov (United States)

    Thibault, Simon; Konen, Pierre; Roulet, Patrice; Villegas, Mathieu

    2008-04-01

    Panoramic and hemispheric lens technologies represent new and exciting opportunities in both imaging and projection systems. Such lenses offer intriguing applications for the transportation/automotive industry, in the protection of civilian and military areas, business. In this paper we describe a new optical design technique that provides a greater degree of freedom in producing a variety of hemispheric spatial light distribution areas. This innovative optical design strategy, of generating and controlling image mapping, has been successful in producing high-resolution imaging and projection systems. This success has subsequently generated increased interest in the high-resolution camera/projector and the concept of absolute measurement with high-resolution wide-angle lenses. The new technique described in this paper uses optimization techniques to improve the performance of a customized wide-angle lens optical system for a specific application. By adding a custom angle-to-pixel ratio at the optical design stage, this customized optical system provides ideal image coverage while reducing and optimizing signal processing. This novel image formation technique requires the development of new algorithms in order to view the panoramic image on a display without any residual distortion.

  1. Image quality of mixed convolution kernel in thoracic computed tomography.

    Science.gov (United States)

    Neubauer, Jakob; Spira, Eva Maria; Strube, Juliane; Langer, Mathias; Voss, Christian; Kotter, Elmar

    2016-11-01

    The mixed convolution kernel alters his properties geographically according to the depicted organ structure, especially for the lung. Therefore, we compared the image quality of the mixed convolution kernel to standard soft and hard kernel reconstructions for different organ structures in thoracic computed tomography (CT) images.Our Ethics Committee approved this prospective study. In total, 31 patients who underwent contrast-enhanced thoracic CT studies were included after informed consent. Axial reconstructions were performed with hard, soft, and mixed convolution kernel. Three independent and blinded observers rated the image quality according to the European Guidelines for Quality Criteria of Thoracic CT for 13 organ structures. The observers rated the depiction of the structures in all reconstructions on a 5-point Likert scale. Statistical analysis was performed with the Friedman Test and post hoc analysis with the Wilcoxon rank-sum test.Compared to the soft convolution kernel, the mixed convolution kernel was rated with a higher image quality for lung parenchyma, segmental bronchi, and the border between the pleura and the thoracic wall (P kernel, the mixed convolution kernel was rated with a higher image quality for aorta, anterior mediastinal structures, paratracheal soft tissue, hilar lymph nodes, esophagus, pleuromediastinal border, large and medium sized pulmonary vessels and abdomen (P kernel cannot fully substitute the standard CT reconstructions. Hard and soft convolution kernel reconstructions still seem to be mandatory for thoracic CT.

  2. Fast vector quantization algorithm preserving color image quality

    Science.gov (United States)

    Charrier, Christophe; Cherifi, Hocine

    1998-04-01

    In the color image compression field, it is well known by researchers that the information is statistically redundant. This redundancy is a handicap in terms of dictionary construction time. A way to counterbalance this time consuming effect is to reduce the redundancy within the original image while keeping the image quality. One can extract a random sample of the initial training set on which one constructs the codebook whose quality is equal to the quality of the codebook generated from the entire training set. We applied this idea in the color vector quantization (VQ) compression scheme context. We propose an algorithm to reduce the complexity of the standard LBG technique. We searched for a measure of relevance of each block from the entire training set. Under the assumption that the measure of relevance is a independent random variable, we applied the Kolmogorov statistical test to define the smallest size of a random sample, and then the sample itself. Finally, from blocks associated to each measure of relevance of the random sample, we compute the standard LBG algorithm to construct the codebook. Psychophysics and statistical measures of image quality allow us to find the best measure of relevance to reduce the training set while preserving the image quality and decreasing the computational cost.

  3. Recent applications of hyperspectral imaging in microbiology.

    Science.gov (United States)

    Gowen, Aoife A; Feng, Yaoze; Gaston, Edurne; Valdramidis, Vasilis

    2015-05-01

    Hyperspectral chemical imaging (HSI) is a broad term encompassing spatially resolved spectral data obtained through a variety of modalities (e.g. Raman scattering, Fourier transform infrared microscopy, fluorescence and near-infrared chemical imaging). It goes beyond the capabilities of conventional imaging and spectroscopy by obtaining spatially resolved spectra from objects at spatial resolutions varying from the level of single cells up to macroscopic objects (e.g. foods). In tandem with recent developments in instrumentation and sampling protocols, applications of HSI in microbiology have increased rapidly. This article gives a brief overview of the fundamentals of HSI and a comprehensive review of applications of HSI in microbiology over the past 10 years. Technical challenges and future perspectives for these techniques are also discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Body image and quality of life in a Spanish population

    Directory of Open Access Journals (Sweden)

    Ignacio Jáuregui Lobera

    2011-01-01

    Full Text Available Ignacio Jáuregui Lobera1, Patricia Bolaños Ríos21Department of Nutrition and Bromatology, Pablo de Olavide University, Seville, Spain; 2Behavior Science Institute, Seville, SpainPurpose: The aim of the current study was to analyze the psychometric properties, factor structure, and internal consistency of the Spanish version of the Body Image Quality of Life Inventory (BIQLI-SP as well as its test–retest reliability. Further objectives were to analyze different relationships with key dimensions of psychosocial functioning (ie, self-esteem, presence of psychopathological symptoms, eating and body image-related problems, and perceived stress and to evaluate differences in body image quality of life due to gender.Patients and methods: The sample comprised 417 students without any psychiatric history, recruited from the Pablo de Olavide University and the University of Seville. There were 140 men (33.57% and 277 women (66.43%, and the mean age was 21.62 years (standard deviation = 5.12. After obtaining informed consent from all participants, the following questionnaires were administered: BIQLI, Eating Disorder Inventory-2 (EDI-2, Perceived Stress Questionnaire (PSQ, Self-Esteem Scale (SES, and Symptom Checklist-90-Revised (SCL-90-R.Results: The BIQLI-SP shows adequate psychometric properties, and it may be useful to determine the body image quality of life in different physical conditions. A more positive body image quality of life is associated with better self-esteem, better psychological wellbeing, and fewer eating-related dysfunctional attitudes, this being more evident among women.Conclusion: The BIQLI-SP may be useful to determine the body image quality of life in different contexts with regard to dermatology, cosmetic and reconstructive surgery, and endocrinology, among others. In these fields of study, a new trend has emerged to assess body image-related quality of life.Keywords: body appreciation, wellbeing, self-esteem, social

  5. Functional imaging in oncology. Clinical applications. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Luna, Antonio [Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Radiology; MRI Health Time Group, Jaen (Spain); Vilanova, Joan C. [Girona Univ. (Spain). Clinica Girona - Hospital Sta. Caterina; Hygino da Cruz, L. Celso Jr. (ed.) [CDPI and IRM, Rio de Janeiro (Brazil). Dept. of Radiology; Rossi, Santiago E. [Centro de Diagnostico, Buenos Aires (Argentina)

    2014-06-01

    Easy-to-read manual on new functional imaging techniques in oncology. Explains current clinical applications and outlines future avenues. Includes numerous high-quality illustrations to highlight the major teaching points. In the new era of functional and molecular imaging, both currently available imaging biomarkers and biomarkers under development are expected to lead to major changes in the management of oncological patients. This two-volume book is a practical manual on the various imaging techniques capable of delivering functional information on cancer, including diffusion MRI, perfusion CT and MRI, dual-energy CT, spectroscopy, dynamic contrast-enhanced ultrasonography, PET, and hybrid modalities. This second volume considers the applications and benefits of these techniques in a wide range of tumor types, including their role in diagnosis, prediction of treatment outcome, and early evaluation of treatment response. Each chapter addresses a specific malignancy and is written by one or more acclaimed experts. The lucid text is complemented by numerous high-quality illustrations that highlight key features and major teaching points.

  6. High Throughput Multispectral Image Processing with Applications in Food Science.

    Science.gov (United States)

    Tsakanikas, Panagiotis; Pavlidis, Dimitris; Nychas, George-John

    2015-01-01

    Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT) in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing's outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models) and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples.

  7. High Throughput Multispectral Image Processing with Applications in Food Science.

    Directory of Open Access Journals (Sweden)

    Panagiotis Tsakanikas

    Full Text Available Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing's outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples.

  8. High Throughput Multispectral Image Processing with Applications in Food Science

    Science.gov (United States)

    Tsakanikas, Panagiotis; Pavlidis, Dimitris; Nychas, George-John

    2015-01-01

    Recently, machine vision is gaining attention in food science as well as in food industry concerning food quality assessment and monitoring. Into the framework of implementation of Process Analytical Technology (PAT) in the food industry, image processing can be used not only in estimation and even prediction of food quality but also in detection of adulteration. Towards these applications on food science, we present here a novel methodology for automated image analysis of several kinds of food products e.g. meat, vanilla crème and table olives, so as to increase objectivity, data reproducibility, low cost information extraction and faster quality assessment, without human intervention. Image processing’s outcome will be propagated to the downstream analysis. The developed multispectral image processing method is based on unsupervised machine learning approach (Gaussian Mixture Models) and a novel unsupervised scheme of spectral band selection for segmentation process optimization. Through the evaluation we prove its efficiency and robustness against the currently available semi-manual software, showing that the developed method is a high throughput approach appropriate for massive data extraction from food samples. PMID:26466349

  9. Interpretation of medical imaging data with a mobile application: a mobile digital imaging processing environment

    Directory of Open Access Journals (Sweden)

    Meng Kuan eLin

    2013-07-01

    Full Text Available Digital Imaging Processing (DIP requires data extraction and output from a visualization tool to be consistent. Data handling and transmission between the server and a user is a systematic process in service interpretation. The use of integrated medical services for management and viewing of imaging data in combination with a mobile visualization tool can be greatly facilitated by data analysis and interpretation. This paper presents an integrated mobile application and digital imaging processing service, called M-DIP. The objective of the system is to (1 automate the direct data tiling, conversion, pre-tiling of brain images from Medical Imaging NetCDF (MINC, Neuroimaging Informatics Technology Initiative (NIFTI to RAW formats; (2 speed up querying of imaging measurement; and (3 display high level of images with three dimensions in real world coordinates. In addition, M-DIP provides the ability to work on a mobile or tablet device without any software installation using web-based protocols. M-DIP implements three levels of architecture with a relational middle- layer database, a stand-alone DIP server and a mobile application logic middle level realizing user interpretation for direct querying and communication. This imaging software has the ability to display biological imaging data a multiple zoom levels and to increase its quality to meet users expectations. Interpretation of bioimaging data is facilitated by an interface analogous to online mapping services using real world coordinate browsing. This allows mobile devices to display multiple datasets simultaneously from a remote site. M-DIP can be used as a measurement repository that can be accessed by any network environment, such as a portable mobile or tablet device. In addition, this system and combination with mobile applications are establishing a virtualization tool in the neuroinformatics field to speed interpretation services.

  10. Real-time computer treatment of THz passive device images with the high image quality

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2012-06-01

    We demonstrate real-time computer code improving significantly the quality of images captured by the passive THz imaging system. The code is not only designed for a THz passive device: it can be applied to any kind of such devices and active THz imaging systems as well. We applied our code for computer processing of images captured by four passive THz imaging devices manufactured by different companies. It should be stressed that computer processing of images produced by different companies requires using the different spatial filters usually. The performance of current version of the computer code is greater than one image per second for a THz image having more than 5000 pixels and 24 bit number representation. Processing of THz single image produces about 20 images simultaneously corresponding to various spatial filters. The computer code allows increasing the number of pixels for processed images without noticeable reduction of image quality. The performance of the computer code can be increased many times using parallel algorithms for processing the image. We develop original spatial filters which allow one to see objects with sizes less than 2 cm. The imagery is produced by passive THz imaging devices which captured the images of objects hidden under opaque clothes. For images with high noise we develop an approach which results in suppression of the noise after using the computer processing and we obtain the good quality image. With the aim of illustrating the efficiency of the developed approach we demonstrate the detection of the liquid explosive, ordinary explosive, knife, pistol, metal plate, CD, ceramics, chocolate and other objects hidden under opaque clothes. The results demonstrate the high efficiency of our approach for the detection of hidden objects and they are a very promising solution for the security problem.

  11. Multimodal interaction in image and video applications

    CERN Document Server

    Sappa, Angel D

    2013-01-01

    Traditional Pattern Recognition (PR) and Computer Vision (CV) technologies have mainly focused on full automation, even though full automation often proves elusive or unnatural in many applications, where the technology is expected to assist rather than replace the human agents. However, not all the problems can be automatically solved being the human interaction the only way to tackle those applications. Recently, multimodal human interaction has become an important field of increasing interest in the research community. Advanced man-machine interfaces with high cognitive capabilities are a hot research topic that aims at solving challenging problems in image and video applications. Actually, the idea of computer interactive systems was already proposed on the early stages of computer science. Nowadays, the ubiquity of image sensors together with the ever-increasing computing performance has open new and challenging opportunities for research in multimodal human interaction. This book aims to show how existi...

  12. Body image quality of life in eating disorders

    Directory of Open Access Journals (Sweden)

    Ignacio Jáuregui Lobera

    2011-03-01

    Full Text Available Ignacio Jáuregui Lobera1, Patricia Bolaños Ríos21Department of Nutrition and Bromatology, Pablo de Olavide University, Seville, Spain; 2Behavior Sciences Institute, Seville, SpainPurpose: The objective was to examine how body image affects quality of life in an eating-disorder (ED clinical sample, a non-ED clinical sample, and a nonclinical sample. We hypothesized that ED patients would show the worst body image quality of life. We also hypothesized that body image quality of life would have a stronger negative association with specific ED-related variables than with other psychological and psychopathological variables, mainly among ED patients. On the basis of previous studies, the influence of gender on the results was explored, too.Patients and methods: The final sample comprised 70 ED patients (mean age 22.65 ± 7.76 years; 59 women and 11 men; 106 were patients with other psychiatric disorders (mean age 28.20 ± 6.52; 67 women and 39 men, and 135 were university students (mean age 21.57 ± 2.58; 81 women and 54 men, with no psychiatric history. After having obtained informed consent, the following questionnaires were administered: Body Image Quality of Life Inventory-Spanish version (BIQLI-SP, Eating Disorders Inventory-2 (EDI-2, Perceived Stress Questionnaire (PSQ, Self-Esteem Scale (SES, and Symptom Checklist-90-Revised (SCL-90-R.Results: The ED patients' ratings on the BIQLI-SP were the lowest and negatively scored (BIQLI-SP means: +20.18, +5.14, and —6.18, in the student group, the non-ED patient group, and the ED group, respectively. The effect of body image on quality of life was more negative in the ED group in all items of the BIQLI-SP. Body image quality of life was negatively associated with specific ED-related variables, more than with other psychological and psychopathological variables, but not especially among ED patients.Conclusion: Body image quality of life was affected not only by specific pathologies related to body

  13. Mineral mapping and applications of imaging spectroscopy

    Science.gov (United States)

    Clark, R.N.; Boardman, J.; Mustard, J.; Kruse, F.; Ong, C.; Pieters, C.; Swayze, G.A.

    2006-01-01

    Spectroscopy is a tool that has been used for decades to identify, understand, and quantify solid, liquid, or gaseous materials, especially in the laboratory. In disciplines ranging from astronomy to chemistry, spectroscopic measurements are used to detect absorption and emission features due to specific chemical bonds, and detailed analyses are used to determine the abundance and physical state of the detected absorbing/emitting species. Spectroscopic measurements have a long history in the study of the Earth and planets. Up to the 1990s remote spectroscopic measurements of Earth and planets were dominated by multispectral imaging experiments that collect high-quality images in a few, usually broad, spectral bands or with point spectrometers that obtained good spectral resolution but at only a few spatial positions. However, a new generation of sensors is now available that combines imaging with spectroscopy to create the new discipline of imaging spectroscopy. Imaging spectrometers acquire data with enough spectral range, resolution, and sampling at every pixel in a raster image so that individual absorption features can be identified and spatially mapped (Goetz et al., 1985).

  14. Applications of Imaging Flow Cytometry for Microalgae.

    Science.gov (United States)

    Hildebrand, Mark; Davis, Aubrey; Abbriano, Raffaela; Pugsley, Haley R; Traller, Jesse C; Smith, Sarah R; Shrestha, Roshan P; Cook, Orna; Sánchez-Alvarez, Eva L; Manandhar-Shrestha, Kalpana; Alderete, Benjamin

    2016-01-01

    The ability to image large numbers of cells at high resolution enhances flow cytometric analysis of cells and cell populations. In particular, the ability to image intracellular features adds a unique aspect to analyses, and can enable correlation between molecular phenomena resulting in alterations in cellular phenotype. Unicellular microalgae are amenable to high-throughput analysis to capture the diversity of cell types in natural samples, or diverse cellular responses in clonal populations, especially using imaging cytometry. Using examples from our laboratory, we review applications of imaging cytometry, specifically using an Amnis(®) ImageStream(®)X instrument, to characterize photosynthetic microalgae. Some of these examples highlight advantages of imaging flow cytometry for certain research objectives, but we also include examples that would not necessarily require imaging and could be performed on a conventional cytometer to demonstrate other concepts in cytometric evaluation of microalgae. We demonstrate the value of these approaches for (1) analysis of populations, (2) documentation of cellular features, and (3) analysis of gene expression.

  15. Genitourinary imaging: Current and emerging applications

    Directory of Open Access Journals (Sweden)

    O′ Donoghue P

    2010-01-01

    Full Text Available This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT and magnetic resonance (MR in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  16. Genitourinary imaging: current and emerging applications.

    Science.gov (United States)

    O' Donoghue, P M; McSweeney, S E; Jhaveri, K

    2010-01-01

    This review discusses the current and emerging techniques in urinary tract imaging. Recent technical advances and novel discoveries make this an exciting but challenging time for urinary tract imaging. The first section describes the imaging of the adrenal gland which has made great strides in the last decade, the current major adrenal imaging modalities as well as new applications are discussed with particular attention to the role of imaging in the incidentally detected adrenal lesion. In the second section the role of ultrasound, computed tomography (CT) and magnetic resonance (MR) in evaluation of the renal tract are discussed with the new technical advances leading to earlier detection and characterization of renal lesions. Complementary to this is the emerging role of CT and MR urography in assessment of the urinary tract and bladder in contrast to the demise of plain film studies/intravenous urography. The role of CT angiography in assessment of the renal vasculature is also discussed. The third section discusses the role of prostate imaging in the diagnosis, staging and management of prostate cancer. Transrectal ultrasonography, can be used to guide biopsy, CT is frequently used in staging, with bone scintigraphy and positron emission tomography having roles in advanced disease. Currently, all imaging modalities, especially MR are evolving to improve disease detection and staging. The final section discusses the recently encountered adverse reaction of nephrogenic systemic fibrosis in patients post gadolinium-enhanced MRI and how to help prevent this adverse reaction.

  17. Subpixel shift with Fourier transform to achieve efficient and high-quality image interpolation

    Science.gov (United States)

    Chen, Qin-Sheng; Weinhous, Martin S.

    1999-05-01

    A new approach to image interpolation is proposed. Different from the conventional scheme, the interpolation of a digital image is achieved with a sub-unity coordinate shift technique. In the approach, the original image is first shifted by sub-unity distances matching the locations where the image values need to be restored. The original and the shifted images are then interspersed together, yielding an interpolated image. High quality sub-unity image shift which is crucial to the approach is accomplished by implementing the shift theorem of Fourier transformation. It is well known that under the Nyquist sampling criterion, the most accurate image interpolation can be achieved with the interpolating function (sinc function). A major drawback is its computation efficiency. The present approach can achieve an interpolation quality as good as that with the sinc function since the sub-unity shift in Fourier domain is equivalent to shifting the sinc function in spatial domain, while the efficiency, thanks to the fast Fourier transform, is very much improved. In comparison to the conventional interpolation techniques such as linear or cubic B-spline interpolation, the interpolation accuracy is significantly enhanced. In order to compensate for the under-sampling effects in the interpolation of 3D medical images owing to a larger inter-slice distance, proper window functions were recommended. The application of the approach to 2- and 3-D CT and MRI images produced satisfactory interpolation results.

  18. Exploratory survey of image quality on CR digital mammography imaging systems in Mexico.

    Science.gov (United States)

    Gaona, E; Rivera, T; Arreola, M; Franco, J; Molina, N; Alvarez, B; Azorín, C G; Casian, G

    2014-01-01

    The purpose of this study was to assess the current status of image quality and dose in computed radiographic digital mammography (CRDM) systems. Studies included CRDM systems of various models and manufacturers which dose and image quality comparisons were performed. Due to the recent rise in the use of digital radiographic systems in Mexico, CRDM systems are rapidly replacing conventional film-screen systems without any regard to quality control or image quality standards. Study was conducted in 65 mammography facilities which use CRDM systems in the Mexico City and surrounding States. The systems were tested as used clinically. This means that the dose and beam qualities were selected using the automatic beam selection and photo-timed features. All systems surveyed generate laser film hardcopies for the radiologist to read on a scope or mammographic high luminance light box. It was found that 51 of CRDM systems presented a variety of image artefacts and non-uniformities arising from inadequate acquisition and processing, as well as from the laser printer itself. Undisciplined alteration of image processing settings by the technologist was found to be a serious prevalent problem in 42 facilities. Only four of them showed an image QC program which is periodically monitored by a medical physicist. The Average Glandular Dose (AGD) in the surveyed systems was estimated to have a mean value of 2.4 mGy. To improve image quality in mammography and make more efficient screening mammographic in early detection of breast cancer is required new legislation.

  19. Management of Mobile Web Application Development with Quality Assurance

    Directory of Open Access Journals (Sweden)

    Alin Zamfiroiu

    2013-06-01

    Full Text Available Mobile applications are becoming increasingly used because of the multitude of existing mobile devices. Mobile application development becomes more complex. For mobile devices there are native applications that run directly on the device, web applications accessed via mobile browsers and hybrid applications. Mobile Application Development in any form should be made with quality assurance since when determining the target group and the application architecture. Management of mobile application development is the result obtained and the quality of applications developed in the decisions taken. In this paper decisions made in the development of mobile web applications are presented and how this mobile web application is used by the students.

  20. Image-Processing Techniques for the Creation of Presentation-Quality Astronomical Images

    CERN Document Server

    Rector, T A; Frattare, L M; English, J; Puuohau-Pummill, K

    2004-01-01

    The quality of modern astronomical data, the power of modern computers and the agility of current image-processing software enable the creation of high-quality images in a purely digital form. The combination of these technological advancements has created a new ability to make color astronomical images. And in many ways it has led to a new philosophy towards how to create them. A practical guide is presented on how to generate astronomical images from research data with powerful image-processing programs. These programs use a layering metaphor that allows for an unlimited number of astronomical datasets to be combined in any desired color scheme, creating an immense parameter space to be explored using an iterative approach. Several examples of image creation are presented. A philosophy is also presented on how to use color and composition to create images that simultaneously highlight scientific detail and are aesthetically appealing. This philosophy is necessary because most datasets do not correspond to t...

  1. The effect of defect cluster size and interpolation on radiographic image quality

    Science.gov (United States)

    Töpfer, Karin; Yip, Kwok L.

    2011-03-01

    For digital X-ray detectors, the need to control factory yield and cost invariably leads to the presence of some defective pixels. Recently, a standard procedure was developed to identify such pixels for industrial applications. However, no quality standards exist in medical or industrial imaging regarding the maximum allowable number and size of detector defects. While the answer may be application specific, the minimum requirement for any defect specification is that the diagnostic quality of the images be maintained. A more stringent criterion is to keep any changes in the images due to defects below the visual threshold. Two highly sensitive image simulation and evaluation methods were employed to specify the fraction of allowable defects as a function of defect cluster size in general radiography. First, the most critical situation of the defect being located in the center of the disease feature was explored using image simulation tools and a previously verified human observer model, incorporating a channelized Hotelling observer. Detectability index d' was obtained as a function of defect cluster size for three different disease features on clinical lung and extremity backgrounds. Second, four concentrations of defects of four different sizes were added to clinical images with subtle disease features and then interpolated. Twenty observers evaluated the images against the original on a single display using a 2-AFC method, which was highly sensitive to small changes in image detail. Based on a 50% just-noticeable difference, the fraction of allowed defects was specified vs. cluster size.

  2. Uncooled LWIR imaging: applications and market analysis

    Science.gov (United States)

    Takasawa, Satomi

    2015-05-01

    The evolution of infrared (IR) imaging sensor technology for defense market has played an important role in developing commercial market, as dual use of the technology has expanded. In particular, technologies of both reduction in pixel pitch and vacuum package have drastically evolved in the area of uncooled Long-Wave IR (LWIR; 8-14 μm wavelength region) imaging sensor, increasing opportunity to create new applications. From the macroscopic point of view, the uncooled LWIR imaging market is divided into two areas. One is a high-end market where uncooled LWIR imaging sensor with sensitivity as close to that of cooled one as possible is required, while the other is a low-end market which is promoted by miniaturization and reduction in price. Especially, in the latter case, approaches towards consumer market have recently appeared, such as applications of uncooled LWIR imaging sensors to night visions for automobiles and smart phones. The appearance of such a kind of commodity surely changes existing business models. Further technological innovation is necessary for creating consumer market, and there will be a room for other companies treating components and materials such as lens materials and getter materials and so on to enter into the consumer market.

  3. Dose and diagnostic image quality in digital tomosynthesis imaging of facial bones in pediatrics

    Science.gov (United States)

    King, J. M.; Hickling, S.; Elbakri, I. A.; Reed, M.; Wrogemann, J.

    2011-03-01

    The purpose of this study was to evaluate the use of digital tomosynthesis (DT) for pediatric facial bone imaging. We compared the eye lens dose and diagnostic image quality of DT facial bone exams relative to digital radiography (DR) and computed tomography (CT), and investigated whether we could modify our current DT imaging protocol to reduce patient dose while maintaining sufficient diagnostic image quality. We measured the dose to the eye lens for all three modalities using high-sensitivity thermoluminescent dosimeters (TLDs) and an anthropomorphic skull phantom. To assess the diagnostic image quality of DT compared to the corresponding DR and CT images, we performed an observer study where the visibility of anatomical structures in the DT phantom images were rated on a four-point scale. We then acquired DT images at lower doses and had radiologists indicate whether the visibility of each structure was adequate for diagnostic purposes. For typical facial bone exams, we measured eye lens doses of 0.1-0.4 mGy for DR, 0.3-3.7 mGy for DT, and 26 mGy for CT. In general, facial bone structures were visualized better with DT then DR, and the majority of structures were visualized well enough to avoid the need for CT. DT imaging provides high quality diagnostic images of the facial bones while delivering significantly lower doses to the lens of the eye compared to CT. In addition, we found that by adjusting the imaging parameters, the DT effective dose can be reduced by up to 50% while maintaining sufficient image quality.

  4. A new method to evaluate imaging quality of CCD cameras

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; DU Hai-hui; DAI Jing-min; CHEN Ying-hang

    2005-01-01

    In order to evaluate the imaging quality of CCD cameras fully and rapidly,the minimum resolvable contrast (MRC) is presented in this paper and the system of measuring MRC is constructed as well,in which two integrating spheres are proposed to illuminate two sides of the target respectively.The variable contrast can be obtained by regulating the luminance of integrating spheres. Experimental results indicate that the error of measuring luminance is within ±0.3 cd/m2,MRC rises with the increase of the spatial frequency.The experimental results show that the method proposed is an effective approach to evaluate the imaging quality of CCD cameras.

  5. Radiation dose and image quality for paediatric interventional cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Vano, E [Radiology Department, Medicine School, Complutense University and San Carlos University Hospital, 28040 Madrid (Spain); Ubeda, C [Clinical Sciences Department, Faculty of the Science of Health, Tarapaca University, 18 de Septiembre 2222, Arica (Chile); Leyton, F [Institute of Public Health of Chile, Marathon 1000, Nunoa, Santiago (Chile); Miranda, P [Hemodynamic Department, Cardiovascular Service, Luis Calvo Mackenna Hospital, Avenida Antonio Varas 360, Providencia, Santiago (Chile)], E-mail: eliseov@med.ucm.es

    2008-08-07

    Radiation dose and image quality for paediatric protocols in a biplane x-ray system used for interventional cardiology have been evaluated. Entrance surface air kerma (ESAK) and image quality using a test object and polymethyl methacrylate (PMMA) phantoms have been measured for the typical paediatric patient thicknesses (4-20 cm of PMMA). Images from fluoroscopy (low, medium and high) and cine modes have been archived in digital imaging and communications in medicine (DICOM) format. Signal-to-noise ratio (SNR), figure of merit (FOM), contrast (CO), contrast-to-noise ratio (CNR) and high contrast spatial resolution (HCSR) have been computed from the images. Data on dose transferred to the DICOM header have been used to test the values of the dosimetric display at the interventional reference point. ESAK for fluoroscopy modes ranges from 0.15 to 36.60 {mu}Gy/frame when moving from 4 to 20 cm PMMA. For cine, these values range from 2.80 to 161.10 {mu}Gy/frame. SNR, FOM, CO, CNR and HCSR are improved for high fluoroscopy and cine modes and maintained roughly constant for the different thicknesses. Cumulative dose at the interventional reference point resulted 25-45% higher than the skin dose for the vertical C-arm (depending of the phantom thickness). ESAK and numerical image quality parameters allow the verification of the proper setting of the x-ray system. Knowing the increases in dose per frame when increasing phantom thicknesses together with the image quality parameters will help cardiologists in the good management of patient dose and allow them to select the best imaging acquisition mode during clinical procedures.

  6. Radiation dose and image quality for paediatric interventional cardiology

    Science.gov (United States)

    Vano, E.; Ubeda, C.; Leyton, F.; Miranda, P.

