WorldWideScience

Sample records for digital image interpretation

  1. Digital training platform for interpreting radiographic images of the chest.

    Science.gov (United States)

    McLaughlin, L; Woznitza, N; Cairns, A; McFadden, S L; Bond, R; Hughes, C M; Elsayed, A; Finlay, D; McConnell, J

    2018-05-01

    Time delays and errors exist which lead to delays in patient care and misdiagnosis. Reporting clinicians follow guidance to form their own search strategy. However, little research has tested these training guides. With the use of eye tracking technology and expert input we developed a digital training platform to be used in chest image interpretation learning. Two sections of a digital training platform were planned and developed; A) a search strategy training tool to assist reporters during their interpretation of images, and B) an educational tool to communicate the search strategies of expert viewers to trainees by using eye tracking technology. A digital training platform for use in chest image interpretation was created based on evidence within the literature, expert input and two search strategies previously used in clinical practice. Images and diagrams, aiding translation of the platform content, were incorporated where possible. The platform is structured to allow the chest image interpretation process to be clear, concise and methodical. A search strategy was incorporated within the tool to investigate its use, with the possibility that it could be recommended as an evidence based approach for use by reporting clinicians. Eye tracking, a checklist and voice recordings have been combined to form a multi-dimensional learning tool, which has never been used in chest image interpretation learning before. The training platform for use in chest image interpretation learning has been designed, created and digitised. Future work will establish the efficacy of the developed approaches. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  2. Quality control of the interpretation monitors of digital radiological images

    International Nuclear Information System (INIS)

    Favero, Mariana S.; Goulart, Adriano Oliveira S.

    2016-01-01

    The performance monitors has great importance in image quality of digital radiographic systems. In environments without films, it became necessary to implement acceptance testing and quality control monitors used for interpretation of medical images. The monitors dedicated to radiodiagnostic should provide information that represent slight differences in x-ray attenuation or minor differences in some anatomical region of interest. This should also result in small differences in luminance of an image represented. Factors affecting the quality of medical imaging are contrast, noise, resolution, artifacts and distortions. Therefore, a monitor must have specific characteristics, making it possible for the observer to carry out an assessment that leads to better diagnosis. Based on the need to evaluate diagnostic monitors in various radiological applications, this paper presents a summary for implementation and standardization of tests that are recommended by the publication AAPM Report 03. (author)

  3. 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.

  4. The effects of gray scale image processing on digital mammography interpretation performance.

    Science.gov (United States)

    Cole, Elodia B; Pisano, Etta D; Zeng, Donglin; Muller, Keith; Aylward, Stephen R; Park, Sungwook; Kuzmiak, Cherie; Koomen, Marcia; Pavic, Dag; Walsh, Ruth; Baker, Jay; Gimenez, Edgardo I; Freimanis, Rita

    2005-05-01

    To determine the effects of three image-processing algorithms on diagnostic accuracy of digital mammography in comparison with conventional screen-film mammography. A total of 201 cases consisting of nonprocessed soft copy versions of the digital mammograms acquired from GE, Fischer, and Trex digital mammography systems (1997-1999) and conventional screen-film mammograms of the same patients were interpreted by nine radiologists. The raw digital data were processed with each of three different image-processing algorithms creating three presentations-manufacturer's default (applied and laser printed to film by each of the manufacturers), MUSICA, and PLAHE-were presented in soft copy display. There were three radiologists per presentation. Area under the receiver operating characteristic curve for GE digital mass cases was worse than screen-film for all digital presentations. The area under the receiver operating characteristic for Trex digital mass cases was better, but only with images processed with the manufacturer's default algorithm. Sensitivity for GE digital mass cases was worse than screen film for all digital presentations. Specificity for Fischer digital calcifications cases was worse than screen film for images processed in default and PLAHE algorithms. Specificity for Trex digital calcifications cases was worse than screen film for images processed with MUSICA. Specific image-processing algorithms may be necessary for optimal presentation for interpretation based on machine and lesion type.

  5. Addition of tomosynthesis to conventional digital mammography: effect on image interpretation time of screening examinations.

    Science.gov (United States)

    Dang, Pragya A; Freer, Phoebe E; Humphrey, Kathryn L; Halpern, Elkan F; Rafferty, Elizabeth A

    2014-01-01

    To determine the effect of implementing a screening tomosynthesis program on real-world clinical performance by quantifying differences between interpretation times for conventional screening mammography and combined tomosynthesis and mammography for multiple participating radiologists with a wide range of experience in a large academic center. In this HIPAA-compliant, institutional review board-approved study, 10 radiologists prospectively read images from screening digital mammography or screening combined tomosynthesis and mammography examinations for 1-hour-long uninterrupted sessions. Images from 3665 examinations (1502 combined and 2163 digital mammography) from July 2012 to January 2013 were interpreted in at least five sessions per radiologist per modality. The number of cases reported during each session was recorded for each reader. The experience level for each radiologist was also correlated to the average number of cases reported per hour. Analysis of variance was used to assess the number of studies interpreted per hour. A linear regression model was used to evaluate correlation between breast imaging experience and time taken to interpret images from both modalities. The mean number of studies interpreted in hour was 23.8 ± 0.55 (standard deviation) (range, 14.4-40.4) for combined tomosynthesis and mammography and 34.0 ± 0.55 (range, 20.4-54.3) for digital mammography alone. A mean of 10.2 fewer studies were interpreted per hour during combined tomosynthesis and mammography compared with digital mammography sessions (P tomosynthesis and mammography and 1.9 minutes ± 0.6 (range, 1.1-3.0) for digital mammography; interpretation time with combined tomosynthesis and mammography was 0.9 minute longer (47% longer) compared with digital mammography alone (P tomosynthesis and mammography examinations decreased (R(2) = 0.52, P = .03). Addition of tomosynthesis to mammography results in increased time to interpret images from screening examinations compared

  6. 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.

  7. Teleradiology in a neonatal intensive care unit: Comparison between the interpretation of transmitted digital images and film radiographs

    International Nuclear Information System (INIS)

    McFee, W.H.; Bramson, R.T.; Cates, J.D.; Curran, J.S.

    1987-01-01

    Using a Raytel teleradiology system, a prospective comparison was made between the interpretations of 700 transmitted digital images and the film radiographs from which these digital images were made. The original films consisted of all of the radiographs obtained from the infants in a 40-bed level III neonatal intensive care unit over a 6-week period. Interpretations were done by two radiologists, initially from transmitted images and subsequently from the original films. Comparison of the interpretations demonstrates a remarkably high degree of correlation, with less than 0.5% clinically significant discrepancies reported

  8. Effect of the Availability of Prior Full-Field Digital Mammography and Digital Breast Tomosynthesis Images on the Interpretation of Mammograms

    Science.gov (United States)

    Catullo, Victor J.; Chough, Denise M.; Ganott, Marie A.; Kelly, Amy E.; Shinde, Dilip D.; Sumkin, Jules H.; Wallace, Luisa P.; Bandos, Andriy I.; Gur, David

    2015-01-01

    Purpose To assess the effect of and interaction between the availability of prior images and digital breast tomosynthesis (DBT) images in decisions to recall women during mammogram interpretation. Materials and Methods Verbal informed consent was obtained for this HIPAA-compliant institutional review board–approved protocol. Eight radiologists independently interpreted twice deidentified mammograms obtained in 153 women (age range, 37–83 years; mean age, 53.7 years ± 9.3 [standard deviation]) in a mode by reader by case-balanced fully crossed study. Each study consisted of current and prior full-field digital mammography (FFDM) images and DBT images that were acquired in our facility between June 2009 and January 2013. For one reading, sequential ratings were provided by using (a) current FFDM images only, (b) current FFDM and DBT images, and (c) current FFDM, DBT, and prior FFDM images. The other reading consisted of (a) current FFDM images only, (b) current and prior FFDM images, and (c) current FFDM, prior FFDM, and DBT images. Fifty verified cancer cases, 60 negative and benign cases (clinically not recalled), and 43 benign cases (clinically recalled) were included. Recall recommendations and interaction between the effect of prior FFDM and DBT images were assessed by using a generalized linear model accounting for case and reader variability. Results Average recall rates in noncancer cases were significantly reduced with the addition of prior FFDM images by 34% (145 of 421) and 32% (106 of 333) without and with DBT images, respectively (P < .001). However, this recall reduction was achieved at the cost of a corresponding 7% (23 of 345) and 4% (14 of 353) reduction in sensitivity (P = .006). In contrast, availability of DBT images resulted in a smaller reduction in recall rates (false-positive interpretations) of 19% (76 of 409) and 26% (71 of 276) without and with prior FFDM images, respectively (P = .001). Availability of DBT images resulted in 4% (15 of

  9. An experimental study regarding diagnostic accuracy on image interpretation of the digital image film by using viewboxes of different luminance

    International Nuclear Information System (INIS)

    Song Shaojuan; Huang Ling; Liu Chuanya; Zhang Xiaojing

    2009-01-01

    Objective: To evaluate diagnostic accuracy of image interpretation using viewboxes at different luminance with ALVIM statistical phantom (TRG). Methods: A digital film of TRG image was obtained by exposing the phantom of TRG with Kodak DR 3000 using proper parameter. Viewboxes with three different luminance were selected from those used in daily work. The film of TRG was evaluated with these viewboxes of three different luminance by three different radiologists with experience of five, eight and sixteen years respectively. A grade scale of 5 was used to evaluate each row of signal and noise. According to the results and formula, the probabilities of true-positive [P(S/s)], false-positive [P(S/n)] and true answer (P det ) were obtained. Results: The three kinds of luminance used in viewboxes were: (3489± 256), (2231±220), (816±168) cd/m 2 . When the average luminance of viewbox was 3489 cd/m 2 , P det of 0.6,0.7,0.8 mm in bone substitute was 0.558±0.009, 0.788±0.008, 0.813±0.006, P det of 0.9, 1.0, 1.2 mm in muscle substitute was 0.663±0.010, 0.750±0.008, 0.933±0.005; When the average luminance of viewbox was 2231 cd/m 2 , P det of 0.6,0.7,0.8 mm in bone substitute was 0.525±0.013, 0.713±0.013,0.775±0.016, P det of 0.9,1.0,1.2 mm in muscle substitute was 0.613±0.019, 0.650± 0.013,0.850±0.019; When the average luminance of viewbox was 816 cd/m 2 , Pact of 0.6,0.7,0.8 mm in bone substitute was 0.475±0.022,0.550±0.018,0.688±0.020, P det of 0.9, 1.0, 1.2 mm in muscle substitute was 0.550±0.025,0.575±0.021,0.725±0.016. Viewboxes of different luminance were compared to one another by paired t-test. The results of comparison all had significant statistical differences (t=5.057 and 4.681, P<0.05). Conclusions: The image displayed by viewboxes at different luminance had significant influence on image interpretation. The higher the luminace of viewbox, the richer the information displayed, and the higher the accuracy of diagnosis. (authors)

  10. Methods of digital image processing

    International Nuclear Information System (INIS)

    Doeler, W.

    1985-01-01

    Increasing use of computerized methods for diagnostical imaging of radiological problems will open up a wide field of applications for digital image processing. The requirements set by routine diagnostics in medical radiology point to picture data storage and documentation and communication as the main points of interest for application of digital image processing. As to the purely radiological problems, the value of digital image processing is to be sought in the improved interpretability of the image information in those cases where the expert's experience and image interpretation by human visual capacities do not suffice. There are many other domains of imaging in medical physics where digital image processing and evaluation is very useful. The paper reviews the various methods available for a variety of problem solutions, and explains the hardware available for the tasks discussed. (orig.) [de

  11. Digital image processing techniques in archaeology

    Digital Repository Service at National Institute of Oceanography (India)

    Santanam, K.; Vaithiyanathan, R.; Tripati, S.

    Digital image processing involves the manipulation and interpretation of digital images with the aid of a computer. This form of remote sensing actually began in the 1960's with a limited number of researchers analysing multispectral scanner data...

  12. The Movement-Image Compatibility Effect: Embodiment Theory Interpretations of Motor Resonance With Digitized Photographs, Drawings, and Paintings

    Directory of Open Access Journals (Sweden)

    Mark-Oliver Casper

    2018-06-01

    Full Text Available To evoke the impression of movement in the “immobile” image is one of the central motivations of the visual art, and the activating effect of images has been discussed in art psychology already some 100 years ago. However, this topic has up to now been largely neglected by the researchers in cognitive psychology and neuroscience. This study investigates – from an interdisciplinary perspective – the formation of lateralized instances of motion when an observer perceives movement in an image. A first step was to identify images that evoke a perception of movement in a certain direction and to give this a rating. Reaction times leading to the engagement of a joystick following the presentation of images are used to evidence the postulated movement occasioned by the perception of movement in an image. Where the required direction of joystick moves matched the expected perception of movement direction in the image, significantly shorter reaction times were recorded. The experiment was able to prove a “movement-image compatibility effect” in observers of images. Based on this, the paper revisits and brings up to date the theses on motor sensory response to images which were developed in art psychology at the beginning of the 20th century. It furthermore contributes an embodiment theory interpretation to the prevalent representational explanation of compatibility effects.

  13. Digital Imaging. Chapter 16

    Energy Technology Data Exchange (ETDEWEB)

    Clunie, D. [CoreLab Partners, Princeton (United States)

    2014-09-15

    The original means of recording X ray images was a photographic plate. Nowadays, all medical imaging modalities provide for digital acquisition, though globally, the use of radiographic film is still widespread. Many modalities are fundamentally digital in that they require image reconstruction from quantified digital signals, such as computed tomography (CT) and magnetic resonance imaging (MRI)

  14. Interpretation of computed tomographic images

    International Nuclear Information System (INIS)

    Stickle, R.L.; Hathcock, J.T.

    1993-01-01

    This article discusses the production of optimal CT images in small animal patients as well as principles of radiographic interpretation. Technical factors affecting image quality and aiding image interpretation are included. Specific considerations for scanning various anatomic areas are given, including indications and potential pitfalls. Principles of radiographic interpretation are discussed. Selected patient images are illustrated

  15. Quality control of the interpretation monitors of digital radiological images; Controle de qualidade dos monitores de interpretacao de imagens radiologicas digitais: uma revisao

    Energy Technology Data Exchange (ETDEWEB)

    Favero, Mariana S.; Goulart, Adriano Oliveira S., E-mail: mariana@phymed.com.br [PhyMED - Consultores em Fisica Medica e Radioprotecao Ltda, Porto Alegre, RS (Brazil)

    2016-07-01

    The performance monitors has great importance in image quality of digital radiographic systems. In environments without films, it became necessary to implement acceptance testing and quality control monitors used for interpretation of medical images. The monitors dedicated to radiodiagnostic should provide information that represent slight differences in x-ray attenuation or minor differences in some anatomical region of interest. This should also result in small differences in luminance of an image represented. Factors affecting the quality of medical imaging are contrast, noise, resolution, artifacts and distortions. Therefore, a monitor must have specific characteristics, making it possible for the observer to carry out an assessment that leads to better diagnosis. Based on the need to evaluate diagnostic monitors in various radiological applications, this paper presents a summary for implementation and standardization of tests that are recommended by the publication AAPM Report 03. (author)

  16. Digital cine-imaging

    International Nuclear Information System (INIS)

    Masuda, Kazuhiro

    1992-01-01

    Digitization of fluoroscopic images has been developed for the digital cine imaging system as a result of the computer technology, television technology, and popularization of interventional radiology. Present digital cine imaging system is able to offer images similar to cine film because of the higher operatability and better image quality with the development of interventional radiology. As a result, its higher usefulness for catheter diagnosis examination except for interventional radiology was reported, and the possibility of having filmless cine is close to becoming a reality. However several problems have been pointed out, such as spatial resolution, time resolution, storage and exchangeability of data, disconsolidated viewing functions, etc. Anyhow, digital cine imaging system has some unresolved points and lots the needs to be discussed. The tendency of digitization is the passage of the time and we have to promote a study for more useful digital cine imaging system in team medical treatment which centers on the patients. (author)

  17. Scanning Tunneling Microscopy - image interpretation

    International Nuclear Information System (INIS)

    Maca, F.

    1998-01-01

    The basic ideas of image interpretation in Scanning Tunneling Microscopy are presented using simple quantum-mechanical models and supplied with examples of successful application. The importance is stressed of a correct interpretation of this brilliant experimental surface technique

  18. IMAGE INTERPRETATION OF COASTAL AREAS

    Directory of Open Access Journals (Sweden)

    M. A. Lazaridou

    2012-07-01

    Full Text Available Coasts were formed with the overall shape of earth's surface. Τhey represent a landform, as determined by the science of geomorphology. Being the boundary between land and sea, they present important features – particularities such as water currents, waves, winds, estuaries, drainage network, pollution etc. Coasts are examined at various levels: continents – oceans, states – large seas, as for example Mediterranean Sea. Greece, because of its horizontal and vertical partitioning, presents great extent and variety of coasts as mainland, peninsulas and islands. Depending on geomorphology, geology, soils, hydrology, land use of the inland and the coasts themselves, these are very diverse. Photogrammetry and Remote Sensing (defined by Statute II of ISPRS is the art, science, and technology of obtaining reliable information from non-contact imaging and other sensor systems about the Earth and its environment, and other physical objects and of processes through recording, measuring, analyzing and representation. This paper concerns critical considerations on the above. It also includes the case of Thessaloniki coasts in Greece, particularly river estuaries areas (river delta. The study of coastal areas of the wide surroundings of Thessaloniki city includes visual image interpretationdigital image processing techniques on satellite data of high spatial resolution.

  19. Digital image processing mathematical and computational methods

    CERN Document Server

    Blackledge, J M

    2005-01-01

    This authoritative text (the second part of a complete MSc course) provides mathematical methods required to describe images, image formation and different imaging systems, coupled with the principle techniques used for processing digital images. It is based on a course for postgraduates reading physics, electronic engineering, telecommunications engineering, information technology and computer science. This book relates the methods of processing and interpreting digital images to the 'physics' of imaging systems. Case studies reinforce the methods discussed, with examples of current research

  20. Digital cardiovascular imaging

    International Nuclear Information System (INIS)

    Myerowitz, P.D.; Mistretta, C.A.; Shaw, C.-G.; Van Lysel, M.S.; Swanson, D.K.; Lasser, T.A.; Dhanani, S.P.; Zarnstorff, W.C.; Vander Ark, C.R.; Dobbins, J.T.; Peppler, W.W.; Crummy, A.B.