    2008-08-01

    Radiation dose and image quality for paediatric protocols in a biplane x-ray system used for interventional cardiology have been evaluated. Entrance surface air kerma (ESAK) and image quality using a test object and polymethyl methacrylate (PMMA) phantoms have been measured for the typical paediatric patient thicknesses (4-20 cm of PMMA). Images from fluoroscopy (low, medium and high) and cine modes have been archived in digital imaging and communications in medicine (DICOM) format. Signal-to-noise ratio (SNR), figure of merit (FOM), contrast (CO), contrast-to-noise ratio (CNR) and high contrast spatial resolution (HCSR) have been computed from the images. Data on dose transferred to the DICOM header have been used to test the values of the dosimetric display at the interventional reference point. ESAK for fluoroscopy modes ranges from 0.15 to 36.60 µGy/frame when moving from 4 to 20 cm PMMA. For cine, these values range from 2.80 to 161.10 µGy/frame. SNR, FOM, CO, CNR and HCSR are improved for high fluoroscopy and cine modes and maintained roughly constant for the different thicknesses. Cumulative dose at the interventional reference point resulted 25-45% higher than the skin dose for the vertical C-arm (depending of the phantom thickness). ESAK and numerical image quality parameters allow the verification of the proper setting of the x-ray system. Knowing the increases in dose per frame when increasing phantom thicknesses together with the image quality parameters will help cardiologists in the good management of patient dose and allow them to select the best imaging acquisition mode during clinical procedures.

  7. Investigation of cone-beam CT image quality trade-off for image-guided radiation therapy

    Science.gov (United States)

    Bian, Junguo; Sharp, Gregory C.; Park, Yang-Kyun; Ouyang, Jinsong; Bortfeld, Thomas; El Fakhri, Georges

    2016-05-01

    It is well-known that projections acquired over an angular range slightly over 180° (so-called short scan) are sufficient for fan-beam reconstruction. However, due to practical imaging conditions (projection data and reconstruction image discretization, physical factors, and data noise), the short-scan reconstructions may have different appearances and properties from the full-scan (scans over 360°) reconstructions. Nevertheless, short-scan configurations have been used in applications such as cone-beam CT (CBCT) for head-neck-cancer image-guided radiation therapy (IGRT) that only requires a small field of view due to the potential reduced imaging time and dose. In this work, we studied the image quality trade-off for full, short, and full/short scan configurations with both conventional filtered-backprojection (FBP) reconstruction and iterative reconstruction algorithms based on total-variation (TV) minimization for head-neck-cancer IGRT. Anthropomorphic and Catphan phantoms were scanned at different exposure levels with a clinical scanner used in IGRT. Both visualization- and numerical-metric-based evaluation studies were performed. The results indicate that the optimal exposure level and number of views are in the middle range for both FBP and TV-based iterative algorithms and the optimization is object-dependent and task-dependent. The optimal view numbers decrease with the total exposure levels for both FBP and TV-based algorithms. The results also indicate there are slight differences between FBP and TV-based iterative algorithms for the image quality trade-off: FBP seems to be more in favor of larger number of views while the TV-based algorithm is more robust to different data conditions (number of views and exposure levels) than the FBP algorithm. The studies can provide a general guideline for image-quality optimization for CBCT used in IGRT and other applications.

  8. Presence capture cameras - a new challenge to the image quality

    Science.gov (United States)

    Peltoketo, Veli-Tapani

    2016-04-01

    Commercial presence capture cameras are coming to the markets and a new era of visual entertainment starts to get its shape. Since the true presence capturing is still a very new technology, the real technical solutions are just passed a prototyping phase and they vary a lot. Presence capture cameras have still the same quality issues to tackle as previous phases of digital imaging but also numerous new ones. This work concentrates to the quality challenges of presence capture cameras. A camera system which can record 3D audio-visual reality as it is has to have several camera modules, several microphones and especially technology which can synchronize output of several sources to a seamless and smooth virtual reality experience. Several traditional quality features are still valid in presence capture cameras. Features like color fidelity, noise removal, resolution and dynamic range create the base of virtual reality stream quality. However, co-operation of several cameras brings a new dimension for these quality factors. Also new quality features can be validated. For example, how the camera streams should be stitched together with 3D experience without noticeable errors and how to validate the stitching? The work describes quality factors which are still valid in the presence capture cameras and defines the importance of those. Moreover, new challenges of presence capture cameras are investigated in image and video quality point of view. The work contains considerations how well current measurement methods can be used in presence capture cameras.

  9. Achieving quality in cardiovascular imaging: proceedings from the American College of Cardiology-Duke University Medical Center Think Tank on Quality in Cardiovascular Imaging.

    Science.gov (United States)

    Douglas, Pamela; Iskandrian, Ami E; Krumholz, Harlan M; Gillam, Linda; Hendel, Robert; Jollis, James; Peterson, Eric; Chen, Jersey; Masoudi, Frederick; Mohler, Emile; McNamara, Robert L; Patel, Manesh R; Spertus, John

    2006-11-21

    Cardiovascular imaging has enjoyed both rapid technological advances and sustained growth, yet less attention has been focused on quality than in other areas of cardiovascular medicine. To address this deficit, representatives from cardiovascular imaging societies, private payers, government agencies, the medical imaging industry, and experts in quality measurement met, and this report provides an overview of the discussions. A consensus definition of quality in imaging and a convergence of opinion on quality measures across imaging modalities was achieved and are intended to be the start of a process culminating in the development, dissemination, and adoption of quality measures for all cardiovascular imaging modalities.

  10. Image quality in CT: From physical measurements to model observers.

    OpenAIRE

    2015-01-01

    Evaluation of image quality (IQ) in Computed Tomography (CT) is important to ensure that diagnostic questions are correctly answered, whilst keeping radiation dose to the patient as low as is reasonably possible. The assessment of individual aspects of IQ is already a key component of routine quality control of medical x-ray devices. These values together with standard dose indicators can be used to give rise to 'figures of merit' (FOM) to characterise the dose efficiency of the CT scanners o...

  11. Scanner-based image quality measurement system for automated analysis of EP output

    Science.gov (United States)

    Kipman, Yair; Mehta, Prashant; Johnson, Kate

    2003-12-01

    Inspection of electrophotographic print cartridge quality and compatibility requires analysis of hundreds of pages on a wide population of printers and copiers. Although print quality inspection is often achieved through the use of anchor prints and densitometry, more comprehensive analysis and quantitative data is desired for performance tracking, benchmarking and failure mode analysis. Image quality measurement systems range in price and performance, image capture paths and levels of automation. In order to address the requirements of a specific application, careful consideration was made to print volume, budgetary limits, and the scope of the desired image quality measurements. A flatbed scanner-based image quality measurement system was selected to support high throughput, maximal automation, and sufficient flexibility for both measurement methods and image sampling rates. Using an automatic document feeder (ADF) for sample management, a half ream of prints can be measured automatically without operator intervention. The system includes optical character recognition (OCR) for automatic determination of target type for measurement suite selection. This capability also enables measurement of mixed stacks of targets since each sample is identified prior to measurement. In addition, OCR is used to read toner ID, machine ID, print count, and other pertinent information regarding the printing conditions and environment. This data is saved to a data file along with the measurement results for complete test documentation. Measurement methods were developed to replace current methods of visual inspection and densitometry. The features that were being analyzed visually could be addressed via standard measurement algorithms. Measurement of density proved to be less simple since the scanner is not a densitometer and anything short of an excellent estimation would be meaningless. In order to address the measurement of density, a transfer curve was built to translate the

  12. Pharmaceutical applications of vibrational chemical imaging and chemometrics: a review.

    Science.gov (United States)

    Gendrin, C; Roggo, Y; Collet, C

    2008-11-04

    The emergence of chemical imaging (CI) has gifted spectroscopy an additional dimension. Chemical imaging systems complement chemical identification by acquiring spatially located spectra that enable visualization of chemical compound distributions. Such techniques are highly relevant to pharmaceutics in that the distribution of excipients and active pharmaceutical ingredient informs not only a product's behavior during manufacture but also its physical attributes (dissolution properties, stability, etc.). The rapid image acquisition made possible by the emergence of focal plane array detectors, combined with publication of the Food and Drug Administration guidelines for process analytical technology in 2001, has heightened interest in the pharmaceutical applications of CI, notably as a tool for enhancing drug quality and understanding process. Papers on the pharmaceutical applications of CI have been appearing in steadily increasing numbers since 2000. The aim of the present paper is to give an overview of infrared, near-infrared and Raman imaging in pharmaceutics. Sections 2 and 3 deal with the theory, device set-ups, mode of acquisition and processing techniques used to extract information of interest. Section 4 addresses the pharmaceutical applications.

  13. Interpretation of medical imaging data with a mobile application: a mobile digital imaging processing environment.

    Science.gov (United States)

    Lin, Meng Kuan; Nicolini, Oliver; Waxenegger, Harald; Galloway, Graham J; Ullmann, Jeremy F P; Janke, Andrew L

    2013-01-01

    Digital Imaging Processing (DIP) requires data extraction and output from a visualization tool to be consistent. Data handling and transmission between the server and a user is a systematic process in service interpretation. The use of integrated medical services for management and viewing of imaging data in combination with a mobile visualization tool can be greatly facilitated by data analysis and interpretation. This paper presents an integrated mobile application and DIP service, called M-DIP. The objective of the system is to (1) automate the direct data tiling, conversion, pre-tiling of brain images from Medical Imaging NetCDF (MINC), Neuroimaging Informatics Technology Initiative (NIFTI) to RAW formats; (2) speed up querying of imaging measurement; and (3) display high-level of images with three dimensions in real world coordinates. In addition, M-DIP provides the ability to work on a mobile or tablet device without any software installation using web-based protocols. M-DIP implements three levels of architecture with a relational middle-layer database, a stand-alone DIP server, and a mobile application logic middle level realizing user interpretation for direct querying and communication. This imaging software has the ability to display biological imaging data at multiple zoom levels and to increase its quality to meet users' expectations. Interpretation of bioimaging data is facilitated by an interface analogous to online mapping services using real world coordinate browsing. This allows mobile devices to display multiple datasets simultaneously from a remote site. M-DIP can be used as a measurement repository that can be accessed by any network environment, such as a portable mobile or tablet device. In addition, this system and combination with mobile applications are establishing a virtualization tool in the neuroinformatics field to speed interpretation services.

  14. PLÉIADES PROJECT: ASSESSMENT OF GEOREFERENCING ACCURACY, IMAGE QUALITY, PANSHARPENING PERFORMENCE AND DSM/DTM QUALITY

    Directory of Open Access Journals (Sweden)

    H. Topan

    2016-06-01

    Full Text Available Pléiades 1A and 1B are twin optical satellites of Optical and Radar Federated Earth Observation (ORFEO program jointly running by France and Italy. They are the first satellites of Europe with sub-meter resolution. Airbus DS (formerly Astrium Geo runs a MyGIC (formerly Pléiades Users Group program to validate Pléiades images worldwide for various application purposes. The authors conduct three projects, one is within this program, the second is supported by BEU Scientific Research Project Program, and the third is supported by TÜBİTAK. Assessment of georeferencing accuracy, image quality, pansharpening performance and Digital Surface Model/Digital Terrain Model (DSM/DTM quality subjects are investigated in these projects. For these purposes, triplet panchromatic (50 cm Ground Sampling Distance (GSD and VNIR (2 m GSD Pléiades 1A images were investigated over Zonguldak test site (Turkey which is urbanised, mountainous and covered by dense forest. The georeferencing accuracy was estimated with a standard deviation in X and Y (SX, SY in the range of 0.45m by bias corrected Rational Polynomial Coefficient (RPC orientation, using ~170 Ground Control Points (GCPs. 3D standard deviation of ±0.44m in X, ±0.51m in Y, and ±1.82m in Z directions have been reached in spite of the very narrow angle of convergence by bias corrected RPC orientation. The image quality was also investigated with respect to effective resolution, Signal to Noise Ratio (SNR and blur coefficient. The effective resolution was estimated with factor slightly below 1.0, meaning that the image quality corresponds to the nominal resolution of 50cm. The blur coefficients were achieved between 0.39-0.46 for triplet panchromatic images, indicating a satisfying image quality. SNR is in the range of other comparable space borne images which may be caused by de-noising of Pléiades images. The pansharpened images were generated by various methods, and are validated by most common

  15. PLÉIADES Project: Assessment of Georeferencing Accuracy, Image Quality, Pansharpening Performence and Dsm/dtm Quality

    Science.gov (United States)

    Topan, Hüseyin; Cam, Ali; Özendi, Mustafa; Oruç, Murat; Jacobsen, Karsten; Taşkanat, Talha

    2016-06-01

    Pléiades 1A and 1B are twin optical satellites of Optical and Radar Federated Earth Observation (ORFEO) program jointly running by France and Italy. They are the first satellites of Europe with sub-meter resolution. Airbus DS (formerly Astrium Geo) runs a MyGIC (formerly Pléiades Users Group) program to validate Pléiades images worldwide for various application purposes. The authors conduct three projects, one is within this program, the second is supported by BEU Scientific Research Project Program, and the third is supported by TÜBİTAK. Assessment of georeferencing accuracy, image quality, pansharpening performance and Digital Surface Model/Digital Terrain Model (DSM/DTM) quality subjects are investigated in these projects. For these purposes, triplet panchromatic (50 cm Ground Sampling Distance (GSD)) and VNIR (2 m GSD) Pléiades 1A images were investigated over Zonguldak test site (Turkey) which is urbanised, mountainous and covered by dense forest. The georeferencing accuracy was estimated with a standard deviation in X and Y (SX, SY) in the range of 0.45m by bias corrected Rational Polynomial Coefficient (RPC) orientation, using ~170 Ground Control Points (GCPs). 3D standard deviation of ±0.44m in X, ±0.51m in Y, and ±1.82m in Z directions have been reached in spite of the very narrow angle of convergence by bias corrected RPC orientation. The image quality was also investigated with respect to effective resolution, Signal to Noise Ratio (SNR) and blur coefficient. The effective resolution was estimated with factor slightly below 1.0, meaning that the image quality corresponds to the nominal resolution of 50cm. The blur coefficients were achieved between 0.39-0.46 for triplet panchromatic images, indicating a satisfying image quality. SNR is in the range of other comparable space borne images which may be caused by de-noising of Pléiades images. The pansharpened images were generated by various methods, and are validated by most common statistical

  16. CCD Astrophotography High-Quality Imaging from the Suburbs

    CERN Document Server

    Stuart, Adam

    2006-01-01

    This is a reference book for amateur astronomers who have become interested in CCD imaging. Those glorious astronomical images found in astronomy magazines might seem out of reach to newcomers to CCD imaging, but this is not the case. Great pictures are attainable with modest equipment. Adam Stuart’s many beautiful images, reproduced in this book, attest to the quality of – initially – a beginner’s efforts. Chilled-chip astronomical CCD-cameras and software are also wonderful tools for cutting through seemingly impenetrable light-pollution. CCD Astrophotography from the Suburbs describes one man’s successful approach to the problem of getting high-quality astronomical images under some of the most light-polluted conditions. Here is a complete and thoroughly tested program that will help every CCD-beginner to work towards digital imaging of the highest quality. It is equally useful to astronomers who have perfect observing conditions, as to those who have to observe from light-polluted city skies.

  17. 心电编辑对提高双源CT冠脉图像质量的初步研究%Preliminary application of ECG-editing technique in improving image quality of dual-source CT coronary angiography

    Institute of Scientific and Technical Information of China (English)

    杨立民; 刘成磊; 徐凯

    2012-01-01

    目的:探讨心电编辑在改善双源CT冠脉图像质量中的作用.方法:以冠脉分支为单位,回顾性分析60例心率变异过大或心律失常患者双源CT冠脉成像编辑前后的图像质量,总结不同类型的心电编辑方法.结果:60例心率变异过大或心律失常患者,心率范围为55~269次/min,平均心率(92.8±31.9)次/min,冠脉图像编辑前后的图像质量总评分分别为2.26±1.03、3.5±0.61(t=-17.85,P=0.001);表明编辑前后图像质量的评分有统计学意义,编辑后图像质量明显改善.结论:心电编辑技术可以明显改善心率变异过大或心律失常患者双源CT冠脉成像的图像质量.%Objective:To evaluate the effect of ECG-editing technique on dual-source CT coronary angiography. Methods: Based on per-segment analysis, image quality before and after ECG editing were retrospectively analyzed in 60 patients with heart rate variability or arrhythmia. Different types of ECG editing methods were summarized. Results:In 60 patients without stable sinus rhythm,the heart rate was (55~269) bpm/min. And mean heart rate was (92. 8±31. 9) bpm/min. The over all mean image quality scores before and after ECG editing were (2. 26±1. 03) and (3. 50±0. 61), respectively. There was statistical difference in pre-editing and post-editing reconstructed images quality, suggesting ECG editing significantly improving the image quality ( P <0. 01). Conclusion: ECG editing technique significantly improves image quality of coronary artery in patients with heart rate variability or arrhythmia.

  18. Innovative Hyperspectral Imaging-Based Techniques for Quality Evaluation of Fruits and Vegetables: A Review

    Directory of Open Access Journals (Sweden)

    Yuzhen Lu

    2017-02-01

    Full Text Available New, non-destructive sensing techniques for fast and more effective quality assessment of fruits and vegetables are needed to meet the ever-increasing consumer demand for better, more consistent and safer food products. Over the past 15 years, hyperspectral imaging has emerged as a new generation of sensing technology for non-destructive food quality and safety evaluation, because it integrates the major features of imaging and spectroscopy, thus enabling the acquisition of both spectral and spatial information from an object simultaneously. This paper first provides a brief overview of hyperspectral imaging configurations and common sensing modes used for food quality and safety evaluation. The paper is, however, focused on the three innovative hyperspectral imaging-based techniques or sensing platforms, i.e., spectral scattering, integrated reflectance and transmittance, and spatially-resolved spectroscopy, which have been developed in our laboratory for property and quality evaluation of fruits, vegetables and other food products. The basic principle and instrumentation of each technique are described, followed by the mathematical methods for processing and extracting critical information from the acquired data. Applications of these techniques for property and quality evaluation of fruits and vegetables are then presented. Finally, concluding remarks are given on future research needs to move forward these hyperspectral imaging techniques.

  19. Extended SWIR imaging sensors for hyperspectral imaging applications

    Science.gov (United States)

    Weber, A.; Benecke, M.; Wendler, J.; Sieck, A.; Hübner, D.; Figgemeier, H.; Breiter, R.

    2016-05-01

    AIM has developed SWIR modules including FPAs based on liquid phase epitaxy (LPE) grown MCT usable in a wide range of hyperspectral imaging applications. Silicon read-out integrated circuits (ROIC) provide various integration and readout modes including specific functions for spectral imaging applications. An important advantage of MCT based detectors is the tunable band gap. The spectral sensitivity of MCT detectors can be engineered to cover the extended SWIR spectral region up to 2.5μm without compromising in performance. AIM developed the technology to extend the spectral sensitivity of its SWIR modules also into the VIS. This has been successfully demonstrated for 384x288 and 1024x256 FPAs with 24μm pitch. Results are presented in this paper. The FPAs are integrated into compact dewar cooler configurations using different types of coolers, like rotary coolers, AIM's long life split linear cooler MCC030 or extreme long life SF100 Pulse Tube cooler. The SWIR modules include command and control electronics (CCE) which allow easy interfacing using a digital standard interface. The development status and performance results of AIM's latest MCT SWIR modules suitable for hyperspectral systems and applications will be presented.

  20. NEW MODEL FOR EVALUATION OF THE PERCEIVED IMAGE QUALITY BY SMARTPHONE USERS

    Directory of Open Access Journals (Sweden)

    Pinchas ZOREA

    2015-12-01

    Full Text Available Mobile devices, like smartphones and tablet computers, became an essential part in our life. Image quality assessment plays an important role in various image processing applications. A great deal of effort has been made in recent years to develop “objective” image quality metrics that correlate with perceived quality measurement. Unfortunately, only limi-ted success has been achieved. In this paper, I provide a quantitative method to evaluate perceived image quality of color images on mobile displays. Five image quality factors - Vividness, Brightness, Clarity, Sharpness and Contrast were chosen to represent perceived image quality. Image quality assessment models are constructed based on results of human visual experiments compared with image analysis by SW tool. Values of parameters of image quality assessment models are estimated based on results from human visual experiments, and a new model is proposed based on the human visual tests and computer image analysis.MODEL NOU DE EVALUARE A CALITĂŢII IMAGINII PERCEPUTE DE CĂTRE UTILIZATORII DE SMARTPHONEDispozitivele mobile (ca exemplu – smartphone şi tablete au devenit o parte esenţială din viaţa noastră. Evaluarea calităţii imaginii joacă un rol important în diverse aplicaţii de procesare a imaginii. O mare parte din efort a fost făcut în ultimii ani pentru a dezvolta metrici „obiective” de evaluare a calităţii imaginii, care corelează cu măsurarea calităţii percepute. Spre regret, doar un succes limitat a fost atins în acest domeniu. În lucrare este prezentată o metodă cantitativă de evaluare a calităţii imaginii percepute cu referire la imaginile color pe ecranele dispozitivelor mobile. Cinci factori de calitate a imaginii – Intensitate, Luminozitate, Claritate, Rezoluţie şi Contrast – au fost aleşi pentru a reprezenta calitatea imaginii percepute. Modelele de evaluare a calităţii imaginii sunt construite pe baza rezultatelor experimentelor

  1. Pitch and image quality in computed tomography; Pitch et qualite d'image en tomodensitometrie

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, B.; Le Marec, E.; Pharaboz, C. [Hopital d' Instruction des Armees Begin, 94 - Saint-Mande (France); Le Bruno, B. [Siemens SA, 92 - Saint-Denis (France)

    1999-10-01

    Pitch is a specific parameter in helical computed tomography. Once the definition of the pitch and its situation in parameters obtaining the image have been resumed, we propose to evaluate theoretic and experimental influence of the pitch on image quality. Best indications of pitch values greater than 1.0 are discussed. (author)

  2. IMPROVING THE QUALITY OF NEAR-INFRARED IMAGING OF IN VIVOBLOOD VESSELS USING IMAGE FUSION METHODS

    DEFF Research Database (Denmark)

    Jensen, Andreas Kryger; Savarimuthu, Thiusius Rajeeth; Sørensen, Anders Stengaard

    2009-01-01

    We investigate methods for improving the visual quality of in vivo images of blood vessels in the human forearm. Using a near-infrared light source and a dual CCD chip camera system capable of capturing images at visual and nearinfrared spectra, we evaluate three fusion methods in terms of their ...

  3. TU-CD-207-08: Intrinsic Image Quality Comparison of Synthesized 2-D and FFDM Images

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, J; Wells, J; Samei, E [Clinical Imaging Physics Group, Duke University Medical Center, Durham, NC (United States)

    2015-06-15

    Purpose: With the combined interest of managing patient dose, maintaining or improving image quality, and maintaining or improving the diagnostic utility of mammographic data, this study aims to compare the intrinsic image quality of Hologic’s synthesized 2-D (C-View) and 2-D FFDM images in terms of resolution, contrast, and noise. Methods: This study utilized a novel 3-D printed anthropomorphic breast phantom in addition to the American College of Radiology (ACR) mammography accreditation phantom. Analysis of the 3-D anthropomorphic phantom included visual assessment of resolution and analysis of the normalized noise power spectrum. Analysis of the ACR phantom included both visual inspection and objective automated analysis using in-house software. The software incorporates image- and object-specific CNR visibility thresholds which account for image characteristics such as noise texture which affect object visualization. T- test statistical analysis was also performed on ACR phantom scores. Results: The spatial resolution of C-View images is markedly lower (at least 50% worse) than that of FFDM. And while this is generally associated with the benefit of reduced relative noise magnitude, the noise in C-View images tends to have a more mottled (predominantly low-frequency) texture. In general, for high contrast objects, C-View provides superior visualization over FFDM; however this benefit diminishes for low contrast objects and is applicable only to objects that are sufficiently larger than the spatial resolution threshold. Based on both observer and automated ACR phantom analysis, between 50–70% of C-View images failed to meet ACR minimum accreditation requirements – primarily due to insufficient (unbroken) fiber visibility. Conclusion: Compared to FFDM, C-View offers better depiction of objects of certain size and contrast, but provides poorer overall resolution and noise properties. Based on these findings, the utilization of C-View images in the clinical

  4. A Methodology for Anatomic Ultrasound Image Diagnostic Quality Assessment.

    Science.gov (United States)

    Hemmsen, Martin Christian; Lange, Theis; Brandt, Andreas Hjelm; Nielsen, Michael Bachmann; Jensen, Jorgen Arendt

    2017-01-01

    This paper discusses the methods for the assessment of ultrasound image quality based on our experiences with evaluating new methods for anatomic imaging. It presents a methodology to ensure a fair assessment between competing imaging methods using clinically relevant evaluations. The methodology is valuable in the continuing process of method optimization and guided development of new imaging methods. It includes a three phased study plan covering from initial prototype development to clinical assessment. Recommendations to the clinical assessment protocol, software, and statistical analysis are presented. Earlier uses of the methodology has shown that it ensures validity of the assessment, as it separates the influences between developer, investigator, and assessor once a research protocol has been established. This separation reduces confounding influences on the result from the developer to properly reveal the clinical value. This paper exemplifies the methodology using recent studies of synthetic aperture sequential beamforming tissue harmonic imaging.

  5. Image quality and high contrast improvements on VLT/NACO

    CERN Document Server

    Girard, Julien H V; Mawet, Dimitri; Kasper, Markus; Zins, Gérard; Neichel, Benoît; Kolb, Johann; Christiaens, Valentin; Tourneboeuf, Martin; 10.1117/12.925660

    2012-01-01

    NACO is the famous and versatile diffraction limited NIR imager and spectrograph with which ESO celebrated 10 years of Adaptive Optics at the VLT. Since two years a substantial effort has been put in to understanding and fixing issues that directly affect the image quality and the high contrast performances of the instrument. Experiments to compensate the non-common-path aberrations and recover the highest possible Strehl ratios have been carried out successfully and a plan is hereafter described to perform such measurements regularly. The drift associated to pupil tracking since 2007 was fixed in October 2011. NACO is therefore even better suited for high contrast imaging and can be used with coronagraphic masks in the image plane. Some contrast measurements are shown and discussed. The work accomplished on NACO will serve as reference for the next generation instruments on the VLT, especially those working at the diffraction limit and making use of angular differential imaging (i.e. SPHERE, VISIR, possibly ...

  6. Multispectral Imaging of Meat Quality - Color and Texture

    DEFF Research Database (Denmark)

    Trinderup, Camilla Himmelstrup

    of meat quality parameters, especially with regards to meat color and texture. Several image modalities have been applied, all considering multi- or hyper spectral imaging. The work demonstrates the use of computer vision systems for meat color measurements. The color is assessed by suitable...... transformations to the CIELAB color space, the common color space within food science. The results show that meat color assessment with a multispectral imaging is a great alternative to the traditional colorimeter, i.e. the vision system meets some of the limitations that the colorimeter possesses. To mention one......, it is possible to assess color of very complicated structures, such as salamis, with a vision system. More importantly though, the vision system embraces the complicated scattering properties of meat. The images can also lead to other analyses, e.g. image texture analysis relating to the structure of the meat...

  7. Whole body MR imaging: applications in oncology.

    Science.gov (United States)

    Johnston, C; Brennan, S; Ford, S; Eustace, S

    2006-04-01

    This article reviews technique and clinical applications of whole body MR imaging as a diagnostic tool in cancer staging. In particular the article reviews its role as an alternative to scintigraphy (bone scan and PET) in staging skeletal spread of disease, its role in assessing total tumour burden, its role in multiple myeloma and finally its evolving non oncologic role predominantly assessing total body composition.

  8. 现代光学成像技术在食品品质快速检测中的应用%Applications of Modern Optical Imaging Technologies for Rapid Quality Inspection of Food Products

    Institute of Scientific and Technical Information of China (English)

    孙大文; 吴迪; 何鸿举; 冯耀泽

    2012-01-01

    In order to meet the consumers' demands on the quality and safety of food products, it is required to apply rapid and non-invasive inspection during production and processing of food products in the modern food industry. The quality and safety issues of food products in China have raised a high attention of the whole society in recent years. By acquiring the images of food products in different spectral ranges, modern optical imaging techniques use digital image processing algorithms to extract feature information from digital images of food products and establish quantitative relationships between features and quality attributes of the products, resulting in realizing rapid, non-invasive, efficient, and low-cost assessment of food products and providing information support to automatic sorting and grading management, and to quality inspection in modern food process operations. Food Refrigeration & Computerised Food Technology (FRCFT) in University College Dublin (UCD) led by Professor Da-Wen Sun has carried out a series of research works on applying the advanced optical imaging techniques including computer vision and hyperspectral imaging to determine food quality in a rapid and non-invasive way. Their leading research works are well recognized by their international peers. This paper reviews the research results of UCD-FRCFT on food quality inspection using computer vision and hyperspectral imaging in the past decade.%食品现代化生产、加工过程中需要对食品品质信息进行快速无损获取,以保证食品品质安全,满足消费者的需要.近年来国内频发的食品质量与安全问题也要求实现食品品质安全信息的客观准确检测.现代光学成像技术透过获取食品在不同光谱波段下的图像信息,然后采用数字图像处理算法进行特征信息提取,并通过模式识别算法建立食品品质定量关系模型,从而实现食品品质信息的快速、无损、高效、低成本检测,为食品现

  9. Microtomographic imaging of multiphase flow in porous media: Validation of image analysis algorithms, and assessment of data representativeness and quality

    Science.gov (United States)

    Wildenschild, D.; Porter, M. L.

    2009-04-01

    Significant strides have been made in recent years in imaging fluid flow in porous media using x-ray computerized microtomography (CMT) with 1-20 micron resolution; however, difficulties remain in combining representative sample sizes with optimal image resolution and data quality; and in precise quantification of the variables of interest. Tomographic imaging was for many years focused on volume rendering and the more qualitative analyses necessary for rapid assessment of the state of a patient's health. In recent years, many highly quantitative CMT-based studies of fluid flow processes in porous media have been reported; however, many of these analyses are made difficult by the complexities in processing the resulting grey-scale data into reliable applicable information such as pore network structures, phase saturations, interfacial areas, and curvatures. Yet, relatively few rigorous tests of these analysis tools have been reported so far. The work presented here was designed to evaluate the effect of image resolution and quality, as well as the validity of segmentation and surface generation algorithms as they were applied to CMT images of (1) a high-precision glass bead pack and (2) gas-fluid configurations in a number of glass capillary tubes. Interfacial areas calculated with various algorithms were compared to actual interfacial geometries and we found very good agreement between actual and measured surface and interfacial areas. (The test images used are available for download at the website listed below). http://cbee.oregonstate.edu/research/multiphase_data/index.html

  10. Quality measures for HRR alignment based ISAR imaging algorithms

    CSIR Research Space (South Africa)

    Janse van Rensburg, V

    2013-05-01

    Full Text Available Some Inverse Synthetic Aperture Radar (ISAR) algorithms form the image in a two-step process of range alignment and phase conjugation. This paper discusses a comprehensive set of measures used to quantify the quality of range alignment, with the aim...