    1982-01-01

    The authors have previously reported on real time digital fluoroscopic subtraction techniques developed in the laboratory during the past 10 years. This paper outlines basic apparatus configuration and imaging modes used for preliminary studies involving visualization of the canine and human heart. All of the techniques involve the use of real time digital subtraction processing of data from an image intensified television fluoroscopy system. Based on the configuration of the digital processing equipment a number of different imaging modalities are possible. A brief description of the apparatus and these imaging modes is given. (Auth.)

  1. Interpretations of NMR images

    International Nuclear Information System (INIS)

    Shi, J.Z.; McFarland, W.D.; Chen, S.S.; Sadhu, V.K.

    1986-01-01

    Two color display schemes are generally considered in medical images: pseudo-color and color composite. Psuedo-color technique maps the intensity means of a single monochrome image into a three dimensional color space, the gray level is thus replaced by the assigned color. Such a psuedo-color assignment is somewhat arbitrary but may be advantageous if the monochrome image is composed of simple intensity patterns. A good example of psuedo-color application is in nuclear medicine: The change of gray levels can be simply determined and the isocounts from two regions with different surroundings can be readily recognized. However, the use of psuedo-color in CT or MR imaging is controversial because it does not give additional information and may exaggerate insignificant gray scale differences. The color composite technique maps three parametric image data into a three dimensional color space, and thus three monochrome images are merged to form a single color image. The color composite technique increases the number of ways information can be displayed and provides both quantitative and qualitative data about the object or event represented. This paper describes the application of color composite in NMR images

  2. Digital image processing

    National Research Council Canada - National Science Library

    Gonzalez, Rafael C; Woods, Richard E

    2008-01-01

    Completely self-contained-and heavily illustrated-this introduction to basic concepts and methodologies for digital image processing is written at a level that truly is suitable for seniors and first...

  3. Interpretation of radiograms using digital computers

    International Nuclear Information System (INIS)

    Kuzin, M.I.; Den'shchikov, K.K.; Sal'man, M.M.; Pechennikov, L.M.

    1986-01-01

    The potentialities of the use of a combined method of interactive and automated processing of radiograms with the help of digital computers (DC) are discussed. The data obtained have shown that DC-assissted interpretation of radiograms makes it possible to detect small formations in the chest undectable in a routine X-ray examination. However there can occur undesirable false detection of pathology resulting from algorithm sensitivity

  4. Eliminating "Hotspots" in Digital Image Processing

    Science.gov (United States)

    Salomon, P. M.

    1984-01-01

    Signals from defective picture elements rejected. Image processing program for use with charge-coupled device (CCD) or other mosaic imager augmented with algorithm that compensates for common type of electronic defect. Algorithm prevents false interpretation of "hotspots". Used for robotics, image enhancement, image analysis and digital television.

  5. Image analysis enhancement and interpretation

    International Nuclear Information System (INIS)

    Glauert, A.M.

    1978-01-01

    The necessary practical and mathematical background are provided for the analysis of an electron microscope image in order to extract the maximum amount of structural information. Instrumental methods of image enhancement are described, including the use of the energy-selecting electron microscope and the scanning transmission electron microscope. The problems of image interpretation are considered with particular reference to the limitations imposed by radiation damage and specimen thickness. A brief survey is given of the methods for producing a three-dimensional structure from a series of two-dimensional projections, although emphasis is really given on the analysis, processing and interpretation of the two-dimensional projection of a structure. (Auth.)

  6. Digital imaging primer

    CERN Document Server

    Parkin, Alan

    2016-01-01

    Digital Imaging targets everyyone with an interest in digital imaging, be they professional or private, who uses even quite modest equipment such as a PC, digital camera and scanner, a graphics editor such as Paint, and an inkjet printer. Uniquely, it is intended to fill the gap between highly technical texts for academics (with access to expensive equipment) and superficial introductions for amateurs. The four-part treatment spans theory, technology, programs and practice. Theory covers integer arithmetic, additive and subtractive color, greyscales, computational geometry, and a new presentation of discrete Fourier analysis; Technology considers bitmap file structures, scanners, digital cameras, graphic editors, and inkjet printers; Programs develops several processing tools for use in conjunction with a standard Paint graphics editor and supplementary processing tools; Practice discusses 1-bit, greyscale, 4-bit, 8-bit, and 24-bit images for the practice section. Relevant QBASIC code is supplied an accompa...

  7. Digital imaging in health care

    International Nuclear Information System (INIS)

    1987-01-01

    This volume describes equipment for the generation and processing of digital images in medicine. Separate chapters deal with international trade i this equipment, with economic and social considerations of digital imaging, with experiences in the use and production of digital imaging equipment and with the current status and likely trends in applications of digital imaging. 84 refs, figs and tabs

  8. Digital medical imaging

    International Nuclear Information System (INIS)

    Goeringer, F.; Mun, S.K.; Kerlin, B.D.

    1989-01-01

    In formulating an implementation strategy for digital medical imaging, three interrelated thrusts have emerged for the defense medical establishment. These thrusts: totally filmless medical imaging on the battlefield, teleradiology, and DIN/PACS for peacetime military health care are discussed. They have implications in their fully developed form as resource savers and quality improvers for the unique aspects of military health care

  9. Digital vascular imaging

    International Nuclear Information System (INIS)

    Ludwig, J.W.; Engels, B.C.H.

    1981-01-01

    Digitalizing videosignals from an image intensifying TV-chain, followed by subtraction, contrast intensifying, and reformation to analogous signal deliver angiography pictures of high quality after intravenous injection of the contrast medium. As the examination is only little invasive it can be carried out on outdoor patients or in the polyclinics. The possibilities of the digital vessel imagination (DVI) are shown at vessel images of different parts of the body; a 36 cm image intensifyer which can be switched to 3 different sorts of operation and has a plumbicon-TV recording tube is used as receiver. (orig.) [de

  10. Modeling and interpretation of images*

    Directory of Open Access Journals (Sweden)

    Min Michiel

    2015-01-01

    Full Text Available Imaging protoplanetary disks is a challenging but rewarding task. It is challenging because of the glare of the central star outshining the weak signal from the disk at shorter wavelengths and because of the limited spatial resolution at longer wavelengths. It is rewarding because it contains a wealth of information on the structure of the disks and can (directly probe things like gaps and spiral structure. Because it is so challenging, telescopes are often pushed to their limitations to get a signal. Proper interpretation of these images therefore requires intimate knowledge of the instrumentation, the detection method, and the image processing steps. In this chapter I will give some examples and stress some issues that are important when interpreting images from protoplanetary disks.

  11. Digital image information systems in radiology

    International Nuclear Information System (INIS)

    Greinacher, C.F.C.; Luetke, B.; Seufert, G.

    1987-01-01

    About 25% of all patient examinations are performed digitally in a today's radiological department. A computerized system is described that supports generation, transport, interpretation and archiving of digital radiological images (Picture Archiving and Communication System PACS). The technical features concerning image communication via local area networks, image storage on magnetic and optical media and digital workstations for image display and manipulation are described. A structured system architecture is introduced. It allows flexible adaption to individual organizations and minimizes the requirements of the communication network. (orig.) [de

  12. Digital color imaging

    CERN Document Server

    Fernandez-Maloigne, Christine; Macaire, Ludovic

    2013-01-01

    This collective work identifies the latest developments in the field of the automatic processing and analysis of digital color images.For researchers and students, it represents a critical state of the art on the scientific issues raised by the various steps constituting the chain of color image processing.It covers a wide range of topics related to computational color imaging, including color filtering and segmentation, color texture characterization, color invariant for object recognition, color and motion analysis, as well as color image and video indexing and retrieval. <

  13. Digital image analysis

    DEFF Research Database (Denmark)

    Riber-Hansen, Rikke; Vainer, Ben; Steiniche, Torben

    2012-01-01

    Digital image analysis (DIA) is increasingly implemented in histopathological research to facilitate truly quantitative measurements, decrease inter-observer variation and reduce hands-on time. Originally, efforts were made to enable DIA to reproduce manually obtained results on histological slides...... reproducibility, application of stereology-based quantitative measurements, time consumption, optimization of histological slides, regions of interest selection and recent developments in staining and imaging techniques....

  14. Computer assisted visualization of digital mammography images

    International Nuclear Information System (INIS)

    Funke, M.; Breiter, N.; Grabbe, E.; Netsch, T.; Biehl, M.; Peitgen, H.O.

    1999-01-01

    Purpose: In a clinical study, the feasibility of using a mammography workstation for the display and interpretation of digital mammography images was evaluated and the results were compared with the corresponding laser film hard copies. Materials and Methods: Digital phosphorous plate radiographs of the entire breast were obtained in 30 patients using a direct magnification mammography system. The images were displayed for interpretation on the computer monitor of a dedicated mammography workstation and also presented as laser film hard copies on a film view box for comparison. The images were evaluted with respect to the image handling, the image quality and the visualization of relevant structures by 3 readers. Results: Handling and contrast of the monitor displayed images were found to be superior compared with the film hard copies. Image noise was found in some cases but did not compromise the interpretation of the monitor images. The visualization of relevant structures was equal with both modalities. Altogether, image interpretation with the mammography workstation was considered to be easy, quick and confident. Conclusions: Computer-assisted visualization and interpretation of digital mammography images using a dedicated workstation can be performed with sufficiently high diagnostic accuracy. (orig.) [de

  15. Digital stereoscopic imaging

    Science.gov (United States)

    Rao, A. Ravishankar; Jaimes, Alejandro

    1999-05-01

    The convergence of inexpensive digital cameras and cheap hardware for displaying stereoscopic images has created the right conditions for the proliferation of stereoscopic imagin applications. One application, which is of growing importance to museums and cultural institutions, consists of capturing and displaying 3D images of objects at multiple orientations. In this paper, we present our stereoscopic imaging system and methodology for semi-automatically capturing multiple orientation stereo views of objects in a studio setting, and demonstrate the superiority of using a high resolution, high fidelity digital color camera for stereoscopic object photography. We show the superior performance achieved with the IBM TDI-Pro 3000 digital camera developed at IBM Research. We examine various choices related to the camera parameters, image capture geometry, and suggest a range of optimum values that work well in practice. We also examine the effect of scene composition and background selection on the quality of the stereoscopic image display. We will demonstrate our technique with turntable views of objects from the IBM Corporate Archive.

  16. Managing digitally formatted diagnostic image data

    International Nuclear Information System (INIS)

    Templeton, A.W.; Dwyer, S.J.

    1985-01-01

    Diagnostic radiologists are very comfortable using analog radiographic film and interpreting its recorded images. To improve patient care, the radiologist has sought the finest quality radiographic film for use with the best radiographic imaging systems. The proper choice and use of x-ray tubes, generators, film-screen combinations, and contrast media has occupied the professional attention of the radiologist since the inception of radiology. Image quality can be significantly improved with digitally formatted diagnostic imaging systems by providing dynamic ranges in excess of those possible with analog x-ray films. In a CT scanner, the digital acquisition and reconstruction system can obtain a dynamic range (contrast resolution) of 10,000 to 1. Digital subtraction angiography systems achieve 10-bit dynamic ranges for each of the acquired television frames. Increases in the dynamic ranges of the various imaging modalities have been coupled with improved spatial resolution. A digitally formatted image is a two-dimensional, numerical array of discrete image elements. Each picture element is called a pixel. Each pixel has a discrete size. Figure 15.1 illustrates a digitally formatted image depicting the spatial resolution, array size, and quantization or numerical range of the pixel values. Currently, 512 x 512 image arrays are standard. Development of 1024 x 1024 digital arrays are underway. Significant improvements have also been achieved in the rates at which digital diagnostic imaging data can be acquired, manipulated, and archived

  17. Guide to Magellan image interpretation

    Science.gov (United States)

    Ford, John P.; Plaut, Jeffrey J.; Weitz, Catherine M.; Farr, Tom G.; Senske, David A.; Stofan, Ellen R.; Michaels, Gregory; Parker, Timothy J.; Fulton, D. (Editor)

    1993-01-01

    An overview of Magellan Mission requirements, radar system characteristics, and methods of data collection is followed by a description of the image data, mosaic formats, areal coverage, resolution, and pixel DN-to-dB conversion. The availability and sources of image data are outlined. Applications of the altimeter data to estimate relief, Fresnel reflectivity, and surface slope, and the radiometer data to derive microwave emissivity are summarized and illustrated in conjunction with corresponding SAR image data. Same-side and opposite-side stereo images provide examples of parallax differences from which to measure relief with a lateral resolution many times greater than that of the altimeter. Basic radar interactions with geologic surfaces are discussed with respect to radar-imaging geometry, surface roughness, backscatter modeling, and dielectric constant. Techniques are described for interpreting the geomorphology and surface properties of surficial features, impact craters, tectonically deformed terrain, and volcanic landforms. The morphologic characteristics that distinguish impact craters from volcanic craters are defined. Criteria for discriminating extensional and compressional origins of tectonic features are discussed. Volcanic edifices, constructs, and lava channels are readily identified from their radar outlines in images. Geologic map units are identified on the basis of surface texture, image brightness, pattern, and morphology. Superposition, cross-cutting relations, and areal distribution of the units serve to elucidate the geologic history.

  18. Digital imaging in dentistry.

    Science.gov (United States)

    Essen, S Donovan

    2011-01-01

    Information technology is vital to operations, marketing, accounting, finance and administration. One of the most exciting and quickly evolving technologies in the modern dental office is digital applications. The dentist is often the business manager, information technology officer and strategic planning chief for his small business. The information systems triangle applies directly to this critical manager supported by properly trained ancillary staff and good equipment. With emerging technology driving all medical disciplines and the rapid pace at which it emerges, it is vital for the contemporary practitioner to keep abreast of the newest information technology developments. This article compares the strategic and operational advantages of digital applications, specifically imaging. The focus of this paper will be on digital radiography (DR), 3D computerized tomography, digital photography and digitally-driven CAD/CAM to what are now considered obsolescing modalities and contemplates what may arrive in the future. It is the purpose of this essay to succinctly evaluate the decisions involved in the role, application and implications of employing this tool in the dental environment

  19. Analog and digital image quality:

    OpenAIRE

    Sardo, Alberto

    2004-01-01

    Background. Lastly the X ray facilities are moving to a slow, but continuous process of digitalization. The dry laser printers allow hardcopy images with optimum resolution and contrast for all the modalities. In breast imaging, thedelay of digitalization depends to the high cost of digital systems and, attimes, to the doubts of the diagnostic accuracy of reading the breast digital images. Conclusions. The Screen film mammography (SFM) is the most efficient diagnostic modality to detect the b...

  20. Digital imaging in diagnostic radiology

    International Nuclear Information System (INIS)

    Newell, J.D. Jr.; Kelsey, C.A.

    1990-01-01

    This monograph on digital imaging provides a basic overview of this field at the present time. This paper covers clinical application, including subtraction angiography; chest radiology; genitourinary, gastrointestinal, and breast radiology; and teleradiology. The chest section also includes an explanation of multiple beam equalization radiography. The remaining chapters discuss some of the technical aspects of digital radiology. It includes the basic technology of digital radiography, image compression, and reconstruction information on the economics of digital radiography

  1. 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

  2. Image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Manninen, H.; Partanen, K.; Lehtovirta, J.; Matsi, P.; Soimakallio, S.

    1992-01-01

    The usefulness of digital image processing of chest radiographs was evaluated in a clinical study. In 54 patients, chest radiographs in the posteroanterior projection were obtained by both 14 inch digital image intensifier equipment and the conventional screen-film technique. The digital radiographs (512x512 image format) viewed on a 625 line monitor were processed in 3 different ways: 1.standard display; 2.digital edge enhancement for the standard display; 3.inverse intensity display. The radiographs were interpreted independently by 3 radiologists. Diagnoses were confirmed by CT, follow-up radiographs and clinical records. Chest abnormalities of the films analyzed included 21 primary lung tumors, 44 pulmonary nodules, 16 cases with mediastinal disease, 17 with pneumonia /atelectasis. Interstitial lung disease, pleural plaques, and pulmonary emphysema were found in 30, 18 and 19 cases respectively. Sensitivity of conventional radiography when averaged overall findings was better than that of digital techniques (P<0.001). Differences in diagnostic accuracy measured by sensitivity and specificity between the 3 digital display modes were small. Standard image display showed better sensitivity for pulmonary nodules (0.74 vs 0.66; P<0.05) but poorer specificity for pulmonary emphysema (0.85 vs 0.93; P<0.05) compared with inverse intensity display. It is concluded that when using 512x512 image format, the routine use of digital edge enhancement and tone reversal at digital chest radiographs is not warranted. (author). 12 refs.; 4 figs.; 2 tabs

  3. Digital imaging in cardiovascular radiology

    International Nuclear Information System (INIS)

    Heintzen, P.H.; Brennecke, R.

    1983-01-01

    The present book contains 27 papers presented at an international symposium on digital imaging in cardiovascular radiology held in Kiel in 1982. The main themes were as follows. Introductory reviews, digital systems for X-ray video imaging, quantitative X-ray image analysis, and clinical applications. (MG)

  4. Digital Images and Globalized Conflict

    DEFF Research Database (Denmark)

    Blaagaard, Bolette; Mortensen, Mette; Neumayer, Christina

    2017-01-01

    As the number of digital images of globalized conflicts online grow, critical examination of their impact and consequence is timely. This editorial provides an overview of digital images and globalized conflict as a field of study by discussing regimes of visibility and invisibility, proximity...... of conflict-related images raise issues of knowledge production and research....

  5. Image quality in digital radiography

    International Nuclear Information System (INIS)

    Kuhn, H.

    1986-01-01

    The contribution deals with the potentials of digital radiography and critically evaluates the advantages of drawbacks of the image intensifier-tv-digital system; digitalisation of the X-ray film and scanning of luminescent storage foils. The evaluation is done in comparison with the image quality of the traditional, large-size X-ray picture. (orig.) [de

  6. Introduction to digital image processing

    CERN Document Server

    Pratt, William K

    2013-01-01

    CONTINUOUS IMAGE CHARACTERIZATION Continuous Image Mathematical Characterization Image RepresentationTwo-Dimensional SystemsTwo-Dimensional Fourier TransformImage Stochastic CharacterizationPsychophysical Vision Properties Light PerceptionEye PhysiologyVisual PhenomenaMonochrome Vision ModelColor Vision ModelPhotometry and ColorimetryPhotometryColor MatchingColorimetry ConceptsColor SpacesDIGITAL IMAGE CHARACTERIZATION Image Sampling and Reconstruction Image Sampling and Reconstruction ConceptsMonochrome Image Sampling SystemsMonochrome Image Reconstruction SystemsColor Image Sampling SystemsImage QuantizationScalar QuantizationProcessing Quantized VariablesMonochrome and Color Image QuantizationDISCRETE TWO-DIMENSIONAL LINEAR PROCESSING Discrete Image Mathematical Characterization Vector-Space Image RepresentationGeneralized Two-Dimensional Linear OperatorImage Statistical CharacterizationImage Probability Density ModelsLinear Operator Statistical RepresentationSuperposition and ConvolutionFinite-Area Superp...

  7. Interpretation of quasi-static and dynamic tensile behavior by digital image correlation technique in TWinning Induced Plasticity (TWIP) and low-carbon steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Minju; Park, Jaeyeong; Sohn, Seok Su; Kim, Hyoung Seop [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kim, Nack J. [Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, Sunghak, E-mail: shlee@postech.ac.kr [Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2017-05-02

    In this study, dynamic tensile tests were conducted on TWinning Induced Plasticity (TWIP) and low-carbon (LC) steel sheets at a strain rate of 1500–2000/s by using a split Hopkinson tensile bar, and deformation mechanisms related with improvement of dynamic tensile properties were investigated by a digital image correlation (DIC) technique. The dynamic tensile strength was higher than the quasi-static tensile strength in both TWIP and LC sheets, while the dynamic elongation was same to the quasi-static elongation in the TWIP sheet and was much lower than the quasi-static elongation in the LC sheet. According to the DIC results of the dynamically tensioned TWIP sheet, the homogeneous deformation occurred before the necking at the strain of 47.4%. This indicated that the dynamic deformation processes were almost similar to the quasi-static ones as the TWIP sheet was homogeneously deformed in the initial and intermediate deformation stages. This could be explained by deformation mechanisms including twinning, in consideration of favorable effect of increased twinning on tensile properties under the dynamic loading. On the other hand, the dynamically tensioned LC sheet was rapidly deformed and fractured as the necking was intensified in a narrow strain-concentrated region. The present DIC technique is an outstanding method for detailed dynamic deformation analyses, and provides an important idea for practical safety analyses of automotive steel sheets.

  8. Digital Images and Globalized Conflict

    DEFF Research Database (Denmark)

    Blaagaard, Bolette; Mortensen, Mette; Neumayer, Christina

    2017-01-01

    As the number of digital images of globalized conflicts online grow, critical examination of their impact and consequence is timely. This editorial provides an overview of digital images and globalized conflict as a field of study by discussing regimes of visibility and invisibility, proximity...... and distance, and the multiplicity of images. It engages critically with these interlinking themes as they are addressed in the contributing articles to the Special Issue as well as beyond, asking how genres and tropes are reproduced, how power plays a role in access to images, and how the sheer quantity...... of conflict-related images raise issues of knowledge production and research....

  9. Imagers for digital still photography

    Science.gov (United States)

    Bosiers, Jan; Dillen, Bart; Draijer, Cees; Manoury, Erik-Jan; Meessen, Louis; Peters, Inge

    2006-04-01

    This paper gives an overview of the requirements for, and current state-of-the-art of, CCD and CMOS imagers for use in digital still photography. Four market segments will be reviewed: mobile imaging, consumer "point-and-shoot cameras", consumer digital SLR cameras and high-end professional camera systems. The paper will also present some challenges and innovations with respect to packaging, testing, and system integration.

  10. Generative Interpretation of Medical Images

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille

    2004-01-01

    This thesis describes, proposes and evaluates methods for automated analysis and quantification of medical images. A common theme is the usage of generative methods, which draw inference from unknown images by synthesising new images having shape, pose and appearance similar to the analysed images......, handling of non-Gaussian variation by means of cluster analysis, correction of respiratory noise in cardiac MRI, and the extensions to multi-slice two-dimensional time-series and bi-temporal three-dimensional models. The medical applications include automated estimation of: left ventricular ejection...

  11. Digital Capture and Fabrication Tools for Interpretation of Historic Sites

    Science.gov (United States)

    Ackerman, A.; Glekas, E.

    2017-08-01

    Historic sites and the narratives they produce can have a lasting impact on the community through public engagement and education. However, when these sites are neglected and lost over time, opportunities to engage the public with the history of these places is lost with them. The interpretation of heritage that has been lost or forgotten is an emerging trend in humanities studies. This trend, in combination with technological advancements in digital media and representation, presents an innovative opportunity for historic preservation professionals to create new paths for public engagement. This paper discusses applications of photogrammetry, 3D modeling, and digital fabrication in digitally reconstructing interpretive models of the Larz Anderson Estate (now Larz Anderson Park). This site has changed dramatically through its transition from a private estate to a public park and recreation area, with few remnants of the original estate remaining extant. The above stated use of digital strategies aims to create digital and physical models of the estate's change over time, with the aim of interpreting the site's lost heritage for the public. Combining existing archival research and heritage documentation methods with these digital representation techniques tells the story of a place that no longer exists.

  12. Digital Data Processing of Images

    African Journals Online (AJOL)

    Digital data processing was investigated to perform image processing. Image smoothing and restoration were explored and promising results obtained. The use of the computer, not only as a data management device, but as an important tool to render quantitative information, was illustrated by lung function determination.

  13. Gestalt descriptions embodiments and medical image interpretation

    DEFF Research Database (Denmark)

    Friis, Jan Kyrre Berg Olsen

    2017-01-01

    In this paper I will argue that medical specialists interpret and diagnose through technological mediations like X-ray and fMRI images, and by actualizing embodied skills tacitly they are determining the identity of objects in the perceptual field. The initial phase of human interpretation of vis...

  14. Digital imaging - future visions

    International Nuclear Information System (INIS)

    Sanford, L.

    1993-01-01

    The reality of a filmless future in medicine is closer in the UK than in the US. The initiative with digital data processing, however, is not. Despite the glowing promises in the literature of such visionware', there is as yet no filmless system anywhere in the World. This article examines research in this field. (Author)

  15. Principles of digital image synthesis

    CERN Document Server

    Glassner, Andrew S

    1995-01-01

    Image synthesis, or rendering, is a field of transformation: it changesgeometry and physics into meaningful images. Because the most popularalgorithms frequently change, it is increasingly important for researchersand implementors to have a basic understanding of the principles of imagesynthesis. Focusing on theory, Andrew Glassner provides a comprehensiveexplanation of the three core fields of study that come together to formdigital image synthesis: the human visual system, digital signalprocessing, and the interaction of matter and light. Assuming no more thana basic background in calculus,

  16. Pediatric digital chest imaging.

    Science.gov (United States)

    Tarver, R D; Cohen, M; Broderick, N J; Conces, D J

    1990-01-01

    The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughout of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology.

  17. Pediatric digital chest imaging

    International Nuclear Information System (INIS)

    Tarver, R.D.; Cohen, M.; Broderick, N.J.; Conces, D.J. Jr.

    1990-01-01

    The Philips Computed Radiography system performs well with pediatric portable chest radiographs, handling the throughout of a busy intensive care service 24 hours a day. Images are excellent and routinely provide a conventional (unenhanced) image and an edge-enhanced image. Radiation dose is decreased by the lowered frequency of repeat examinations and the ability of the plates to respond to a much lower dose and still provide an adequate image. The high quality and uniform density of serial PCR portable radiographs greatly enhances diagnostic content of the films. Decreased resolution has not been a problem clinically. Image manipulation and electronic transfer to remote viewing stations appear to be helpful and are currently being evaluated further. The PCR system provides a marked improvement in pediatric portable chest radiology

  18. Digital image processing

    National Research Council Canada - National Science Library

    Gonzalez, Rafael C; Woods, Richard E

    2008-01-01

    ...-year graduate students in almost any technical discipline. The leading textbook in its field for more than twenty years, it continues its cutting-edge focus on contemporary developments in all mainstream areas of image processing-e.g...

  19. Interpretation of ultrasonic images; Interpretation von Ultraschall-Abbildungen

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, W; Schmitz, V; Kroening, M [Fraunhofer-Institut fuer Zerstoerungsfreie Pruefverfahren, Saarbruecken (Germany)

    1998-11-01

    During the evaluation of ultrasonic images, e.g. SAFT-reconstructed B-scan images (SAFT=Synthetic Aperture Focusing Technique) it is often difficult to decide, what is the origin of reconstructed image points: were they caused by defects, specimens geometry or mode-conversions. To facilitate this evaluation a tool based on the comparison of data was developed. Different kinds of data comparison are possible: identification of that RF-signals, which caused the reconstructed image point. This is the comparison of a reconstructed image with the corresponding RF-data. Comparison of two reconstructed images performing a superposition using logical operators. In this case e.g. the reconstruction of an unknown reflector is compared with that of a known one. Comparison of raw-RF-data by simultaneous scanning through two data sets. Here the echoes of an unknown reflector are compared with the echoes of a known one. The necessary datasets of known reflectors may be generated experimentally on reference reflectors or modelled. The aim is the identification of the reflector type, e.g. cracklike or not, the determination of position, size and orientation as well as the identification of accompanying satellite echoes. The interpretation of the SAFT-reconstructed B-scan image is carried out by a complete description of the reflector. In addition to the aim of interpretation the tool described is well suited to educate and train ultrasonic testers. (orig./MM) [Deutsch] Bei der Auswertung von Ultraschall-Abbildungen, z.B. SAFT-rekonstruierten B-Bildern (SAFT=Synthetische Apertur Fokus Technik), ist es oft schwierig zu entscheiden, wo rekonstruierte Bildpunkte herruehren: wurden sie durch Materialfehler, Bauteilgeometrie oder durch Wellenumwandlungen versursacht. Um diese Auswertung zu erleichtern, wurde ein Werkzeug entwickelt, welches auf dem Vergleich von Datensaetzen basiert. Es koennen verschiedene Arten des Datenvergleichs durchgefuehrt werden: Identifikation der HF

  20. Image processing techniques for digital orthophotoquad production

    Science.gov (United States)

    Hood, Joy J.; Ladner, L. J.; Champion, Richard A.

    1989-01-01

    Orthophotographs have long been recognized for their value as supplements or alternatives to standard maps. Recent trends towards digital cartography have resulted in efforts by the US Geological Survey to develop a digital orthophotoquad production system. Digital image files were created by scanning color infrared photographs on a microdensitometer. Rectification techniques were applied to remove tile and relief displacement, thereby creating digital orthophotos. Image mosaicking software was then used to join the rectified images, producing digital orthophotos in quadrangle format.

  1. Digital Radiology Image Learning Library

    International Nuclear Information System (INIS)

    Arenson, R.L.; Greenes, R.; Allman, R.; Swett, H.

    1989-01-01

    The Digital Radiology Image Learning Library (DRILL) is designed as an interactive teaching tool targeted to the radiologic community. The DRILL pilot comprises a comprehensive mammographic information base consisting of factual data in a relational database, an extensive knowledge base in semantic nets and high-resolution images. A flexible query module permits the user to browse and retrieve examination data, case discussions, and related images. Other applications, including expert systems, instructional programs, and skill building exercises, can be accessed through well-defined software constructs

  2. Digital radiology and digitally formatted image management systems

    International Nuclear Information System (INIS)

    Cox, G.G.; Dwyer, S.J. III; Templeton, A.W.

    1987-01-01

    The number of diagnostic examinations performed with digitally formatted imaging equipment is increasing. Digital general-purpose and fluoroscopic radiology systems are being clinically evaluated. Digitizing conventional x-ray films, such as mammograms, frequently improves the diagnostic quality of the images. The digitizing process with laser has also afforded the opportunity to document required spatial resolution for digital imaging and network systems. The use of digitally formatted image instrumentation imposes new requirements on the acquisition, display and manipulation, transmission, hard copy image recording, and archiving of diagnostic data. Networking of digitally formatted image data offers many advantages for managing digital information. This paper identifies and describes digital radiographic systems. Parameters required for designing and implementing a digital image management system are outlined. Spatial and contrast resolution requirements are identified. The key parameters include the amount of image data generated each working day, the retrieval rate of the generated data, the display hardware and software needed for interactive diagnosis display stations, the requirements for analog hard copy generation, and on-line and long-term archiving requirements. These image management systems are often called PACS (Picture Archiving and Communication Systems)

  3. Comparison of conventional radiography and digital teleradiography in interpretation of musculoskeletal abnormalities

    International Nuclear Information System (INIS)

    Wegryn, S.A.; Uetani, M.; Piraino, D.W.; Richmond, B.J.; Meziane, M.A.; Freed, H.A.; Belhobek, G.H.

    1988-01-01

    The authors are currently evaluating the accuracy of image interpretation with a teleradiography system, compared with readings of the original, analog musculoskeletal radiographs. One hundred twenty-two original radiographs are being evaluated independently by four readers. Teleradiographic images are obtained from the original analog images with use of a laser film digitizer with a 1,680 X 2,048 X 12-bit matrix and 840 X 1,024 line display. Images are interpreted without clinical information, and a minimum of 4 weeks separates film interpretation to minimize observer recall. Subtle, nonsubtle, and normal cases chosen by a nonreviewer are included. Readers detail any abnormalities and final diagnoses with estimation of confidence levels. Sensitivity, specificity, and receiver operating characteristic analysis will be formulated for each reader and overall for level of diagnostic difficulty

  4. 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.

  5. Distributed data collection for a database of radiological image interpretations

    Science.gov (United States)

    Long, L. Rodney; Ostchega, Yechiam; Goh, Gin-Hua; Thoma, George R.

    1997-01-01

    The National Library of Medicine, in collaboration with the National Center for Health Statistics and the National Institute for Arthritis and Musculoskeletal and Skin Diseases, has built a system for collecting radiological interpretations for a large set of x-ray images acquired as part of the data gathered in the second National Health and Nutrition Examination Survey. This system is capable of delivering across the Internet 5- and 10-megabyte x-ray images to Sun workstations equipped with X Window based 2048 X 2560 image displays, for the purpose of having these images interpreted for the degree of presence of particular osteoarthritic conditions in the cervical and lumbar spines. The collected interpretations can then be stored in a database at the National Library of Medicine, under control of the Illustra DBMS. This system is a client/server database application which integrates (1) distributed server processing of client requests, (2) a customized image transmission method for faster Internet data delivery, (3) distributed client workstations with high resolution displays, image processing functions and an on-line digital atlas, and (4) relational database management of the collected data.

  6. Higuchi dimension of digital images.

    Directory of Open Access Journals (Sweden)

    Helmut Ahammer

    Full Text Available There exist several methods for calculating the fractal dimension of objects represented as 2D digital images. For example, Box counting, Minkowski dilation or Fourier analysis can be employed. However, there appear to be some limitations. It is not possible to calculate only the fractal dimension of an irregular region of interest in an image or to perform the calculations in a particular direction along a line on an arbitrary angle through the image. The calculations must be made for the whole image. In this paper, a new method to overcome these limitations is proposed. 2D images are appropriately prepared in order to apply 1D signal analyses, originally developed to investigate nonlinear time series. The Higuchi dimension of these 1D signals is calculated using Higuchi's algorithm, and it is shown that both regions of interests and directional dependencies can be evaluated independently of the whole picture. A thorough validation of the proposed technique and a comparison of the new method to the Fourier dimension, a common two dimensional method for digital images, are given. The main result is that Higuchi's algorithm allows a direction dependent as well as direction independent analysis. Actual values for the fractal dimensions are reliable and an effective treatment of regions of interests is possible. Moreover, the proposed method is not restricted to Higuchi's algorithm, as any 1D method of analysis, can be applied.

  7. Digital image analyser for autoradiography

    International Nuclear Information System (INIS)

    Muth, R.A.; Plotnick, J.

    1985-01-01

    The most critical parameter in quantitative autoradiography for assay of tissue concentrations of tracers is the ability to obtain precise and accurate measurements of optical density of the images. Existing high precision systems for image analysis, rotating drum densitometers, are expensive, suffer from mechanical problems and are slow. More moderately priced and reliable video camera based systems are available, but their outputs generally do not have the uniformity and stability necessary for high resolution quantitative autoradiography. The authors have designed and constructed an image analyser optimized for quantitative single and multiple tracer autoradiography which the authors refer to as a memory-mapped charged-coupled device scanner (MM-CCD). The input is from a linear array of CCD's which is used to optically scan the autoradiograph. Images are digitized into 512 x 512 picture elements with 256 gray levels and the data is stored in buffer video memory in less than two seconds. Images can then be transferred to RAM memory by direct memory-mapping for further processing. Arterial blood curve data and optical density-calibrated standards data can be entered and the optical density images can be converted automatically to tracer concentration or functional images. In double tracer studies, images produced from both exposures can be stored and processed in RAM to yield ''pure'' individual tracer concentration or functional images. Any processed image can be transmitted back to the buffer memory to be viewed on a monitor and processed for region of interest analysis

  8. Radiological interpretation 2020: Toward quantitative image assessment

    International Nuclear Information System (INIS)

    Boone, John M.

    2007-01-01

    The interpretation of medical images by radiologists is primarily and fundamentally a subjective activity, but there are a number of clinical applications such as tumor imaging where quantitative imaging (QI) metrics (such as tumor growth rate) would be valuable to the patient’s care. It is predicted that the subjective interpretive environment of the past will, over the next decade, evolve toward the increased use of quantitative metrics for evaluating patient health from images. The increasing sophistication and resolution of modern tomographic scanners promote the development of meaningful quantitative end points, determined from images which are in turn produced using well-controlled imaging protocols. For the QI environment to expand, medical physicists, physicians, other researchers and equipment vendors need to work collaboratively to develop the quantitative protocols for imaging, scanner calibrations, and robust analytical software that will lead to the routine inclusion of quantitative parameters in the diagnosis and therapeutic assessment of human health. Most importantly, quantitative metrics need to be developed which have genuine impact on patient diagnosis and welfare, and only then will QI techniques become integrated into the clinical environment.