  11. Imaging through turbid media via sparse representation: imaging quality comparison of three projection matrices

    Science.gov (United States)

    Shao, Xiaopeng; Li, Huijuan; Wu, Tengfei; Dai, Weijia; Bi, Xiangli

    2015-05-01

    The incident light will be scattered away due to the inhomogeneity of the refractive index in many materials which will greatly reduce the imaging depth and degrade the imaging quality. Many exciting methods have been presented in recent years for solving this problem and realizing imaging through a highly scattering medium, such as the wavefront modulation technique and reconstruction technique. The imaging method based on compressed sensing (CS) theory can decrease the computational complexity because it doesn't require the whole speckle pattern to realize reconstruction. One of the key premises of this method is that the object is sparse or can be sparse representation. However, choosing a proper projection matrix is very important to the imaging quality. In this paper, we analyzed that the transmission matrix (TM) of a scattering medium obeys circular Gaussian distribution, which makes it possible that a scattering medium can be used as the measurement matrix in the CS theory. In order to verify the performance of this method, a whole optical system is simulated. Various projection matrices are introduced to make the object sparse, including the fast Fourier transform (FFT) basis, the discrete cosine transform (DCT) basis and the discrete wavelet transform (DWT) basis, the imaging performances of each of which are compared comprehensively. Simulation results show that for most targets, applying the discrete wavelet transform basis will obtain an image in good quality. This work can be applied to biomedical imaging and used to develop real-time imaging through highly scattering media.

  12. Simultaneous analysis and quality assurance for diffusion tensor imaging.

    Directory of Open Access Journals (Sweden)

    Carolyn B Lauzon

    Full Text Available Diffusion tensor imaging (DTI enables non-invasive, cyto-architectural mapping of in vivo tissue microarchitecture through voxel-wise mathematical modeling of multiple magnetic resonance imaging (MRI acquisitions, each differently sensitized to water diffusion. DTI computations are fundamentally estimation processes and are sensitive to noise and artifacts. Despite widespread adoption in the neuroimaging community, maintaining consistent DTI data quality remains challenging given the propensity for patient motion, artifacts associated with fast imaging techniques, and the possibility of hardware changes/failures. Furthermore, the quantity of data acquired per voxel, the non-linear estimation process, and numerous potential use cases complicate traditional visual data inspection approaches. Currently, quality inspection of DTI data has relied on visual inspection and individual processing in DTI analysis software programs (e.g. DTIPrep, DTI-studio. However, recent advances in applied statistical methods have yielded several different metrics to assess noise level, artifact propensity, quality of tensor fit, variance of estimated measures, and bias in estimated measures. To date, these metrics have been largely studied in isolation. Herein, we select complementary metrics for integration into an automatic DTI analysis and quality assurance pipeline. The pipeline completes in 24 hours, stores statistical outputs, and produces a graphical summary quality analysis (QA report. We assess the utility of this streamlined approach for empirical quality assessment on 608 DTI datasets from pediatric neuroimaging studies. The efficiency and accuracy of quality analysis using the proposed pipeline is compared with quality analysis based on visual inspection. The unified pipeline is found to save a statistically significant amount of time (over 70% while improving the consistency of QA between a DTI expert and a pool of research associates. Projection of QA

  13. Simultaneous analysis and quality assurance for diffusion tensor imaging.

    Science.gov (United States)

    Lauzon, Carolyn B; Asman, Andrew J; Esparza, Michael L; Burns, Scott S; Fan, Qiuyun; Gao, Yurui; Anderson, Adam W; Davis, Nicole; Cutting, Laurie E; Landman, Bennett A

    2013-01-01

    Diffusion tensor imaging (DTI) enables non-invasive, cyto-architectural mapping of in vivo tissue microarchitecture through voxel-wise mathematical modeling of multiple magnetic resonance imaging (MRI) acquisitions, each differently sensitized to water diffusion. DTI computations are fundamentally estimation processes and are sensitive to noise and artifacts. Despite widespread adoption in the neuroimaging community, maintaining consistent DTI data quality remains challenging given the propensity for patient motion, artifacts associated with fast imaging techniques, and the possibility of hardware changes/failures. Furthermore, the quantity of data acquired per voxel, the non-linear estimation process, and numerous potential use cases complicate traditional visual data inspection approaches. Currently, quality inspection of DTI data has relied on visual inspection and individual processing in DTI analysis software programs (e.g. DTIPrep, DTI-studio). However, recent advances in applied statistical methods have yielded several different metrics to assess noise level, artifact propensity, quality of tensor fit, variance of estimated measures, and bias in estimated measures. To date, these metrics have been largely studied in isolation. Herein, we select complementary metrics for integration into an automatic DTI analysis and quality assurance pipeline. The pipeline completes in 24 hours, stores statistical outputs, and produces a graphical summary quality analysis (QA) report. We assess the utility of this streamlined approach for empirical quality assessment on 608 DTI datasets from pediatric neuroimaging studies. The efficiency and accuracy of quality analysis using the proposed pipeline is compared with quality analysis based on visual inspection. The unified pipeline is found to save a statistically significant amount of time (over 70%) while improving the consistency of QA between a DTI expert and a pool of research associates. Projection of QA metrics to a low

  14. New opportunities for quality enhancing of images captured by passive THz camera

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Trofimov, Vladislav V.

    2014-10-01

    As it is well-known, the passive THz camera allows seeing concealed object without contact with a person and this camera is non-dangerous for a person. Obviously, efficiency of using the passive THz camera depends on its temperature resolution. This characteristic specifies possibilities of the detection for concealed object: minimal size of the object; maximal distance of the detection; image quality. Computer processing of the THz image may lead to many times improving of the image quality without any additional engineering efforts. Therefore, developing of modern computer code for its application to THz images is urgent problem. Using appropriate new methods one may expect such temperature resolution which will allow to see banknote in pocket of a person without any real contact. Modern algorithms for computer processing of THz images allow also to see object inside the human body using a temperature trace on the human skin. This circumstance enhances essentially opportunity of passive THz camera applications for counterterrorism problems. We demonstrate opportunities, achieved at present time, for the detection both of concealed objects and of clothes components due to using of computer processing of images captured by passive THz cameras, manufactured by various companies. Another important result discussed in the paper consists in observation of both THz radiation emitted by incandescent lamp and image reflected from ceramic floorplate. We consider images produced by THz passive cameras manufactured by Microsemi Corp., and ThruVision Corp., and Capital Normal University (Beijing, China). All algorithms for computer processing of the THz images under consideration in this paper were developed by Russian part of author list. Keywords: THz wave, passive imaging camera, computer processing, security screening, concealed and forbidden objects, reflected image, hand seeing, banknote seeing, ceramic floorplate, incandescent lamp.

  15. Image Quality Enhancement Using the Direction and Thickness of Vein Lines for Finger-Vein Recognition

    Directory of Open Access Journals (Sweden)

    Young Ho Park

    2012-10-01

    Full Text Available On the basis of the increased emphasis placed on the protection of privacy, biometric recognition systems using physical or behavioural characteristics such as fingerprints, facial characteristics, iris and finger-vein patterns or the voice have been introduced in applications including door access control, personal certification, Internet banking and ATM machines. Among these, finger-vein recognition is advantageous in that it involves the use of inexpensive and small devices that are difficult to counterfeit. In general, finger-vein recognition systems capture images by using near infrared (NIR illumination in conjunction with a camera. However, such systems can face operational difficulties, since the scattering of light from the skin can make capturing a clear image difficult. To solve this problem, we proposed new image quality enhancement method that measures the direction and thickness of vein lines. This effort represents novel research in four respects. First, since vein lines are detected in input images based on eight directional profiles of a grey image instead of binarized images, the detection error owing to the non-uniform illumination of the finger area can be reduced. Second, our method adaptively determines a Gabor filter for the optimal direction and width on the basis of the estimated direction and thickness of a detected vein line. Third, by applying this optimized Gabor filter, a clear vein image can be obtained. Finally, the further processing of the morphological operation is applied in the Gabor filtered image and the resulting image is combined with the original one, through which finger-vein image of a higher quality is obtained. Experimental results from application of our proposed image enhancement method show that the equal error rate (EER of finger-vein recognition decreases to approximately 0.4% in the case of a local binary pattern-based recognition and to approximately 0.3% in the case of a wavelet transform

  16. Thermoluminescence dosimetry in quality imaging in CR mammography systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Franco E, J.G. [UAM-Xochimilco, 04960 Mexico D.F. (Mexico); Azorin N, J. [UAM-Iztapalapa, 09340 Mexico D.F. (Mexico); Diaz G, J.A.I. [CICATA, Unidad Legaria, Av. Legaria 694, 11599 mexico D.F. (Mexico); Arreola, M. [Department of Radiology, Shands Hospital at UF, PO Box 100374, Gainesville, FL 32610-0374 (United States)

    2006-07-01

    The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

  17. Thermoluminescence dosimetry in quality imaging in CR mammography systems

    Energy Technology Data Exchange (ETDEWEB)

    Gaona, E.; Franco E, J.G. [UAM-Xochimilco, 04960 Mexico D.F. (Mexico); Azorin N, J. [UAM-Iztapalapa, 09340 Mexico D.F. (Mexico); Diaz G, J.A.I. [CICATA, Unidad Legaria, Av. Legaria 694, 11599 mexico D.F. (Mexico); Arreola, M. [Department of Radiology, Shands Hospital at UF, PO Box 100374, Gainesville, FL 32610-0374 (United States)

    2006-07-01

    The aim of this work is to estimate the average glandular dose with Thermoluminescence Dosimetry (TLD) and comparison with quality imaging in CR mammography. For measuring dose, FDA and ACR use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, Full Field Digital Mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one CR mammography system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium fluoro halide. We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated x-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose that overcomes 3.0 mGy and it doesn't improve the image quality and dose to the breast will be excessive. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement. (Author)

  18. Management of Mobile Web Application Development with Quality Assurance

    OpenAIRE

    Alin Zamfiroiu; Bogdan Vintila

    2013-01-01

    Mobile applications are becoming increasingly used because of the multitude of existing mobile devices. Mobile application development becomes more complex. For mobile devices there are native applications that run directly on the device, web applications accessed via mobile browsers and hybrid applications. Mobile Application Development in any form should be made with quality assurance since when determining the target group and the application architecture. Management of mobile application...

  19. Applications of superconducting bolometers in security imaging

    Science.gov (United States)

    Luukanen, A.; Leivo, M. M.; Rautiainen, A.; Grönholm, M.; Toivanen, H.; Grönberg, L.; Helistö, P.; Mäyrä, A.; Aikio, M.; Grossman, E. N.

    2012-12-01

    Millimeter-wave (MMW) imaging systems are currently undergoing deployment World-wide for airport security screening applications. Security screening through MMW imaging is facilitated by the relatively good transmission of these wavelengths through common clothing materials. Given the long wavelength of operation (frequencies between 20 GHz to ~ 100 GHz, corresponding to wavelengths between 1.5 cm and 3 mm), existing systems are suited for close-range imaging only due to substantial diffraction effects associated with practical aperture diameters. The present and arising security challenges call for systems that are capable of imaging concealed threat items at stand-off ranges beyond 5 meters at near video frame rates, requiring substantial increase in operating frequency in order to achieve useful spatial resolution. The construction of such imaging systems operating at several hundred GHz has been hindered by the lack of submm-wave low-noise amplifiers. In this paper we summarize our efforts in developing a submm-wave video camera which utilizes cryogenic antenna-coupled microbolometers as detectors. Whilst superconducting detectors impose the use of a cryogenic system, we argue that the resulting back-end complexity increase is a favorable trade-off compared to complex and expensive room temperature submm-wave LNAs both in performance and system cost.

  20. Simultaneous Objective Measurements Of Dose And Image Quality In Mammography

    Science.gov (United States)

    Pochon, Y.; Depeursinge, Ch.; Hessler, Ch.; Raimondi, S.; Valley, J.-F.

    1982-12-01

    The performance of a radiological system can be evaluated on the one hand by an objective determination of the quality of the produced image and, on the other hand, by the dose delivered to the patient. In order to measure these two factors in a single exposure a Kodak breast phantom has been modified so as to simulate the breast absorption. The dose distribution is measured with thermoluminescent detectors. By consideration of a theoretical model of the X-ray imaging in mammography, a single quality factor is computed from the contrast, the spatial resolution and the noise measured on the phantom image. We present results obtained in various working conditions, i.e. variable X-ray tube voltages, use of different screen-film combinations, use of a grid.

  1. A NEW IMAGE QUALITY ASSESSMENT BASED ON HVS

    Institute of Scientific and Technical Information of China (English)

    Du Juan; Yu Yinglin; Xie Shengli

    2005-01-01

    This letter proposes a new kind of image quality philosophy-Modulate Quality based on Fixation Points (MQFP) based on Human Visual System (HVS) model. Dissimilar to the former HVS-based quality assessment, the new measure emphasizes particularly on modeling the jumping phenomenon of human sight instead of modeling the visual perception of human.In other words, to model the HVS using fixation points and stay-frequency instead of Contrast Sensitive Function (CSF) etc. which models the visual perception of HVS. The experiment on various frequency-distortion images indicates that the new measure is correlated with the subjective judgment more than the former HVS-based measure and is a robust measure.

  2. Mass spectrometry imaging: applications to food science.

    Science.gov (United States)

    Taira, Shu; Uematsu, Kohei; Kaneko, Daisaku; Katano, Hajime

    2014-01-01

    Two-dimensional mass spectrometry (MS) analysis of biological samples by means of what is called MS imaging (MSI) is now being used to analyze analyte distribution because it facilitates determination of the existence (what is it?) and localization (where is it?) of biomolecules. Reconstruction of mass image by target signal is given after two-dimensional MS measurements on a sample section. From only one section, we can understand the existence and localization of many molecules without the need of an antibody or fluorescent reagent. In this review, we introduce the analysis of localization of functional constituents and nutrients in herbal medicine products via MSI. The ginsenosides were mainly distributed in the periderm and the tip region of the root of Panax ginseng. The capsaicin was found to be more dominantly localized in the placenta than the pericarp and seed in Capsicum fruits. We expect MSI will be a useful technique for optical quality assurance.

  3. Application of UV Imaging in Formulation Development

    DEFF Research Database (Denmark)

    Sun, Yu; Østergaard, Jesper

    2017-01-01

    defining formulation behavior after exposure to the aqueous environments and pharmaceutical performance is critical in pharmaceutical development, manufacturing and quality control of drugs. UV imaging has been explored as a tool for qualitative and quantitative characterization of drug dissolution...... and release with the characteristic feature of providing real-time visualization of the solution phase drug transport in the vicinity of the formulation. Events occurring during drug dissolution and release, such as polymer swelling, drug precipitation/recrystallization, or solvent-mediated phase transitions...

  4. Face Image Quality and its Improvement in a Face Detection System

    DEFF Research Database (Denmark)

    Kamal, Nasrollahi; Moeslund, Thomas B.

    2008-01-01

    When a person passes by a surveillance camera a sequence of images is obtained. Most of these images are redundant and usually keeping some of them which have better quality is sufficient. So before performing any analysis on the face of a person, the face at the first step needs to be detected....... In the second step the quality of the different face images needs to be evaluated. Finally, after choosing the best image(s) based on this quality assessment, in the third step, if this image(s) is not satisfying a predefined set of measures for good quality images, its quality should be improved. In this work...

  5. Image quality specification and maintenance for airborne SAR

    Science.gov (United States)

    Clinard, Mark S.

    2004-08-01

    Specification, verification, and maintenance of image quality over the lifecycle of an operational airborne SAR begin with the specification for the system itself. Verification of image quality-oriented specification compliance can be enhanced by including a specification requirement that a vendor provide appropriate imagery at the various phases of the system life cycle. The nature and content of the imagery appropriate for each stage of the process depends on the nature of the test, the economics of collection, and the availability of techniques to extract the desired information from the data. At the earliest lifecycle stages, Concept and Technology Development (CTD) and System Development and Demonstration (SDD), the test set could include simulated imagery to demonstrate the mathematical and engineering concepts being implemented thus allowing demonstration of compliance, in part, through simulation. For Initial Operational Test and Evaluation (IOT&E), imagery collected from precisely instrumented test ranges and targets of opportunity consisting of a priori or a posteriori ground-truthed cultural and natural features are of value to the analysis of product quality compliance. Regular monitoring of image quality is possible using operational imagery and automated metrics; more precise measurements can be performed with imagery of instrumented scenes, when available. A survey of image quality measurement techniques is presented along with a discussion of the challenges of managing an airborne SAR program with the scarce resources of time, money, and ground-truthed data. Recommendations are provided that should allow an improvement in the product quality specification and maintenance process with a minimal increase in resource demands on the customer, the vendor, the operational personnel, and the asset itself.

  6. Image Segmentation for Food Quality Evaluation Using Computer Vision System

    Directory of Open Access Journals (Sweden)

    Nandhini. P

    2014-02-01

    Full Text Available Quality evaluation is an important factor in food processing industries using the computer vision system where human inspection systems provide high variability. In many countries food processing industries aims at producing defect free food materials to the consumers. Human evaluation techniques suffer from high labour costs, inconsistency and variability. Thus this paper provides various steps for identifying defects in the food material using the computer vision systems. Various steps in computer vision system are image acquisition, Preprocessing, image segmentation, feature identification and classification. The proposed framework provides the comparison of various filters where the hybrid median filter was selected as the filter with the high PSNR value and is used in preprocessing. Image segmentation techniques such as Colour based binary Image segmentation, Particle swarm optimization are compared and image segmentation parameters such as accuracy, sensitivity , specificity are calculated and found that colour based binary image segmentation is well suited for food quality evaluation. Finally this paper provides an efficient method for identifying the defected parts in food materials.

  7. Investigation of grid performance using simple image quality tests

    Directory of Open Access Journals (Sweden)

    Dogan Bor

    2016-01-01

    Full Text Available Antiscatter grids improve the X-ray image contrast at a cost of patient radiation doses. The choice of appropriate grid or its removal requires a good knowledge of grid characteristics, especially for pediatric digital imaging. The aim of this work is to understand the relation between grid performance parameters and some numerical image quality metrics for digital radiological examinations. The grid parameters such as bucky factor (BF, selectivity (Σ, Contrast improvement factor (CIF, and signal-to-noise improvement factor (SIF were determined following the measurements of primary, scatter, and total radiations with a digital fluoroscopic system for the thicknesses of 5, 10, 15, 20, and 25 cm polymethyl methacrylate blocks at the tube voltages of 70, 90, and 120 kVp. Image contrast for low- and high-contrast objects and high-contrast spatial resolution were measured with simple phantoms using the same scatter thicknesses and tube voltages. BF and SIF values were also calculated from the images obtained with and without grids. The correlation coefficients between BF values obtained using two approaches (grid parameters and image quality metrics were in good agreement. Proposed approach provides a quick and practical way of estimating grid performance for different digital fluoroscopic examinations.

  8. Correlation of bone quality in radiographic images with clinical bone quality classification

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Woo; Huh, Kyung Hoe; Kim, Jeong Hwa; Yi, Won Jin; Heo, Min Suk; Lee, Sam Sun; Choi, Soon Chul [Seoul National University, Seoul (Korea, Republic of); Park, Kwan Soo [Inje University, Seoul (Korea, Republic of)

    2006-03-15

    To investigate the validity of digital image processing on panoramic radiographs in estimating bone quality before endosseous dental implant installation by correlating bone quality in radiographic images with clinical bone quality classification. An experienced surgeon assessed and classified bone quality for implant sites with tactile sensation at the time of implant placement. Including fractal dimension eighteen morphologic features of trabecular pattern were examined in each anatomical sites on panoramic radiographs. Finally bone quality of 67 implant sites were evaluated in 42 patients. Pearson correlation analysis showed that three morphologic parameters had weak linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.276, -0.280, and -0.289, respectively (p<0.05). And other three morphologic parameters had obvious linear negative correlation with clinical bone quality classification showing correlation coefficients of -0.346, -0.488, and -0.343 respectively (p<0.05). Fractal dimension also had a linear correlating with clinical bone quality classification with correlation coefficients -0.506 significantly (P<0.05). This study suggests that fractal and morphometric analysis using digital panoramic radiographs can be used to evaluate bone quality for implant recipient sites.

  9. Full-Reference Image Quality Assessment with Linear Combination of Genetically Selected Quality Measures.

    Directory of Open Access Journals (Sweden)

    Mariusz Oszust

    Full Text Available Information carried by an image can be distorted due to different image processing steps introduced by different electronic means of storage and communication. Therefore, development of algorithms which can automatically assess a quality of the image in a way that is consistent with human evaluation is important. In this paper, an approach to image quality assessment (IQA is proposed in which the quality of a given image is evaluated jointly by several IQA approaches. At first, in order to obtain such joint models, an optimisation problem of IQA measures aggregation is defined, where a weighted sum of their outputs, i.e., objective scores, is used as the aggregation operator. Then, the weight of each measure is considered as a decision variable in a problem of minimisation of root mean square error between obtained objective scores and subjective scores. Subjective scores reflect ground-truth and involve evaluation of images by human observers. The optimisation problem is solved using a genetic algorithm, which also selects suitable measures used in aggregation. Obtained multimeasures are evaluated on four largest widely used image benchmarks and compared against state-of-the-art full-reference IQA approaches. Results of comparison reveal that the proposed approach outperforms other competing measures.

  10. Optimization of Segmentation Quality of Integrated Circuit Images

    Directory of Open Access Journals (Sweden)

    Gintautas Mušketas

    2012-04-01

    Full Text Available The paper presents investigation into the application of genetic algorithms for the segmentation of the active regions of integrated circuit images. This article is dedicated to a theoretical examination of the applied methods (morphological dilation, erosion, hit-and-miss, threshold and describes genetic algorithms, image segmentation as optimization problem. The genetic optimization of the predefined filter sequence parameters is carried out. Improvement to segmentation accuracy using a non optimized filter sequence makes 6%.Artcile in Lithuanian

  11. Online hyperspectral imaging system for evaluating quality of agricultural products

    Science.gov (United States)

    Mo, Changyeun; Kim, Giyoung; Lim, Jongguk

    2017-06-01

    The consumption of fresh-cut agricultural produce in Korea has been growing. The browning of fresh-cut vegetables that occurs during storage and foreign substances such as worms and slugs are some of the main causes of consumers' concerns with respect to safety and hygiene. The purpose of this study is to develop an on-line system for evaluating quality of agricultural products using hyperspectral imaging technology. The online evaluation system with single visible-near infrared hyperspectral camera in the range of 400 nm to 1000 nm that can assess quality of both surfaces of agricultural products such as fresh-cut lettuce was designed. Algorithms to detect browning surface were developed for this system. The optimal wavebands for discriminating between browning and sound lettuce as well as between browning lettuce and the conveyor belt were investigated using the correlation analysis and the one-way analysis of variance method. The imaging algorithms to discriminate the browning lettuces were developed using the optimal wavebands. The ratio image (RI) algorithm of the 533 nm and 697 nm images (RI533/697) for abaxial surface lettuce and the ratio image algorithm (RI533/697) and subtraction image (SI) algorithm (SI538-697) for adaxial surface lettuce had the highest classification accuracies. The classification accuracy of browning and sound lettuce was 100.0% and above 96.0%, respectively, for the both surfaces. The overall results show that the online hyperspectral imaging system could potentially be used to assess quality of agricultural products.

  12. High-quality digital imaging of art in Europe

    Science.gov (United States)

    Martinez, Kirk

    1996-02-01

    In the past decade various museums and galleries around Europe have been developing digital imaging as a tool for archiving and analysis. Accurate digital images can replace the conventional film archives which are not stable or accurate but are the standard record of art. The digital archives open up new research possibilities as well as become resources for CD- ROM production, damage analysis, research and publishing. In the VASARI project new scanners were devised to produce colorimetric images directly from paintings using multispectral (six band) imaging. These can produce images in CIE Lab format with resolutions over 10 k multiplied by 10 k and have been installed in London, England; Munich, Germany; and Florence, Italy. They are based around a large stepper-motor controlled scanner moving a high resolution CCD camera to obtain patches of 3 k multiplied by 2 k pels which are mosaiced together. The scanners can also be used for infra-red imaging with a different camera. The MARC project produced a portable scan-back, RGB camera capable of similar output and techniques for calibrated printing. The Narcisse project produced a fast high resolution scanner for X-radiographs and film and many projects have worked on networking the growing number of image databases. This paper presents a survey of some key European projects, particularly those funded by the European Union, involved in high resolution and colorimetric imaging of art. The design of the new scanners and examples of the applications of these images are presented.

  13. An adaptive toolkit for image quality evaluation in system performance test of digital breast tomosynthesis

    Science.gov (United States)

    Zhang, Guozhi; Petrov, Dimitar; Marshall, Nicholas; Bosmans, Hilde

    2017-03-01

    Digital breast tomosynthesis (DBT) is a relatively new diagnostic imaging modality for women. Currently, various models of DBT systems are available on the market and the number of installations is rapidly increasing. EUREF, the European Reference Organization for Quality Assured Breast Screening and Diagnostic Services, has proposed a preliminary Guideline - protocol for the quality control of the physical and technical aspects of digital breast tomosynthesis systems, with an ultimate aim of providing limiting values guaranteeing proper performance for different applications of DBT. In this work, we introduce an adaptive toolkit developed in accordance with this guideline to facilitate the process of image quality evaluation in DBT performance test. This toolkit implements robust algorithms to quantify various technical parameters of DBT images and provides a convenient user interface in practice. Each test is built into a separate module with configurations set corresponding to the European guideline, which can be easily adapted to different settings and extended with additional tests. This toolkit largely improves the efficiency for image quality evaluation of DBT. It is also going to evolve with the development of protocols in quality control of DBT systems.

  14. Development of an image processing system in splendid squid quality classification

    Science.gov (United States)

    Masunee, Niyada; Chaiprapat, Supapan; Waiyagan, Kriangkrai

    2013-07-01

    Agricultural products typically exhibit high variance in quality characteristics. To assure customer satisfaction and control manufacturing productivity, quality classification is necessary to screen off defective items and to grade the products. This article presents an application of image processing techniques on squid grading and defect discrimination. A preliminary study indicated that surface color was an efficient determinant to justify quality of splendid squids. In this study, a computer vision system (CVS) was developed to examine the characteristics of splendid squids. Using image processing techniques, squids could be classified into three different quality grades as in accordance with an industry standard. The developed system first sifted through squid images to reject ones with black marks. Qualified squids were graded on a proportion of white, pink, and red regions appearing on their bodies by using fuzzy logic. The system was evaluated on 100 images of squids at different quality levels. It was found that accuracy obtained by the proposed technique was 95% compared with sensory evaluation of an expert.

  15. Achieving Quality in Cardiovascular Imaging II: proceedings from the Second American College of Cardiology -- Duke University Medical Center Think Tank on Quality in Cardiovascular Imaging.

    Science.gov (United States)

    Douglas, Pamela S; Chen, Jersey; Gillam, Linda; Hendel, Robert; Hundley, W Gregory; Masoudi, Frederick; Patel, Manesh R; Peterson, Eric

    2009-02-01

    Despite rapid technologic advances and sustained growth, less attention has been focused on quality in imaging than in other areas of cardiovascular medicine. To address this deficit, representatives from cardiovascular imaging societies, private payers, government agencies, the medical imaging industry, and experts in quality measurement met in the second Quality in Cardiovascular Imaging Think Tank. The participants endorsed the previous consensus definition of quality in imaging and proposed quality measures. Additional areas of needed effort included data standardization and structured reporting, appropriateness criteria, imaging registries, laboratory accreditation, partnership development, and imaging research. The second American College of Cardiology-Duke University Think Tank continued the process of the development, dissemination, and adoption of quality improvement initiatives for all cardiovascular imaging modalities.

  16. A Medical Image Watermarking Technique for Embedding EPR and Its Quality Assessment Using No-Reference Metrics

    Directory of Open Access Journals (Sweden)

    Rupinder Kaur

    2013-01-01

    Full Text Available Digital watermarking can be used as an important tool for the security and copyright protection of digital multimedia content. The present paper explores its applications as a quality indicator of a watermarked medical image when subjected to intentional (noise, cropping, alteration or unintentional (compression, transmission or filtering operations. The watermark also carries EPR data along with a binary mark (used for quality assessment. The binary mark is used as a No-Reference (NR quality metrics that blindly estimates the quality of an image without the need of original image. It is a semi-fragile watermark which degrades at around the same rate as the original image and thus gives an indication of the quality degradation of the host image at the receiving end. In the proposed method, the original image is divided into two parts- ROI and non-ROI. ROI is an area that contains diagnostically important information and must be processed without any distortion. The binary mark and EPR are embedded into the DCT domain of Non-ROI. Embedding EPR within a medical image reduces storage and transmission overheads and no additional file has to be sent along with an image. The watermark (binary mark and EPR is extracted from non-ROI part at the receiving end and a measure of degradation of binary mark is used to estimate the quality of the original image. The performance of the proposed method is evaluated by calculating MSE and PSNR of original and extracted mark.

  17. Monitoring the Water Quality of Lake Koronia Using Long Time-Series of Multispectral Satellite Images

    Science.gov (United States)

    Perivolioti, Triantafyllia-Maria; Mouratidis, Antonios; Doxani, Georgia; Bobori, Dimitra

    2016-08-01

    In this study, a comprehensive 30-year (1984-2016) water quality parameter database for lake Koronia - one of the most important Ramsar wetlands of Greece - was compiled from Landsat imagery. The reliability of the data was evaluated by comparing water Quality Element (QE) values computed from Landsat data against in-situ data. Water quality algorithms developed from previous studies, specifically for the determination of Water Temperature, pH, Transparency/Secchi Disk Depth (SDD), Chlorophyll a and Conductivity, were applied to Landsat images. In addition, Water Depth, as well as the distribution of floating vegetation and cyanobacterial blooms were mapped. The performed comprehensive analysis posed certain questions, regarding the applicability of single empirical models across multi- temporal, multi-sensor datasets, towards the accurate prediction of key water quality indicators for shallow inland systems. This assessment demonstrates that satellite imagery can provide an accurate method for obtaining comprehensive spatial and temporal coverage of key water quality characteristics.