  9. Digital image transformation and rectification of spacecraft and radar images

    Science.gov (United States)

    Wu, S. S. C.

    1985-01-01

    The application of digital processing techniques to spacecraft television pictures and radar images is discussed. The use of digital rectification to produce contour maps from spacecraft pictures is described; images with azimuth and elevation angles are converted into point-perspective frame pictures. The digital correction of the slant angle of radar images to ground scale is examined. The development of orthophoto and stereoscopic shaded relief maps from digital terrain and digital image data is analyzed. Digital image transformations and rectifications are utilized on Viking Orbiter and Lander pictures of Mars.

  10. Digital processing of radiographic images

    Science.gov (United States)

    Bond, A. D.; Ramapriyan, H. K.

    1973-01-01

    Some techniques are presented and the software documentation for the digital enhancement of radiographs. Both image handling and image processing operations are considered. The image handling operations dealt with are: (1) conversion of format of data from packed to unpacked and vice versa; (2) automatic extraction of image data arrays; (3) transposition and 90 deg rotations of large data arrays; (4) translation of data arrays for registration; and (5) reduction of the dimensions of data arrays by integral factors. Both the frequency and the spatial domain approaches are presented for the design and implementation of the image processing operation. It is shown that spatial domain recursive implementation of filters is much faster than nonrecursive implementations using fast fourier transforms (FFT) for the cases of interest in this work. The recursive implementation of a class of matched filters for enhancing image signal to noise ratio is described. Test patterns are used to illustrate the filtering operations. The application of the techniques to radiographic images of metallic structures is demonstrated through several examples.

  11. New directions in pediatric digital imaging

    International Nuclear Information System (INIS)

    Fletcher, B.D.; Adams, R.B.; Blackham, W.C.

    1985-01-01

    In this chapter the authors describe several simple experiments performed utilizing digital equipment which apply to clinical situations in pediatrics and which suggest future directions for research in digital imaging. They also discuss experimental systems which they believe will overcome certain limitations of current equipment and might be applicable to pediatric digital imaging in the future

  12. eCTG: an automatic procedure to extract digital cardiotocographic signals from digital images.

    Science.gov (United States)

    Sbrollini, Agnese; Agostinelli, Angela; Marcantoni, Ilaria; Morettini, Micaela; Burattini, Luca; Di Nardo, Francesco; Fioretti, Sandro; Burattini, Laura

    2018-03-01

    Cardiotocography (CTG), consisting in the simultaneous recording of fetal heart rate (FHR) and maternal uterine contractions (UC), is a popular clinical test to assess fetal health status. Typically, CTG machines provide paper reports that are visually interpreted by clinicians. Consequently, visual CTG interpretation depends on clinician's experience and has a poor reproducibility. The lack of databases containing digital CTG signals has limited number and importance of retrospective studies finalized to set up procedures for automatic CTG analysis that could contrast visual CTG interpretation subjectivity. In order to help overcoming this problem, this study proposes an electronic procedure, termed eCTG, to extract digital CTG signals from digital CTG images, possibly obtainable by scanning paper CTG reports. eCTG was specifically designed to extract digital CTG signals from digital CTG images. It includes four main steps: pre-processing, Otsu's global thresholding, signal extraction and signal calibration. Its validation was performed by means of the "CTU-UHB Intrapartum Cardiotocography Database" by Physionet, that contains digital signals of 552 CTG recordings. Using MATLAB, each signal was plotted and saved as a digital image that was then submitted to eCTG. Digital CTG signals extracted by eCTG were eventually compared to corresponding signals directly available in the database. Comparison occurred in terms of signal similarity (evaluated by the correlation coefficient ρ, and the mean signal error MSE) and clinical features (including FHR baseline and variability; number, amplitude and duration of tachycardia, bradycardia, acceleration and deceleration episodes; number of early, variable, late and prolonged decelerations; and UC number, amplitude, duration and period). The value of ρ between eCTG and reference signals was 0.85 (P digital FHR and UC signals from digital CTG images. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Image Acquisition and Quality in Digital Radiography.

    Science.gov (United States)

    Alexander, Shannon

    2016-09-01

    Medical imaging has undergone dramatic changes and technological breakthroughs since the introduction of digital radiography. This article presents information on the development of digital radiography and types of digital radiography systems. Aspects of image quality and radiation exposure control are highlighted as well. In addition, the article includes related workplace changes and medicolegal considerations in the digital radiography environment. ©2016 American Society of Radiologic Technologists.

  14. Interpretation of medical images by model guided analysis

    International Nuclear Information System (INIS)

    Karssemeijer, N.

    1989-01-01

    Progress in the development of digital pictorial information systems stimulates a growing interest in the use of image analysis techniques in medicine. Especially when precise quantitative information is required the use of fast and reproducable computer analysis may be more appropriate than relying on visual judgement only. Such quantitative information can be valuable, for instance, in diagnostics or in irradiation therapy planning. As medical images are mostly recorded in a prescribed way, human anatomy guarantees a common image structure for each particular type of exam. In this thesis it is investigated how to make use of this a priori knowledge to guide image analysis. For that purpose models are developed which are suited to capture common image structure. The first part of this study is devoted to an analysis of nuclear medicine images of myocardial perfusion. In ch. 2 a model of these images is designed in order to represent characteristic image properties. It is shown that for these relatively simple images a compact symbolic description can be achieved, without significant loss of diagnostically importance of several image properties. Possibilities for automatic interpretation of more complex images is investigated in the following chapters. The central topic is segmentation of organs. Two methods are proposed and tested on a set of abdominal X-ray CT scans. Ch. 3 describes a serial approach based on a semantic network and the use of search areas. Relational constraints are used to guide the image processing and to classify detected image segments. In teh ch.'s 4 and 5 a more general parallel approach is utilized, based on a markov random field image model. A stochastic model used to represent prior knowledge about the spatial arrangement of organs is implemented as an external field. (author). 66 refs.; 27 figs.; 6 tabs

  15. Advanced techniques in digital mammographic images recognition

    International Nuclear Information System (INIS)

    Aliu, R. Azir

    2011-01-01

    Computer Aided Detection and Diagnosis is used in digital radiography as a second thought in the process of determining diagnoses, which reduces the percentage of wrong diagnoses of the established interpretation of mammographic images. The issues that are discussed in the dissertation are the analyses and improvement of advanced technologies in the field of artificial intelligence, more specifically in the field of machine learning for solving diagnostic problems and automatic detection of speculated lesions in digital mammograms. The developed of SVM-based ICAD system with cascade architecture for analyses and comparison mammographic images in both projections (CC and MLO) gives excellent result for detection and masses and microcalcifications. In order to develop a system with optimal performances of sensitivity, specificity and time complexity, a set of relevant characteristics need to be created which will show all the pathological regions that might be present in the mammographic image. The structure of the mammographic image, size and the large number of pathological structures in this area are the reason why the creation of a set of these features is necessary for the presentation of good indicators. These pathological structures are a real challenge today and the world of science is working in that direction. The doctoral dissertation showed that the system has optimal results, which are confirmed by experts, and institutions, which are dealing with these same issues. Also, the thesis presents a new approach for automatic identification of regions of interest in the mammographic image where regions of interest are automatically selected for further processing mammography in cases when the number of examined patients is higher. Out of 480 mammographic images downloaded from MIAS database and tested with ICAD system the author shows that, after separation and selection of relevant features of ICAD system the accuracy is 89.7% (96.4% for microcalcifications

  16. Blackboard architecture for medical image interpretation

    Science.gov (United States)

    Davis, Darryl N.; Taylor, Christopher J.

    1991-06-01

    There is a growing interest in using sophisticated knowledge-based systems for biomedical image interpretation. We present a principled attempt to use artificial intelligence methodologies in interpreting lateral skull x-ray images. Such radiographs are routinely used in cephalometric analysis to provide quantitative measurements useful to clinical orthodontists. Manual and interactive methods of analysis are known to be error prone and previous attempts to automate this analysis typically fail to capture the expertise and adaptability required to cope with the variability in biological structure and image quality. An integrated model-based system has been developed which makes use of a blackboard architecture and multiple knowledge sources. A model definition interface allows quantitative models, of feature appearance and location, to be built from examples as well as more qualitative modelling constructs. Visual task definition and blackboard control modules allow task-specific knowledge sources to act on information available to the blackboard in a hypothesise and test reasoning cycle. Further knowledge-based modules include object selection, location hypothesis, intelligent segmentation, and constraint propagation systems. Alternative solutions to given tasks are permitted.

  17. Digital image analysis of NDT radiographs

    International Nuclear Information System (INIS)

    Graeme, W.A. Jr.; Eizember, A.C.; Douglass, J.

    1989-01-01

    Prior to the introduction of Charge Coupled Device (CCD) detectors the majority of image analysis performed on NDT radiographic images was done visually in the analog domain. While some film digitization was being performed, the process was often unable to capture all the usable information on the radiograph or was too time consuming. CCD technology now provides a method to digitize radiographic film images without losing the useful information captured in the original radiograph in a timely process. Incorporating that technology into a complete digital radiographic workstation allows analog radiographic information to be processed, providing additional information to the radiographer. Once in the digital domain, that data can be stored, and fused with radioscopic and other forms of digital data. The result is more productive analysis and management of radiographic inspection data. The principal function of the NDT Scan IV digital radiography system is the digitization, enhancement and storage of radiographic images

  18. Digital X-ray imager

    International Nuclear Information System (INIS)

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying source voltage and filtering (predicting the required dynamic range for the detector); evaluating CsI:Tl, CdWO4 and scintillating glass as image converters; recommending image enhancement algorithms. The LLNL modeling results guided the design and experimental elements of the project. The Laboratory's unique array of sources and detectors was employed to resolve specific technical questions. Our image processing expertise was applied to the selection of enhancement tools for image display

  19. AUTOMATIC INTERPRETATION OF HIGH RESOLUTION SAR IMAGES: FIRST RESULTS OF SAR IMAGE SIMULATION FOR SINGLE BUILDINGS

    Directory of Open Access Journals (Sweden)

    J. Tao

    2012-09-01

    Full Text Available Due to the all-weather data acquisition capabilities, high resolution space borne Synthetic Aperture Radar (SAR plays an important role in remote sensing applications like change detection. However, because of the complex geometric mapping of buildings in urban areas, SAR images are often hard to interpret. SAR simulation techniques ease the visual interpretation of SAR images, while fully automatic interpretation is still a challenge. This paper presents a method for supporting the interpretation of high resolution SAR images with simulated radar images using a LiDAR digital surface model (DSM. Line features are extracted from the simulated and real SAR images and used for matching. A single building model is generated from the DSM and used for building recognition in the SAR image. An application for the concept is presented for the city centre of Munich where the comparison of the simulation to the TerraSAR-X data shows a good similarity. Based on the result of simulation and matching, special features (e.g. like double bounce lines, shadow areas etc. can be automatically indicated in SAR image.

  20. Three dimensional digital imaging of environmental data

    International Nuclear Information System (INIS)

    Nichols, R.L.; Eddy, C.A.

    1991-01-01

    The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site

  1. Digital X-ray Imaging in Dentistry

    International Nuclear Information System (INIS)

    Kim, Eun Kyung

    1999-01-01

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  2. Digital X-ray Imaging in Dentistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Dankook University, Yongin (Korea, Republic of)

    1999-08-15

    In dentistry, Radio Visio Graphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter, many types of direct digital radiographic systems have been produced in the last decade. They are based either on charge-coupled device (CCD) or on storage phosphor technology. In addition, new types of digital radiographic system using amorphous selenium, image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose, image processing, computer storage, electronic transfer of images and so on. Image processing includes image enhancement, image reconstruction, digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system (IMACS) for dentomaxillofacial radiology was reported in 1992, IMACS in dental hospital has been increasing. Meanwhile, researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible, feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis, have been performed actively in the last decade. Further developments in digital radiographic imaging modalities, image transmission system, imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

  3. Digital image analysis of X-ray television with an image digitizer

    International Nuclear Information System (INIS)

    Mochizuki, Yasuo; Akaike, Hisahiko; Ogawa, Hitoshi; Kyuma, Yukishige

    1995-01-01

    When video signals of X-ray fluoroscopy were transformed from analog-to-digital ones with an image digitizer, their digital characteristic curves, pre-sampling MTF's and digital Wiener spectral could be measured. This method was advant ageous in that it was able to carry out data sampling because the pixel values inputted could be verified on a CRT. The system of image analysis by this method is inexpensive and effective in evaluating the image quality of digital system. Also, it is expected that this method can be used as a tool for learning the measurement techniques and physical characteristics of digital image quality effectively. (author)

  4. Practical aspects of MR image interpretation

    International Nuclear Information System (INIS)

    Bradley, W.G.

    1987-01-01

    This is a practical course designed for those already reading CT scans who will be interpreting MR images. The course focuses on the unique information available from MR imaging that distinguishes it from CT. The following questions in specific subject areas are addressed: (1) What determines the proton density and T1 and T2 times of a particular tissue? How and why do these parameters change in certain disease states? (2) How does the protein content affect signal intensity through the mechanism of ''hydration layer water''? Why does hemorrhage sometimes appear dark and sometimes bright? Why do some paramagnetic substances (e.g., methemoglobin and Gd-DTPA) increase signal intensity and others (e.g., deoxyhemoglobin, hemosiderin, and ferritin) decrease signal intensity? How do the magnetic susceptibility effects depend on field strength and imaging technique (e.g., traditional Hahn spin echo versus gradient echo)? (3) What determines T1, T2, and proton density contrast in the traditional spin-echo and inversion-recovery images and in the new fast partial saturation techniques that use gradient echoes and reduced flip angles? (4) Why do flowing blood and CSF sometimes appear dark and sometimes bright? Exactly how do time-of-flight effects, turbulence, and odd-echo dephasing decrease signal intensity while flow-related enhancement, even-echo rephasing, and diastolic pseudogating increase signal intensity? How does one distinguish intraluminal pathology from high-intensity flow effects? How does one utilize the information in these flow phenomena and turn these ''artifacts'' to clinical advantage? Why do flowing blood and CSF generally appear bright on the new fast scan (e.g., FLASH and GRASS) images?

  5. Ethical Implications of Digital Imaging in Photojournalism.

    Science.gov (United States)

    Terry, Danal; Lasorsa, Dominic L.

    Arguing that the news media are about to adopt digital imaging systems that will have far-reaching implications for the practice of journalism, this paper discusses how the news media is expected to adopt the new technology and explains why the marriage of journalism and digital imaging will create ethical issues with respect to photo manipulation…

  6. Computing Hypercrossed Complex Pairings in Digital Images

    Directory of Open Access Journals (Sweden)

    Simge Öztunç

    2013-01-01

    Full Text Available We consider an additive group structure in digital images and introduce the commutator in digital images. Then we calculate the hypercrossed complex pairings which generates a normal subgroup in dimension 2 and in dimension 3 by using 8-adjacency and 26-adjacency.

  7. Digital Imaging: An Adobe Photoshop Course

    Science.gov (United States)

    Cobb, Kristine

    2007-01-01

    This article introduces digital imaging, an Adobe Photoshop course at Shrewsbury High School in Shrewsbury, Massachusetts. Students are able to earn art credits to graduate by successfully completing the course. Digital imaging must cover art criteria as well as technical skills. The course begins with tutorials created by the instructor and other…

  8. Visual Interpretation with Three-Dimensional Annotations (VITA): Three-Dimensional Image Interpretation Tool for Radiological Reporting

    OpenAIRE

    Roy, Sharmili; Brown, Michael S.; Shih, George L.

    2013-01-01

    This paper introduces a software framework called Visual Interpretation with Three-Dimensional Annotations (VITA) that is able to automatically generate three-dimensional (3D) visual summaries based on radiological annotations made during routine exam reporting. VITA summaries are in the form of rotating 3D volumes where radiological annotations are highlighted to place important clinical observations into a 3D context. The rendered volume is produced as a Digital Imaging and Communications i...

  9. How Digital Image Processing Became Really Easy

    Science.gov (United States)

    Cannon, Michael

    1988-02-01

    In the early and mid-1970s, digital image processing was the subject of intense university and corporate research. The research lay along two lines: (1) developing mathematical techniques for improving the appearance of or analyzing the contents of images represented in digital form, and (2) creating cost-effective hardware to carry out these techniques. The research has been very effective, as evidenced by the continued decline of image processing as a research topic, and the rapid increase of commercial companies to market digital image processing software and hardware.

  10. Standard digital reference images for titanium castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 The digital reference images provided in the adjunct to this standard illustrate various types and degrees of discontinuities occurring in titanium castings. Use of this standard for the specification or grading of castings requires procurement of the adjunct digital reference images, which illustrate the discontinuity types and severity levels. They are intended to provide the following: 1.1.1 A guide enabling recognition of titanium casting discontinuities and their differentiation both as to type and degree through digital radiographic examination. 1.1.2 Example digital radiographic illustrations of discontinuities and a nomenclature for reference in acceptance standards, specifications and drawings. 1.2 The digital reference images consist of seventeen digital files each illustrating eight grades of increasing severity. The files illustrate seven common discontinuity types representing casting sections up to 1-in. (25.4-mm). 1.3 The reference radiographs were developed for casting sections up to 1...

  11. Compression and archiving of digital images

    International Nuclear Information System (INIS)

    Huang, H.K.