  18. Development of profession and quality in radiography with focus on evaluation criteria and image quality of chest x-rays

    DEFF Research Database (Denmark)

    Debess, Jeanne; Thomsen, Henrik; Conradsen, Jacob

    2011-01-01

    Learning Objectives: Learning Objectives: To improve quality of chest xrays by Education Conferences for radiographers and evaluation of image quality. Background: Introduction of digital imaging technology and picture archiving and communication system (PACS) has changed the workflow in the x......-ray department including evaluation of image quality and feedback from radiologist to radiographer. Imaging Findings or Procedure Details: Procedure Details: Data for evaluation of image quality was collected by questionnaires aimed at: anatomy, image-focusing, image-collimation, exposure and body habitus...... collection were found. Evaluation results from anatomy, image-focusing, image-collimation and exposure from first data collection shows variations from 7 % to 37 % between evaluation at primary monitor by the radiographers and diagnostic monitor by the radiologist. In relation to anatomy, the quality...

  19. COATLI: an all-sky robotic optical imager with 0.3 arcsec image quality

    CERN Document Server

    Watson, Alan M; Núñez, Luis C Álvarez; Ángeles, Fernando; Becerra-Godínez, Rosa L; Chapa, Oscar; Farah, Alejandro S; Fuentes-Fernández, Jorge; Figueroa, Liliana; Lebre, Rosalía Langarica; Quirós, Fernando; Román-Zúñiga, Carlos G; Ruíz-Diáz-Soto, Jaime; Tejada, Carlos G; Tinoco, Silvio J

    2016-01-01

    COATLI will provide 0.3 arcsec FWHM images from 550 to 900 nm over a large fraction of the sky. It consists of a robotic 50-cm telescope with a diffraction-limited fast-guiding imager. Since the telescope is small, fast guiding will provide diffraction-limited image quality over a field of at least 1 arcmin and with coverage of a large fraction of the sky, even in relatively poor seeing. The COATLI telescope will be installed at the at the Observatorio Astron\\'omico Nacional in Sierra San Pedro M\\'artir, M\\'exico, during 2016 and the diffraction-limited imager will follow in 2017.

  20. Image Understanding Applications of Lattice Autoassociative Memories.

    Science.gov (United States)

    Grana, Manuel; Chyzhyk, Darya

    2016-09-01

    Multivariate mathematical morphology (MMM) aims to extend the mathematical morphology from gray scale images to images whose pixels are high-dimensional vectors, such as remote sensing hyperspectral images and functional magnetic resonance images (fMRIs). Defining an ordering over the multidimensional image data space is a fundamental issue MMM, to ensure that ensuing morphological operators and filters are mathematically consistent. Recent approaches use the outputs of two-class classifiers to build such reduced orderings. This paper presents the applications of MMM built on reduced supervised orderings based on lattice autoassociative memories (LAAMs) recall error measured by the Chebyshev distance. Foreground supervised orderings use one set of training data from a foreground class, whereas background/foreground supervised orderings use two training data sets, one for each relevant class. The first case study refers to the realization of the thematic segmentation of the hyperspectral images using spatial-spectral information. Spectral classification is enhanced by a spatial processing consisting in the spatial correction guided by a watershed segmentation computed by the LAAM-based morphological operators. The approach improves the state-of-the-art hyperspectral spatial-spectral thematic map building approaches. The second case study is the analysis of resting state fMRI data, working on a data set of healthy controls, schizophrenia patients with and without auditory hallucinations. We perform two experiments: 1) the localization of differences in brain functional networks on population-dependent templates and 2) the classification of subjects into each possible pair of cases. In this data set, we find that the LAAM-based morphological features improve over the conventional correlation-based graph measure features often employed in fMRI data classification.

  1. A New Approach for Enhancing the Quality of Medical Computerized Tomography Images

    Directory of Open Access Journals (Sweden)

    Mutaz Al-Frejat

    2016-05-01

    Full Text Available Computerized tomography (CT images contribute immensely to medical research and diagnosis. However, due to degradative factors such as noise, low contrast, and blurring, CT images tend to be a degraded representation of the actual body or part under investigation. To reduce the risk of imprecise diagnosis associated with poor-quality CT images, this paper presents a new technique designed to enhance the quality of medical CT images. The main objective is to improve the appearance of CT images in order to obtain better visual interpretation and analysis, which is expected to ease the diagnosis process. The proposed technique involves applying a median filter to remove noise from the CT images and then using a Laplacian filter to enhance the edges and the contrast in the images. Also, as CT images suffer from low contrast, a Contrast Limited Adaptive Histogram Equalization transform is also applied to solve this problem. The main strength of this transform is its modest computational requirements, ease of application, and excellent results for most images. According to a subjective assessment by a group of radiologists, the proposed technique resulted in excellent enhancement, including that of the contrast and the edges of medical CT images. From a medical perspective, the proposed technique was able to clarify the arteries, tissues, and lung nodules in the CT images. In addition, blurred nodules in chest CT images were enhanced effectively. Therefore the proposed technique can help radiologists to better detect lung nodules and can also assist in diagnosing the presence of tumours and in the detection of abnormal growths.

  2. Metal artifact reduction and image quality evaluation of lumbar spine CT images using metal sinogram segmentation.

    Science.gov (United States)

    Kaewlek, Titipong; Koolpiruck, Diew; Thongvigitmanee, Saowapak; Mongkolsuk, Manus; Thammakittiphan, Sastrawut; Tritrakarn, Siri-on; Chiewvit, Pipat

    2015-01-01

    Metal artifacts often appear in the images of computed tomography (CT) imaging. In the case of lumbar spine CT images, artifacts disturb the images of critical organs. These artifacts can affect the diagnosis, treatment, and follow up care of the patient. One approach to metal artifact reduction is the sinogram completion method. A mixed-variable thresholding (MixVT) technique to identify the suitable metal sinogram is proposed. This technique consists of four steps: 1) identify the metal objects in the image by using k-mean clustering with the soft cluster assignment, 2) transform the image by separating it into two sinograms, one of which is the sinogram of the metal object, with the surrounding tissue shown in the second sinogram. The boundary of the metal sinogram is then found by the MixVT technique, 3) estimate the new value of the missing data in the metal sinogram by linear interpolation from the surrounding tissue sinogram, 4) reconstruct a modified sinogram by using filtered back-projection and complete the image by adding back the image of the metal object into the reconstructed image to form the complete image. The quantitative and clinical image quality evaluation of our proposed technique demonstrated a significant improvement in image clarity and detail, which enhances the effectiveness of diagnosis and treatment.

  3. Applications of scientific imaging in environmental toxicology

    Science.gov (United States)

    El-Demerdash, Aref M.

    The national goals of clean air, clean water, and healthy ecosystems are a few of the primary forces that drive the need for better environmental monitoring. As we approach the end of the 1990s, the environmental questions at regional to global scales are being redefined and refined in the light of developments in environmental understanding and technological capability. Research in the use of scientific imaging data for the study of the environment is urgently needed in order to explore the possibilities of utilizing emerging new technologies. The objective of this research proposal is to demonstrate the usability of a wealth of new technology made available in the last decade to providing a better understanding of environmental problems. Research is focused in two imaging techniques macro and micro imaging. Several examples of applications of scientific imaging in research in the field of environmental toxicology were presented. This was achieved on two scales, micro and macro imaging. On the micro level four specific examples were covered. First, the effect of utilizing scanning electron microscopy as an imaging tool in enhancing taxa identification when studying diatoms was presented. Second, scanning electron microscopy combined with energy dispersive x-ray analyzer were demonstrated as a valuable and effective tool for identifying and analyzing household dust samples. Third, electronic autoradiography combined with FT-IR microscopy were used to study the distribution pattern of [14C]-Malathion in rats as a result of dermal exposure. The results of the autoradiography made on skin sections of the application site revealed the presence of [ 14C]-activity in the first region of the skin. These results were evidenced by FT-IR microscopy. The obtained results suggest that the penetration of Malathion into the skin and other tissues is vehicle and dose dependent. The results also suggest the use of FT-IR microscopy imaging for monitoring the disposition of

  4. TL dosimetry for quality control of CR mammography imaging systems

    Science.gov (United States)

    Gaona, E.; Nieto, J. A.; Góngora, J. A. I. D.; Arreola, M.; Enríquez, J. G. F.

    The aim of this work is to estimate the average glandular dose with thermoluminescent (TL) dosimetry and comparison with quality imaging in computed radiography (CR) mammography. For a measuring dose, the Food and Drug Administration (FDA) and the American College of Radiology (ACR) use a phantom, so that dose and image quality are assessed with the same test object. The mammography is a radiological image to visualize early biological manifestations of breast cancer. Digital systems have two types of image-capturing devices, full field digital mammography (FFDM) and CR mammography. In Mexico, there are several CR mammography systems in clinical use, but only one system has been approved for use by the FDA. Mammography CR uses a photostimulable phosphor detector (PSP) system. Most CR plates are made of 85% BaFBr and 15% BaFI doped with europium (Eu) commonly called barium flourohalideE We carry out an exploratory survey of six CR mammography units from three different manufacturers and six dedicated X-ray mammography units with fully automatic exposure. The results show three CR mammography units (50%) have a dose greater than 3.0 mGy without demonstrating improved image quality. The differences between doses averages from TLD system and dosimeter with ionization chamber are less than 10%. TLD system is a good option for average glandular dose measurement for X-rays with a HVL (0.35-0.38 mmAl) and kVp (24-26) used in quality control procedures with ACR Mammography Accreditation Phantom.

  5. Diffusion weighted magnetic resonance imaging of the breast: protocol optimization, interpretation, and clinical applications.

    Science.gov (United States)

    Partridge, Savannah C; McDonald, Elizabeth S

    2013-08-01

    Diffusion-weighted magnetic resonance (MR) imaging (DWI) has shown promise for improving the positive predictive value of breast MR imaging for detection of breast cancer, evaluating tumor response to neoadjuvant chemotherapy, and as a noncontrast alternative to MR imaging in screening for breast cancer. However, data quality varies widely. Before implementing DWI into clinical practice, one must understand the pertinent technical considerations and current evidence regarding clinical applications of breast DWI. This article provides an overview of basic principles of DWI, optimization of breast DWI protocols, imaging features of benign and malignant breast lesions, promising clinical applications, and potential future directions.

  6. Characterization of image quality and image-guidance performance of a preclinical microirradiator

    Energy Technology Data Exchange (ETDEWEB)

    Clarkson, R.; Lindsay, P. E.; Ansell, S.; Wilson, G.; Jelveh, S.; Hill, R. P.; Jaffray, D. A. [Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 1A1 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5 2M9 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada) and Ontario Cancer Institute, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Ontario Cancer Institute, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A1 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 1A1 (Canada); Radiation Medicine Program, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Ontario Cancer Institute, Princess Margaret Hospital, 610 University Avenue, Toronto, Ontario M5G 2M9 (Canada); Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A1 (Canada) and Department of Radiation Oncology, University of Toronto, Toronto, Ontario M5S 1A1 (Canada)

    2011-02-15

    Purpose: To assess image quality and image-guidance capabilities of a cone-beam CT based small-animal image-guided irradiation unit (micro-IGRT). Methods: A micro-IGRT system has been developed in collaboration with the authors' laboratory as a means to study the radiobiological effects of conformal radiation dose distributions in small animals. The system, the X-Rad 225Cx, consists of a 225 kVp x-ray tube and a flat-panel amorphous silicon detector mounted on a rotational C-arm gantry and is capable of both fluoroscopic x-ray and cone-beam CT imaging, as well as image-guided placement of the radiation beams. Image quality (voxel noise, modulation transfer, CT number accuracy, and geometric accuracy characteristics) was assessed using water cylinder and micro-CT test phantoms. Image guidance was tested by analyzing the dose delivered to radiochromic films fixed to BB's through the end-to-end process of imaging, targeting the center of the BB, and irradiation of the film/BB in order to compare the offset between the center of the field and the center of the BB. Image quality and geometric studies were repeated over a 5-7 month period to assess stability. Results: CT numbers reported were found to be linear (R{sup 2}{>=}0.998) and the noise for images of homogeneous water phantom was 30 HU at imaging doses of approximately 1 cGy (to water). The presampled MTF at 50% and 10% reached 0.64 and 1.35 mm{sup -1}, respectively. Targeting accuracy by means of film irradiations was shown to have a mean displacement error of [{Delta}x,{Delta}y,{Delta}z]=[-0.12,-0.05,-0.02] mm, with standard deviations of [0.02, 0.20, 0.17] mm. The system has proven to be stable over time, with both the image quality and image-guidance performance being reproducible for the duration of the studies. Conclusions: The micro-IGRT unit provides soft-tissue imaging of small-animal anatomy at acceptable imaging doses ({<=}1 cGy). The geometric accuracy and targeting systems permit dose

  7. METHOD OF IMAGE QUALITY ENHANCEMENT FOR SPACE OBJECTS

    Directory of Open Access Journals (Sweden)

    D. S. Korshunov

    2014-07-01

    Full Text Available The paper deals with an approach for image quality improvement of the space objects in the visible range of electromagnetic wave spectrum. The proposed method is based on the joint taking into account of both the motion velocity of the space supervisory apparatus and a space object observed in the near-earth space when the time of photo-detector exposure is chosen. The timing of exposure is carried out by light-signal characteristics, which determines the optimal value of the charge package formed in the charge-coupled device being irradiated. Thus, the parameters of onboard observation equipment can be selected, which provides space images suitable for interpretation. The linear resolving capacity is used as quality indicator for space images, giving a complete picture for the image contrast and geometric properties of the object on the photo. Observation scenario modeling of the space object, done by sputnik-inspector, has shown the possibility of increasing the linear resolution up to10% - 20% or up to 40% - 50% depending on the non-complanarity angle at the movement along orbits. The proposed approach to the increase of photographs quality provides getting sharp and highcontrast images of space objects by the optical-electronic equipment of the space-based remote sensing. The usage of these images makes it possible to detect in time the space technology failures, which are the result of its exploitation in the nearearth space. The proposed method can be also applied at the stage of space systems design for optical-electronic surveillance in computer models used for facilities assessment of the shooting equipment information tract.

  8. Eye Model for Inspecting the Image Quality of IOLs

    Institute of Scientific and Technical Information of China (English)

    Zhenping Huang; Renfeng Xu; Chunyan Xue; Yong Wu; Huachun Wang; Degao Zhao

    2007-01-01

    Purpose: To inspect and compare the image quality of an aspheric intraocular lens (IQ, Alcon) with those of conventional monofocal silicone and acrylic intraocular lens and multifocal intraocular lens (Array).Methods: The IOLs were tested in the eye model, which was designed to be optically equivalent to the theoretical eye model. The eye model is a combination of a spherical photographic lens with 35 mm focal length (IOL put in a water cell) and a charge coupled device (CCD) camera. The images constructed by the lenses are observed on a monitor of personal computer and the contrasts of the images are analyzed by using commercial image processing software. SHARP value is used to measure and estimate image definition.Results: The images constructed by changing the diameter of aperture stop and IOL. Observed by this eye model, the image definition of aspheric intraocular lens (IQ, Alcon) is better than others.Discussion: The proposed eye model is useful for testing functional vision and for inspecting the differences of intraocular lens.

  9. Clinical applications of cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Marcu, C.B.; Beek, A.M.; Van Rossum, A.C. [Hospital of Saint Raphael, Cardiac Diagnostic Unit, New Haven, CT (United States)], E-mail: bogmarcu@pol.net

    2006-10-15

    Cardiovascular magnetic resonance imaging (MRI) has evolved from an effective research tool into a clinically proven, safe and comprehensive imaging modality. It provides anatomic and functional information in acquired and congenital heart disease and is the most precise technique for quantification of ventricular volumes, function and mass. Owing to its excellent interstudy reproducibility, cardiovascular MRI is the optimal method for assessment of changes in ventricular parameters after therapeutic intervention. Delayed contrast enhancement is an accurate and robust method used in the diagnosis of ischemic and nonischemic cardiomyopathies and less common diseases, such as cardiac sarcoidosis and myocarditis. First-pass magnetic contrast myocardial perfusion is becoming an alternative to radionuclide techniques for the detection of coronary atherosclerotic disease. In this review we outline the techniques used in cardiovascular MRI and discuss the most common clinical applications. (author)

  10. Quality assessment of butter cookies applying multispectral imaging

    Science.gov (United States)

    Andresen, Mette S; Dissing, Bjørn S; Løje, Hanne

    2013-01-01

    A method for characterization of butter cookie quality by assessing the surface browning and water content using multispectral images is presented. Based on evaluations of the browning of butter cookies, cookies were manually divided into groups. From this categorization, reference values were calculated for a statistical prediction model correlating multispectral images with a browning score. The browning score is calculated as a function of oven temperature and baking time. It is presented as a quadratic response surface. The investigated process window was the intervals 4–16 min and 160–200°C in a forced convection electrically heated oven. In addition to the browning score, a model for predicting the average water content based on the same images is presented. This shows how multispectral images of butter cookies may be used for the assessment of different quality parameters. Statistical analysis showed that the most significant wavelengths for browning predictions were in the interval 400–700 nm and the wavelengths significant for water prediction were primarily located in the near-infrared spectrum. The water prediction model was found to correctly estimate the average water content with an absolute error of 0.22%. From the images it was also possible to follow the browning and drying propagation from the cookie edge toward the center. PMID:24804036

  11. Spread spectrum image watermarking based on perceptual quality metric.

    Science.gov (United States)

    Zhang, Fan; Liu, Wenyu; Lin, Weisi; Ngan, King Ngi

    2011-11-01

    Efficient image watermarking calls for full exploitation of the perceptual distortion constraint. Second-order statistics of visual stimuli are regarded as critical features for perception. This paper proposes a second-order statistics (SOS)-based image quality metric, which considers the texture masking effect and the contrast sensitivity in Karhunen-Loève transform domain. Compared with the state-of-the-art metrics, the quality prediction by SOS better correlates with several subjectively rated image databases, in which the images are impaired by the typical coding and watermarking artifacts. With the explicit metric definition, spread spectrum watermarking is posed as an optimization problem: we search for a watermark to minimize the distortion of the watermarked image and to maximize the correlation between the watermark pattern and the spread spectrum carrier. The simple metric guarantees the optimal watermark a closed-form solution and a fast implementation. The experiments show that the proposed watermarking scheme can take full advantage of the distortion constraint and improve the robustness in return.

  12. Application of imaging plate neutron detector to neutron radiography

    CERN Document Server

    Fujine, S; Kamata, M; Etoh, M

    1999-01-01

    As an imaging plate neutron detector (IP-ND) has been available for thermal neutron radiography (TNR) which has high resolution, high sensitivity and wide range, some basic characteristics of the IP-ND system were measured at the E-2 facility of the KUR. After basic performances of the IP were studied, images with high quality were obtained at a neutron fluence of 2 to 7x10 sup 8 n cm sup - sup 2. It was found that the IP-ND system with Gd sub 2 O sub 3 as a neutron converter material has a higher sensitivity to gamma-ray than that of a conventional film method. As a successful example, clear radiographs of the flat view for the fuel side plates with boron burnable poison were obtained. An application of the IP-ND system to neutron radiography (NR) is presented in this paper.

  13. The Importance of Store Image and Retail Service Quality in Private Brand Image-Building

    Directory of Open Access Journals (Sweden)

    Adi Alić

    2017-03-01

    Full Text Available Objective: The purpose of this research is to highlight the role which store image and retail service quality can play in private brand image-building in the context of an emerging market in South-Eastern Europe (i.e. Bosnia and Herzegovina. We propose to address this issue by seeking answers to the following questions: (1 Does a ‘halo effect’ take place between the store image and the private brand image? (2 How does consumer’s evaluation of the quality of the service delivered by a retailer affect the image of its private brand? Research Design & Methods: Data were collected through a field survey via the store-intercept method. The sample consisted of 699 customers of two large retail chains. The data were analysed using the Structural Equation Modelling technique. Findings: The findings of the present study suggest that store image and retail service quality are important factors in the formation of the image of product-branded products. Implications & Recommendations: This study offers some important insights for retailers who intend to develop their private brand. First, the image transfer from store brand to private brand suggests that retailers should consider the introduction of a private brand as a brand extension, with their stores as the parent brand. Second, we recommend that retailers put more emphasis on quality improvement initiatives related to the store environment attributes. Contribution & Value Added: This study enhances the discussion on the phenomenon of private branding by analysing the store-level factors which underpin the formation of private brand image in the context of less developed European markets.

  14. Multiresolution approach to processing images for different applications interaction of lower processing with higher vision

    CERN Document Server

    Vujović, Igor

    2015-01-01

    This book presents theoretical and practical aspects of the interaction between low and high level image processing. Multiresolution analysis owes its popularity mostly to wavelets and is widely used in a variety of applications. Low level image processing is important for the performance of many high level applications. The book includes examples from different research fields, i.e. video surveillance; biomedical applications (EMG and X-ray); improved communication, namely teleoperation, telemedicine, animation, augmented/virtual reality and robot vision; monitoring of the condition of ship systems and image quality control.

  15. Creation of DICOM--aware applications using ImageJ.

    Science.gov (United States)

    Barboriak, Daniel P; Padua, Anthony O; York, Gerald E; Macfall, James R

    2005-06-01

    The demand for image-processing software for radiology applications has been increasing, fueled by advancements in both image-acquisition and image-analysis techniques. The utility of existing image-processing software is often limited by cost, lack of flexibility, and/or specific hardware requirements. In particular, many existing packages cannot directly utilize images formatted using the specifications in part 10 of the DICOM standard ("DICOM images"). We show how image analyses can be performed directly on DICOM images by using ImageJ, a free, Java-based image-processing package (http://rsb.info.nih.gov/ij/). We demonstrate how plug-ins written in our laboratory can be used along with the ImageJ macro script language to create flexible, low-cost, multiplatform image-processing applications that can be directed by information contained in the DICOM image header.

  16. Radiation dose reduction without degrading image quality during computed tomography examinations: Dosimetry and quality control study

    Directory of Open Access Journals (Sweden)

    George Felix Acquah

    2014-08-01

    Full Text Available Purpose: Computed tomography (CT, is an X-ray procedure that generates high quality cross-sectional images of the body, and by comparison to other radiological diagnosis, is responsible for higher doses to patients. This work studies the doses and image qualities produced from the default primary scanning factors of a Siemens CT machine and afterwards came up with scanning protocols that allow radiologists to obtain the necessary diagnostic information while reducing radiation doses to as low as reasonably achievable. Methods: Approximately 1000 CT scans from mostly common examinations; head, thorax, abdomen and pelvis routines were selected and analyzed for their image quality and radiation doses over a two year interval. Dose measurements were performed for the same routines using Computed Tomography Dose Index (CTDI phantoms, RTI barracuda system with electrometer, and CT dose Profiler detector to evaluate the doses delivered during these CT procedures. Subsequently, image quality checks were performed using the CT Catphan 600 and anthropomorphic phantoms. CTDI and Dose Length Product (DLP values were calculated for each scan. From analyzing these measurements, the appropriate machine scanning parameters were adjusted to reduce radiation does while at the same time providing good image quality.Results: Doses to patients using the default head sequence protocol had an average CTDIvol value of 65.45 mGy and a range of 7.10-16.80 mGy for thorax, abdomen and pelvis examinations whiles the new protocol had an average CTDIvol of 58.32 mGy for the head and a range of 3.83-15.24 mGy for the truck region. The DLP value for default head scans decreased from an average of 2279.85 mGy.cm to 874.53 mGy.cm with the new protocol. Tube potentials (KV and tube current-time (mAs had an effect on spatial resolution and low contrast detectability as well as doses. Conclusion: From the new protocols, lower values of KV and mAs together with other factors were

  17. Image quality evaluation of linear plastic scintillating fiber array detector for X-ray imaging

    Institute of Scientific and Technical Information of China (English)

    Mohammad Mehdi NASSERI; MA Qing-Li; YIN Ze-Jie

    2004-01-01

    It is important to assess image quality, in order to ensure that the imaging system is performing optimally and also identify the weak points in an imaging system. Three parameters mostly leading to image degradation are contrast, spatial resolution and noise. There is always a trade-off between spatial resolution and signal to noise ratio,but in scintillating fiber array detectors spatial resolution is not as important as signal to noise ratio, so we paid more attention to contrast and SNR of the system. By using GEANT4 Monte Carlo detector simulation toolkit, some effective parameters of the linear plastic scintillating fiber (PSF) array as an imaging detector were investigated. Finally we show that it is possible to use this kind of detector to take CT and DR (Digital Radiography) image under certain conditions.

  18. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children.

    Science.gov (United States)

    Olivieri, Laura; Cross, Russell; O'Brien, Kendall J; Xue, Hui; Kellman, Peter; Hansen, Michael S

    2016-06-01

    The value of late-gadolinium-enhancement (LGE) imaging in the diagnosis and management of pediatric and congenital heart disease is clear; however current acquisition techniques are susceptible to error and artifacts when performed in children because of children's higher heart rates, higher prevalence of sinus arrhythmia, and inability to breath-hold. Commonly used techniques in pediatric LGE imaging include breath-held segmented FLASH (segFLASH) and steady-state free precession-based (segSSFP) imaging. More recently, single-shot SSFP techniques with respiratory motion-corrected averaging have emerged. This study tested and compared single-shot free-breathing LGE techniques with standard segmented breath-held techniques in children undergoing LGE imaging. Thirty-two consecutive children underwent clinically indicated late-enhancement imaging using intravenous gadobutrol 0.15 mmol/kg. Breath-held segSSFP, breath-held segFLASH, and free-breathing single-shot SSFP LGE sequences were performed in consecutive series in each child. Two blinded reviewers evaluated the quality of the images and rated them on a scale of 1-5 (1 = poor, 5 = superior) based on blood pool-myocardial definition, presence of cardiac motion, presence of respiratory motion artifacts, and image acquisition artifact. We used analysis of variance (ANOVA) to compare groups. Patients ranged in age from 9 months to 18 years, with a mean +/- standard deviation (SD) of 13.3 +/- 4.8 years. R-R interval at the time of acquisition ranged 366-1,265 milliseconds (ms) (47-164 beats per minute [bpm]), mean +/- SD of 843+/-231 ms (72+/-21 bpm). Mean +/- SD quality ratings for long-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.1+/-0.9, 3.4+/-0.9 and 4.0+/-0.9, respectively (P quality ratings for short-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.4+/-1, 3.8+/-0.9 and 4.3+/-0.7, respectively (P quality ratings than standard breath-held techniques. Use of free

  19. Effect of administered radioactive dose level on image quality of brain perfusion imaging with 99mTc-HMPAO

    Directory of Open Access Journals (Sweden)

    I.Armeniakos

    2008-01-01

    Full Text Available Brain perfusion imaging by means of 99mTc-labeled hexamethyl propylene amine oxime (HMPAO is a well-established Nuclear Medicine diagnostic procedure. The administered dose range recommended by the supplying company and reported in bibliography is rather wide (approximately 9.5-27 mCi. This fact necessitates further quantitative analysis of the technique, so as to minimise patient absorbed dose without compromising the examination diagnostic value. In this study, a quantitative evaluation of the radiopharmaceutical performance for different values of administered dose (10, 15, 20 mCi was carried out. Subsequently, a generic image quality index was correlated with the administered dose, to produce an overall performance indicator. Through this cost-to-benefit type analysis, the necessity of administration of higher radioactive dose levels in order to perform the specific diagnostic procedure was examined.Materials & methods: The study was based on a sample of 78 patients (56 administered with 10 mCi, 10 with 15 mCi and 12 with 20 mCi. Some patients were classified as normal, while others presented various forms of pathology. Evaluation of image quality was based on contrast, noise and contrast-to-noise ratio indicators, denoted CI, NI and CNR respectively. Calculation of all indicators was based on wavelet transform. An overall performance indicator (denoted PI, produced by the ratio of CNR by administered dose, was also calculated.Results: Calculation of skewness parameter revealed the normality of CI, NI and non-normality of CNR, PI populations. Application of appropriate statistical tests (analysis of variance for normal and Kruskal-Wallis test for non-normal populations showed that there is a statistically significant difference in CI (p0.05 values. Application of Tukey test for normal populations CI, NI led to the conclusion that CI(10 mCi = CI(20 mCiNI(20 mCi, while NI(15 mCi can not be characterised. Finally, application of non

  20. Data path design and image quality aspects of the next generation multifunctional printer

    Science.gov (United States)

    Brassé, M. H. H.; de Smet, S. P. R. C.

    2008-01-01

    Multifunctional devices (MFDs) are increasingly used as a document hub. The MFD is used as a copier, scanner, printer, and it facilitates digital document distribution and sharing. This imposes new requirements on the design of the data path and its image processing. Various design aspects need to be taken into account, including system performance, features, image quality, and cost price. A good balance is required in order to develop a competitive MFD. A modular datapath architecture is presented that supports all the envisaged use cases. Besides copying, colour scanning is becoming an important use case of a modern MFD. The copy-path use case is described and it is shown how colour scanning can also be supported with a minimal adaptation to the architecture. The key idea is to convert the scanner data to an opponent colour space representation at the beginning of the image processing pipeline. The sub-sampling of chromatic information allows for the saving of scarce hardware resources without significant perceptual loss of quality. In particular, we have shown that functional FPGA modules from the copy application can also be used for the scan-to-file application. This makes the presented approach very cost-effective while complying with market conform image quality standards.

  1. Terahertz electronics for sensing and imaging applications

    Science.gov (United States)

    Shur, Michael

    2015-05-01

    Short channel field effect transistors can detect terahertz radiation. Such detection is enabled by the excitation of the plasma waves rectified due to the device nonlinearities. The resulting response has nanometer scale spatial resolution and can be modulated in the sub THz range. This technology could enable a variety of sensing, imaging, and wireless communication applications, including detection of biological and chemical hazardous agents, cancer detection, shortrange covert communications (in THz and sub-THz windows), and applications in radio astronomy. Field effect transistors implemented using III-V, III-N, Si, SiGe, and graphene have been used to detect THz radiation. Using silicon transistors in plasmonic regimes is especially appealing because of compatibility with standard readout silicon VLSI components.