    1988-01-01

    This paper describes the application of a full-frame bit-allocation image compression technique to a hierarchical digital image archiving system consisting of magnetic disks, optical disks and an optical disk library. The digital archiving system without the compression has been in clinical operation in the Pediatric Radiology for more than half a year. The database in the system consists of all pediatric inpatients including all images from computed radiography, digitized x-ray films, CT, MR, and US. The rate of image accumulation is approximately 1,900 megabytes per week. The hardware design of the compression module is based on a Motorola 68020 microprocessor, A VME bus, a 16 megabyte image buffer memory board, and three Motorola digital signal processing 56001 chips on a VME board for performing the two-dimensional cosine transform and the quantization. The clinical evaluation of the compression module with the image archiving system is expected to be in February 1988

  12. Image rejects in general direct digital radiography

    International Nuclear Information System (INIS)

    Hofmann, Bjørn; Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-01-01

    The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality

  13. Image rejects in general direct digital radiography.

    Science.gov (United States)

    Hofmann, Bjørn; Rosanowsky, Tine Blomberg; Jensen, Camilla; Wah, Kenneth Hong Ching

    2015-10-01

    The number of rejected images is an indicator of image quality and unnecessary imaging at a radiology department. Image reject analysis was frequent in the film era, but comparably few and small studies have been published after converting to digital radiography. One reason may be a belief that rejects have been eliminated with digitalization. To measure the extension of deleted images in direct digital radiography (DR), in order to assess the rates of rejects and unnecessary imaging and to analyze reasons for deletions, in order to improve the radiological services. All exposed images at two direct digital laboratories at a hospital in Norway were reviewed in January 2014. Type of examination, number of exposed images, and number of deleted images were registered. Each deleted image was analyzed separately and the reason for deleting the image was recorded. Out of 5417 exposed images, 596 were deleted, giving a deletion rate of 11%. A total of 51.3% were deleted due to positioning errors and 31.0% due to error in centering. The examinations with the highest percentage of deleted images were the knee, hip, and ankle, 20.6%, 18.5%, and 13.8% respectively. The reject rate is at least as high as the deletion rate and is comparable with previous film-based imaging systems. The reasons for rejection are quite different in digital systems. This falsifies the hypothesis that digitalization would eliminates rejects. A deleted image does not contribute to diagnostics, and therefore is an unnecessary image. Hence, the high rates of deleted images have implications for management, training, education, as well as for quality.

  14. Could digital imaging be an alternative for digital colorimeters?

    Science.gov (United States)

    Caglar, Alper; Yamanel, Kivanc; Gulsahi, Kamran; Bagis, Bora; Ozcan, Mutlu

    2010-12-01

    This study evaluated the colour parameters of composite and ceramic shade guides determined using a colorimeter and digital imaging method with illuminants at different colour temperatures. Two different resin composite shade guides, namely Charisma (Heraeus Kulzer) and Premise (Kerr Corporation), and two different ceramic shade guides, Vita Lumin Vacuum (VITA Zahnfabrik) and Noritake (Noritake Co.), were evaluated at three different colour temperatures (2,700 K, 2,700-6,500 K, and 6500 K) of illuminants. Ten shade tabs were selected (A1, A2, A3, A3,5, A4, B1, B2, B3, C2 and C3) from each shade guide. CIE Lab values were obtained using digital imaging and a colorimeter (ShadeEye NCC Dental Chroma Meter, Shofu Inc.). The data were analysed using two-way ANOVA, and Pearson's correlation. While mean L* values of both composite and ceramic shade guides were not affected from the colour temperature, L* values obtained with the colorimeter showed significantly lower values than those of the digital imaging (p colorimeter and digital imaging did not show significant differences (p > 0.05). For both composite and ceramic shade guides, L* and b* values obtained from colorimeter and digital imaging method presented a high level of correlation. High-level correlations were also acquired for a* values in all shade guides except for the Charisma composite shade guide. Digital imaging method could be an alternative for the colorimeters unless the proper object-camera distance, digital camera settings and suitable illumination conditions could be supplied. However, variations in shade guides, especially for composites, may affect the correlation.

  15. DHM (Digital Holography Microscope) for imaging cells

    International Nuclear Information System (INIS)

    Emery, Yves; Cuche, Etienne; Colomb, Tristan; Depeursinge, Christian; Rappaz, Benjamin; Marquet, Pierre; Magistretti, Pierre

    2007-01-01

    Light interaction with a sample modifies both intensity and phase of the illuminating wave. Any available supports for image recording are only sensitive to intensity, but Denis Gabor [P. Marquet, B. Rappaz, P. Magistretti, et. al. Digital Holography for quantitative phase-contrast imaging, Optics Letters, 30, 5, pp 291-93 (2005)] invented in 1948 a way to encode the phase as an intensity variation: the h ologram . Digital Holographic Microscopy (DHM) [D. Gabor, A new microscopic principle, Nature, 1948] implements digitally this powerful hologram. Characterization of various pollen grains and of morphology changes of neurones associated with hypotonic shock demonstrates the potential of DHM for imaging cells

  16. Digital image display system for emergency room

    International Nuclear Information System (INIS)

    Murry, R.C.; Lane, T.J.; Miax, L.S.

    1989-01-01

    This paper reports on a digital image display system for the emergency room (ER) in a major trauma hospital. Its objective is to reduce radiographic image delivery time to a busy ER while simultaneously providing a multimodality capability. Image storage, retrieval, and display will also be facilitated with this system. The system's backbone is a token-ring network of RISC and personal computers. The display terminals are higher- function RISC computers with 1,024 2 color or gray-scale monitors. The PCs serve as administrative terminals. Nuclear medicine, CT, MR, and digitized film images are transferred to the image display system

  17. The use of digital images in pathology.

    Science.gov (United States)

    Furness, P N

    1997-11-01

    Digital images are routinely used by the publishing industry, but most diagnostic pathologists are unfamiliar with the technology and its possibilities. This review aims to explain the basic principles of digital image acquisition, storage, manipulation and use, and the possibilities provided not only in research, but also in teaching and in routine diagnostic pathology. Images of natural objects are usually expressed digitally as 'bitmaps'--rectilinear arrays of small dots. The size of each dot can vary, but so can its information content in terms, for example, of colour, greyscale or opacity. Various file formats and compression algorithms are available. Video cameras connected to microscopes are familiar to most pathologists; video images can be converted directly to a digital form by a suitably equipped computer. Digital cameras and scanners are alternative acquisition tools of relevance to pathologists. Once acquired, a digital image can easily be subjected to the digital equivalent of any conventional darkroom manipulation and modern software allows much more flexibility, to such an extent that a new tool for scientific fraud has been created. For research, image enhancement and analysis is an increasingly powerful and affordable tool. Morphometric measurements are, after many predictions, at last beginning to be part of the toolkit of the diagnostic pathologist. In teaching, the potential to create dramatic yet informative presentations is demonstrated daily by the publishing industry; such methods are readily applicable to the classroom. The combination of digital images and the Internet raises many possibilities; for example, instead of seeking one expert diagnostic opinion, one could simultaneously seek the opinion of many, all around the globe. It is inevitable that in the coming years the use of digital images will spread from the laboratory to the medical curriculum and to the whole of diagnostic pathology.

  18. Converting analog interpretive data to digital formats for use in database and GIS applications

    Science.gov (United States)

    Flocks, James G.

    2004-01-01

    database and GIS software as point, vector or text information is commonly lost. Sediment core descriptions and interpretation of geophysical profiles are usually portrayed as lines, curves, symbols and text information. They have vertical and horizontal dimensions associated with depth, category, time, or geographic position. These dimensions are displayed in consistent positions, which can be digitized and converted to a digital format, such as a spreadsheet. Once this data is in a digital, tabulated form it can easily be made available to a wide variety of imaging and data manipulation software for compilation and world-wide dissemination.

  19. Fractal Image Coding with Digital Watermarks

    Directory of Open Access Journals (Sweden)

    Z. Klenovicova

    2000-12-01

    Full Text Available In this paper are presented some results of implementation of digitalwatermarking methods into image coding based on fractal principles. Thepaper focuses on two possible approaches of embedding digitalwatermarks into fractal code of images - embedding digital watermarksinto parameters for position of similar blocks and coefficients ofblock similarity. Both algorithms were analyzed and verified on grayscale static images.

  20. Better imaging: the advantages of digital radiography

    NARCIS (Netherlands)

    van der Stelt, P.F.

    2008-01-01

    Background. Digital radiography has been available in dentistry for more than 25 years, but it has not replaced conventional film-based radiography completely. This could be because of the costs involved in replacing conventional radiographic equipment with a digital imaging system, or because

  1. Digital image processing in art conservation

    Czech Academy of Sciences Publication Activity Database

    Zitová, Barbara; Flusser, Jan

    č. 53 (2003), s. 44-45 ISSN 0926-4981 Institutional research plan: CEZ:AV0Z1075907 Keywords : art conservation * digital image processing * change detection Subject RIV: JD - Computer Applications, Robotics

  2. Structure of the medical digital image

    International Nuclear Information System (INIS)

    Baltadzhiev, D.

    1997-01-01

    In up-to-date medical practice diagnostic imaging techniques are the most powerful tools available to clinicians. The modern medical equipment is entirely based on digital technology. In this article the principle of generating medical images is presented. The concept for gray scale where medical images are commonly presented is described. The patterns of gray images transformation into colour scale are likewise outlined. Basic notions from medical imaging terminology such as image matrix, pixel, spatial and contrast resolution power, bit, byte and the like are explained. Also an example is given of how the binary system treats images. On the basis of digital technology the obtained medical images lend themselves readily to additional processing, reconstruction (including 3D) and storage for subsequent utilization. The ceaseless progress of computerized communications promote easy and prompt access for clinicians to the diagnostic images needed as well as realization of expert consultations by teleconference contact (author)

  3. Steganography and Steganalysis in Digital Images

    Science.gov (United States)

    2012-01-01

    REPORT Steganography and Steganalysis in Digital Images 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: Steganography (from the Greek for "covered writing...12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS Least Significant Bit ( LSB ), steganography , steganalysis, stegogramme. Dr. Jeff Duffany...Z39.18 - Steganography and Steganalysis in Digital Images Report Title ABSTRACT Steganography (from the Greek for "covered writing") is the secret

  4. Digital Data Processing of Images

    African Journals Online (AJOL)

    be concerned with the image enhancement of scintigrams. Two applications of image ... obtained from scintigraphic equipment, image enhance- ment by computer was ... used as an example. ..... Using video-tape display, areas of interest are ...

  5. Three-dimensional facial digitization using advanced digital image correlation.

    Science.gov (United States)

    Nguyen, Hieu; Kieu, Hien; Wang, Zhaoyang; Le, Hanh N D

    2018-03-20

    Presented in this paper is an effective technique to acquire the three-dimensional (3D) digital images of the human face without the use of active lighting and artificial patterns. The technique is based on binocular stereo imaging and digital image correlation, and it includes two key steps: camera calibration and image matching. The camera calibration involves a pinhole model and a bundle-adjustment approach, and the governing equations of the 3D digitization process are described. For reliable pixel-to-pixel image matching, the skin pores and freckles or lentigines on the human face serve as the required pattern features to facilitate the process. It employs feature-matching-based initial guess, multiple subsets, iterative optimization algorithm, and reliability-guided computation path to achieve fast and accurate image matching. Experiments have been conducted to demonstrate the validity of the proposed technique. The simplicity of the approach and the affordable cost of the implementation show its practicability in scientific and engineering applications.

  6. Digital image envelope: method and evaluation

    Science.gov (United States)

    Huang, H. K.; Cao, Fei; Zhou, Michael Z.; Mogel, Greg T.; Liu, Brent J.; Zhou, Xiaoqiang

    2003-05-01

    Health data security, characterized in terms of data privacy, authenticity, and integrity, is a vital issue when digital images and other patient information are transmitted through public networks in telehealth applications such as teleradiology. Mandates for ensuring health data security have been extensively discussed (for example The Health Insurance Portability and Accountability Act, HIPAA) and health informatics guidelines (such as the DICOM standard) are beginning to focus on issues of data continue to be published by organizing bodies in healthcare; however, there has not been a systematic method developed to ensure data security in medical imaging Because data privacy and authenticity are often managed primarily with firewall and password protection, we have focused our research and development on data integrity. We have developed a systematic method of ensuring medical image data integrity across public networks using the concept of the digital envelope. When a medical image is generated regardless of the modality, three processes are performed: the image signature is obtained, the DICOM image header is encrypted, and a digital envelope is formed by combining the signature and the encrypted header. The envelope is encrypted and embedded in the original image. This assures the security of both the image and the patient ID. The embedded image is encrypted again and transmitted across the network. The reverse process is performed at the receiving site. The result is two digital signatures, one from the original image before transmission, and second from the image after transmission. If the signatures are identical, there has been no alteration of the image. This paper concentrates in the method and evaluation of the digital image envelope.

  7. Volumetric CT-images improve testing of radiological image interpretation skills

    Energy Technology Data Exchange (ETDEWEB)

    Ravesloot, Cécile J., E-mail: C.J.Ravesloot@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Schaaf, Marieke F. van der, E-mail: M.F.vanderSchaaf@uu.nl [Department of Pedagogical and Educational Sciences at Utrecht University, Heidelberglaan 1, 3584 CS Utrecht (Netherlands); Schaik, Jan P.J. van, E-mail: J.P.J.vanSchaik@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Cate, Olle Th.J. ten, E-mail: T.J.tenCate@umcutrecht.nl [Center for Research and Development of Education at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Gijp, Anouk van der, E-mail: A.vanderGijp-2@umcutrecht.nl [Radiology Department at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht, Room E01.132 (Netherlands); Mol, Christian P., E-mail: C.Mol@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands); Vincken, Koen L., E-mail: K.Vincken@umcutrecht.nl [Image Sciences Institute at University Medical Center Utrecht, Heidelberglaan 100, 3508 GA Utrecht (Netherlands)

    2015-05-15

    Rationale and objectives: Current radiology practice increasingly involves interpretation of volumetric data sets. In contrast, most radiology tests still contain only 2D images. We introduced a new testing tool that allows for stack viewing of volumetric images in our undergraduate radiology program. We hypothesized that tests with volumetric CT-images enhance test quality, in comparison with traditional completely 2D image-based tests, because they might better reflect required skills for clinical practice. Materials and methods: Two groups of medical students (n = 139; n = 143), trained with 2D and volumetric CT-images, took a digital radiology test in two versions (A and B), each containing both 2D and volumetric CT-image questions. In a questionnaire, they were asked to comment on the representativeness for clinical practice, difficulty and user-friendliness of the test questions and testing program. Students’ test scores and reliabilities, measured with Cronbach's alpha, of 2D and volumetric CT-image tests were compared. Results: Estimated reliabilities (Cronbach's alphas) were higher for volumetric CT-image scores (version A: .51 and version B: .54), than for 2D CT-image scores (version A: .24 and version B: .37). Participants found volumetric CT-image tests more representative of clinical practice, and considered them to be less difficult than volumetric CT-image questions. However, in one version (A), volumetric CT-image scores (M 80.9, SD 14.8) were significantly lower than 2D CT-image scores (M 88.4, SD 10.4) (p < .001). The volumetric CT-image testing program was considered user-friendly. Conclusion: This study shows that volumetric image questions can be successfully integrated in students’ radiology testing. Results suggests that the inclusion of volumetric CT-images might improve the quality of radiology tests by positively impacting perceived representativeness for clinical practice and increasing reliability of the test.

  8. Interpretation of digital breast tomosynthesis: preliminary study on comparison with picture archiving and communication system (PACS) and dedicated workstation.

    Science.gov (United States)

    Kim, Young Seon; Chang, Jung Min; Yi, Ann; Shin, Sung Ui; Lee, Myung Eun; Kim, Won Hwa; Cho, Nariya; Moon, Woo Kyung

    2017-08-01

    To compare the diagnostic accuracy and efficiency in the interpretation of digital breast tomosynthesis (DBT) images using a picture archiving and communication system (PACS) and a dedicated workstation. 97 DBT images obtained for screening or diagnostic purposes were stored in both a workstation and a PACS and evaluated in combination with digital mammography by three independent radiologists retrospectively. Breast Imaging-Reporting and Data System final assessments and likelihood of malignancy (%) were assigned and the interpretation time when using the workstation and PACS was recorded. Receiver operating characteristic curve analysis, sensitivities and specificities were compared with histopathological examination and follow-up data as a reference standard. Area under the receiver operating characteristic curve values for cancer detection (0.839 vs 0.815, p = 0.6375) and sensitivity (81.8% vs 75.8%, p = 0.2188) showed no statistically significant differences between the workstation and PACS. However, specificity was significantly higher when analysing on the workstation than when using PACS (83.7% vs 76.9%, p = 0.009). When evaluating DBT images using PACS, only one case was deemed necessary to be reanalysed using the workstation. The mean time to interpret DBT images on PACS (1.68 min/case) was significantly longer than that to interpret on the workstation (1.35 min/case) (p < 0.0001). Interpretation of DBT images using PACS showed comparable diagnostic performance to a dedicated workstation, even though it required a longer reading time. Advances in knowledge: Interpretation of DBT images using PACS is an alternative to evaluate the images when a dedicated workstation is not available.

  9. Three-Dimensional Interpretation of Sculptural Heritage with Digital and Tangible 3D Printed Replicas

    Science.gov (United States)

    Saorin, José Luis; Carbonell-Carrera, Carlos; Cantero, Jorge de la Torre; Meier, Cecile; Aleman, Drago Diaz

    2017-01-01

    Spatial interpretation features as a skill to acquire in the educational curricula. The visualization and interpretation of three-dimensional objects in tactile devices and the possibility of digital manufacturing with 3D printers, offers an opportunity to include replicas of sculptures in teaching and, thus, facilitate the 3D interpretation of…

  10. Image digitizer system for bubble chamber laser

    International Nuclear Information System (INIS)

    Haggerty, H.

    1986-01-01

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

  11. Photography/Digital Imaging: Parallel & Paradoxical Histories.

    Science.gov (United States)

    Witte, Mary Stieglitz

    With the introduction of photography and photomechanical printing processes in the 19th century, the first age of machine pictures and reproductions emerged. The 20th century introduced computer image processing systems, creating a digital imaging revolution. Rather than concentrating on the adversarial aspects of the computer's influence on…

  12. Panoramic images of conventional radiographs: digital panoramic dynamic images

    International Nuclear Information System (INIS)

    Schultze, M.