  2. A virtual image chain for perceived image quality of medical display

    Science.gov (United States)

    Marchessoux, Cédric; Jung, Jürgen

    2006-03-01

    This paper describes a virtual image chain for medical display (project VICTOR: granted in the 5th framework program by European commission). The chain starts from raw data of an image digitizer (CR, DR) or synthetic patterns and covers image enhancement (MUSICA by Agfa) and both display possibilities, hardcopy (film on viewing box) and softcopy (monitor). Key feature of the chain is a complete image wise approach. A first prototype is implemented in an object-oriented software platform. The display chain consists of several modules. Raw images are either taken from scanners (CR-DR) or from a pattern generator, in which characteristics of DR- CR systems are introduced by their MTF and their dose-dependent Poisson noise. The image undergoes image enhancement and comes to display. For soft display, color and monochrome monitors are used in the simulation. The image is down-sampled. The non-linear response of a color monitor is taken into account by the GOG or S-curve model, whereas the Standard Gray-Scale-Display-Function (DICOM) is used for monochrome display. The MTF of the monitor is applied on the image in intensity levels. For hardcopy display, the combination of film, printer, lightbox and viewing condition is modeled. The image is up-sampled and the DICOM-GSDF or a Kanamori Look-Up-Table is applied. An anisotropic model for the MTF of the printer is applied on the image in intensity levels. The density-dependent color (XYZ) of the hardcopy film is introduced by Look-Up-tables. Finally a Human Visual System Model is applied to the intensity images (XYZ in terms of cd/m2) in order to eliminate nonvisible differences. Comparison leads to visible differences, which are quantified by higher order image quality metrics. A specific image viewer is used for the visualization of the intensity image and the visual difference maps.

  3. Image quality vs. sensitivity: fundamental sensor system engineering

    Science.gov (United States)

    Schueler, Carl F.

    2008-08-01

    This paper focuses on the fundamental system engineering tradeoff driving almost all remote sensing design efforts, affecting complexity, cost, performance, schedule, and risk: image quality vs. sensitivity. This single trade encompasses every aspect of performance, including radiometric accuracy, dynamic range and precision, as well as spatial, spectral, and temporal coverage and resolution. This single trade also encompasses every aspect of design, including mass, dimensions, power, orbit selection, spacecraft interface, sensor and spacecraft functional trades, pointing or scanning architecture, sensor architecture (e.g., field-of-view, optical form, aperture, f/#, material properties), electronics, mechanical and thermal properties. The relationship between image quality and sensitivity is introduced based on the concepts of modulation transfer function (MTF) and signal-to-noise ratio (SNR) with examples to illustrate the balance to be achieved by the system architect to optimize cost, complexity, performance and risk relative to end-user requirements.

  4. Reproducibility of Mammography Units, Film Processing and Quality Imaging

    Science.gov (United States)

    Gaona, Enrique

    2003-09-01

    The purpose of this study was to carry out an exploratory survey of the problems of quality control in mammography and processors units as a diagnosis of the current situation of mammography facilities. Measurements of reproducibility, optical density, optical difference and gamma index are included. Breast cancer is the most frequently diagnosed cancer and is the second leading cause of cancer death among women in the Mexican Republic. Mammography is a radiographic examination specially designed for detecting breast pathology. We found that the problems of reproducibility of AEC are smaller than the problems of processors units because almost all processors fall outside of the acceptable variation limits and they can affect the mammography quality image and the dose to breast. Only four mammography units agree with the minimum score established by ACR and FDA for the phantom image.

  5. Enhanced imaging of DNA via active quality factor control

    Science.gov (United States)

    Humphris, A. D. L.; Round, A. N.; Miles, M. J.

    2001-10-01

    Adsorption processes at single molecule level are of fundamental importance for the understanding and development of biomaterials. Atomic force microscopy (AFM) has played a critical role in this field due to its high resolution and ability to image in a liquid environment. We present a method that improves the dynamic force sensitivity and the resolution of a conventional AFM. This is achieved via a positive feedback loop that enhances the effective quality factor of the cantilever in a liquid environment to values in excess of 300, compared to a nominal value of ˜1. This active quality factor enhancement has been used to image DNA and an increase in the height of the molecule observed.

  6. Quality Control in Automated Manufacturing Processes – Combined Features for Image Processing

    Directory of Open Access Journals (Sweden)

    B. Kuhlenkötter

    2006-01-01

    Full Text Available In production processes the use of image processing systems is widespread. Hardware solutions and cameras respectively are available for nearly every application. One important challenge of image processing systems is the development and selection of appropriate algorithms and software solutions in order to realise ambitious quality control for production processes. This article characterises the development of innovative software by combining features for an automatic defect classification on product surfaces. The artificial intelligent method Support Vector Machine (SVM is used to execute the classification task according to the combined features. This software is one crucial element for the automation of a manually operated production process. 

  7. Quality evaluation of edge detection in a road image sequences

    Directory of Open Access Journals (Sweden)

    Rodrigo B. de A. Gallis

    2004-12-01

    Full Text Available Terrestrial mobile mapping systems map interest features along roads such as poles, traffic signs, curb lines, garbage cans etc. The lab work, concerned to the object reconstruction, consists of transforming the video into still images on which homologous points and features of the road sequence are selected and measured. By means of photogrammetric intersection the object coordinates of these features and points are computed for 3D reconstruction. Using Canny algorithm for the automatic edge detection in a road image sequence the article initially focuses on the empiric determination of the required parameters (standard deviation s and high Ta and low Tb threshold. Then it presents the quality in terms of displacement of the automatically detected edges similar to those visually (manually selected straight features extracted by a human operator that takes them as correct, therefore, as reference for the automatic extraction comparison and the quality evaluation. The results of the tests are discussed and show that the quality of the automatic detection – measured by a quantity of rights and wrongs – vary accordingly to the empirically determined standard deviation and high and low thresholds and also to the image sequence environment (street or road.

  8. Hyperspectral Imaging as a Rapid Quality Control Method for Herbal Tea Blends

    Directory of Open Access Journals (Sweden)

    Majolie Djokam

    2017-03-01

    Full Text Available In South Africa, indigenous herbal teas are enjoyed due to their distinct taste and aroma. The acclaimed health benefits of herbal teas include the management of chronic diseases such as hypertension and diabetes. Quality control of herbal teas has become important due to the availability of different brands of varying quality and the production of tea blends. The potential of hyperspectral imaging as a rapid quality control method for herbal tea blends from rooibos (Aspalathus linearis, honeybush (Cyclopia intermedia, buchu (Agathosma Betulina and cancerbush (Sutherlandia frutescens was investigated. Hyperspectral images of raw materials and intact tea bags were acquired using a sisuChema shortwave infrared (SWIR hyperspectral pushbroom imaging system (920–2514 nm. Principal component analysis (PCA plots showed clear discrimination between raw materials. Partial least squares discriminant analysis (PLS-DA models correctly predicted the raw material constituents of each blend and accurately determined the relative proportions. The results were corroborated independently using ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS. This study demonstrated the application of hyperspectral imaging coupled with chemometric modelling as a reliable, rapid and non-destructive quality control method for authenticating herbal tea blends and to determine relative proportions in a tea bag.

  9. PREDICTION OF SMARTPHONES’ PERCEIVED IMAGE QUALITY USING SOFTWARE EVALUATION TOOL VIQET

    Directory of Open Access Journals (Sweden)

    Pinchas ZOREA

    2016-12-01

    Full Text Available A great deal of resources and efforts have been made in recent years to assess how the smartphones users perceived the image quality. Unfortunately, only limited success has been achieved and the image quality assessment still based on many physical human visual test. The paper describes the new model proposed for perceived quality based on human visual tests compared with image analysis by the software application tool. The values of parameters of perceived image quality (brightness, contrast, color saturation and sharpness were calibrated based on results from human visual experiments.PREDICŢIA CALITĂŢII PERCEPUTE A IMAGINILOR AFIȘATE DE SMARTPHONE-URI UTILIZÂND APLICAŢIA DE EVALUARE VIQETÎn ultimii ani au fost depuse eforturi semnificative pentru a evalua modul în care utilizatorii de smartphone  percep calitatea imaginilor. Din păcate, a fost atins doar un progres limitat, evaluarea calităţii imaginiilor bazându-se încă pe multiple teste vizuale umane. În lucrare este descris un nou model al calităţii percepute pe baza testelor vizuale umane, comparate cu analiza imaginii efectuate cu o aplicaţie software. Valorile parametrilor calităţii  percepute a imaginii (lu­minozitate, contrast, saturaţia culorilor şi claritatea au fost calibrate pe baza rezultatelor experimentelor vizuale umane.

  10. Robust image obfuscation for privacy protection in Web 2.0 applications

    Science.gov (United States)

    Poller, Andreas; Steinebach, Martin; Liu, Huajian

    2012-03-01

    We present two approaches to robust image obfuscation based on permutation of image regions and channel intensity modulation. The proposed concept of robust image obfuscation is a step towards end-to-end security in Web 2.0 applications. It helps to protect the privacy of the users against threats caused by internet bots and web applications that extract biometric and other features from images for data-linkage purposes. The approaches described in this paper consider that images uploaded to Web 2.0 applications pass several transformations, such as scaling and JPEG compression, until the receiver downloads them. In contrast to existing approaches, our focus is on usability, therefore the primary goal is not a maximum of security but an acceptable trade-off between security and resulting image quality.

  11. Image Quality Assessment for Performance Evaluation of Focus Measure Operators

    Directory of Open Access Journals (Sweden)

    Farida Memon

    2015-10-01

    Full Text Available This paper presents the performance evaluation of eight focus measure operators namely Image CURV (Curvature, GRAE (Gradient Energy, HISE (Histogram Entropy, LAPM (Modified Laplacian, LAPV (Variance of Laplacian, LAPD (Diagonal Laplacian, LAP3 (Laplacian in 3D Window and WAVS (Sum of Wavelet Coefficients. Statistical matrics such as MSE (Mean Squared Error, PNSR (Peak Signal to Noise Ratio, SC (Structural Content, NCC (Normalized Cross Correlation, MD (Maximum Difference and NAE (Normalized Absolute Error are used to evaluate stated focus measures in this research. . FR (Full Reference method of the image quality assessment is utilized in this paper. Results indicate that LAPD method is comparatively better than other seven focus operators at typical imaging conditions

  12. Image Restoration Using Functional and Anatomical Information Fusion with Application to SPECT-MRI Images

    Directory of Open Access Journals (Sweden)

    S. Benameur

    2009-01-01

    Full Text Available Image restoration is usually viewed as an ill-posed problem in image processing, since there is no unique solution associated with it. The quality of restored image closely depends on the constraints imposed of the characteristics of the solution. In this paper, we propose an original extension of the NAS-RIF restoration technique by using information fusion as prior information with application in SPECT medical imaging. That extension allows the restoration process to be constrained by efficiently incorporating, within the NAS-RIF method, a regularization term which stabilizes the inverse solution. Our restoration method is constrained by anatomical information extracted from a high resolution anatomical procedure such as magnetic resonance imaging (MRI. This structural anatomy-based regularization term uses the result of an unsupervised Markovian segmentation obtained after a preliminary registration step between the MRI and SPECT data volumes from each patient. This method was successfully tested on 30 pairs of brain MRI and SPECT acquisitions from different subjects and on Hoffman and Jaszczak SPECT phantoms. The experiments demonstrated that the method performs better, in terms of signal-to-noise ratio, than a classical supervised restoration approach using a Metz filter.

  13. NEW VISUAL PERCEPTUAL POOLING STRATEGY FOR IMAGE QUALITY ASSESSMENT

    Institute of Scientific and Technical Information of China (English)

    Zhou Wujie; Jiang Gangyi; Yu Mei

    2012-01-01

    Most of Image Quality Assessment (IQA) metrics consist of two processes.In the first process,quality map of image is measured locally.In the second process,the last quality score is converted from the quality map by using the pooling strategy.The first process had been made effective and significant progresses,while the second process was always done in simple ways.In the second process of the pooling strategy,the optimal perceptual pooling weights should be determined and computed according to Human Visual System (HVS).Thus,a reliable spatial pooling mathematical model based on HVS is an important issue worthy of study.In this paper,a new Visual Perceptual Pooling Strategy (VPPS) for IQA is presented based on contrast sensitivity and luminance sensitivity of HVS.Experimental results with the LIVE database show that the visual perceptual weights,obtained by the proposed pooling strategy,can effectively and significantly improve the performances of the IQA metrics with Mean Structural SIMilarity (MSSIM) or Phase Quantization Code (PQC).It is confirmed that the proposed VPPS demonstrates promising results for improving the performances of existing IQA metrics.

  14. Evaluation of mobile phone camera benchmarking using objective camera speed and image quality metrics

    Science.gov (United States)

    Peltoketo, Veli-Tapani

    2014-11-01

    When a mobile phone camera is tested and benchmarked, the significance of image quality metrics is widely acknowledged. There are also existing methods to evaluate the camera speed. However, the speed or rapidity metrics of the mobile phone's camera system has not been used with the quality metrics even if the camera speed has become a more and more important camera performance feature. There are several tasks in this work. First, the most important image quality and speed-related metrics of a mobile phone's camera system are collected from the standards and papers and, also, novel speed metrics are identified. Second, combinations of the quality and speed metrics are validated using mobile phones on the market. The measurements are done toward application programming interface of different operating systems. Finally, the results are evaluated and conclusions are made. The paper defines a solution to combine different image quality and speed metrics to a single benchmarking score. A proposal of the combined benchmarking metric is evaluated using measurements of 25 mobile phone cameras on the market. The paper is a continuation of a previous benchmarking work expanded with visual noise measurement and updates of the latest mobile phone versions.

  15. SU-E-J-36: Comparison of CBCT Image Quality for Manufacturer Default Imaging Modes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, G [University of Wisconsin, Madison, WI (United States)

    2015-06-15

    Purpose CBCT is being increasingly used in patient setup for radiotherapy. Often the manufacturer default scan modes are used for performing these CBCT scans with the assumption that they are the best options. To quantitatively assess the image quality of these scan modes, all of the scan modes were tested as well as options with the reconstruction algorithm. Methods A CatPhan 504 phantom was scanned on a TrueBeam Linear Accelerator using the manufacturer scan modes (FSRT Head, Head, Image Gently, Pelvis, Pelvis Obese, Spotlight, & Thorax). The Head mode scan was then reconstructed multiple times with all filter options (Smooth, Standard, Sharp, & Ultra Sharp) and all Ring Suppression options (Disabled, Weak, Medium, & Strong). An open source ImageJ tool was created for analyzing the CatPhan 504 images. Results The MTF curve was primarily dictated by the voxel size and the filter used in the reconstruction algorithm. The filters also impact the image noise. The CNR was worst for the Image Gently mode, followed by FSRT Head and Head. The sharper the filter, the worse the CNR. HU varied significantly between scan modes. Pelvis Obese had lower than expected HU values than most while the Image Gently mode had higher than expected HU values. If a therapist tried to use preset window and level settings, they would not show the desired tissue for some scan modes. Conclusion Knowing the image quality of the set scan modes, will enable users to better optimize their setup CBCT. Evaluation of the scan mode image quality could improve setup efficiency and lead to better treatment outcomes.

  16. The New Approach of Using Image and Range Based Methods for Quality Control of Dimension Stone

    Science.gov (United States)

    Levytskyi, Volodymyr

    2017-06-01

    The basis for the quality control of commodity dimension stone blocks for mining industry is the study of fracturing. The identification of fracturing in rock masses is one of the most important aspects in rock mass modelling. Traditional methods for determination properties of fracturing are difficult and hazardous. This paper describes a new approach of fracturing identification, based on image and range data, which realized by image processing and special software. In this article describes a method using new computer algorithms that allow for automated identification and calculation of fracturing parameters. Different digital filters for image processing and mathematical dependences are analyzed. The digital imaging technique has the potential for being used in real time applications. The purpose of this paper is the accurate and fast mapping of fracturing in some walls of the Bukinsky gabbro deposit.

  17. Multispectral UV imaging for fast and non-destructive quality control of chemical and physical tablet attributes

    DEFF Research Database (Denmark)

    Klukkert, Marten; Wu, Jian X; Rantanen, Jukka

    2016-01-01

    in the surface density. In conclusion, this study demonstrates that UV imaging combined with image analysis is an effective and non-destructive method to determine chemical and physical quality attributes of tablets and is a promising approach for (near) real-time monitoring of the tablet compaction process......Monitoring of tablet quality attributes in direct vicinity of the production process requires analytical techniques that allow fast, non-destructive, and accurate tablet characterization. The overall objective of this study was to investigate the applicability of multispectral UV imaging...... the potential of UV imaging for automatized quality control of tablets with respect to their intactness and surface density profile. Various tablets of different composition and different quality regarding their API content, radial tensile strength, intactness, and surface density profile were prepared using...

  18. 2003 SNL ASCI applications software quality engineering assessment report.

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, Joseph Richard, Jr.; Ellis, Molly A.; Williamson, Charles Michael; Bonano, Lora A.

    2004-02-01

    This document describes the 2003 SNL ASCI Software Quality Engineering (SQE) assessment of twenty ASCI application code teams and the results of that assessment. The purpose of this assessment was to determine code team compliance with the Sandia National Laboratories ASCI Applications Software Quality Engineering Practices, Version 2.0 as part of an overall program assessment.

  19. Creation of DICOM—Aware Applications Using ImageJ

    OpenAIRE

    2005-01-01

    The demand for image-processing software for radiology applications has been increasing, fueled by advancements in both image-acquisition and image-analysis techniques. The utility of existing image-processing software is often limited by cost, lack of flexibility, and/or specific hardware requirements. In particular, many existing packages cannot directly utilize images formatted using the specifications in part 10 of the DICOM standard (“DICOM images”). We show how image analyses can be per...

  20. Image Quality of the Helioseismic and Magnetic Imager (HMI) Onboard the Solar Dynamics Observatory (SDO)

    Science.gov (United States)

    Wachter, R.; Schou, Jesper; Rabello-Soares, M. C.; Miles, J. W.; Duvall, T. L., Jr.; Bush, R. I.

    2011-01-01

    We describe the imaging quality of the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) as measured during the ground calibration of the instrument. We describe the calibration techniques and report our results for the final configuration of HMI. We present the distortion, modulation transfer function, stray light,image shifts introduced by moving parts of the instrument, best focus, field curvature, and the relative alignment of the two cameras. We investigate the gain and linearity of the cameras, and present the measured flat field.

  1. C-11 radiochemistry in cancer imaging applications.

    Science.gov (United States)

    Tu, Z; Mach, R H

    2010-01-01

    Carbon-11 (C-11) radiotracers are widely used for the early diagnosis of cancer, monitoring therapeutic response to cancer treatment, and pharmacokinetic investigations of anticancer drugs. PET imaging permits non-invasive monitoring of metabolic processes and molecular targets, while carbon-11 radiotracers allow a "hot-for cold" substitution of biologically active molecules. Advances in organic synthetic chemistry and radiochemistry as well as improved automated techniques for radiosynthesis have encouraged investigators in developing carbon-11 tracers for use in oncology imaging studies. The short half-life of carbon-11 (20.38 minutes) creates special challenges for the synthesis of C-11 labeled tracers; these include the challenges of synthesizing C-11 target compounds with high radiochemical yield, high radiochemical purity and high specific activity in a short time and on a very small scale. The optimization of conditions for making a carbon-11 tracer include the late introduction of the C-11 isotope, the rapid formation and purification of the target compound, and the use of automated systems to afford a high yield of the target compound in a short time. In this review paper, we first briefly introduce some basic principles of PET imaging of cancer; we then discuss principles of carbon-11 radiochemistry, focus on specific advances in radiochemistry, and describe the synthesis of C-11 radiopharmaceuticals developed for cancer imaging. The carbon-11 radiochemistry approaches described include the N,O, and S-alkylations of [(11)C]methyl iodide/[(11)C]methyl triflate and analogues of [(11)C]methyl iodide and their applications for making carbon-11 tracers; we then address recent advances in exploring a transmetallic complex mediated [(11)C]carbonyl reaction for oncologic targets.

  2. Intelligent decision making in quality management theory and applications

    CERN Document Server

    Yanık, Seda

    2016-01-01

      This book presents recently developed intelligent techniques with applications and theory in the area of quality management. The involved applications of intelligence include techniques such as fuzzy sets, neural networks, genetic algorithms, etc. The book consists of classical quality management topics dealing with intelligent techniques for solving the complex quality management problems. The book will serve as an excellent reference for quality managers, researchers, lecturers and postgraduate students in this area. The authors of the chapters are well-known researchers in the area of quality management.  .

  3. Imaging quality evaluation method of pixel coupled electro-optical imaging system

    Science.gov (United States)

    He, Xu; Yuan, Li; Jin, Chunqi; Zhang, Xiaohui

    2017-09-01

    With advancements in high-resolution imaging optical fiber bundle fabrication technology, traditional photoelectric imaging system have become ;flexible; with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the coupling discrete sampling effect of fiber-optic image bundles and charge-coupled device (CCD) pixels. This limitation substantially complicates the design, optimization, assembly, and evaluation image quality of the coupled discrete sampling imaging system. Based on the transfer process of grayscale cosine distribution optical signal in the fiber-optic image bundle and CCD, a mathematical model of coupled modulation transfer function (coupled-MTF) is established. This model can be used as a basis for following studies on the convergence and periodically oscillating characteristics of the function. We also propose the concept of the average coupled-MTF, which is consistent with the definition of traditional MTF. Based on this concept, the relationships among core distance, core layer radius, and average coupled-MTF are investigated.

  4. A Fast Computation of Attention Selection Map and Its Application in Image Quality Assessment%快速注意力选择计算及其在图像质量评价中的应用

    Institute of Scientific and Technical Information of China (English)

    马奇; 张立明

    2009-01-01

    针对现有的模拟视觉注意力选择模型计算复杂度高、参数选取困难的问题,提出一种快速的频率域算法.将各频点上的幅度设为同一常数,保留其相位信息;对反变换到空间域的图像滤波后,得到视觉注意力显著图,其效果与现有的模型相似;并将显著图信息作为权重加入到几种主要的图像质量评价标准中.实验结果表明:带有注意力选择的图像质量评价标准更接近于人的主观评价,便于实时应用.%Existing computation methods of Human visual attention are rather impractical due to either the involved high computational complexity or the difficulties of selecting suitable parameters. In this paper, we propose a fast method to simulate attention selection in frequency domain. We set the amplitude spectrum to a constant and preserve phase spectrum, then transform them back into the spatial domain. After filtering, the resultant saliency map is quite similar to those of existing methods. In addition, we treat the salient information as weights to adjust several main existing criteria of image quality assessment. Experimental results show that our image quality assessment with attention selection is more consistent with human's subjective evaluation, besides its computational efficiency.

  5. Optimum image compression rate maintaining diagnostic image quality of digital intraoral radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ju Seop; Koh, Kwang Joon [Dept. of Oral and Maxillofacial Radiology and Institute of Oral Bio Science, School of Dentistry, Chonbuk National University, Chonju (Korea, Republic of)

    2000-12-15

    The aims of the present study are to determine the optimum compression rate in terms of file size reduction and diagnostic quality of the images after compression and evaluate the transmission speed of original or each compressed images. The material consisted of 24 extracted human premolars and molars. The occlusal surfaces and proximal surfaces of the teeth had a clinical disease spectrum that ranged from sound to varying degrees of fissure discoloration and cavitation. The images from Digora system were exported in TIFF and the images from conventional intraoral film were scanned and digitalized in TIFF by Nikon SF-200 scanner(Nikon, Japan). And six compression factors were chosen and applied on the basis of the results from a pilot study. The total number of images to be assessed were 336. Three radiologists assessed the occlusal and proximal surfaces of the teeth with 5-rank scale. Finally diagnosed as either sound or carious lesion by one expert oral pathologist. And sensitivity and specificity and kappa value for diagnostic agreement was calculated. Also the area (Az) values under the ROC curve were calculated and paired t-test and oneway ANOVA test was performed. Thereafter, transmission time of the image files of the each compression level were compared with that of the original image files. No significant difference was found between original and the corresponding images up to 7% (1:14) compression ratio for both the occlusal and proximal caries (p<0.05). JPEG3 (1:14) image files are transmitted fast more than 10 times, maintained diagnostic information in image, compared with original image files. 1:14 compressed image file may be used instead of the original image and reduce storage needs and transmission time.

  6. Standard Practice for Design, Manufacture, and Material Grouping Classification of Hole-Type Image Quality Indicators (IQI) Used for Radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This practice covers the design, material grouping classification, and manufacture of hole-type image quality indicators (IQI) used to indicate the quality of radiologic images. 1.2 This practice is applicable to X-ray and gamma-ray radiology. 1.3 The values stated in inch-pound units are to be regarded as standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  7. Analysis of filtering techniques and image quality in pixel duplicated images

    Science.gov (United States)

    Mehrubeoglu, Mehrube; McLauchlan, Lifford

    2009-08-01

    When images undergo filtering operations, valuable information can be lost besides the intended noise or frequencies due to averaging of neighboring pixels. When the image is enlarged by duplicating pixels, such filtering effects can be reduced and more information retained, which could be critical when analyzing image content automatically. Analysis of retinal images could reveal many diseases at early stage as long as minor changes that depart from a normal retinal scan can be identified and enhanced. In this paper, typical filtering techniques are applied to an early stage diabetic retinopathy image which has undergone digital pixel duplication. The same techniques are applied to the original images for comparison. The effects of filtering are then demonstrated for both pixel duplicated and original images to show the information retention capability of pixel duplication. Image quality is computed based on published metrics. Our analysis shows that pixel duplication is effective in retaining information on smoothing operations such as mean filtering in the spatial domain, as well as lowpass and highpass filtering in the frequency domain, based on the filter window size. Blocking effects due to image compression and pixel duplication become apparent in frequency analysis.

  8. Patient dose and image quality from mega-voltage cone beam computed tomography imaging.

    Science.gov (United States)

    Gayou, Olivier; Parda, David S; Johnson, Mark; Miften, Moyed

    2007-02-01

    The evolution of ever more conformal radiation delivery techniques makes the subject of accurate localization of increasing importance in radiotherapy. Several systems can be utilized including kilo-voltage and mega-voltage cone-beam computed tomography (MV-CBCT), CT on rail or helical tomography. One of the attractive aspects of mega-voltage cone-beam CT is that it uses the therapy beam along with an electronic portal imaging device to image the patient prior to the delivery of treatment. However, the use of a photon beam energy in the mega-voltage range for volumetric imaging degrades the image quality and increases the patient radiation dose. To optimize image quality and patient dose in MV-CBCT imaging procedures, a series of dose measurements in cylindrical and anthropomorphic phantoms using an ionization chamber, radiographic films, and thermoluminescent dosimeters was performed. Furthermore, the dependence of the contrast to noise ratio and spatial resolution of the image upon the dose delivered for a 20-cm-diam cylindrical phantom was evaluated. Depending on the anatomical site and patient thickness, we found that the minimum dose deposited in the irradiated volume was 5-9 cGy and the maximum dose was between 9 and 17 cGy for our clinical MV-CBCT imaging protocols. Results also demonstrated that for high contrast areas such as bony anatomy, low doses are sufficient for image registration and visualization of the three-dimensional boundaries between soft tissue and bony structures. However, as the difference in tissue density decreased, the dose required to identify soft tissue boundaries increased. Finally, the dose delivered by MV-CBCT was simulated using a treatment planning system (TPS), thereby allowing the incorporation of MV-CBCT dose in the treatment planning process. The TPS-calculated doses agreed well with measurements for a wide range of imaging protocols.

  9. MR imaging of the cervical spine: assessment of image quality with parallel imaging compared to non-accelerated MR measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noebauer-Huhmann, I.M.; Imhof, Herwig [Medical University of Vienna, Department of Radiology, Vienna (Austria); Glaser, Christian; Dietrich, Olaf; Wallner, C.P.; Klinger, Wolfgang; Schoenberg, Stefan O. [Ludwig-Maximilians-University of Munich, Institute of Clinical Radiology, Munich (Germany)

    2007-05-15

    To compare the quality of cervical spine MR images obtained by parallel imaging [generalized autocalibrating partially parallel acquisition (GRAPPA)] with those of non-accelerated imaging, we conducted both phantom studies and examinations of ten volunteers at 1.5Tesla with a dedicated 12-element coil system and a head-spine-neck coil combination. Acquisitions included axial T2-weighted (T2w) images with both methods, and sagittal T2w and T1w images in vivo with the latter coil combination. Non-accelerated MRI with two averages and GRAPPA (acceleration factor 2) with two averages (GRAPPA/2AV, time reduction of approximately 50%) and four averages (GRAPPA/4AV) were compared. In the phantom, the signal-to-noise ratio of the GRAPPA/2AV was lower than that of the other two settings. In vivo, the image inhomogeneity (non-uniformity, NU) was significantly higher in T2w GRAPPA/2AV than in both other settings, and in T1w GRAPPA/2AV compared to GRAPPA/4AV. Subjectively, the delineation of anatomical structures was sufficient in all sequences. Only the spinal cord was considered to be better delineable on the non-accelerated T1w sequence compared to GRAPPA/2AV. In part, GRAPPA/4AV performed better than the other settings. The subjective image noise was lowest with GRAPPA/4AV. In cervical spine MRI, the examination time can be reduced by nearly 42% with GRAPPA, while preserving sufficient image quality. (orig.)

  10. Poor quality of early evaluations of magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, L.S.; Chalmers, T.C.; McCally, M.; Berrier, J.; Sacks, H.S.

    1988-06-10

    To study the quality of early research on the clinical efficacy of diagnostic imaging with magnetic resonance, they assessed 54 evaluations published in the first four years after introduction of this modality using ten commonly accepted criteria of research methodology. The terms sensitivity, specificity, false-positive or false-negative, accuracy, and predictive values were used infrequently. 19% of the evaluations used three terms appropriately, 48% used one or two terms, and 33% used none. Data were presented appropriately for one or more of the five terms in 59% of evaluations. A gold standard comparison with the results of an independent procedure, such as surgical or autopsy findings, was presented in 22% of evaluations. Results of another imaging procedure were described in 63% of evaluations. Only one evaluation clearly described a prospective study design, although 11 evaluations apparently were planned in advance. Not one evaluation contained an appropriate statistical analysis of the distributions of quantitative readings, blinded image readers to diagnosis or other test results, measured observer error, or randomized the order of magnetic resonance imaging and other imaging procedures. The authors concludes that health care professionals paying for expensive innovative diagnostic technology should demand better research on diagnostic efficacy.