    2001-01-01

    The benefits of digital technic s to od ontology are evident. Instant images, the possibility to handle them, the reduction of exposition time to radiations, better quality image, better quality information, Stocking them in a compact disc, occupying very little space, allows an easy transport and duplication, as well as the possibility to transfer and save it in an electronica l support.This kind of communication allows the transmission of digital images and every other type of data, instantaneously and no matter distances or geographical borders. Anyway, we should point out that conventional and digital technic s reveal the same information contents

  13. Existential space understanding through digital image

    Directory of Open Access Journals (Sweden)

    Susana Iñarra Abad

    2013-10-01

    Full Text Available The logical way to learn from the architectural space and then be able to design and represent it is, undoubtedly, that of experiencing it through all the sensitive channels that the space wakes up us.  But since the last 30 years, much of our learning about space comes from images of architecture and not from the space itself. The art of architecture is drifting towards a visual art and moving away from its existential side. In digital images that have flooded the architectural media, digital photographs of existing spaces intermingle with non-existent space renderings (photographs with a virtual camera. The first ones represent existing places but can be altered to change the perception that  the observer of the image will have, the second ones speak to us about places that do not exist yet but they present reality portions through extracts from digital photography (textures, trees, people... that compose the image.

  14. Image quality analysis of digital mammographic equipments

    Energy Technology Data Exchange (ETDEWEB)

    Mayo, P.; Pascual, A.; Verdu, G. [Valencia Univ. Politecnica, Chemical and Nuclear Engineering Dept. (Spain); Rodenas, F. [Valencia Univ. Politecnica, Applied Mathematical Dept. (Spain); Campayo, J.M. [Valencia Univ. Hospital Clinico, Servicio de Radiofisica y Proteccion Radiologica (Spain); Villaescusa, J.I. [Hospital Clinico La Fe, Servicio de Proteccion Radiologica, Valencia (Spain)

    2006-07-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  15. Image quality analysis of digital mammographic equipments

    International Nuclear Information System (INIS)

    Mayo, P.; Pascual, A.; Verdu, G.; Rodenas, F.; Campayo, J.M.; Villaescusa, J.I.

    2006-01-01

    The image quality assessment of a radiographic phantom image is one of the fundamental points in a complete quality control programme. The good functioning result of all the process must be an image with an appropriate quality to carry out a suitable diagnostic. Nowadays, the digital radiographic equipments are replacing the traditional film-screen equipments and it is necessary to update the parameters to guarantee the quality of the process. Contrast-detail phantoms are applied to digital radiography to study the threshold contrast detail sensitivity at operation conditions of the equipment. The phantom that is studied in this work is C.D.M.A.M. 3.4, which facilitates the evaluation of image contrast and detail resolution. One of the most extended indexes to measure the image quality in an objective way is the Image Quality Figure (I.Q.F.). This parameter is useful to calculate the image quality taking into account the contrast and detail resolution of the image analysed. The contrast-detail curve is useful as a measure of the image quality too, because it is a graphical representation in which the hole thickness and diameter are plotted for each contrast-detail combination detected in the radiographic image of the phantom. It is useful for the comparison of the functioning of different radiographic image systems, for phantom images under the same exposition conditions. The aim of this work is to study the image quality of different images contrast-detail phantom C.D.M.A.M. 3.4, carrying out the automatic detection of the contrast-detail combination and to establish a parameter which characterize in an objective way the mammographic image quality. This is useful to compare images obtained at different digital mammographic equipments to study the functioning of the equipments. (authors)

  16. A digital library of radiology images.

    Science.gov (United States)

    Kahn, Charles E

    2006-01-01

    A web-based virtual library of peer-reviewed radiological images was created for use in education and clinical decision support. Images were obtained from open-access content of five online radiology journals and one e-learning web site. Figure captions were indexed by Medical Subject Heading (MeSH) codes, imaging modality, and patient age and sex. This digital library provides a new, valuable online resource.

  17. Remote sensing image fusion in the context of Digital Earth

    International Nuclear Information System (INIS)

    Pohl, C

    2014-01-01

    The increase in the number of operational Earth observation satellites gives remote sensing image fusion a new boost. As a powerful tool to integrate images from different sensors it enables multi-scale, multi-temporal and multi-source information extraction. Image fusion aims at providing results that cannot be obtained from a single data source alone. Instead it enables feature and information mining of higher reliability and availability. The process required to prepare remote sensing images for image fusion comprises most of the necessary steps to feed the database of Digital Earth. The virtual representation of the planet uses data and information that is referenced and corrected to suit interpretation and decision-making. The same pre-requisite is valid for image fusion, the outcome of which can directly flow into a geographical information system. The assessment and description of the quality of the results remains critical. Depending on the application and information to be extracted from multi-source images different approaches are necessary. This paper describes the process of image fusion based on a fusion and classification experiment, explains the necessary quality measures involved and shows with this example which criteria have to be considered if the results of image fusion are going to be used in Digital Earth

  18. Digital fluoroscopy: a new development in medical imaging

    International Nuclear Information System (INIS)

    Maher, K.P.; Malone, J.F.; Dublin Inst. of Technology

    1986-01-01

    Medical fluoroscopy is briefly reviewed and video-image digitization is described. Image processing requirements and image processors available for digital fluoroscopy are discussed in detail. Specific reference is made to an application of digital fluoroscopy in the imaging of blood-vessels. This application involves an image substraction technique which is referred to as digital subtraction angiography (DSA). A number of DSA images of relevance to the discussion are included. (author)

  19. An Archive of Digital Images.

    Science.gov (United States)

    Fantini, M.; And Others

    1990-01-01

    Describes the architecture of the prototype of an image management system that has been used to develop an application concerning images of frescoes in the Sistina Chapel in the Vatican. Hardware and software design are described, the use of local area networks (LANs) is discussed, and data organization is explained. (15 references) (LRW)

  20. Digital memory for TV image information

    International Nuclear Information System (INIS)

    Paretti, C.

    1975-01-01

    A system employing closed circuit TV camera and MOS memory is presented to take image information and store it. The apparatus is made in two sections: analog filters and digital memory. Filters have been used to select low amplitude signals from high frequency and low frequency noise components. The memory is arranged to make nondestroying overlap of digit array: this facility is useful for microscope image prejection to overcome depth of field limits, as in automatic nuclear emulsion scanners for personnel radiation monitoring. (author)

  1. Digital networks for the image management

    International Nuclear Information System (INIS)

    Gomez del Campo L, A.

    1999-01-01

    The digital networks designed specifically for the X-ray departments in the hospitals already were found in open development at beginning the 80's decade. Actually the digital network will be present include the image generation without the necessity to use film in direct form and in its case to print it through a laser ray printers network, an electronic image file, the possibility to integrate the hospitable information system to the electronic expedient which will allow communicate radiograph electronic files and consult by satellite via the problem cases. (Author)

  2. Processing of space images and geologic interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Yudin, V S

    1981-01-01

    Using data for standard sections, a correlation was established between natural formations in geologic/geophysical dimensions and the form they take in the imaging. With computer processing, important data can be derived from the image. Use of the above correlations has allowed to make a number of preliminary classifications of tectonic structures, and to determine certain ongoing processes in the given section. The derived data may be used for search of useful minerals.

  3. Fundamental concepts of digital image processing

    Energy Technology Data Exchange (ETDEWEB)

    Twogood, R.E.

    1983-03-01

    The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under observation rather than days later.

  4. Fundamental Concepts of Digital Image Processing

    Science.gov (United States)

    Twogood, R. E.

    1983-03-01

    The field of a digital-image processing has experienced dramatic growth and increasingly widespread applicability in recent years. Fortunately, advances in computer technology have kept pace with the rapid growth in volume of image data in these and other applications. Digital image processing has become economical in many fields of research and in industrial and military applications. While each application has requirements unique from the others, all are concerned with faster, cheaper, more accurate, and more extensive computation. The trend is toward real-time and interactive operations, where the user of the system obtains preliminary results within a short enough time that the next decision can be made by the human processor without loss of concentration on the task at hand. An example of this is the obtaining of two-dimensional (2-D) computer-aided tomography (CAT) images. A medical decision might be made while the patient is still under observation rather than days later.

  5. Digital subtraction imaging in cardiac investigations

    International Nuclear Information System (INIS)

    Partridge, J.B.; Dickinson, D.F.

    1984-01-01

    The role of digital subtraction imaging (DSI) in the investigation of heart disease in patients of all ages, including neonates, was evaluated by the addition of a continuous fluoroscopy system to an existing, single-plane catheterisation laboratory. In some situations, DSI provided diagnostic images where conventional radiography could not and, in general, provided images of comparable quality to cineangiography. The total dose of contrast medium was usually less than that which would have been required for biplane cineangiography and the dose of radiation was always less. Digital subtraction imaging can make a significant contribution to the investigation of congenital heart disease and has some useful features in the study of acquired heart disease. (author)

  6. Digital X-ray imager

    CERN Document Server

    LLNL &MedOptics Corporation

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying so...

  7. COMPARISON OF DIGITAL IMAGE STEGANOGRAPHY METHODS

    Directory of Open Access Journals (Sweden)

    S. A. Seyyedi

    2013-01-01

    Full Text Available Steganography is a method of hiding information in other information of different format (container. There are many steganography techniques with various types of container. In the Internet, digital images are the most popular and frequently used containers. We consider main image steganography techniques and their advantages and disadvantages. We also identify the requirements of a good steganography algorithm and compare various such algorithms.

  8. Interpreting the ASTM 'content standard for digital geospatial metadata'

    Science.gov (United States)

    Nebert, Douglas D.

    1996-01-01

    ASTM and the Federal Geographic Data Committee have developed a content standard for spatial metadata to facilitate documentation, discovery, and retrieval of digital spatial data using vendor-independent terminology. Spatial metadata elements are identifiable quality and content characteristics of a data set that can be tied to a geographic location or area. Several Office of Management and Budget Circulars and initiatives have been issued that specify improved cataloguing of and accessibility to federal data holdings. An Executive Order further requires the use of the metadata content standard to document digital spatial data sets. Collection and reporting of spatial metadata for field investigations performed for the federal government is an anticipated requirement. This paper provides an overview of the draft spatial metadata content standard and a description of how the standard could be applied to investigations collecting spatially-referenced field data.

  9. Bone age assessment by digital images

    International Nuclear Information System (INIS)

    Silva, Ana Maria Marques da

    1996-01-01

    An algorithm which allows bone age assessment by digital radiological images was developed. For geometric parameters extraction, the phalangeal and metacarpal regions of interest are enhanced and segmented, through spatial and morphological filtering. This study is based on perimeter, length and area, from distal to proximal portions. The quantification of these parameters make possible comparison between chronological and skeletal age, using growth standard tables

  10. Cherenkov ring imaging using a television digitizer

    International Nuclear Information System (INIS)

    Charpak, G.; Peisert, A.; Sauli, F.; Cavestro, A.; Vascon, M.; Zanella, G.

    1981-01-01

    A Cherenkov ring imaging device using as photon detector a multistep spark chamber coupled to a television digitizer is described. Results of a test run using triethylamine as photo-ionizing vapour are presented, as well as preliminary results obtained with a new vapour having an extremely low ionization potential. (orig.)

  11. Advantages of digital imaging for radiological diagnostic

    International Nuclear Information System (INIS)

    Trapero, M. A.; Gonzalez, S.; Albillos, J. C.; Martel, J.; Rebollo, M.

    2006-01-01

    The advantages and limitations of radiological digital images in comparison with analogic ones are analyzed. We discuss three main topics: acquisition, post-procedure manipulation, and visualization, archive and communication. Digital acquisition with computed radiology systems present a global sensitivity very close to conventional film for diagnostic purposes. However, flat panel digital systems seems to achieve some advantages in particular clinical situations. A critical issue is the radiation dose-reduction that can be accomplished without reducing image quality nor diagnostic exactitude. The post-procedure manipulation allows, particularly in multiplanar modalities like CT or MR, to extract all implicit diagnostic information in the images: Main procedures are multiplanar and three-dimensional reformations, dynamic acquisitions, functional studies and image fusion. The use of PACS for visualization, archive and communication of images, improves the effectiveness and the efficiency of the workflow, allows a more comfortable diagnosis for the radiologist and gives way to improvements in the communication of images, allowing tele consulting and the tele radiology. (Author) 6 refs

  12. Comparison of Diagnostic Accuracy of Breast Masses Using Digitized Images Versus Screen-Film Mammography

    International Nuclear Information System (INIS)

    Zhigang Liang; Xiangying Du; Jiabin Liu; Xinyu Yao; Yanhui Yang; Kuncheng Li

    2008-01-01

    Background: Medical film digitizers play an important transitory role as digital-analogue bridges in radiology. Digitized mammograms require evaluation of performance to assure medical image quality. Purpose: To compare the diagnostic accuracy in the interpretation of breast masses using original screen-film mammograms versus digitized images. Material and Methods: A total of 72 female patients between 55 and 81 years of age suspected of having breast cancer were selected by two non-observing radiologists. Of these, 31 cases were benign lesions and 41 cases were cancer. The mammography films were digitized using a laser film digitizer. Three radiologists, each with more than 10 years of experience in mammography, interpreted the screen-film mammograms and digitized images respectively. The time interval was 4 weeks. A four-point malignancy scale was used, with 1 defined as definitely not malignant, 2 as probably not malignant, 3 as probably malignant, and 4 as definitely malignant. Receiver operating characteristic (Roc) curves, sensitivity, and specificity were compared. Results: The average area-under-the-curve (Az) value of the original screen-film mammograms was 0.921, and the average Az value of the digitized images was 0.859. This difference was not statistically significant (P=0.131). The detection specificity of extremely dense breasts was lower than that for other breast compositions for both digitized images and screen-film mammograms. No statistical significance in sensitivity and specificity was observed between digitized images and mammograms for each breast composition. Original screen-film mammograms were observed to perform better than digitized images. Conclusion: Digitized images with a spatial resolution of 175 μm can be used instead of screen-film mammograms in the diagnosis of breast cancer

  13. Multichannel deblurring of digital images

    Czech Academy of Sciences Publication Activity Database

    Šorel, Michal; Šroubek, Filip; Flusser, Jan

    2011-01-01

    Roč. 47, č. 3 (2011), s. 439-454 ISSN 0023-5954 R&D Projects: GA MŠk 1M0572 Institutional research plan: CEZ:AV0Z10750506 Keywords : image restoration * blind deconvolution * deblurring Subject RIV: JD - Computer Applications, Robotics Impact factor: 0.454, year: 2011 http://library.utia.cas.cz/separaty/2011/ZOI/sorel-0360217.pdf

  14. Volumetric image interpretation in radiology: scroll behavior and cognitive processes.

    Science.gov (United States)

    den Boer, Larissa; van der Schaaf, Marieke F; Vincken, Koen L; Mol, Chris P; Stuijfzand, Bobby G; van der Gijp, Anouk

    2018-05-16

    The interpretation of medical images is a primary task for radiologists. Besides two-dimensional (2D) images, current imaging technologies allow for volumetric display of medical images. Whereas current radiology practice increasingly uses volumetric images, the majority of studies on medical image interpretation is conducted on 2D images. The current study aimed to gain deeper insight into the volumetric image interpretation process by examining this process in twenty radiology trainees who all completed four volumetric image cases. Two types of data were obtained concerning scroll behaviors and think-aloud data. Types of scroll behavior concerned oscillations, half runs, full runs, image manipulations, and interruptions. Think-aloud data were coded by a framework of knowledge and skills in radiology including three cognitive processes: perception, analysis, and synthesis. Relating scroll behavior to cognitive processes showed that oscillations and half runs coincided more often with analysis and synthesis than full runs, whereas full runs coincided more often with perception than oscillations and half runs. Interruptions were characterized by synthesis and image manipulations by perception. In addition, we investigated relations between cognitive processes and found an overall bottom-up way of reasoning with dynamic interactions between cognitive processes, especially between perception and analysis. In sum, our results highlight the dynamic interactions between these processes and the grounding of cognitive processes in scroll behavior. It suggests, that the types of scroll behavior are relevant to describe how radiologists interact with and manipulate volumetric images.

  15. The impact of digital imaging in the field of cytopathology.

    Science.gov (United States)

    Pantanowitz, Liron; Hornish, Maryanne; Goulart, Robert A

    2009-03-06

    With the introduction of digital imaging, pathology is undergoing a digital transformation. In the field of cytology, digital images are being used for telecytology, automated screening of Pap test slides, training and education (e.g. online digital atlases), and proficiency testing. To date, there has been no systematic review on the impact of digital imaging on the practice of cytopathology. This article critically addresses the emerging role of computer-assisted screening and the application of digital imaging to the field of cytology, including telecytology, virtual microscopy, and the impact of online cytology resources. The role of novel diagnostic techniques like image cytometry is also reviewed.

  16. Use of film digitizers to assist radiology image management

    Science.gov (United States)

    Honeyman-Buck, Janice C.; Frost, Meryll M.; Staab, Edward V.

    1996-05-01

    The purpose of this development effort was to evaluate the possibility of using digital technologies to solve image management problems in the Department of Radiology at the University of Florida. The three problem areas investigated were local interpretation of images produced in remote locations, distribution of images to areas outside of radiology, and film handling. In all cases the use of a laser film digitizer interfaced to an existing Picture Archiving and Communication System (PACS) was investigated as a solution to the problem. In each case the volume of studies involved were evaluated to estimate the impact of the solution on the network, archive, and workstations. Communications were stressed in the analysis of the needs for all image transmission. The operational aspects of the solution were examined to determine the needs for training, service, and maintenance. The remote sites requiring local interpretation included were a rural hospital needing coverage for after hours studies, the University of Florida student infirmary, and the emergency room. Distribution of images to the intensive care units was studied to improve image access and patient care. Handling of films originating from remote sites and those requiring urgent reporting were evaluated to improve management functions. The results of our analysis and the decisions that were made based on the analysis are described below. In the cases where systems were installed, a description of the system and its integration into the PACS system is included. For all three problem areas, although we could move images via a digitizer to the archive and a workstation, there was no way to inform the radiologist that a study needed attention. In the case of outside films, the patient did not always have a medical record number that matched one in our Radiology Information Systems (RIS). In order to incorporate all studies for a patient, we needed common locations for orders, reports, and images. RIS orders

  17. Diagnostic image quality of video-digitized chest images

    International Nuclear Information System (INIS)

    Winter, L.H.; Butler, R.B.; Becking, W.B.; Warnars, G.A.O.; Haar Romeny, B. ter; Ottes, F.P.; Valk, J.-P.J. de

    1989-01-01

    The diagnostic accuracy obtained with the Philips picture archiving and communications subsystem was investigated by means of an observer performance study using receiver operating characteristic (ROC) analysis. The image qualities of conventional films and video digitized images were compared. The scanner had a 1024 x 1024 x 8 bit memory. The digitized images were displayed on a 60 Hz interlaced display monitor 1024 lines. Posteroanterior (AP) roetgenograms of a chest phantom with superimposed simulated interstitial pattern disease (IPD) were produced; there were 28 normal and 40 abnormal films. Normal films were produced by the chest phantom alone. Abnormal films were taken of the chest phantom with varying degrees of superimposed simulated intersitial disease (PND) for an observer performance study, because the results of a simulated interstitial pattern disease study are less likely to be influenced by perceptual capabilities. The conventional films and the video digitized images were viewed by five experienced observers during four separate sessions. Conventional films were presented on a viewing box, the digital images were displayed on the monitor described above. The presence of simulated intersitial disease was indicated on a 5-point ROC certainty scale by each observer. We analyzed the differences between ROC curves derived from correlated data statistically. The mean time required to evaluate 68 digitized images is approximately four times the mean time needed to read the convential films. The diagnostic quality of the video digitized images was significantly lower (at the 5% level) than that of the conventional films (median area under the curve (AUC) of 0.71 and 0.94, respectively). (author). 25 refs.; 2 figs.; 4 tabs

  18. Crack Length Detection by Digital Image Processing

    DEFF Research Database (Denmark)

    Lyngbye, Janus; Brincker, Rune

    1990-01-01

    It is described how digital image processing is used for measuring the length of fatigue cracks. The system is installed in a Personal Computer equipped with image processing hardware and performs automated measuring on plane metal specimens used in fatigue testing. Normally one can not achieve...... a resolution better then that of the image processing equipment. To overcome this problem an extrapolation technique is used resulting in a better resolution. The system was tested on a specimen loaded with different loads. The error σa was less than 0.031 mm, which is of the same size as human measuring...

  19. Crack Detection by Digital Image Processing

    DEFF Research Database (Denmark)

    Lyngbye, Janus; Brincker, Rune

    It is described how digital image processing is used for measuring the length of fatigue cracks. The system is installed in a Personal, Computer equipped with image processing hardware and performs automated measuring on plane metal specimens used in fatigue testing. Normally one can not achieve...... a resolution better than that of the image processing equipment. To overcome this problem an extrapolation technique is used resulting in a better resolution. The system was tested on a specimen loaded with different loads. The error σa was less than 0.031 mm, which is of the same size as human measuring...

  20. Narrative Writing in Digital Formats: Interpreting the Impact of Audience

    Directory of Open Access Journals (Sweden)

    Lawrence Joshua Fahey

    2015-12-01

    Full Text Available Digital writing has enabled students to write for a variety of authentic audiences, both in and out of the classroom. As they consider audience, students shoulder a cognitive burden that they must juggle in addition to the task of composition. At the same time, writing provides students with opportunities to craft and express their identities. The ways that identity formation and cognitive load intersect may be particularly complex in digital, online writing environments, as students gain the ability to share and receive feedback from global and local audiences. In this counterbalanced experimental study, 86 seventh- and eighth-grade students responded to two narrative prompts. One prompt was written for the teacher and the other was written for the teacher and peers in an online forum. We examined student writing fluency, mechanical errors, academic word use, and setting. Students were found to be more likely to set narratives in private settings when writing for an audience that included peers. We discuss this finding from cognitive and sociocultural perspectives and how it might inform networked communication research.

  1. Digital Image Watermarking in Transform Domains

    International Nuclear Information System (INIS)

    EL-Shazly, E.H.M.

    2012-01-01

    Fast development of internet and availability of huge digital content make it easy to create, modify and copy digital media such as audio, video and images. This causes a problem for owners of that content and hence a need to copy right protection tool was essential. First, encryption was proposed but it ensures protection during transmission only and once decryption occurred any one can modify the data. at that point watermarking was introduced as a solution to such problem. Watermarking is a process of inserting a low energy signal in to a high energy one so that it doesn't affect the main signal features. A good digital image watermarking technique should satisfy four requirements: 1) Embedding of a watermark should not degrade the host image visual quality (imperceptibility). 2) The embedded watermark should stick to the host image so that it couldn’t be removed by common image processing operation and could be extracted from the attacked watermarked image (robustness). 3) Knowing the embedding and extraction procedures is sufficient but not enough to extract the watermark; extra keys should be needed (security). 4) The watermarking technique should allow embedding and extraction of more than one watermark each independent of the other (capacity). This thesis presents a watermarking scheme that full fill the mentioned four requirements by jointing transform domains with Fractional Fourier Transform Domain (FracFT). More work on cascaded Discrete Wavelet Transform DWT with FracFT was done to develop a joint transform simply called Fractional Wavelet Transform (FWT). The proposed schemes were tested with different image processing attacks to verify its robustness. Finally, the watermarked image is transmitted over simulated MC CDMA channel to prove robustness in real transmission conditions case.

  2. 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.

  3. Lossless Compression of Digital Images

    DEFF Research Database (Denmark)

    Martins, Bo

    Presently, tree coders are the best bi-level image coders. The currentISO standard, JBIG, is a good example.By organising code length calculations properly a vast number of possible models (trees) can be investigated within reasonable time prior to generating code.A number of general-purpose coders...... version that is substantially faster than its precursorsand brings it close to the multi-pass coders in compression performance.Handprinted characters are of unequal complexity; recent work by Singer and Tishby demonstrates that utilizing the physiological process of writing one can synthesize cursive.......The feature vector of a bitmap initially constitutes a lossy representation of the contour(s) of the bitmap. The initial feature space is usually too large but can be reduced automatically by use ofa predictive code length or predictive error criterion....

  4. Cardiac imaging: working towards fully-automated machine analysis & interpretation.

    Science.gov (United States)

    Slomka, Piotr J; Dey, Damini; Sitek, Arkadiusz; Motwani, Manish; Berman, Daniel S; Germano, Guido

    2017-03-01

    Non-invasive imaging plays a critical role in managing patients with cardiovascular disease. Although subjective visual interpretation remains the clinical mainstay, quantitative analysis facilitates objective, evidence-based management, and advances in clinical research. This has driven developments in computing and software tools aimed at achieving fully automated image processing and quantitative analysis. In parallel, machine learning techniques have been used to rapidly integrate large amounts of clinical and quantitative imaging data to provide highly personalized individual patient-based conclusions. Areas covered: This review summarizes recent advances in automated quantitative imaging in cardiology and describes the latest techniques which incorporate machine learning principles. The review focuses on the cardiac imaging techniques which are in wide clinical use. It also discusses key issues and obstacles for these tools to become utilized in mainstream clinical practice. Expert commentary: Fully-automated processing and high-level computer interpretation of cardiac imaging are becoming a reality. Application of machine learning to the vast amounts of quantitative data generated per scan and integration with clinical data also facilitates a move to more patient-specific interpretation. These developments are unlikely to replace interpreting physicians but will provide them with highly accurate tools to detect disease, risk-stratify, and optimize patient-specific treatment. However, with each technological advance, we move further from human dependence and closer to fully-automated machine interpretation.

  5. Machine Learning in Radiology: Applications Beyond Image Interpretation.

    Science.gov (United States)

    Lakhani, Paras; Prater, Adam B; Hutson, R Kent; Andriole, Kathy P; Dreyer, Keith J; Morey, Jose; Prevedello, Luciano M; Clark, Toshi J; Geis, J Raymond; Itri, Jason N; Hawkins, C Matthew

    2018-02-01

    Much attention has been given to machine learning and its perceived impact in radiology, particularly in light of recent success with image classification in international competitions. However, machine learning is likely to impact radiology outside of image interpretation long before a fully functional "machine radiologist" is implemented in practice. Here, we describe an overview of machine learning, its application to radiology and other domains, and many cases of use that do not involve image interpretation. We hope that better understanding of these potential applications will help radiology practices prepare for the future and realize performance improvement and efficiency gains. Copyright © 2017 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  6. Knowledge-based interpretation of cranial MR images

    International Nuclear Information System (INIS)

    Kuhn, M.H.; Menhardt, W.; Schmidt, K.H.

    1987-01-01

    A computerized system is described that can be used to evaluate an MR tomogram automatically to support clinical identification of anatomic and pathologic structures and to aid in planning MR measurements. Knowledge from three domains is used for the interpretation of an MR image: nosologic knowledge, knowledge of MR imaging parameters, and anatomic and morphologic knowledge. Nosologic information is used to generate hypotheses about possible pathologies and their locations, based on the signs and symptoms of the patient. With this information, a sequence of interpretation modules, each able to detect substructures in already detected structures with the aid of techniques from image processing, pattern recognition, and artificial intelligence, is generated and executed

  7. ASTM reference radiologic digital image standards

    International Nuclear Information System (INIS)

    Wysnewski, R.; Wysnewski, D.

    1996-01-01

    ASTM Reference Radiographs have been essential in defining industry's material defect grade levels for many years. ASTM Reference Radiographs are used extensively as even the American Society for Metals Nondestructive Inspection and Quality Control Metals Handbook, Volume 11, eighth edition refers to ASTM Standard Reference Radiographs. The recently published E 1648 Standard Reference Radiographs for Examination of Aluminum Fusion Welds is a prime example of the on-going need for these references. To date, 14 Standard Reference Radiographs have been published to characterize material defects. Standard Reference Radiographs do not adequately address film-less radiologic methods. There are differences in mediums to content with. On a computer CRT defect indications appear differently when compared to indications viewed in a radiograph on a view box. Industry that uses non-film radiologic methods of inspection can be burdened with additional time and money developing internal standard reference radiologic images. These references may be deemed necessary for grading levels of product defects. Because there are no ASTM Standard Reference Radiologic data files for addressing this need in the industry, the authors of this paper suggested implementing a method for their creation under ASTM supervision. ASTM can assure continuity to those users making the transition from analog radiographic images to digital image data by swiftly addressing the requirements for reference digital image standards. The current status and possible future activities regarding a method to create digital data files is presented in this paper summary

  8. Digital Shaded-Relief Image of Alaska

    Science.gov (United States)

    Riehle, J.R.; Fleming, Michael D.; Molnia, B.F.; Dover, J.H.; Kelley, J.S.; Miller, M.L.; Nokleberg, W.J.; Plafker, George; Till, A.B.

    1997-01-01

    Introduction One of the most spectacular physiographic images of the conterminous United States, and the first to have been produced digitally, is that by Thelin and Pike (USGS I-2206, 1991). The image is remarkable for its crispness of detail and for the natural appearance of the artificial land surface. Our goal has been to produce a shaded-relief image of Alaska that has the same look and feel as the Thelin and Pike image. The Alaskan image could have been produced at the same scale as its lower 48 counterpart (1:3,500,000). But by insetting the Aleutian Islands into the Gulf of Alaska, we were able to print the Alaska map at a larger scale (1:2,500,000) and about the same physical size as the Thelin and Pike image. Benefits of the 1:2,500,000 scale are (1) greater resolution of topographic features and (2) ease of reference to the U.S. Geological Survey (USGS) (1987) Alaska Map E and the statewide geologic map (Beikman, 1980), which are both 1:2,500,000 scale. Manually drawn, shaded-relief images of Alaska's land surface have long been available (for example, Department of the Interior, 1909; Raisz, 1948). The topography depicted on these early maps is mainly schematic. Maps showing topographic contours were first available for the entire State in 1953 (USGS, 1:250,000) (J.H. Wittmann, USGS, written commun., 1996). The Alaska Map E was initially released in 1954 in both planimetric (revised in 1973 and 1987) and shaded-relief versions (revised in 1973, 1987, and 1996); topography depicted on the shaded-relief version is based on the 1:250,000-scale USGS topographic maps. Alaska Map E was later modified to include hypsometric tinting by Raven Maps and Images (1989, revised 1993) as copyrighted versions. Other shaded-relief images were produced for The National Geographic Magazine (LaGorce, 1956; 1:3,000,000) or drawn by Harrison (1970; 1:7,500,000) for The National Atlas of the United States. Recently, the State of Alaska digitally produced a shaded-relief image

  9. Is screening with digital imaging using one retinal view adequate?

    Science.gov (United States)

    Herbert, H M; Jordan, K; Flanagan, D W

    2003-05-01

    To compare the detection of diabetic retinopathy from digital images with slit-lamp biomicroscopy, and to determine whether British Diabetic Association (BDA) screening criteria are attained (>80% sensitivity, >95% specificity, &fashion. A single 45 degrees fundus image was obtained using the nonmydriatic digital camera. Each patient subsequently underwent slit-lamp biomicroscopy and diabetic retinopathy grading by a consultant ophthalmologist. Diabetic retinopathy and maculopathy was graded according to the Early Treatment of Diabetic Retinopathy Study. A total of 145 patients (288 eyes) were identified for screening. Of these, 26% of eyes had diabetic retinopathy, and eight eyes (3%) had sight-threatening diabetic retinopathy requiring treatment. The sensitivity for detection of any diabetic retinopathy was 38% and the specificity 95%. There was a 4% technical failure rate. There were 42/288 false negatives and 10/288 false positives. Of the 42 false negatives, 18 represented diabetic maculopathy, 20 represented peripheral diabetic retinopathy and four eyes had both macular and peripheral changes. Three eyes in the false-negative group (1% of total eyes) had sight-threatening retinopathy. There was good concordance between the two consultants (79% agreement on slit-lamp biomicroscopy and 84% on digital image interpretation). The specificity value and technical failure rate compare favourably with BDA guidelines. The low sensitivity for detection of any retinopathy reflects failure to detect minimal maculopathy and retinopathy outside the 45 degrees image. This could be improved by an additional nasal image and careful evaluation of macular images with a low threshold for slit-lamp biomicroscopy if image quality is poor.

  10. Three-dimensional digital breast histopathology imaging

    Science.gov (United States)

    Clarke, G. M.; Peressotti, C.; Mawdsley, G. E.; Eidt, S.; Ge, M.; Morgan, T.; Zubovits, J. T.; Yaffe, M. J.

    2005-04-01

    We have developed a digital histology imaging system that has the potential to improve the accuracy of surgical margin assessment in the treatment of breast cancer by providing finer sampling and 3D visualization. The system is capable of producing a 3D representation of histopathology from an entire lumpectomy specimen. We acquire digital photomicrographs of a stack of large (120 x 170 mm) histology slides cut serially through the entire specimen. The images are then registered and displayed in 2D and 3D. This approach dramatically improves sampling and can improve visualization of tissue structures compared to current, small-format histology. The system consists of a brightfield microscope, adapted with a freeze-frame digital video camera and a large, motorized translation stage. The image of each slide is acquired as a mosaic of adjacent tiles, each tile representing one field-of-view of the microscope, and the mosaic is assembled into a seamless composite image. The assembly is done by a program developed to build image sets at six different levels within a multiresolution pyramid. A database-linked viewing program has been created to efficiently register and display the animated stack of images, which occupies about 80 GB of disk space per lumpectomy at full resolution, on a high-resolution (3840 x 2400 pixels) colour monitor. The scanning or tiling approach to digitization is inherently susceptible to two artefacts which disrupt the composite image, and which impose more stringent requirements on system performance. Although non-uniform illumination across any one isolated tile may not be discernible, the eye readily detects this non-uniformity when the entire assembly of tiles is viewed. The pattern is caused by deficiencies in optical alignment, spectrum of the light source, or camera corrections. The imaging task requires that features as small as 3.2 &mum in extent be seamlessly preserved. However, inadequate accuracy in positioning of the translation

  11. [Digital thoracic radiology: devices, image processing, limits].

    Science.gov (United States)

    Frija, J; de Géry, S; Lallouet, F; Guermazi, A; Zagdanski, A M; De Kerviler, E

    2001-09-01

    In a first part, the different techniques of digital thoracic radiography are described. Since computed radiography with phosphore plates are the most commercialized it is more emphasized. But the other detectors are also described, as the drum coated with selenium and the direct digital radiography with selenium detectors. The other detectors are also studied in particular indirect flat panels detectors and the system with four high resolution CCD cameras. In a second step the most important image processing are discussed: the gradation curves, the unsharp mask processing, the system MUSICA, the dynamic range compression or reduction, the soustraction with dual energy. In the last part the advantages and the drawbacks of computed thoracic radiography are emphasized. The most important are the almost constant good quality of the pictures and the possibilities of image processing.

  12. The iconic image in a digital age

    DEFF Research Database (Denmark)

    Mortensen, Mette; Allan, Stuart; Peters, Chris

    2017-01-01

    This article investigates selected newspapers’ editorial mediations over contrasting perceptions regarding the significance of a controversial set of “iconic” news photographs, namely images of Alan Kurdi, a three-year-old Syrian refugee, whose drowned corpse washed ashore in September, 2015. Spe......-reflexivity within a convergent digital media ecology, this article offers original insights into how and why the epistemic values governing visual communication are being reconsidered and redrawn under pressure from institutional imperatives....

  13. Speckle pattern processing by digital image correlation

    Directory of Open Access Journals (Sweden)

    Gubarev Fedor

    2016-01-01

    Full Text Available Testing the method of speckle pattern processing based on the digital image correlation is carried out in the current work. Three the most widely used formulas of the correlation coefficient are tested. To determine the accuracy of the speckle pattern processing, test speckle patterns with known displacement are used. The optimal size of a speckle pattern template used for determination of correlation and corresponding the speckle pattern displacement is also considered in the work.

  14. Storage and retrieval of large digital images

    Science.gov (United States)

    Bradley, J.N.

    1998-01-20

    Image compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets T{sub ij}(x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles T{sub ij}(x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles T{sub ij}(x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval. 6 figs.

  15. Digital image intensifier radiography: first experiences with the DSI (Digital Spot Imaging)

    International Nuclear Information System (INIS)

    Rueckforth, J.; Wein, B.; Stargardt, A.; Guenther, R.W.