  11. Quality Assurance of Multiport Image-Guided Minimally Invasive Surgery at the Lateral Skull Base

    Directory of Open Access Journals (Sweden)

    Maria Nau-Hermes

    2014-01-01

    Full Text Available For multiport image-guided minimally invasive surgery at the lateral skull base a quality management is necessary to avoid the damage of closely spaced critical neurovascular structures. So far there is no standardized method applicable independently from the surgery. Therefore, we adapt a quality management method, the quality gates (QG, which is well established in, for example, the automotive industry and apply it to multiport image-guided minimally invasive surgery. QG divide a process into different sections. Passing between sections can only be achieved if previously defined requirements are fulfilled which secures the process chain. An interdisciplinary team of otosurgeons, computer scientists, and engineers has worked together to define the quality gates and the corresponding criteria that need to be fulfilled before passing each quality gate. In order to evaluate the defined QG and their criteria, the new surgery method was applied with a first prototype at a human skull cadaver model. We show that the QG method can ensure a safe multiport minimally invasive surgical process at the lateral skull base. Therewith, we present an approach towards the standardization of quality assurance of surgical processes.

  12. Quality control of systems of portal imaging; Control de calidad de sistemas de imagen portal

    Energy Technology Data Exchange (ETDEWEB)

    Olasolo Alonso, J.; Martin Albina, M. L.; Otal Palacin, A.; Fuentemilla Urio, N.; Miquelez Alonso, S.; Pellejero Pellejero, S.; Maneru Camara, F.; Lozares Cordero, S.; Rubio Arroniz, A.

    2013-07-01

    The importance of accuracy and reproducibility of the positioning of the patient for the radiotherapy treatment, makes key the image quality of the image device portal used for the verification of such positioning. the objective of this work is the implementation of a procedure of quality control that easily and quickly verify the main parameters of image quality of the EPID. (Author)

  13. Using full-reference image quality metrics for automatic image sharpening

    Science.gov (United States)

    Krasula, Lukas; Fliegel, Karel; Le Callet, Patrick; Klíma, Miloš

    2014-05-01

    Image sharpening is a post-processing technique employed for the artificial enhancement of the perceived sharpness by shortening the transitions between luminance levels or increasing the contrast on the edges. The greatest challenge in this area is to determine the level of perceived sharpness which is optimal for human observers. This task is complex because the enhancement is gained only until the certain threshold. After reaching it, the quality of the resulting image drops due to the presence of annoying artifacts. Despite the effort dedicated to the automatic sharpness estimation, none of the existing metrics is designed for localization of this threshold. Nevertheless, it is a very important step towards the automatic image sharpening. In this work, possible usage of full-reference image quality metrics for finding the optimal amount of sharpening is proposed and investigated. The intentionally over-sharpened "anchor image" was included to the calculation as the "anti-reference" and the final metric score was computed from the differences between reference, processed, and anchor versions of the scene. Quality scores obtained from the subjective experiment were used to determine the optimal combination of partial metric values. Five popular fidelity metrics - SSIM, MS-SSIM, IW-SSIM, VIF, and FSIM - were tested. The performance of the proposed approach was then verified in the subjective experiment.

  14. Quality of Experience: From Assessment to Application (Dagstuhl Seminar 15022)

    OpenAIRE

    De Moor, Katrien; Fiedler, Markus; Reichl, Peter; Varela, Martín

    2015-01-01

    This report provides an overview of the program, discussions and outcomes of Dagstuhl Seminar 15022 "Quality of Experience: From Assessment to Application", which took place from 4 - 7 January 2015 at Schloss Dagstuhl - Leibniz Center for Informatics. The seminar and the challenges that were addressed have their roots in the earlier Dagstuhl Seminars 09192 "From Quality of Service to Quality of Experience" and 12181 "Quality of Experience: From User Perception to Instrumental Metrics". The ma...

  15. Application of PET/SPECT imaging in vascular disease

    NARCIS (Netherlands)

    van der Vaart, M. G.; Meerwaidt, R.; Slart, R. H. J. A.; van Dam, G. M.; Tio, R. A.; Zeebregts, C. J.

    2008-01-01

    Background. Nuclear medicine imaging differs from other imaging modalities by showing physiological processes instead of anatomical details. Objective. To describe the current applications of positron emission tomography (PET) and single photon emission computed tomography (SPECT) as a diagnostic to

  16. Oriented diffusion filtering for enhancing low-quality fingerprint images

    KAUST Repository

    Gottschlich, C.

    2012-01-01

    To enhance low-quality fingerprint images, we present a novel method that first estimates the local orientation of the fingerprint ridge and valley flow and next performs oriented diffusion filtering, followed by a locally adaptive contrast enhancement step. By applying the authors\\' new approach to low-quality images of the FVC2004 fingerprint databases, the authors are able to show its competitiveness with other state-of-the-art enhancement methods for fingerprints like curved Gabor filtering. A major advantage of oriented diffusion filtering over those is its computational efficiency. Combining oriented diffusion filtering with curved Gabor filters led to additional improvements and, to the best of the authors\\' knowledge, the lowest equal error rates achieved so far using MINDTCT and BOZORTH3 on the FVC2004 databases. The recognition performance and the computational efficiency of the method suggest to include oriented diffusion filtering as a standard image enhancement add-on module for real-time fingerprint recognition systems. In order to facilitate the reproduction of these results, an implementation of the oriented diffusion filtering for Matlab and GNU Octave is made available for download. © 2012 The Institution of Engineering and Technology.

  17. Quantitative phase imaging for cell culture quality control.

    Science.gov (United States)

    Kastl, Lena; Isbach, Michael; Dirksen, Dieter; Schnekenburger, Jürgen; Kemper, Björn

    2017-05-01

    The potential of quantitative phase imaging (QPI) with digital holographic microscopy (DHM) for quantification of cell culture quality was explored. Label-free QPI of detached single cells in suspension was performed by Michelson interferometer-based self-interference DHM. Two pancreatic tumor cell lines were chosen as cellular model and analyzed for refractive index, volume, and dry mass under varying culture conditions. Firstly, adequate cell numbers for reliable statistics were identified. Then, to characterize the performance and reproducibility of the method, we compared results from independently repeated measurements and quantified the cellular response to osmolality changes of the cell culture medium. Finally, it was demonstrated that the evaluation of QPI images allows the extraction of absolute cell parameters which are related to cell layer confluence states. In summary, the results show that QPI enables label-free imaging cytometry, which provides novel complementary integral biophysical data sets for sophisticated quantification of cell culture quality with minimized sample preparation. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  18. A hyperspectral imaging prototype for online quality evaluation of pickling cucumbers

    Science.gov (United States)

    A hyperspectral imaging prototype was developed for online evaluation of external and internal quality of pickling cucumbers. The prototype had several new, unique features including simultaneous reflectance and transmittance imaging and inline, real time calibration of hyperspectral images of each ...

  19. Short communication: A printed image quality test phantom for mammography.

    Science.gov (United States)

    Kotre, C J; Porter, D J T

    2005-08-01

    This communication describes a novel design for a mammographic image quality test phantom, the final design of which was produced as a radiographer weekly quality assurance phantom for breast screening and symptomatic mammography. The phantom is based on low contrast test features which are built up by superimposing sheets of Mylar overhead projector transparency, on which the test features are printed using a standard LaserJet printer. The required radiation contrast at mammographic energies is produced by the approximately 50% by weight component of iron oxide (Fe(3)O(4)) present in the toner. An easily replicated design of mammographic image quality phantom based on LaserJet printed test features is described. Approximately 40 of these phantoms were constructed, and these have been used successfully for 5 years in both breast screening and symptomatic mammography. The phantom design offers a performance similar to much more expensive mammographic contrast-detail phantoms, but suffers from the disadvantage that high contrast resolution bar patterns cannot be produced using the standard printing process.

  20. Comparison of image quality in head CT studies with different dose-reduction strategies

    DEFF Research Database (Denmark)

    Johansen, Jeppe; Nielsen, Rikke; Fink-Jensen, Vibeke

    -reduction maneuvers is reduction of image quality due to image noise or artifacts. The aim of our study was therefore to find the best diagnostic images with lowest possible dose. We present results of dose- and image quality optimizing strategies of brain CT examinations at our institution. We compare sequential...

  1. Inverse synthetic aperture radar imaging principles, algorithms and applications

    CERN Document Server

    Chen , Victor C

    2014-01-01

    Inverse Synthetic Aperture Radar Imaging: Principles, Algorithms and Applications is based on the latest research on ISAR imaging of moving targets and non-cooperative target recognition (NCTR). With a focus on the advances and applications, this book will provide readers with a working knowledge on various algorithms of ISAR imaging of targets and implementation with MATLAB. These MATLAB algorithms will prove useful in order to visualize and manipulate some simulated ISAR images.

  2. Novel Metal Clusters for Imaging Applications

    KAUST Repository

    Alsaiari, Shahad K.

    2014-05-01

    During the past few years, gold nanoparticles (AuNPs) have received considerable attention in many fields due to their optical properties, photothermal effect and biocompatibility. AuNPs, particularly AuNCs and AuNRs, exhibit great potential in diagnostics and imaging. In the present study, AuNCs were used to selectively image and quantify intracellular antioxidants. It was reported by Chen et al. that the strong fluorescence of AuNCs is quenched by highly reactive oxygen species (hROS). Most of applications depend on fluorescence quenching, however, for our project we designed turn-on fluorescent sensors using AuNCs that sense antioxidants. In the presence of antioxidants, AuNCs fluorescence switch on, while in the absence of antioxidants their fluorescence immediately turn off due to hROS effect. AuNRs were also used for cellular imaging in which AuNRs were conjugated to Cy3-labelled molecular beacon (MB) DNA. Next, the previous complex was loaded in two different strains of magnetotactic bacteria (MTB). MTB were used as a targeted delivery vehicle in which magnetosomes direct the movement of bacteria. The DNA sequence was specific to a certain sequence in mitochondria. The exposure of MTB to an alternating magnetic field (AMF) leads to the increase of temperature inside the bacteria, which destruct the cell wall, and hence, bacterial payload is released. When MD-DNA hybrid with the target sequence, AuNR and Cy3 separate from each other, the fluorescence of the Cy3 is restored.

  3. Collimation and Image Quality of C-Arm Computed Tomography: Potential of Radiation Dose Reduction While Maintaining Equal Image Quality.

    Science.gov (United States)

    Werncke, Thomas; von Falck, Christian; Luepke, Matthias; Stamm, Georg; Wacker, Frank K; Meyer, Bernhard Christian

    2015-08-01

    The aim of this study was to assess the potential for radiation dose reduction in collimated C-arm computed tomography (CACT) while maintaining the image quality of the full field of view (FFOV) acquisition. A whole-body anthropomorphic phantom representing a 70-kg male was used in this study. The upper abdomen of the phantom was imaged using an angiographic system (Artis Zeego Q; Siemens Healthcare, Germany) with either the standard detector radiation dose level (RDL; D100, 360 nGy) or 14 experimental reduced RDLs ranging from 95% (D95, 342 nGy) to 30% D100 (D30, 108 nGy). Either the FFOV (craniocaudal coverage, 18 cm) or a collimated field of view (CFOV; craniocaudal coverage, 6 cm) was applied. The organ dose was measured using thermoluminescence detector dosimetry, and the mean effective dose was computed according to the recommendations by the International Commission on Radiological Protection Publication 103. To compare the CFOV and the FFOV data sets, image quality was assessed in terms of high- and low-contrast resolution by calculating the modulation transfer function using the wire method as well as the image noise, signal-to-noise ratio, and contrast-to-noise ratio using a low-contrast insert placed in the upper abdomen (Δ50 HU). Collimated imaging (CFOV) covering 33% of the FFOV led to an increase in the x-ray tube output of 152% for CFOV (D100; FFOV, 95.5 mGy; CFOV, 147.7 mGy) to maintain the detector dose. The mean effective dose of D100 was 6.0 mSv (male) and 6.2 mSv (female) for the FFOV and 3.7 mSv (male) and 4.1 mSv (female) for the CFOV. High-contrast resolution was comparable for all acquisition protocols (mean 10% modulation transfer function ± 95% confidence interval; FFOV, 8.8 ± 0.1 line pairs/cm; CFOV, 8.8 ± 0.1 line pairs/cm). Low-contrast resolution was superior for the CFOV compared with that for the FFOV for each RDL (D100; image noise: FFOV, 34 ± 2 HU; CFOV, 22 ± 1 HU; contrast-to-noise ratio: FFOV, 1.3 ± 0.2; CFOV, 1.8 ± 0

  4. Quality Standards in Interpreting: Theory and Application

    Institute of Scientific and Technical Information of China (English)

    Franz P(o)chhacker

    2007-01-01

    This paper explores the issue of quality in interpreting from two main perspectives-the profession and academic research.Following a review and illustration of conference interpreters'original aspiration to equate quality with professional status,I will examine the contribution of academic research to the issue of quality,with particular emphasis on survey research into interpreters'quality criteria and end-users'expectations.It will be shown that quality can and must be approached from multiple perspectives and with reference to a complex set of criteria relating to both the service aspects and the product features of an interpreter'sperformance.Against the background of this comprehensive view of quality,I will take the notion of quality standards in its specific technical sense and discuss recent efforts at drafting national standards for interpreting services,including the ASTM Standard Guide,the draft Chinese standard,and Austrian Standards 1202and 1203.I will argue that standard-setting for professional interpreting services must be informed by insights from theoretical and empirical research if standards of practice are to reflect the full complexity and variety of professional reality.

  5. Instrumentation challenges of a pushbroom hyperspectral imaging system for currency counterfeit applications

    Science.gov (United States)

    Lim, Hoong-Ta; Vadakke Matham, Murukeshan

    2015-07-01

    Hyperspectral imaging allows the intensity of narrow and adjacent spectral bands over a large spectral range to be recorded, giving rich spectral information for each pixel in the imaged region. The spectral characteristics of each point in the imaged region can thus be detected, which is useful for quantification and classification. Hyperspectral imaging has been used in many applications such as remote sensing, quality assessment of agro-food products, biomedical imaging and document counterfeit application. This paper presents a pushbroom spatial-scanning imager, which gives a higher spectral resolution over a broad spectral range. Although a spatial-scanning imager may be slower due to the need to perform mechanical scanning, such a high spectral resolution is especially important in applications where the capability to perform classification is much more important than speed. The application of this system is demonstrated for currency counterfeit detection applications. The high spectral resolution of a pushbroom imager is able to capture fine spectral details of the samples used in this research, providing important information required for classification. Using this technique, the reflectance is acquired from specific regions of a genuine and counterfeit note. The spectra of the same region from both notes are then compared to distinguish and delineate the differences between them. The spectrum acquired from a genuine note can then be used as a reference from which future comparison can be based upon for identifying currency counterfeit and related relevant applications.

  6. A liquid crystal display with consistent moving image quality regardless of viewing angles

    Science.gov (United States)

    Kim, Jong-Man; Kim, Seung-Ryul; Kim, Jongbin; Kim, Minkoo; Lee, Seung-Woo

    2014-08-01

    This paper proposes a new overdrive (OD) technology to precisely compensate for the viewing angle dependent characteristics of LCDs. This paper reports that optical response of liquid crystal displays (LCDs) is considerably dependent on viewing angles for the first time. The new OD technology applies different OD look-up tables (LUTs) depending on the viewing angles. In addition, we combine a new OD technology with an eye tracker that is usually adopted for autostereoscopic 3D LCD systems. The application results show that a new OD technology improves the motion image quality perfectly regardless of viewing angles. We expect that our proposed method will definitely enable the LCD products to have consistent motion image quality regardless of viewing angles.

  7. Relationship between image plates physical structure and quality of digital radiographic images in weld inspections

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Davi F.; Silva, Aline S.S.; Machado, Alessandra S.; Gomes, Celio S.; Nascimento, Joseilson; Lopes, Ricardo T., E-mail: davi@lin.ufrj.br.br, E-mail: aline@lin.ufrj.br, E-mail: celio@lin.ufrj.br, E-mail: alemachado@lin.ufrj.br, E-mail: joseilson@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear

    2015-07-01

    In the last decades a new type of detector which is based on photostimulable luminescence was developed. There are currently many kinds of image plates (IPs) available on the market, originating from different manufacturers. Each kind of plate distinguishes itself from the others by its peculiar physical structure and composition, two factors which have a direct influence upon the quality of the digital radiographic images obtained through them. For this study, several kinds of IPs were tested in order to determine in which way such influence takes place. For this purpose, each kind of IP has been characterized and correlated to its response in the final image. The aim of this work was to evaluate procedures for employing Computed Radiography (CR) to welding inspections in laboratory conditions using the Simple Wall Simple Image Technique (SWSI). Tests were performed in steel welded joins of thickness 5.33, 12.70 and 25.40 mm, using CR scanner and IPs available on the market. It was used an X-Ray equipment as radiation source. The image quality parameters Basic Spatial Resolution (BSR), Normalized Signal-to-Noise Ratio (SNR{sub N}), contrast and detectability were evaluated. In order to determine in which way the IPs' properties are correlated to its response in the final image, the thickness of the sensitive layer was determined and the grain size and the elemental composition of this layer were evaluated. Based on the results drawn from this study, it is possible to conclude that the physical characteristics of image plates are essential for determining the quality of the digital radiography images acquired with them. Regarding the chemical composition of the plates, it was possible to determine that, apart from the chemical elements that were expected to be found (Ba, I and Br), only two plates, with high resolution, do not have fluorine in their composition; the presence of Strontium was also detected in the chemical composition of the plates supplied by a

  8. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    Directory of Open Access Journals (Sweden)

    Jude Hemanth Duraisamy

    2016-01-01

    Full Text Available Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA and Particle Swarm Optimization (PSO have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT and Finite Ridgelet Transform (FRIT are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  9. Application of Genetic Algorithm and Particle Swarm Optimization techniques for improved image steganography systems

    Science.gov (United States)

    Jude Hemanth, Duraisamy; Umamaheswari, Subramaniyan; Popescu, Daniela Elena; Naaji, Antoanela

    2016-01-01

    Image steganography is one of the ever growing computational approaches which has found its application in many fields. The frequency domain techniques are highly preferred for image steganography applications. However, there are significant drawbacks associated with these techniques. In transform based approaches, the secret data is embedded in random manner in the transform coefficients of the cover image. These transform coefficients may not be optimal in terms of the stego image quality and embedding capacity. In this work, the application of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have been explored in the context of determining the optimal coefficients in these transforms. Frequency domain transforms such as Bandelet Transform (BT) and Finite Ridgelet Transform (FRIT) are used in combination with GA and PSO to improve the efficiency of the image steganography system.

  10. Quality function deployment: application to rehabilitation services.

    Science.gov (United States)

    Einspruch, E M; Omachonu, V K; Einspruch, N G

    1996-01-01

    Describes how the challenge of providing rehabilitative services at reasonable costs is beginning to mount. The management of quality in rehabilitative services is therefore gaining increasing attention in the health care arena. States that if a link is implied between the above stated goal and customer satisfaction, it is imperative to evaluate quality or customer satisfaction in the context of the patient's experience. Describes the quality function deployment (QFD) system and how it leads to a better understanding of the customer's needs and wants. Explores the process of applying the concept of QFD to physical therapy.

  11. Viewpoints on Medical Image Processing: From Science to Application

    Science.gov (United States)

    Deserno (né Lehmann), Thomas M.; Handels, Heinz; Maier-Hein (né Fritzsche), Klaus H.; Mersmann, Sven; Palm, Christoph; Tolxdorff, Thomas; Wagenknecht, Gudrun; Wittenberg, Thomas

    2013-01-01

    Medical image processing provides core innovation for medical imaging. This paper is focused on recent developments from science to applications analyzing the past fifteen years of history of the proceedings of the German annual meeting on medical image processing (BVM). Furthermore, some members of the program committee present their personal points of views: (i) multi-modality for imaging and diagnosis, (ii) analysis of diffusion-weighted imaging, (iii) model-based image analysis, (iv) registration of section images, (v) from images to information in digital endoscopy, and (vi) virtual reality and robotics. Medical imaging and medical image computing is seen as field of rapid development with clear trends to integrated applications in diagnostics, treatment planning and treatment. PMID:24078804

  12. Free-breathing motion-corrected late-gadolinium-enhancement imaging improves image quality in children

    Energy Technology Data Exchange (ETDEWEB)

    Olivieri, Laura; O' Brien, Kendall J. [Children' s National Health System, Division of Cardiology, Washington, DC (United States); National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States); Cross, Russell [Children' s National Health System, Division of Cardiology, Washington, DC (United States); Xue, Hui; Kellman, Peter; Hansen, Michael S. [National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD (United States)

    2016-06-15

    The value of late-gadolinium-enhancement (LGE) imaging in the diagnosis and management of pediatric and congenital heart disease is clear; however current acquisition techniques are susceptible to error and artifacts when performed in children because of children's higher heart rates, higher prevalence of sinus arrhythmia, and inability to breath-hold. Commonly used techniques in pediatric LGE imaging include breath-held segmented FLASH (segFLASH) and steady-state free precession-based (segSSFP) imaging. More recently, single-shot SSFP techniques with respiratory motion-corrected averaging have emerged. This study tested and compared single-shot free-breathing LGE techniques with standard segmented breath-held techniques in children undergoing LGE imaging. Thirty-two consecutive children underwent clinically indicated late-enhancement imaging using intravenous gadobutrol 0.15 mmol/kg. Breath-held segSSFP, breath-held segFLASH, and free-breathing single-shot SSFP LGE sequences were performed in consecutive series in each child. Two blinded reviewers evaluated the quality of the images and rated them on a scale of 1-5 (1 = poor, 5 = superior) based on blood pool-myocardial definition, presence of cardiac motion, presence of respiratory motion artifacts, and image acquisition artifact. We used analysis of variance (ANOVA) to compare groups. Patients ranged in age from 9 months to 18 years, with a mean +/- standard deviation (SD) of 13.3 +/- 4.8 years. R-R interval at the time of acquisition ranged 366-1,265 milliseconds (ms) (47-164 beats per minute [bpm]), mean +/- SD of 843+/-231 ms (72+/-21 bpm). Mean +/- SD quality ratings for long-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.1+/-0.9, 3.4+/-0.9 and 4.0+/-0.9, respectively (P < 0.01 by ANOVA). Mean +/- SD quality ratings for short-axis imaging for segFLASH, segSSFP and single-shot SSFP were 3.4+/-1, 3.8+/-0.9 and 4.3+/-0.7, respectively (P < 0.01 by ANOVA). Single-shot late

  13. Determining quality and maturity of pomegranates using multispectral imaging

    Directory of Open Access Journals (Sweden)

    Rasool Khodabakhshian

    2017-10-01

    Full Text Available In this paper, we investigated the use of multispectral imaging technique to quantify pomegranate fruit quality. Three quality factors including total soluble solids (TSS, pH and firmness were studied at four different maturity stages of 88, 109, 124 and 143 days after full bloom (DAFB and were correlated with the spectral information extracted from images taken at four wavelength spectra. TSS, pH and firmness of the same samples were recorded using nondestructive methods and then modeled with their corresponding spectral data using partial least squire regression (PLSR. The correlation coefficient (r, RMSEC and RPD for the calibration models was found to be: r = 0.97, RMSEC = 0.21 °Brix and RPD = 6.7 °Brix for TSS; r = 0.93, RMSEC = 0.035 and RPD = 5.01 for pH; r = 0.95, RMSEC = 0.65 N and RPD = 5.65 N for firmness. Also these parameters for the validation models were as follows: r = 0.97, RMSEP = 0.22 °Brix and RPD = 5.77 °Brix for TSS; r = 0.94, RMSEP = 0.038 and RPD = 4.98 for pH; r = 0.94, RMSEP = 0.68 N and RPD = 5.33 N for firmness. The results demonstrated the capability of multispectral imaging and chemometrics as useful techniques to nondestructively monitoring pomegranate main quality attributes.

  14. Image quality in CT: From physical measurements to model observers.

    Science.gov (United States)

    Verdun, F R; Racine, D; Ott, J G; Tapiovaara, M J; Toroi, P; Bochud, F O; Veldkamp, W J H; Schegerer, A; Bouwman, R W; Giron, I Hernandez; Marshall, N W; Edyvean, S

    2015-12-01

    Evaluation of image quality (IQ) in Computed Tomography (CT) is important to ensure that diagnostic questions are correctly answered, whilst keeping radiation dose to the patient as low as is reasonably possible. The assessment of individual aspects of IQ is already a key component of routine quality control of medical x-ray devices. These values together with standard dose indicators can be used to give rise to 'figures of merit' (FOM) to characterise the dose efficiency of the CT scanners operating in certain modes. The demand for clinically relevant IQ characterisation has naturally increased with the development of CT technology (detectors efficiency, image reconstruction and processing), resulting in the adaptation and evolution of assessment methods. The purpose of this review is to present the spectrum of various methods that have been used to characterise image quality in CT: from objective measurements of physical parameters to clinically task-based approaches (i.e. model observer (MO) approach) including pure human observer approach. When combined together with a dose indicator, a generalised dose efficiency index can be explored in a framework of system and patient dose optimisation. We will focus on the IQ methodologies that are required for dealing with standard reconstruction, but also for iterative reconstruction algorithms. With this concept the previously used FOM will be presented with a proposal to update them in order to make them relevant and up to date with technological progress. The MO that objectively assesses IQ for clinically relevant tasks represents the most promising method in terms of radiologist sensitivity performance and therefore of most relevance in the clinical environment.

  15. Enhancing the quality metric of protein microarray image

    Institute of Scientific and Technical Information of China (English)

    王立强; 倪旭翔; 陆祖康; 郑旭峰; 李映笙

    2004-01-01

    The novel method of improving the quality metric of protein microarray image presented in this paper reduces impulse noise by using an adaptive median filter that employs the switching scheme based on local statistics characters; and achieves the impulse detection by using the difference between the standard deviation of the pixels within the filter window and the current pixel of concern. It also uses a top-hat filter to correct the background variation. In order to decrease time consumption, the top-hat filter core is cross structure. The experimental results showed that, for a protein microarray image contaminated by impulse noise and with slow background variation, the new method can significantly increase the signal-to-noise ratio, correct the trends in the background, and enhance the flatness of the background and the consistency of the signal intensity.

  16. Modelling the Cost and Quality of Preservation Imaging and Archiving

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad

    2009-01-01

    materials held by national cultural heritage institutions in Denmark, a study was undertaken to provide a generic cost model for digital preservation. The outcome of the study is an activity based cost model, which accounts for full economic costs. It is structured around the functional descriptions...... investigated and specifications based on best practice and testing established. Also, the image quality parameters, which influence the long term preservation costs, were identified. In addition, the suitability for preservation of different image file formats and compression algorithms was evaluated...... in the OAIS Reference Model. The cost model divides the OAIS functions in a hierarchy of cost critical activities and measurable components, which are implemented as formulas in a spreadsheet. So far the model has only been completed for activities relating to preservation planning and digital migrations...

  17. Application of Quantum Dots in Biological Imaging

    Directory of Open Access Journals (Sweden)

    Shan Jin

    2011-01-01

    Full Text Available Quantum dots (QDs are a group of semiconducting nanomaterials with unique optical and electronic properties. They have distinct advantages over traditional fluorescent organic dyes in chemical and biological studies in terms of tunable emission spectra, signal brightness, photostability, and so forth. Currently, the major type of QDs is the heavy metal-containing II-IV, IV-VI, or III-V QDs. Silicon QDs and conjugated polymer dots have also been developed in order to lower the potential toxicity of the fluorescent probes for biological applications. Aqueous solubility is the common problem for all types of QDs when they are employed in the biological researches, such as in vitro and in vivo imaging. To circumvent this problem, ligand exchange and polymer coating are proven to be effective, besides synthesizing QDs in aqueous solutions directly. However, toxicity is another big concern especially for in vivo studies. Ligand protection and core/shell structure can partly solve this problem. With the rapid development of QDs research, new elements and new morphologies have been introduced to this area to fabricate more safe and efficient QDs for biological applications.

  18. SPOT4 HRVIR first in-flight image quality results

    Science.gov (United States)

    Kubik, Philippe; Breton, Eric; Meygret, Aime; Cabrieres, Bernard; Hazane, Philippe; Leger, Dominique

    1998-12-01

    The SPOT4 remote sensing satellite was successfully launched at the end of March 1998. It was designed first of all to guarantee continuity of SPOT services beyond the year 2000 but also to improve the mission. Its two cameras are now called HRVIR since a short-wave infrared (SWIR) spectral band has been added. Like their predecessor HRV cameras, they provide 20-meter multispectral and 10-meter monospectral images with a 60 km swath for nadir viewing. SPOT4's first two months of life in orbit were dedicated to the evaluation of its image quality performances. During this period of time, the CNES team used specific target programming in order to compute image correction parameters and estimate the performance, at system level, of the image processing chain. After a description of SPOT4 system requirements and new features of the HRVIR cameras, this paper focuses on the performance deduced from in-flight measurements, methods used and their accuracy: MTF measurements, refocusing, absolute calibration, signal-to-noise Ratio, location, focal plane cartography, dynamic disturbances.

  19. Color management systems: methods and technologies for increased image quality

    Science.gov (United States)

    Caretti, Maria

    1997-02-01

    All the steps in the imaging chain -- from handling the originals in the prepress to outputting them on any device - - have to be well calibrated and adjusted to each other, in order to reproduce color images in a desktop environment as accurate as possible according to the original. Today most of the steps in the prepress production are digital and therefore it is realistic to believe that the color reproduction can be well controlled. This is true thanks to the last years development of fast, cost effective scanners, digital sources and digital proofing devices not the least. It is likely to believe that well defined tools and methods to control this imaging flow will lead to large cost and time savings as well as increased overall image quality. Until now, there has been a lack of good, reliable, easy-to- use systems (e.g. hardware, software, documentation, training and support) in an extent that has made them accessible to the large group of users of graphic arts production systems. This paper provides an overview of the existing solutions to manage colors in a digital pre-press environment. Their benefits and limitations are discussed as well as how they affect the production workflow and organization. The difference between a color controlled environment and one that is not is explained.

  20. Scale Control and Quality Management of Printed Image Parameters

    Science.gov (United States)

    Novoselskaya, O. A.; Kolesnikov, V. L.; Solov'eva, T. V.; Nagornova, I. V.; Babluyk, E. B.; Trapeznikova, O. V.

    2017-06-01

    The article provides a comparison of the main valuation techniques for a regulated parameter of printability of the offset paper by current standards GOST 24356 and ISO 3783: 2006. The results of development and implementation of a complex test scale for management and control the quality of printed production are represented. The estimation scale is introduced. It includes normalized parameters of print optical density, print uniformity, picking out speed, the value of dot gain, print contrast with the added criteria of minimizing microtexts, a paper slip, resolution threshold and effusing ability of paper surface. The results of analysis allow directionally form surface properties of the substrate to facilitate achieving the required quality of the printed image parameters, i. e. optical density of a print at a predetermined level not less than 1.3, the print uniformity with minimal deviation of dot gain about the order of 10 per cents.

  1. Nonlinear filtering for character recognition in low quality document images

    Science.gov (United States)

    Diaz-Escobar, Julia; Kober, Vitaly

    2014-09-01

    Optical character recognition in scanned printed documents is a well-studied task, where the captured conditions like sheet position, illumination, contrast and resolution are controlled. Nowadays, it is more practical to use mobile devices for document capture than a scanner. So as a consequence, the quality of document images is often poor owing to presence of geometric distortions, nonhomogeneous illumination, low resolution, etc. In this work we propose to use multiple adaptive nonlinear composite filters for detection and classification of characters. Computer simulation results obtained with the proposed system are presented and discussed.

  2. Standard practice for design, manufacture and material grouping classification of wire image quality indicators (IQI) used for radiology

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers the design, material grouping classification, and manufacture of wire image quality indicators (IQI) used to indicate the quality of radiologic images. 1.2 This practice is applicable to X-ray and gamma-ray radiology. 1.3 This practice covers the use of wire penetrameters as the controlling image quality indicator for the material thickness range from 6.4 to 152 mm (0.25 to 6.0 in.). 1.4 The values stated in inch-pound units are to be regarded as standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  3. Evaluation of controlled-drift detectors in X-ray spectroscopic imaging applications.

    Science.gov (United States)

    Castoldi, Andrea; Guazzoni, Chiara; Ozkan, Cigdem; Vedani, Giorgio; Hartmann, Robert; Bjeoumikhov, Aniouar

    2009-06-01

    A detector that looks promising for advanced imaging modalities--such as X-ray absorption contrast imaging, X-ray fluorescence imaging, and diffraction-enhanced imaging--is the controlled-drift detector (CDD). The CDD is a novel two-dimensional X-ray imager with energy resolving capability of spectroscopic quality. It is built on a fully depleted silicon wafer and features fast readout while being operated at or near room temperature. The use of CDDs in the aforementioned applications allows translating these techniques from synchrotron-based experiments to laboratory-size experiments using polychromatic X-ray generators. We have built a dedicated and versatile detection module based on a 36 mm2 CDD chip featuring pixels of 180 x 180 microm 2, and we evaluated the system performance in different X-ray imaging applications both with synchrotron-based experiments and in the laboratory environment.

  4. The Performance of Discret Bandelet Transform Coupled by SPIHT Coder to Improve the Visuel Quality of Biomedical Color Image Compression

    Directory of Open Access Journals (Sweden)

    Beladgham Mohammed

    2014-04-01

    Full Text Available The search for a good representation is a central problem of image processing, this paper explores a new transform type to solve this problem. Color Image compression is now essential for applications such as transmission and storage in data. In the field of medical diagnostics, interested parties have resorted increasingly to color medical imaging. It is well established that the accuracy and completeness of diagnosis are initially connected with the image quality. This paper introduces an algorithm for color medical image compression based on the bandelet transform coupled with SP?HT coding algorithm;bandelet transform is a new method based on capturing the complex geometric content in image. The goal of this paper is to examine the capacity of this transform proposed to offer an optimal representation for image geometric, In order to enhance the compression by our algorithm, we have compared the results obtained with bandelet transform application in satellite image field. For this reason, we evaluated two parameters known for their calculation speed. The first parameter is the PSNR; the second is MSSIM (structural similarity to measure the quality of compressed image. We concluded that the results obtained are very satisfactory for color medical image domain.

  5. Optimal Non-Invasive Fault Classification Model for Packaged Ceramic Tile Quality Monitoring Using MMW Imaging

    Science.gov (United States)

    Agarwal, Smriti; Singh, Dharmendra

    2016-04-01

    Millimeter wave (MMW) frequency has emerged as an efficient tool for different stand-off imaging applications. In this paper, we have dealt with a novel MMW imaging application, i.e., non-invasive packaged goods quality estimation for industrial quality monitoring applications. An active MMW imaging radar operating at 60 GHz has been ingeniously designed for concealed fault estimation. Ceramic tiles covered with commonly used packaging cardboard were used as concealed targets for undercover fault classification. A comparison of computer vision-based state-of-the-art feature extraction techniques, viz, discrete Fourier transform (DFT), wavelet transform (WT), principal component analysis (PCA), gray level co-occurrence texture (GLCM), and histogram of oriented gradient (HOG) has been done with respect to their efficient and differentiable feature vector generation capability for undercover target fault classification. An extensive number of experiments were performed with different ceramic tile fault configurations, viz., vertical crack, horizontal crack, random crack, diagonal crack along with the non-faulty tiles. Further, an independent algorithm validation was done demonstrating classification accuracy: 80, 86.67, 73.33, and 93.33 % for DFT, WT, PCA, GLCM, and HOG feature-based artificial neural network (ANN) classifier models, respectively. Classification results show good capability for HOG feature extraction technique towards non-destructive quality inspection with appreciably low false alarm as compared to other techniques. Thereby, a robust and optimal image feature-based neural network classification model has been proposed for non-invasive, automatic fault monitoring for a financially and commercially competent industrial growth.

  6. The Image Quality of a Digital Chest X-Ray Radiography System: Comparison of Quantitative Image Quality Analysis and Radiologists' Visual Scoring

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Ji Ho [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Chung, Myung Jin [Dept. of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Darl; Kim, Won Taek; Kim, Yong Ho; Ki, Yong Kan; Kim, DFong Hyun; Lee, Ju Hee; Kim, Dong Won [Dept. of Radiology Oncology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of); Jeon, Ho Sang [Reserach Institue for Convergence of Biomedical Science and Technology, Yongsan Hospital, Pusan National University College of Medicine, Yongsan (Korea, Republic of)

    2011-11-15

    To evaluate the performance of imaging devices, which should be periodically monitored to maintain high quality images to the radiologists. Additionally, this evaluation may prevent patients from radiation over-exposure. The most suitable engineering standard for imaging performance evaluation of digital X-ray thoracic images was determined. IEC 62220-1 standards were used to evaluate the performance of the images. In succession, the visibilities of overall image, pneumothorax, and humerus head in anthropomorphic thoracic phantom images were used to evaluate the image qualities by radiologists. The rank correlation coefficient (p) of visual scoring by radiologists with system spatial resolution is not meaningful (p-value, p = 0.295), but is significant with image noise (p-value, p -0.9267). Finally, the noise equivalent quanta (NEQ) presents a high rank correlation for visual scoring of radiologists (p-value, p = 0.9320). Image quality evaluation of radiologists were mainly affected by imaging noise. Hence, the engineered standard for evaluating image noise is the most important index to effectively monitor the performance of X-ray images. Additionally, the NEQ can be used to evaluate the performance of radiographic systems, because it theoretically corresponds to the synthetic image quality of systems.

  7. Application of radiological imaging methods to radioactive waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tessaro, Ana Paula Gimenes; Souza, Daiane Cristini B. de; Vicente, Roberto, E-mail: aptessaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    Radiological imaging technologies are most frequently used for medical diagnostic purposes but are also useful in materials characterization and other non-medical applications in research and industry. The characterization of radioactive waste packages or waste samples can also benefit from these techniques. In this paper, the application of some imaging methods is examined for the physical characterization of radioactive wastes constituted by spent ion-exchange resins and activated charcoal beds stored at the Radioactive Waste Management Department of IPEN. These wastes are generated when the filter media of the water polishing system of the IEA-R1 Nuclear Research Reactor is no longer able to maintain the required water quality and are replaced. The IEA-R1 is a 5MW pool-type reactor, moderated and cooled by light water, and fission and activation products released from the reactor core must be continuously removed to prevent activity buildup in the water. The replacement of the sorbents is carried out by pumping from the filter tanks into several 200 L drums, each drum getting a variable amount of water. Considering that the results of radioanalytical methods to determine the concentrations of radionuclides are usually expressed on dry basis,the amount of water must be known to calculate the total activity of each package. At first sight this is a trivial problem that demanded, however some effort to be solved. The findings on this subject are reported in this paper. (author)

  8. Sleep Applications to Assess Sleep Quality.

    Science.gov (United States)

    Fietze, Ingo

    2016-12-01

    This article highlights the potential uses that smartphone applications may have for helping those with sleep problems. Applications in smartphones offer the promised possibility of detection of sleep. From the author's own experience, one can also conclude that sleep applications are approximately as good as polysomnography in detection of sleep time, similar to the conventional wearable actimeters. In the future, sleep applications will help to further enhance awareness of sleep health and to distinguish those who actually poorly and only briefly sleep from those who suffer more likely from paradox insomnia. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Quality Enhancement and Nerve Fibre Layer Artefacts Removal in Retina Fundus Images by Off Axis Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Giancardo, Luca [ORNL; Meriaudeau, Fabrice [ORNL; Karnowski, Thomas Paul [ORNL; Li, Yaquin [University of Tennessee, Knoxville (UTK); Tobin Jr, Kenneth William [ORNL; Chaum, Edward [University of Tennessee, Knoxville (UTK)

    2011-01-01

    Retinal fundus images acquired with non-mydriatic digital fundus cameras are a versatile tool for the diagnosis of various retinal diseases. Because of the ease of use of newer camera models and their relative low cost, these cameras are employed worldwide by retina specialists to diagnose diabetic retinopathy and other degenerative diseases. Even with relative ease of use, the images produced by these systems sometimes suffer from reflectance artefacts mainly due to the nerve fibre layer (NFL) or other camera lens related reflections. We propose a technique that employs multiple fundus images acquired from the same patient to obtain a single higher quality image without these reflectance artefacts. The removal of bright artefacts, and particularly of NFL reflectance, can have great benefits for the reduction of false positives in the detection of retinal lesions such as exudate, drusens and cotton wool spots by automatic systems or manual inspection. If enough redundant information is provided by the multiple images, this technique also compensates for a suboptimal illumination. The fundus images are acquired in straightforward but unorthodox manner, i.e. the stare point of the patient is changed between each shot but the camera is kept fixed. Between each shot, the apparent shape and position of all the retinal structures that do not exhibit isotropic reflectance (e.g. bright artefacts) change. This physical effect is exploited by our algorithm in order to extract the pixels belonging to the inner layers of the retina, hence obtaining a single artefacts-free image.

  10. An Automatic Image Processing Workflow for Daily Magnetic Resonance Imaging Quality Assurance.

    Science.gov (United States)

    Peltonen, Juha I; Mäkelä, Teemu; Sofiev, Alexey; Salli, Eero

    2017-04-01

    The performance of magnetic resonance imaging (MRI) equipment is typically monitored with a quality assurance (QA) program. The QA program includes various tests performed at regular intervals. Users may execute specific tests, e.g., daily, weekly, or monthly. The exact interval of these measurements varies according to the department policies, machine setup and usage, manufacturer's recommendations, and available resources. In our experience, a single image acquired before the first patient of the day offers a low effort and effective system check. When this daily QA check is repeated with identical imaging parameters and phantom setup, the data can be used to derive various time series of the scanner performance. However, daily QA with manual processing can quickly become laborious in a multi-scanner environment. Fully automated image analysis and results output can positively impact the QA process by decreasing reaction time, improving repeatability, and by offering novel performance evaluation methods. In this study, we have developed a daily MRI QA workflow that can measure multiple scanner performance parameters with minimal manual labor required. The daily QA system is built around a phantom image taken by the radiographers at the beginning of day. The image is acquired with a consistent phantom setup and standardized imaging parameters. Recorded parameters are processed into graphs available to everyone involved in the MRI QA process via a web-based interface. The presented automatic MRI QA system provides an efficient tool for following the short- and long-term stability of MRI scanners.

  11. Pose estimation quality assessment for intra-operative image guidance systems

    Science.gov (United States)

    Egli, Adrian; Kleinszig, Gerhard; John, Adrian; Fernandez, Alberto; Cardelino, Juan

    2013-03-01

    In trauma and orthopedic surgery screw assessment and trajectory prediction using two-dimensional X-ray images is very difficult due to projected 3D information. However screw assessment can be done with multiple X-ray images. If the X-ray image contains the projected implant geometry it can be used as global coordinate reference. Thereby multiple independent X-ray images can be synchronized by estimating the implant pose in each single image. Consequently high accuracy pose estimation is fundamental. To measure the outcome quality an evaluation process has been designed. The evaluation process investigates in its first step several clinical intra-operative anterior-posterior (AP) and medio-lateral (ML) X-ray images which have been analyzed using a manual pose estimation method. With the manual method the six 3D parameters of the implant pose are estimated. These parameters define as well the camera pose relative to the implant. Based on the pose parameters of all clinical cases the capturing range for typical AP and ML images is statistically defined. The implant was attached to a phantom with 16 steel balls which allows to calculate the ground truth pose. Afterwards several X-ray images of the phantom are taken within the statistically defined capturing range. With the known ground truth different pose estimation methods can be compared. For each method the estimation quality can be calculated. In addition this error calculation can be used to adjust the initial manually determined capturing range. This paper explains the error evaluation process and describes how to validate pose estimation methods for clinical applications.

  12. High definition ultrasound imaging for battlefield medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Kwok, K.S.; Morimoto, A.K.; Kozlowski, D.M.; Krumm, J.C.; Dickey, F.M. [Sandia National Labs., Albuquerque, NM (United States); Rogers, B; Walsh, N. [Texas Univ. Health Science Center, San Antonio, TX (United States)

    1996-06-23

    A team has developed an improved resolution ultrasound system for low cost diagnostics. This paper describes the development of an ultrasound based imaging system capable of generating 3D images showing surface and subsurface tissue and bone structures. We include results of a comparative study between images obtained from X-Ray Computed Tomography (CT) and ultrasound. We found that the quality of ultrasound images compares favorably with those from CT. Volumetric and surface data extracted from these images were within 7% of the range between ultrasound and CT scans. We also include images of porcine abdominal scans from two different sets of animal trials.

  13. Evaluation of a software package for automated quality assessment of contrast detail images--comparison with subjective visual assessment.

    Science.gov (United States)

    Pascoal, A; Lawinski, C P; Honey, I; Blake, P

    2005-12-07

    Contrast detail analysis is commonly used to assess image quality (IQ) associated with diagnostic imaging systems. Applications include routine assessment of equipment performance and optimization studies. Most frequently, the evaluation of contrast detail images involves human observers visually detecting the threshold contrast detail combinations in the image. However, the subjective nature of human perception and the variations in the decision threshold pose limits to the minimum image quality variations detectable with reliability. Objective methods of assessment of image quality such as automated scoring have the potential to overcome the above limitations. A software package (CDRAD analyser) developed for automated scoring of images produced with the CDRAD test object was evaluated. Its performance to assess absolute and relative IQ was compared with that of an average observer. Results show that the software does not mimic the absolute performance of the average observer. The software proved more sensitive and was able to detect smaller low-contrast variations. The observer's performance was superior to the software's in the detection of smaller details. Both scoring methods showed frequent agreement in the detection of image quality variations resulting from changes in kVp and KERMA(detector), which indicates the potential to use the software CDRAD analyser for assessment of relative IQ.

  14. Evaluation of a software package for automated quality assessment of contrast detail images-comparison with subjective visual assessment

    Energy Technology Data Exchange (ETDEWEB)

    Pascoal, A [Medical Engineering and Physics, King' s College London, Faraday Building Denmark Hill, London SE5 8RX (Denmark); Lawinski, C P [KCARE - King' s Centre for Assessment of Radiological Equipment, King' s College Hospital, Faraday Building Denmark Hill, London SE5 8RX (Denmark); Honey, I [KCARE - King' s Centre for Assessment of Radiological Equipment, King' s College Hospital, Faraday Building Denmark Hill, London SE5 8RX (Denmark); Blake, P [KCARE - King' s Centre for Assessment of Radiological Equipment, King' s College Hospital, Faraday Building Denmark Hill, London SE5 8RX (Denmark)

    2005-12-07

    Contrast detail analysis is commonly used to assess image quality (IQ) associated with diagnostic imaging systems. Applications include routine assessment of equipment performance and optimization studies. Most frequently, the evaluation of contrast detail images involves human observers visually detecting the threshold contrast detail combinations in the image. However, the subjective nature of human perception and the variations in the decision threshold pose limits to the minimum image quality variations detectable with reliability. Objective methods of assessment of image quality such as automated scoring have the potential to overcome the above limitations. A software package (CDRAD analyser) developed for automated scoring of images produced with the CDRAD test object was evaluated. Its performance to assess absolute and relative IQ was compared with that of an average observer. Results show that the software does not mimic the absolute performance of the average observer. The software proved more sensitive and was able to detect smaller low-contrast variations. The observer's performance was superior to the software's in the detection of smaller details. Both scoring methods showed frequent agreement in the detection of image quality variations resulting from changes in kVp and KERMA{sub detector}, which indicates the potential to use the software CDRAD analyser for assessment of relative IQ.

  15. Resonance Energy Transfer Molecular Imaging Application in Biomedicine

    Directory of Open Access Journals (Sweden)

    NIE Da-hong1,2;TANG Gang-hua1,3

    2016-11-01

    Full Text Available Resonance energy transfer molecular imaging (RETI can markedly improve signal intensity and tissue penetrating capacity of optical imaging, and have huge potential application in the deep-tissue optical imaging in vivo. Resonance energy transfer (RET is an energy transition from the donor to an acceptor that is in close proximity, including non-radiative resonance energy transfer and radiative resonance energy transfer. RETI is an optical imaging technology that is based on RET. RETI mainly contains fluorescence resonance energy transfer imaging (FRETI, bioluminescence resonance energy transfer imaging (BRETI, chemiluminescence resonance energy transfer imaging (CRETI, and radiative resonance energy transfer imaging (RRETI. RETI is the hot field of molecular imaging research and has been widely used in the fields of biology and medicine. This review mainly focuses on RETI principle and application in biomedicine.

  16. Aspects on Image Quality in Radiologic Evaluation of the Urinary Tract

    OpenAIRE

    2012-01-01

    The focus of this document is on image quality as one of the factors fundamental for the diagnostic process. With the rising number of procedures and the trend towards more complicated examinations, urinary tract investigations was chosen in this work as a good clinical model for evaluation of the factors influencing image quality and of the ways of evaluating image quality. In paper I, a method is described for optimisation during the introduction of a new imaging system, with a focus on the...

  17. Minimal form factor digital-image sensor for endoscopic applications

    Science.gov (United States)

    Wäny, Martin; Voltz, Stephan; Gaspar, Fabio; Chen, Lei

    2009-02-01

    This paper presents a digital image sensor SOC featuring a total chip area (including dicing tolerances) of 0.34mm2 for endoscopic applications. Due to this extremely small form factor the sensor enables integration in endoscopes, guide wires and locater devices of less than 1mm outer diameter. The sensor embeds a pixel matrix of 10'000 pixels with a pitch of 3um x 3um covered with RGB filters in Bayer pattern. The sensor operates fully autonomous, controlled by an on chip ring oscillator and readout state machine, which controls integration AD conversion and data transmission, thus the sensor only requires 4 pin's for power supply and data communication. The sensor provides a frame rate of 40Frames per second over a LVDS serial data link. The endoscopic application requires that the sensor must work without any local power decoupling capacitances at the end of up to 2m cabling and be able to sustain data communication over the same wire length without deteriorating image quality. This has been achieved by implementation of a current mode successive approximation ADC and current steering LVDS data transmission. An band gap circuit with -40dB PSRR at the data frequency was implemented as on chip reference to improve robustness against power supply ringing due to the high series inductance of the long cables. The B&W versions of the sensor provides a conversion gain of 30DN/nJ/cm2 at 550nm with a read noise in dark of 1.2DN when operated at 2m cable. Using the photon transfer method according to EMVA1288 standard the full well capacity was determined to be 18ke-. According to our knowledge the presented work is the currently world smallest fully digital image sensor. The chip was designed along with a aspheric single surface lens to assemble on the chip without increasing the form factor. The extremely small form factor of the resulting camera permit's to provide visualization with much higher than state of the art spatial resolution in sub 1mm endoscopic

  18. Despeckle filtering for ultrasound imaging and video II selected applications

    CERN Document Server

    Loizou, Christos P

    2015-01-01

    In ultrasound imaging and video visual perception is hindered by speckle multiplicative noise that degrades the quality. Noise reduction is therefore essential for improving the visual observation quality or as a pre-processing step for further automated analysis, such as image/video segmentation, texture analysis and encoding in ultrasound imaging and video. The goal of the first book (book 1 of 2 books) was to introduce the problem of speckle in ultrasound image and video as well as the theoretical background, algorithmic steps, and the MatlabTM for the following group of despeckle filters:

  19. Image-based cell quality evaluation to detect irregularities under same culture process of human induced pluripotent stem cells.

    Science.gov (United States)

    Nagasaka, Risako; Gotou, Yuto; Yoshida, Kei; Kanie, Kei; Shimizu, Kazunori; Honda, Hiroyuki; Kato, Ryuji

    2017-05-01

    To meet the growing demand for human induced pluripotent stem cells (iPSCs) for various applications, technologies that enable the manufacturing of iPSCs on a large scale should be developed. There are several technological challenges in iPSC manufacturing technology. Image-based cell quality evaluation technology for monitoring iPSC quality in culture enables the manufacture of intact cells for further applications. Although several studies have reported the effectiveness of image-based evaluation of iPSCs, it remains challenging to detect irregularities that may arise using the same processing operations during quality evaluation of automated processing. In this study, we investigated the evaluation performance of image-based cell quality analysis in detecting small differences that can result from human measurement, even when the same protocol is followed. To imitate such culture conditions, by image-analysis guided colony pickup, we changed the proportions of morphologically different subpopulations: "good morphology, regular morphology correlated with undifferentiation marker expression" and "bad morphology, irregular morphology correlated with loss of undifferentiation marker expression". In addition, comprehensive gene-expression and metabolomics analyses were carried out for the same samples to investigate performance differences. Our data shows an example of investigating the usefulness and sensitivity of quality evaluation methods for iPSC quality monitoring. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Pulse foods: processing, quality and nutraceutical applications

    National Research Council Canada - National Science Library

    Tiwari, Brijesh K; Gowen, Aoife; McKenna, B. M

    2011-01-01

    ... Applications Edited by Brijesh K. Tiwari Department of Food and Tourism, Manchester Metropolitan University, Manchester, UK Aoife Gowen UCD School of Agriculture, Food Science and Veterinary ­ M edicine,...

  1. Applications of Digital Image Processing 11

    Science.gov (United States)

    Cho, Y. -C.

    1988-01-01

    A new technique, digital image velocimetry, is proposed for the measurement of instantaneous velocity fields of time dependent flows. A time sequence of single-exposure images of seed particles are captured with a high-speed camera, and a finite number of the single-exposure images are sampled within a prescribed period in time. The sampled images are then digitized on an image processor, enhanced, and superimposed to construct an image which is equivalent to a multiple exposure image used in both laser speckle velocimetry and particle image velocimetry. The superimposed image and a single-exposure Image are digitally Fourier transformed for extraction of information on the velocity field. A great enhancement of the dynamic range of the velocity measurement is accomplished through the new technique by manipulating the Fourier transform of both the single-exposure image and the superimposed image. Also the direction of the velocity vector is unequivocally determined. With the use of a high-speed video camera, the whole process from image acquisition to velocity determination can be carried out electronically; thus this technique can be developed into a real-time capability.

  2. Application of Uncooled Monolithic Thermoelectric Linear Arrays to Imaging Radiometers

    Science.gov (United States)

    Kruse, Paul W.

    Introduction Identification of Incipient Failure of Railcar Wheels Technical Description of the Model IR 1000 Imaging Radiometer Performance of the Model IR 1000 Imaging Radiometer Initial Application Summary Imaging Radiometer for Predictive and Preventive Maintenance Description Operation Specifications Summary References INDEX CONTENTS OF VOLUMES IN THIS SERIES

  3. Additive Manufacturing: Ensuring Quality for Spacecraft Applications

    Science.gov (United States)

    Swanson, Theodore; Stephenson, Timothy

    2014-01-01

    Reliable manufacturing requires that material properties and fabrication processes be well defined in order to insure that the manufactured parts meet specified requirements. While this issue is now relatively straightforward for traditional processes such as subtractive manufacturing and injection molding, this capability is still evolving for AM products. Hence, one of the principal challenges within AM is in qualifying and verifying source material properties and process control. This issue is particularly critical for applications in harsh environments and demanding applications, such as spacecraft.

  4. Statistical iterative reconstruction to improve image quality for digital breast tomosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Shiyu, E-mail: shiyu.xu@gmail.com; Chen, Ying, E-mail: adachen@siu.edu [Department of Electrical and Computer Engineering, Southern Illinois University Carbondale, Carbondale, Illinois 62901 (United States); Lu, Jianping; Zhou, Otto [Department of Physics and Astronomy and Curriculum in Applied Sciences and Engineering, University of North Carolina Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

    2015-09-15

    Purpose: Digital breast tomosynthesis (DBT) is a novel modality with the potential to improve early detection of breast cancer by providing three-dimensional (3D) imaging with a low radiation dose. 3D image reconstruction presents some challenges: cone-beam and flat-panel geometry, and highly incomplete sampling. A promising means to overcome these challenges is statistical iterative reconstruction (IR), since it provides the flexibility of accurate physics modeling and a general description of system geometry. The authors’ goal was to develop techniques for applying statistical IR to tomosynthesis imaging data. Methods: These techniques include the following: a physics model with a local voxel-pair based prior with flexible parameters to fine-tune image quality; a precomputed parameter λ in the prior, to remove data dependence and to achieve a uniform resolution property; an effective ray-driven technique to compute the forward and backprojection; and an oversampled, ray-driven method to perform high resolution reconstruction with a practical region-of-interest technique. To assess the performance of these techniques, the authors acquired phantom data on the stationary DBT prototype system. To solve the estimation problem, the authors proposed an optimization-transfer based algorithm framework that potentially allows fewer iterations to achieve an acceptably converged reconstruction. Results: IR improved the detectability of low-contrast and small microcalcifications, reduced cross-plane artifacts, improved spatial resolution, and lowered noise in reconstructed images. Conclusions: Although the computational load remains a significant challenge for practical development, the superior image quality provided by statistical IR, combined with advancing computational techniques, may bring benefits to screening, diagnostics, and intraoperative imaging in clinical applications.

  5. Recent advances in rapid and non-destructive assessment of meat quality using hyperspectral imaging

    Science.gov (United States)

    Tao, Feifei; Ngadi, Michael

    2016-05-01

    Meat is an important food item in human diet. Its production and consumption has greatly increased in the last decades with the development of economies and improvement of peoples' living standards. However, most of the traditional methods for evaluation of meat quality are time-consuming, laborious, inconsistent and destructive to samples, which make them not appropriate for a fast-paced production and processing environment. Development of innovative and non-destructive optical sensing techniques to facilitate simple, fast, and accurate evaluation of quality are attracting increasing attention in the food industry. Hyperspectral imaging is one of the promising techniques. It integrates the combined merits of imaging and spectroscopic techniques. This paper provides a comprehensive review on recent advances in evaluation of the important quality attributes of meat including color, marbling, tenderness, pH, water holding capacity, and also chemical composition attributes such as moisture content, protein content and fat content in pork, beef and lamb. In addition, the future potential applications and trends of hyperspectral imaging are also discussed in this paper.

  6. SENTINEL-2 image quality and level 1 processing

    Science.gov (United States)

    Meygret, Aimé; Baillarin, Simon; Gascon, Ferran; Hillairet, Emmanuel; Dechoz, Cécile; Lacherade, Sophie; Martimort, Philippe; Spoto, François; Henry, Patrice; Duca, Riccardo

    2009-08-01

    In the framework of the Global Monitoring for Environment and Security (GMES) programme, the European Space Agency (ESA) in partnership with the European Commission (EC) is developing the SENTINEL-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a twin satellites configuration deployed in polar sun-synchronous orbit and is designed to offer a unique combination of systematic global coverage with a wide field of view (290km), a high revisit (5 days at equator with two satellites), a high spatial resolution (10m, 20m and 60 m) and multi-spectral imagery (13 bands in the visible and the short wave infrared spectrum). SENTINEL-2 will ensure data continuity of SPOT and LANDSAT multispectral sensors while accounting for future service evolution. This paper presents the main geometric and radiometric image quality requirements for the mission. The strong multi-spectral and multi-temporal registration requirements constrain the stability of the platform and the ground processing which will automatically refine the geometric physical model through correlation technics. The geolocation of the images will take benefits from a worldwide reference data set made of SENTINEL-2 data strips geolocated through a global space-triangulation. These processing are detailed through the description of the level 1C production which will provide users with ortho-images of Top of Atmosphere reflectances. The huge amount of data (1.4 Tbits per orbit) is also a challenge for the ground processing which will produce at level 1C all the acquired data. Finally we discuss the different geometric (line of sight, focal plane cartography, ...) and radiometric (relative and absolute camera sensitivity) in-flight calibration methods that will take advantage of the on-board sun diffuser and ground targets to answer the severe mission requirements.

  7. Surface Flux Modeling for Air Quality Applications

    Directory of Open Access Journals (Sweden)

    Limei Ran

    2011-08-01

    Full Text Available For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic compounds, can be upward into the air as well as downward to the surface and therefore should be modeled as bi-directional fluxes. Model parameterizations of dry deposition in air quality models have been represented by simple electrical resistance analogs for almost 30 years. Uncertainties in surface flux modeling in global to mesoscale models are being slowly reduced as more field measurements provide constraints on parameterizations. However, at the same time, more chemical species are being added to surface flux models as air quality models are expanded to include more complex chemistry and are being applied to a wider array of environmental issues. Since surface flux measurements of many of these chemicals are still lacking, resistances are usually parameterized using simple scaling by water or lipid solubility and reactivity. Advances in recent years have included bi-directional flux algorithms that require a shift from pre-computation of deposition velocities to fully integrated surface flux calculations within air quality models. Improved modeling of the stomatal component of chemical surface fluxes has resulted from improved evapotranspiration modeling in land surface models and closer integration between meteorology and air quality models. Satellite-derived land use characterization and vegetation products and indices are improving model representation of spatial and temporal variations in surface flux processes. This review describes the current state of chemical dry deposition modeling, recent progress in bi-directional flux modeling, synergistic model development research with field measurements, and coupling with meteorological land surface models.

  8. Application of cone beam computed tomography in facial imaging science

    Institute of Scientific and Technical Information of China (English)

    Zacharias Fourie; Janalt Damstra; Yijin Ren

    2012-01-01

    The use of three-dimensional (3D) methods for facial imaging has increased significantly over the past years.Traditional 2D imaging has gradually being replaced by 3D images in different disciplines,particularly in the fields of orthodontics,maxillofacial surgery,plastic and reconstructive surgery,neurosurgery and forensic sciences.In most cases,3D facial imaging overcomes the limitations of traditional 2D methods and provides the clinician with more accurate information regarding the soft-tissues and the underlying skeleton.The aim of this study was to review the types of imaging methods used for facial imaging.It is important to realize the difference between the types of 3D imaging methods as application and indications thereof may differ.Since 3D cone beam computed tomography (CBCT) imaging will play an increasingly importanl role in orthodontics and orthognathic surgery,special emphasis should be placed on discussing CBCT applications in facial evaluations.

  9. Application of Service Quality Model in Education Environment

    Directory of Open Access Journals (Sweden)

    Ting Ding Hooi

    2016-02-01

    Full Text Available Most of the ideas on service quality stem from the West. The massive developments in research in the West are undeniable of their importance. This leads to the generation and development of new ideas. These ideas were subsequently channeled to developing countries. Ideas obtained were then formulated and used by these developing countries in order to obtain better approach in channeling service quality. There are ample to be learnt from the service quality model, SERVQUAL which attain high acceptance in the West. Service quality in the education system is important to guarantee the effectiveness and quality of education. Effective and quality education will be able to offer quality graduates, which will contribute to the development of the nation. This paper will discuss the application of the SERVQUAL model into the education environment.

  10. Tin-filter enhanced dual-energy-CT: image quality and accuracy of CT numbers in virtual noncontrast imaging.

    Science.gov (United States)

    Kaufmann, Sascha; Sauter, Alexander; Spira, Daniel; Gatidis, Sergios; Ketelsen, Dominik; Heuschmid, Martin; Claussen, Claus D; Thomas, Christoph

    2013-05-01

    To measure and compare the objective image quality of true noncontrast (TNC) images with virtual noncontrast (VNC) images acquired by tin-filter-enhanced, dual-source, dual-energy computed tomography (DECT) of upper abdomen. Sixty-three patients received unenhanced abdominal CT and enhanced abdominal DECT (100/140 kV with tin filter) in portal-venous phase. VNC images were calculated from the DECT datasets using commercially available software. The mean attenuation of relevant tissues and image quality were compared between the TNC and VNC images. Image quality was rated objectively by measuring image noise and the sharpness of object edges using custom-designed software. Measurements were compared using Student two-tailed t-test. Correlation coefficients for tissue attenuation measurements between TNC and VNC were calculated and the relative deviations were illustrated using Bland-Altman plots. Mean attenuation differences between TNC and VNC (HUTNC - HUVNC) image sets were as follows: right liver lobe -4.94 Hounsfield units (HU), left liver lobe -3.29 HU, vena cava -2.19 HU, spleen -7.46 HU, pancreas 1.29 HU, fat -11.14 HU, aorta 1.29 HU, bone marrow 36.83 HU (all P Mean image noise was significantly higher in TNC images (P images (P = .19). The Hounsfield units in VNC images closely resemble TNC images in the majority of the organs of the upper abdomen (kidneys, liver, pancreas). In spleen and fat, Hounsfield numbers in VNC images are tend to be higher than in TNC images. VNC images show a low image noise and satisfactory edge sharpness. Other criteria of image quality and the depiction of certain lesions need to be evaluated additionally. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

  11. The Effect of Image Quality, Repeated Study, and Assessment Method on Anatomy Learning

    Science.gov (United States)

    Fenesi, Barbara; Mackinnon, Chelsea; Cheng, Lucia; Kim, Joseph A.; Wainman, Bruce C.

    2017-01-01

    The use of two-dimensional (2D) images is consistently used to prepare anatomy students for handling real specimen. This study examined whether the quality of 2D images is a critical component in anatomy learning. The visual clarity and consistency of 2D anatomical images was systematically manipulated to produce low-quality and high-quality…

  12. A Bayesian model for predicting face recognition performance using image quality

    NARCIS (Netherlands)

    Dutta, A.; Veldhuis, Raymond N.J.; Spreeuwers, Lieuwe Jan

    2014-01-01

    Quality of a pair of facial images is a strong indicator of the uncertainty in decision about identity based on that image pair. In this paper, we describe a Bayesian approach to model the relation between image quality (like pose, illumination, noise, sharpness, etc) and corresponding face

  13. Sparse Representation-Based Image Quality Index With Adaptive Sub-Dictionaries.

    Science.gov (United States)

    Li, Leida; Cai, Hao; Zhang, Yabin; Lin, Weisi; Kot, Alex C; Sun, Xingming

    2016-08-01

    Distortions cause structural changes in digital images, leading to degraded visual quality. Dictionary-based sparse representation has been widely studied recently due to its ability to extract inherent image structures. Meantime, it can extract image features with slightly higher level semantics. Intuitively, sparse representation can be used for image quality assessment, because visible distortions can cause significant changes to the sparse features. In this paper, a new sparse representation-based image quality assessment model is proposed based on the construction of adaptive sub-dictionaries. An overcomplete dictionary trained from natural images is employed to capture the structure changes between the reference and distorted images by sparse feature extraction via adaptive sub-dictionary selection. Based on the observation that image sparse features are invariant to weak degradations and the perceived image quality is generally influenced by diverse issues, three auxiliary quality features are added, including gradient, color, and luminance information. The proposed method is not sensitive to training images, so a universal dictionary can be adopted for quality evaluation. Extensive experiments on five public image quality databases demonstrate that the proposed method produces the state-of-the-art results, and it delivers consistently well performances when tested in different image quality databases.

  14. Quality assurance of electron beams using a Varian electronic portal imaging device.

    Science.gov (United States)

    Wang, Y; Heaton, R; Norrlinger, B; Islam, M

    2013-08-21

    The feasibility of utilizing an electronic portal imaging device (EPID) for the quality assurance of electron beams was investigated. This work was conducted on a Varian 2100iX machine equipped with an amorphous silicon (aS1000) portal imager. The linearity of the imager pixel response as a function of exposed dose was first confirmed. The short-term reproducibility of the EPID response to electron beams was verified. Low (6 MeV), medium (12 MeV) and high (20 MeV) energies were tested, each along with small (6 × 6 cm(2)), medium (10 × 10 cm(2)) and large (20 × 20 cm(2)) applicators. Acquired EPID images were analyzed using an in-house MATLAB code for radiation field size, penumbra, symmetry and flatness. Field sizes and penumbra values agreed with those from film dosimetry to within 1 mm. Field symmetry and flatness constancies were measured over a period of three weeks. The results indicate that EPID can be used for routine quality assurance of electron beams.

  15. Effect of temporal acquisition parameters on image quality of strain time constant elastography.

    Science.gov (United States)

    Nair, Sanjay; Varghese, Joshua; Chaudhry, Anuj; Righetti, Raffaella

    2015-04-01

    Ultrasound methods to image the time constant (TC) of elastographic tissue parameters have been recently developed. Elastographic TC images from creep or stress relaxation tests have been shown to provide information on the viscoelastic and poroelastic behavior of tissues. However, the effect of temporal ultrasonic acquisition parameters and input noise on the image quality of the resultant strain TC elastograms has not been fully investigated yet. Understanding such effects could have important implications for clinical applications of these novel techniques. This work reports a simulation study aimed at investigating the effects of varying windows of observation, acquisition frame rate, and strain signal-to-noise ratio (SNR) on the image quality of elastographic TC estimates. A pilot experimental study was used to corroborate the simulation results in specific testing conditions. The results of this work suggest that the total acquisition time necessary for accurate strain TC estimates has a linear dependence to the underlying strain TC (as estimated from the theoretical strain-vs.-time curve). The results also indicate that it might be possible to make accurate estimates of the elastographic TC (within 10% error) using windows of observation as small as 20% of the underlying TC, provided sufficiently fast acquisition rates (>100 Hz for typical acquisition depths). The limited experimental data reported in this study statistically confirm the simulation trends, proving that the proposed model can be used as upper bound guidance for the correct execution of the experiments.

  16. An image denoising application using shearlets

    Science.gov (United States)

    Sevindir, Hulya Kodal; Yazici, Cuneyt

    2013-10-01

    Medical imaging is a multidisciplinary field related to computer science, electrical/electronic engineering, physics, mathematics and medicine. There has been dramatic increase in variety, availability and resolution of medical imaging devices for the last half century. For proper medical imaging highly trained technicians and clinicians are needed to pull out clinically pertinent information from medical data correctly. Artificial systems must be designed to analyze medical data sets either in a partially or even a fully automatic manner to fulfil the need. For this purpose there has been numerous ongoing research for finding optimal representations in image processing and computer vision [1, 18]. Medical images almost always contain artefacts and it is crucial to remove these artefacts to obtain healthy results. Out of many methods for denoising images, in this paper, two denoising methods, wavelets and shearlets, have been applied to mammography images. Comparing these two methods, shearlets give better results for denoising such data.

  17. Review of diffusion tensor imaging and its application in children

    Energy Technology Data Exchange (ETDEWEB)

    Vorona, Gregory A. [Children' s Hospital of Richmond at Virginia Commonwealth University, Department of Radiology, Richmond, VA (United States); Berman, Jeffrey I. [Children' s Hospital of Philadelphia, Department of Radiology, Philadelphia, PA (United States)

    2015-09-15

    Diffusion MRI is an imaging technique that uses the random motion of water to probe tissue microstructure. Diffusion tensor imaging (DTI) can quantitatively depict the organization and connectivity of white matter. Given the non-invasiveness of the technique, DTI has become a widely used tool for researchers and clinicians to examine the white matter of children. This review covers the basics of diffusion-weighted imaging and diffusion tensor imaging and discusses examples of their clinical application in children. (orig.)

  18. Application of electrical capacitance tomography for imaging industrial processes

    Institute of Scientific and Technical Information of China (English)

    DYAKOWSKI Tom

    2005-01-01

    Electrical tomography is, in certain cases, the most attractive method for real imaging of industrial processes, because of its inherent simplicity, rugged cons truction of the tomographer and high-speed capability. This paper presents examples illustrating applications of electrical tomography for imaging fluidized beds, bubble columns and pneumatic conveyors. Electrical tomography opens up new ways for processing, imaging and modelling multi-phase flows as shown by 2D and 3D images illustrating the various types of flow morphology.

  19. Quality of Service in Networks Supporting Cultural Multimedia Applications

    Science.gov (United States)

    Kanellopoulos, Dimitris N.

    2011-01-01

    Purpose: This paper aims to provide an overview of representative multimedia applications in the cultural heritage sector, as well as research results on quality of service (QoS) mechanisms in internet protocol (IP) networks that support such applications. Design/methodology/approach: The paper's approach is a literature review. Findings: Cultural…

  20. Digital image analysis of palaeoenvironmental records and applications

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Environmental change signals in geological or biological records are commonly reflected on their reflecting or transmitting images. These environmental signals can be extracted through digital image analysis. The analysis principle involves section line selection, color value reading and calculating environmental proxy index along the section lines, layer identification, auto-chronology and investigation of structure evolution of growth bands. On detailed illustrations of the image technique, this note provides image analyzing procedures of coral, tree-ring and stalagmite records. The environmental implications of the proxy index from image analysis are accordingly given through application demonstration of the image technique.

  1. The image quality of ion computed tomography at clinical imaging dose levels

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, David C., E-mail: dch@oncology.au.dk [Department of Experimental Clinical Oncology, Aarhus University Hospital, 8000 Aarhus (Denmark); Bassler, Niels [Department of Physics and Astronomy, Aarhus University, 8000 Aarhus (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, 8000 Aarhus, Denmark and Department of Clinical Medicine, Aarhus University, 8000 Aarhus (Denmark); Seco, Joao [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School,Boston, Massachusetts 02114 (United States)

    2014-11-01

    Purpose: Accurately predicting the range of radiotherapy ions in vivo is important for the precise delivery of dose in particle therapy. Range uncertainty is currently the single largest contribution to the dose margins used in planning and leads to a higher dose to normal tissue. The use of ion CT has been proposed as a method to improve the range uncertainty and thereby reduce dose to normal tissue of the patient. A wide variety of ions have been proposed and studied for this purpose, but no studies evaluate the image quality obtained with different ions in a consistent manner. However, imaging doses ion CT is a concern which may limit the obtainable image quality. In addition, the imaging doses reported have not been directly comparable with x-ray CT doses due to the different biological impacts of ion radiation. The purpose of this work is to develop a robust methodology for comparing the image quality of ion CT with respect to particle therapy, taking into account different reconstruction methods and ion species. Methods: A comparison of different ions and energies was made. Ion CT projections were simulated for five different scenarios: Protons at 230 and 330 MeV, helium ions at 230 MeV/u, and carbon ions at 430 MeV/u. Maps of the water equivalent stopping power were reconstructed using a weighted least squares method. The dose was evaluated via a quality factor weighted CT dose index called the CT dose equivalent index (CTDEI). Spatial resolution was measured by the modulation transfer function. This was done by a noise-robust fit to the edge spread function. Second, the image quality as a function of the number of scanning angles was evaluated for protons at 230 MeV. In the resolution study, the CTDEI was fixed to 10 mSv, similar to a typical x-ray CT scan. Finally, scans at a range of CTDEI’s were done, to evaluate dose influence on reconstruction error. Results: All ions yielded accurate stopping power estimates, none of which were statistically

  2. A Robust Design Method in Product Quality Applications

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shi-an

    2003-01-01

    In order to express information on the quality grade of product designed, the target value of product quality design was described with a fuzzy number in this paper. An alternative to Taguchi′s, the robustness application design method has been recently presented. However, neither Taguchi′s method nor the alternative method is capable of dealing satisfactorily with the frequently encountered situations in which all the noise variables cannot be studied simultaneously. Based on the ideas from response surface modeling, linear models theory, and random effects models, we provide a method for estimation in the robustness application design method in product quality applications. With this new method used, the high-quality ratio of the product designed could be increased, and the ability to resist the influence of various disturbing factors and noise factors could be enhanced.

  3. The analysis of web application quality for electronic banking

    OpenAIRE

    JANKOVIČ, JERNEJ

    2016-01-01

    The purpose of this thesis is to demonstrate a systematic analysis of web applications quality for electronic banking. In the theoretical part we focused on the ISO/IEC 25000 standard, which deals with quality of the product. With help of SQuaRE set of standards we have reviewed the contents of some standards from ISO/IEC 25000 family. At the and we used ISO/IEC 25010 quality model and ISO/IEC 25040 which contains procedure for assessing the product quality. For the assessment of user in...

  4. Advances in Application of Models in Soil Quality Evaluation

    Institute of Scientific and Technical Information of China (English)

    SI Zhi-guo; WANG Ji-jie; YU Yuan-chun; LIANG Guan-feng; CHEN Chang-ren; SHU Hong-lan

    2012-01-01

    Soil quality is a comprehensive reflection of soil properties.Since the soil quality concept was put forward in the 1970s,the quality of different type soils in different regions have been evaluated through a variety of evaluation methods,but it still lacks universal soil quantity evaluation models and methods.In this paper,the applications and prospects of grey relevancy comprehensive evaluation model,attribute hierarchical model,fuzzy comprehensive evaluation model,matter-element model,RAGA-based PPC /PPE model and GIS model in soil quality evaluation are reviewed.

  5. Quality of tomato seedling in application bioproducts

    OpenAIRE

    BOTEVA, Hriska

    2014-01-01

    The study was performed during the period 2009 - 2011 in the “Maritsa” Vegetable Crops Research Institute, Plovdiv. The effect of organic products Baikal EM – 1У, Bioglobin and Biolan on the quality of seedlings from tomato, variety Yana was studied in unheated glasshouses ro-ON type. Plants were grown on two substrates: peat-perlite substrate and substrate with Lumbrikal. The post-effect of the applied bioproducts on the plant productivity was studied in field conditions. Tomato seeds from Y...

  6. Colour application on mammography image segmentation

    Science.gov (United States)

    Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

    2017-09-01

    The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

  7. Modelling the Cost and Quality of Preservation Imaging and Archiving

    DEFF Research Database (Denmark)

    Kejser, Ulla Bøgvad

    2009-01-01

    in the OAIS Reference Model. The cost model divides the OAIS functions in a hierarchy of cost critical activities and measurable components, which are implemented as formulas in a spreadsheet. So far the model has only been completed for activities relating to preservation planning and digital migrations......, fire and other risks. In this PhD thesis it is examined how one may evaluate the long‐term costs and benefits to cultural heritage institutions of different preservation strategies for digital copies. The investigated alternatives are preserving the copies in a digital repository, and printing...... the files out on microfilm and preserving them in a non‐digital repository. In order to obtain empirical data and to understand the decisive cost factors in preservation copying, a case study was set up in which degrading sheet‐film negatives were digitised. Requirements for image quality and metadata were...

  8. Improved image quality of cone beam CT scans for radiotherapy image guidance using fiber-interspaced antiscatter grid

    Energy Technology Data Exchange (ETDEWEB)

    Stankovic, Uros; Herk, Marcel van; Ploeger, Lennert S.; Sonke, Jan-Jakob, E-mail: j.sonke@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam 1066 CX (Netherlands)

    2014-06-15

    Purpose: Medical linear accelerator mounted cone beam CT (CBCT) scanner provides useful soft tissue contrast for purposes of image guidance in radiotherapy. The presence of extensive scattered radiation has a negative effect on soft tissue visibility and uniformity of CBCT scans. Antiscatter grids (ASG) are used in the field of diagnostic radiography to mitigate the scatter. They usually do increase the contrast of the scan, but simultaneously increase the noise. Therefore, and considering other scatter mitigation mechanisms present in a CBCT scanner, the applicability of ASGs with aluminum interspacing for a wide range of imaging conditions has been inconclusive in previous studies. In recent years, grids using fiber interspacers have appeared, providing grids with higher scatter rejection while maintaining reasonable transmission of primary radiation. The purpose of this study was to evaluate the impact of one such grid on CBCT image quality. Methods: The grid used (Philips Medical Systems) had ratio of 21:1, frequency 36 lp/cm, and nominal selectivity of 11.9. It was mounted on the kV flat panel detector of an Elekta Synergy linear accelerator and tested in a phantom and a clinical study. Due to the flex of the linac and presence of gridline artifacts an angle dependent gain correction algorithm was devised to mitigate resulting artifacts. Scan reconstruction was performed using XVI4.5 augmented with inhouse developed image lag correction and Hounsfield unit calibration. To determine the necessary parameters for Hounsfield unit calibration and software scatter correction parameters, the Catphan 600 (The Phantom Laboratory) phantom was used. Image quality parameters were evaluated using CIRS CBCT Image Quality and Electron Density Phantom (CIRS) in two different geometries: one modeling head and neck and other pelvic region. Phantoms were acquired with and without the grid and reconstructed with and without software correction which was adapted for the different

  9. Signal and image processing in medical applications

    CERN Document Server

    Kumar, Amit; Rahim, B Abdul; Kumar, D Sravan

    2016-01-01

    This book highlights recent findings on and analyses conducted on signals and images in the area of medicine. The experimental investigations involve a variety of signals and images and their methodologies range from very basic to sophisticated methods. The book explains how signal and image processing methods can be used to detect and forecast abnormalities in an easy-to-follow manner, offering a valuable resource for researchers, engineers, physicians and bioinformatics researchers alike.

  10. Perceptual digital imaging methods and applications

    CERN Document Server

    Lukac, Rastislav

    2012-01-01

    Visual perception is a complex process requiring interaction between the receptors in the eye that sense the stimulus and the neural system and the brain that are responsible for communicating and interpreting the sensed visual information. This process involves several physical, neural, and cognitive phenomena whose understanding is essential to design effective and computationally efficient imaging solutions. Building on advances in computer vision, image and video processing, neuroscience, and information engineering, perceptual digital imaging greatly enhances the capabilities of tradition

  11. Practical Applications of Synthetic Aperture Imaging

    DEFF Research Database (Denmark)

    Nikolov, Svetoslav Ivanov; Kortbek, Jacob; Jensen, Jørgen Arendt

    2010-01-01

    Synthetic aperture imaging has been a focus of research for almost 3 decades. The research carried out at the Center for Fast Ultrasound Imaging has demonstrated that synthetic aperture focusing not only can be used in-vivo, but that it also yields superior B-mode and blood flow images. In the last......, and multiple angle flash imaging are just a few of the names used to describe the commercial implementations of synthetic aperture focusing. Although they sound like different algorithms, they are the same in their core, as revealed in this paper....

  12. Application of stereo-imaging technology to medical field.

    Science.gov (United States)

    Nam, Kyoung Won; Park, Jeongyun; Kim, In Young; Kim, Kwang Gi

    2012-09-01

    There has been continuous development in the area of stereoscopic medical imaging devices, and many stereoscopic imaging devices have been realized and applied in the medical field. In this article, we review past and current trends pertaining to the application stereo-imaging technologies in the medical field. We describe the basic principles of stereo vision and visual issues related to it, including visual discomfort, binocular disparities, vergence-accommodation mismatch, and visual fatigue. We also present a brief history of medical applications of stereo-imaging techniques, examples of recently developed stereoscopic medical devices, and patent application trends as they pertain to stereo-imaging medical devices. Three-dimensional (3D) stereo-imaging technology can provide more realistic depth perception to the viewer than conventional two-dimensional imaging technology. Therefore, it allows for a more accurate understanding and analysis of the morphology of an object. Based on these advantages, the significance of stereoscopic imaging in the medical field increases in accordance with the increase in the number of laparoscopic surgeries, and stereo-imaging technology plays a key role in the diagnoses of the detailed morphologies of small biological specimens. The application of 3D stereo-imaging technology to the medical field will help improve surgical accuracy, reduce operation times, and enhance patient safety. Therefore, it is important to develop more enhanced stereoscopic medical devices.

  13. Learning a channelized observer for image quality assessment.

    Science.gov (United States)

    Brankov, Jovan G; Yang, Yongyi; Wei, Liyang; El Naqa, Issam; Wernick, Miles N

    2009-07-01

    It is now widely accepted that image quality should be evaluated using task-based criteria, such as human-observer performance in a lesion-detection task. The channelized Hotelling observer (CHO) has been widely used as a surrogate for human observers in evaluating lesion detectability. In this paper, we propose that the problem of developing a numerical observer can be viewed as a system-identification or supervised-learning problem, in which the goal is to identify the unknown system of the human observer. Following this approach, we explore the possibility of replacing the Hotelling detector within the CHO with an algorithm that learns the relationship between measured channel features and human observer scores. Specifically, we develop a channelized support vector machine (CSVM) which we compare to the CHO in terms of its ability to predict human-observer performance. In the examples studied, we find that the CSVM is better able to generalize to unseen images than the CHO, and therefore may represent a useful improvement on the CHO methodology, while retaining its essential features.

  14. Digital radiography: optimization of image quality and dose using multi-frequency software

    Energy Technology Data Exchange (ETDEWEB)

    Precht, H. [University College Lillebelt, Conrad Research Center, Odense (Denmark); Gerke, O. [Odense University Hospital, Department of Nuclear Medicine, Odense (Denmark); University of Southern Denmark, Research Unit of Health Economics, Odense (Denmark); Rosendahl, K. [Haukeland University Hospital, Section of Pediatric Radiology, Bergen (Norway); University of Bergen, Institute of Surgical Sciences, Bergen (Norway); Tingberg, A. [Skaane University Hospital, Lund University (Sweden); Medical Radiation Physics, Department of Clinical Sciences, Malmoe (Sweden); Waaler, D. [Gjoevik University College, Gjoevik (Norway)

    2012-09-15

    New developments in processing of digital radiographs (DR), including multi-frequency processing (MFP), allow optimization of image quality and radiation dose. This is particularly promising in children as they are believed to be more sensitive to ionizing radiation than adults. To examine whether the use of MFP software reduces the radiation dose without compromising quality at DR of the femur in 5-year-old-equivalent anthropomorphic and technical phantoms. A total of 110 images of an anthropomorphic phantom were imaged on a DR system (Canon DR with CXDI-50 C detector and MLT[S] software) and analyzed by three pediatric radiologists using Visual Grading Analysis. In addition, 3,500 images taken of a technical contrast-detail phantom (CDRAD 2.0) provide an objective image-quality assessment. Optimal image-quality was maintained at a dose reduction of 61% with MLT(S) optimized images. Even for images of diagnostic quality, MLT(S) provided a dose reduction of 88% as compared to the reference image. Software impact on image quality was found significant for dose (mAs), dynamic range dark region and frequency band. By optimizing image processing parameters, a significant dose reduction is possible without significant loss of image quality. (orig.)

  15. Imaging-based logics for ornamental stone quality chart definition

    Science.gov (United States)

    Bonifazi, Giuseppe; Gargiulo, Aldo; Serranti, Silvia; Raspi, Costantino

    2007-02-01

    Ornamental stone products are commercially classified on the market according to several factors related both to intrinsic lythologic characteristics and to their visible pictorial attributes. Sometimes these latter aspects prevail in quality criteria definition and assessment. Pictorial attributes are in any case also influenced by the performed working actions and the utilized tools selected to realize the final stone manufactured product. Stone surface finishing is a critical task because it can contribute to enhance certain aesthetic features of the stone itself. The study was addressed to develop an innovative set of methodologies and techniques able to quantify the aesthetic quality level of stone products taking into account both the physical and the aesthetical characteristics of the stones. In particular, the degree of polishing of the stone surfaces and the presence of defects have been evaluated, applying digital image processing strategies. Morphological and color parameters have been extracted developing specific software architectures. Results showed as the proposed approaches allow to quantify the degree of polishing and to identify surface defects related to the intrinsic characteristics of the stone and/or the performed working actions.

  16. Improved structural similarity metric for the visible quality measurement of images

    Science.gov (United States)

    Lee, Daeho; Lim, Sungsoo

    2016-11-01

    The visible quality assessment of images is important to evaluate the performance of image processing methods such as image correction, compressing, and enhancement. The structural similarity is widely used to determine the visible quality; however, existing structural similarity metrics cannot correctly assess the perceived human visibility of images that have been slightly geometrically transformed or images that have undergone significant regional distortion. We propose an improved structural similarity metric that is more close to human visible evaluation. Compared with the existing metrics, the proposed method can more correctly evaluate the similarity between an original image and various distorted images.

  17. Relationships among muscle dysmorphia characteristics, body image quality of life, and coping in males.

    Science.gov (United States)

    Tod, D; Edwards, C

    2015-09-01

    The purpose of this study was to examine relationships among bodybuilding dependence, muscle satisfaction, body image-related quality of life and body image-related coping strategies, and test the hypothesis that muscle dysmorphia characteristics may predict quality of life via coping strategies. Participants (294 males, Mage=20.5 years, SD=3.1) participated in a cross-sectional survey. Participants completed questionnaires assessing muscle satisfaction, bodybuilding dependence, body image-related quality of life and body image-related coping. Quality of life was correlated positively with muscle satisfaction and bodybuilding dependence but negatively with body image coping (Plife both directly and indirectly via body image coping strategies (as evidenced by the bias corrected and accelerated bootstrapped confidence intervals). These results provide preliminary evidence regarding the ways that muscularity concerns might influence body image-related quality of life. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. BOOK REVIEW: Infrared Thermal Imaging: Fundamentals, Research and Applications Infrared Thermal Imaging: Fundamentals, Research and Applications

    Science.gov (United States)

    Planinsic, Gorazd

    2011-09-01

    Ten years ago, a book with a title like this would be interesting only to a narrow circle of specialists. Thanks to rapid advances in technology, the price of thermal imaging devices has dropped sharply, so they have, almost overnight, become accessible to a wide range of users. As the authors point out in the preface, the growth of this area has led to a paradoxical situation: now there are probably more infrared (IR) cameras sold worldwide than there are people who understand the basic physics behind them and know how to correctly interpret the colourful images that are obtained with these devices. My experience confirms this. When I started using the IR camera during lectures on the didactics of physics, I soon realized that I needed more knowledge, which I later found in this book. A wide range of potential readers and topical areas provides a good motive for writing a book such as this one, but it also represents a major challenge for authors, as compromises in the style of writing and choice of topics are required. The authors of this book have successfully achieved this, and indeed done an excellent job. This book addresses a wide range of readers, from engineers, technicians, and physics and science teachers in schools and universities, to researchers and specialists who are professionally active in the field. As technology in this area has made great progress in recent times, this book is also a valuable guide for those who opt to purchase an infrared camera. Chapters in this book could be divided into three areas: the fundamentals of IR thermal imaging and related physics (two chapters); IR imaging systems and methods (two chapters) and applications, including six chapters on pedagogical applications; IR imaging of buildings and infrastructure, industrial applications, microsystems, selected topics in research and industry, and selected applications from other fields. All chapters contain numerous colour pictures and diagrams, and a rich list of relevant

  19. Novel Card Games for Learning Radiographic Image Quality and Urologic Imaging in Veterinary Medicine.

    Science.gov (United States)

    Ober, Christopher P

    Second-year veterinary students are often challenged by concepts in veterinary radiology, including the fundamentals of image quality and generation of differential lists. Four card games were developed to provide veterinary students with a supplemental means of learning about radiographic image quality and differential diagnoses in urogenital imaging. Students played these games and completed assessments of their subject knowledge before and after playing. The hypothesis was that playing each game would improve students' understanding of the topic area. For each game, students who played the game performed better on the post-test than students who did not play that game (all pgames, students who played each respective game demonstrated significant improvement in scores between the pre-test and the post-test (pgames were both helpful and enjoyable. Educationally focused games can help students learn classroom and laboratory material. However, game design is important, as the game using the most passive learning process also demonstrated the weakest results. In addition, based on participants' comments, the games were ver