    1995-01-01

    We performed a comparative study of digitally and conventionally acquired images in gastrointestinal examinations. Radiation dose and spatial resolution were determined in a water phantom. In 676 examinations with either conventional or digital imaging (system: Diagnost 76, DSI) the number of images and the duration of the fluoroscopy time were compared. 101 examinations with digital as well as conventional documentation were evaluated by using 5 criteria describing the diagnostic performance. The entrance dose of the DSI is 12% to 36% of the film/screen system and the spatial resolution of the DSI may be better than that of a film/screen system with a speed of 200. The fluoroscopy time shows no significant difference between DSI and the film/screen technique. In 2 of 4 examination modes significantly more images were produced by the DSI. With exception of the criterion of edge sharpness, DSI yields a significantly inferior assessment compared with the film/screen technique. (orig./MG) [de

  16. Digital image sequence processing, compression, and analysis

    CERN Document Server

    Reed, Todd R

    2004-01-01

    IntroductionTodd R. ReedCONTENT-BASED IMAGE SEQUENCE REPRESENTATIONPedro M. Q. Aguiar, Radu S. Jasinschi, José M. F. Moura, andCharnchai PluempitiwiriyawejTHE COMPUTATION OF MOTIONChristoph Stiller, Sören Kammel, Jan Horn, and Thao DangMOTION ANALYSIS AND DISPLACEMENT ESTIMATION IN THE FREQUENCY DOMAINLuca Lucchese and Guido Maria CortelazzoQUALITY OF SERVICE ASSESSMENT IN NEW GENERATION WIRELESS VIDEO COMMUNICATIONSGaetano GiuntaERROR CONCEALMENT IN DIGITAL VIDEOFrancesco G.B. De NataleIMAGE SEQUENCE RESTORATION: A WIDER PERSPECTIVEAnil KokaramVIDEO SUMMARIZATIONCuneyt M. Taskiran and Edward

  17. The role of moving images in the conference interpreting classroom

    Directory of Open Access Journals (Sweden)

    Susi Septaviana Rakhmawati

    2016-01-01

    Full Text Available This paper reports on the study of the student interpreters’ performance in conference interpreting classes in an Indonesian university when multimodal texts were provided as part of the teaching methods. It aims to answer how multimodal texts can influence interpreting performance among students. A case study design was used to allow an in-depth analysis of the students’ interpreting performance as the phenomenon described (Yin, 2003 using triangulation of data analysis. Observation, interview, and seven transcription analysis from three students were carried out. Observation and interview result shows that the students used visual information such as lips movement, running text on video, moving images, and the speakers’ gestures in their interpreting processes. Moreover, the students said that the existing method of teaching interpreting using multimodal texts is really helpful for them in developing their interpreting skills. Furthermore, transcription analysis also confirms that the student with multimodal strategies (facing the speaker, the screen/the video performed better during interpreting process. However, a student who faces both did not seem to perform well. The indication is that he was unable to focus, being distracted and nervous. Thus, overall the student interpreters used visual information as part of multimodal communication, in addition to speech, working on the regular mode of listening and speaking during interpreting process, which suggest significant contribution of multimodal texts to better rendition in the target language.

  18. [Digital imaging and robotics in endoscopic surgery].

    Science.gov (United States)

    Go, P M

    1998-05-23

    The introduction of endoscopical surgery has among other things influenced technical developments in surgery. Owing to digitalisation, major progress will be made in imaging and in the sophisticated technology sometimes called robotics. Digital storage makes the results of imaging diagnostics (e.g. the results of radiological examination) suitable for transmission via video conference systems for telediagnostic purposes. The availability of digital video technique renders possible the processing, storage and retrieval of moving images as well. During endoscopical operations use may be made of a robot arm which replaces the camera man. The arm does not grow tired and provides a stable image. The surgeon himself can operate or address the arm and it can remember fixed image positions to which it can return if ordered to do so. The next step is to carry out surgical manipulations via a robot arm. This may make operations more patient-friendly. A robot arm can also have remote control: telerobotics. At the Internet site of this journal a number of supplements to this article can be found, for instance three-dimensional (3D) illustrations (which is the purpose of the 3D spectacles enclosed with this issue) and a quiz (http:@appendix.niwi. knaw.nl).

  19. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various samples. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  20. Digital image processing in neutron radiography

    International Nuclear Information System (INIS)

    Koerner, S.

    2000-11-01

    Neutron radiography is a method for the visualization of the macroscopic inner-structure and material distributions of various materials. The basic experimental arrangement consists of a neutron source, a collimator functioning as beam formatting assembly and of a plane position sensitive integrating detector. The object is placed between the collimator exit and the detector, which records a two dimensional image. This image contains information about the composition and structure of the sample-interior, as a result of the interaction of neutrons by penetrating matter. Due to rapid developments of detector and computer technology as well as deployments in the field of digital image processing, new technologies are nowadays available which have the potential to improve the performance of neutron radiographic investigations enormously. Therefore, the aim of this work was to develop a state-of-the art digital imaging device, suitable for the two neutron radiography stations located at the 250 kW TRIGA Mark II reactor at the Atominstitut der Oesterreichischen Universitaeten and furthermore, to identify and develop two and three dimensional digital image processing methods suitable for neutron radiographic and tomographic applications, and to implement and optimize them within data processing strategies. The first step was the development of a new imaging device fulfilling the requirements of a high reproducibility, easy handling, high spatial resolution, a large dynamic range, high efficiency and a good linearity. The detector output should be inherently digitized. The key components of the detector system selected on the basis of these requirements consist of a neutron sensitive scintillator screen, a CCD-camera and a mirror to reflect the light emitted by the scintillator to the CCD-camera. This detector design enables to place the camera out of the direct neutron beam. The whole assembly is placed in a light shielded aluminum box. The camera is controlled by a

  1. Utility of Digital Stereo Images for Optic Disc Evaluation

    Science.gov (United States)

    Ying, Gui-shuang; Pearson, Denise J.; Bansal, Mayank; Puri, Manika; Miller, Eydie; Alexander, Judith; Piltz-Seymour, Jody; Nyberg, William; Maguire, Maureen G.; Eledath, Jayan; Sawhney, Harpreet

    2010-01-01

    Purpose. To assess the suitability of digital stereo images for optic disc evaluations in glaucoma. Methods. Stereo color optic disc images in both digital and 35-mm slide film formats were acquired contemporaneously from 29 subjects with various cup-to-disc ratios (range, 0.26–0.76; median, 0.475). Using a grading scale designed to assess image quality, the ease of visualizing optic disc features important for glaucoma diagnosis, and the comparative diameters of the optic disc cup, experienced observers separately compared the primary digital stereo images to each subject's 35-mm slides, to scanned images of the same 35-mm slides, and to grayscale conversions of the digital images. Statistical analysis accounted for multiple gradings and comparisons and also assessed image formats under monoscopic viewing. Results. Overall, the quality of primary digital color images was judged superior to that of 35-mm slides (P digital color images were mostly equivalent to the scanned digitized images of the same slides. Color seemingly added little to grayscale optic disc images, except that peripapillary atrophy was best seen in color (P digital over film images was maintained under monoscopic viewing conditions. Conclusions. Digital stereo optic disc images are useful for evaluating the optic disc in glaucoma and allow the application of advanced image processing applications. Grayscale images, by providing luminance distinct from color, may be informative for assessing certain features. PMID:20505199

  2. Multiple interpretations of a pair of images of a surface

    Science.gov (United States)

    Longuet-Higgins, H. C.

    1988-07-01

    It is known that, if two optical images of a visually textured surface, projected from finitely separated viewpoints, allow more than one three-dimensional interpretation, then the surface must be part of a quadric passing through the two viewpoints. It is here shown that this quadric is either a plane or a ruled surface of a type first considered by Maybank (1985) in a study of ambiguous optic flow fields. In the latter case, three is the maximum number of distinct interpretations that the two images can sustain.

  3. DOMstudio: an integrated workflow for Digital Outcrop Model reconstruction and interpretation

    Science.gov (United States)

    Bistacchi, Andrea

    2015-04-01

    Different Remote Sensing technologies, including photogrammetry and LIDAR, allow collecting 3D dataset that can be used to create 3D digital representations of outcrop surfaces, called Digital Outcrop Models (DOM), or sometimes Virtual Outcrop Models (VOM). Irrespective of the Remote Sensing technique used, DOMs can be represented either by photorealistic point clouds (PC-DOM) or textured surfaces (TS-DOM). The first are datasets composed of millions of points with XYZ coordinates and RGB colour, whilst the latter are triangulated surfaces onto which images of the outcrop have been mapped or "textured" (applying a tech-nology originally developed for movies and videogames). Here we present a workflow that allows exploiting in an integrated and efficient, yet flexible way, both kinds of dataset: PC-DOMs and TS-DOMs. The workflow is composed of three main steps: (1) data collection and processing, (2) interpretation, and (3) modelling. Data collection can be performed with photogrammetry, LIDAR, or other techniques. The quality of photogrammetric datasets obtained with Structure From Motion (SFM) techniques has shown a tremendous improvement over the past few years, and this is becoming the more effective way to collect DOM datasets. The main advantages of photogrammetry over LIDAR are represented by the very simple and lightweight field equipment (a digital camera), and by the arbitrary spatial resolution, that can be increased simply getting closer to the out-crop or by using a different lens. It must be noted that concerns about the precision of close-range photogrammetric surveys, that were justified in the past, are no more a problem if modern software and acquisition schemas are applied. In any case, LIDAR is a well-tested technology and it is still very common. Irrespective of the data collection technology, the output will be a photorealistic point cloud and a collection of oriented photos, plus additional imagery in special projects (e.g. infrared images

  4. Body image related negative interpretation bias in anorexia nervosa.

    Science.gov (United States)

    Brockmeyer, Timo; Anderle, Alisa; Schmidt, Hagen; Febry, Stephanie; Wünsch-Leiteritz, Wally; Leiteritz, Andreas; Friederich, Hans-Christoph

    2018-05-01

    A distorted body image and pronounced body dissatisfaction are hallmarks of anorexia nervosa (AN) that typically result in dietary restraint and compensatory behaviours. Cognitive biases such as negative interpretation bias are considered key maintaining factors of these maladaptive cognitions and behaviours. However, little attention has been paid to empirical tests whether negative interpretation bias exists in AN and to what degree it is associated with symptom severity. Participants in the present study were 40 women with AN and 40 healthy women with no history of an eating disorder. Body-related negative interpretation bias (i.e., a tendency to interpret ambiguous information about the own body in a negative way) was measured by a Scrambled Sentences Task. Patients with AN showed a stronger body-related negative interpretation bias than healthy controls. Within both groups, negative interpretation bias correlated strongly and positively with AN symptom severity and these effects were not moderated by levels of depressive symptoms. The findings support the idea that biased interpretation of body-related information is associated with the specific psychopathology of AN. Targeted, computerised interventions (e.g. interpretation bias modification) may help to alter these dysfunctional cognitive schemas that lie at the heart of AN. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Imaging sunlight using a digital spectroheliograph

    CERN Document Server

    Harrison, Ken M

    2016-01-01

    Ken M. Harrison's latest book is a complete guide for amateur astronomers who want to obtain detailed narrowband images of the Sun using a digital spectroheliograph (SHG). The SHG allows the safe imaging of the Sun without the expense of commercial ‘etalon’ solar filters. As the supporting software continues to be refined, the use of the digital spectroheliograph will become more and more mainstream and has the potential to replace the expensive solar filters currently in use. The early chapters briefly explain the concept of the SHG and how it can produce an image from the solar spectrum. A comparison of the currently available narrow band solar filters is followed by a detailed analysis of the critical design, construction and assembly features of the SHG. The design and optimum layout of the instrument is discussed to allow evaluation of performance. This information explains how to assemble a fully functional SHG using readily available components. The software required to process the images is exp...

  6. An image adaptive, wavelet-based watermarking of digital images

    Science.gov (United States)

    Agreste, Santa; Andaloro, Guido; Prestipino, Daniela; Puccio, Luigia

    2007-12-01

    In digital management, multimedia content and data can easily be used in an illegal way--being copied, modified and distributed again. Copyright protection, intellectual and material rights protection for authors, owners, buyers, distributors and the authenticity of content are crucial factors in solving an urgent and real problem. In such scenario digital watermark techniques are emerging as a valid solution. In this paper, we describe an algorithm--called WM2.0--for an invisible watermark: private, strong, wavelet-based and developed for digital images protection and authenticity. Using discrete wavelet transform (DWT) is motivated by good time-frequency features and well-matching with human visual system directives. These two combined elements are important in building an invisible and robust watermark. WM2.0 works on a dual scheme: watermark embedding and watermark detection. The watermark is embedded into high frequency DWT components of a specific sub-image and it is calculated in correlation with the image features and statistic properties. Watermark detection applies a re-synchronization between the original and watermarked image. The correlation between the watermarked DWT coefficients and the watermark signal is calculated according to the Neyman-Pearson statistic criterion. Experimentation on a large set of different images has shown to be resistant against geometric, filtering and StirMark attacks with a low rate of false alarm.

  7. Acceptable levels of digital image compression in chest radiology

    International Nuclear Information System (INIS)

    Smith, I.

    2000-01-01

    The introduction of picture archival and communications systems (PACS) and teleradiology has prompted an examination of techniques that optimize the storage capacity and speed of digital storage and distribution networks. The general acceptance of the move to replace conventional screen-film capture with computed radiography (CR) is an indication that clinicians within the radiology community are willing to accept images that have been 'compressed'. The question to be answered, therefore, is what level of compression is acceptable. The purpose of the present study is to provide an assessment of the ability of a group of imaging professionals to determine whether an image has been compressed. To undertake this study a single mobile chest image, selected for the presence of some subtle pathology in the form of a number of septal lines in both costphrenic angles, was compressed to levels of 10:1, 20:1 and 30:1. These images were randomly ordered and shown to the observers for interpretation. Analysis of the responses indicates that in general it was not possible to distinguish the original image from its compressed counterparts. Furthermore, a preference appeared to be shown for images that have undergone low levels of compression. This preference can most likely be attributed to the 'de-noising' effect of the compression algorithm at low levels. Copyright (1999) Blackwell Science Pty. Ltd

  8. Endless everyday images: links and excesses in digital image

    Directory of Open Access Journals (Sweden)

    Ana Cláudia do Amaral Leão

    2013-08-01

    Full Text Available The research analyzed the relationships and communication links between overproduced images on digital media and their carriers. I start from the hypothesis that the way we look, record, save and access images have been deeply modified with the advent of digital cameras and ‘phone cameras’ – encouraging an addictive behavior for pictures. The method was based on interviews with ten informers – the images’ carriers, who let us conclude that we are overproducing pictures as information. In this context arise the producers of endless everyday pictures, here named ‘photomaniacs’, who give birth two kinds of images: the circulatory infoimages and the everyday infoimages. Overproduced digital images transform devices in our magnifiers of memory and oblivion, undoing the way we compile, save or file – and operating in cumulative, disordered, small and private stock of images. Thus, we try to saturate our most superficial memory, that generates schizophrenic pictures when operates on excess. However, even if the way is only technological, we must remember that the body is the living organism suitable to pictures, the place where we hold deep bonding relations. Over this body surface, images survive impregnated of meanings, links, belonging and healing. The research was based on the theories of communication links of Boris Cyrulnik, Jose Ângelo Gaiarsa and Ashley Montagu, besides the works on images and schizophrenia of Nise da Silveira and Leo Navratil. The research also activated the central European stream of Cultural Semiotics, specially the theories of images proposed by Aby Warburg, Walter Benjamin, Dietmar Kamper, Norval Baitello Junior, Hans Belting and Vilém Flusser.

  9. Losing Images in Digital Radiology: More than You Think

    OpenAIRE

    Oglevee, Catherine; Pianykh, Oleg

    2014-01-01

    It is a common belief that the shift to digital imaging some 20 years ago helped medical image exchange and got rid of any potential image loss that was happening with printed image films. Unfortunately, this is not the case: despite the most recent advances in digital imaging, most hospitals still keep losing their imaging data, with these losses going completely unnoticed. As a result, not only does image loss affect the faith in digital imaging but it also affects patient diagnosis and dai...

  10. Panning artifacts in digital pathology images

    Science.gov (United States)

    Avanaki, Ali R. N.; Lanciault, Christian; Espig, Kathryn S.; Xthona, Albert; Kimpe, Tom R. L.

    2017-03-01

    In making a pathologic diagnosis, a pathologist uses cognitive processes: perception, attention, memory, and search (Pena and Andrade-Filho, 2009). Typically, this involves focus while panning from one region of a slide to another, using either a microscope in a traditional workflow or software program and display in a digital pathology workflow (DICOM Standard Committee, 2010). We theorize that during panning operation, the pathologist receives information important to diagnosis efficiency and/or correctness. As compared to an optical microscope, panning in a digital pathology image involves some visual artifacts due to the following: (i) the frame rate is finite; (ii) time varying visual signals are reconstructed using imperfect zero-order hold. Specifically, after pixel's digital drive is changed, it takes time for a pixel to emit the expected amount of light. Previous work suggests that 49% of navigation is conducted in low-power/overview with digital pathology (Molin et al., 2015), but the influence of display factors has not been measured. We conducted a reader study to establish a relationship between display frame rate, panel response time, and threshold panning speed (above which the artifacts become noticeable). Our results suggest visual tasks that involve tissue structure are more impacted by the simulated panning artifacts than those that only involve color (e.g., staining intensity estimation), and that the panning artifacts versus normalized panning speed has a peak behavior which is surprising and may change for a diagnostic task. This is work in progress and our final findings should be considered in designing future digital pathology systems.

  11. Patient doses in digital cardiac imaging

    International Nuclear Information System (INIS)

    Huda, W.; Ogden, K.M.; Roskopf, M.L.; Phadke, K.

    2001-01-01

    In this pilot study, we obtained estimates of entrance skin doses and the corresponding effective doses to patients undergoing digital cardiac imaging procedures on a GE Advantx LC/LP Plus system. Data were obtained for six patients undergoing diagnostic examinations and six patients who had interventional procedures. For each patient examination, radiographic techniques for fluoroscopic and digital cine imaging were recorded, together with the irradiation geometry. The projection with the highest exposure resulted in an average skin dose of 0.64 ± 0.41 Gy (maximum of 1.6 Gy). The average patient skin doses taking into account overlapping projections was 1.1 ± 0.8 Gy (maximum of 3.0 Gy). The exposure area product (EAP) incident on the patient was converted into the energy imparted to the patient and the corresponding effective dose. The average patient effective dose was 28 ± 14 mSv (maximum 62 mSv), with the resultant average fatal cancer risk estimated to be of the order of 8x10 -3 . Average doses for interventional procedures in cardiac imaging are higher than those associated with diagnostic examinations by approximately 50%. (author)

  12. Creating a panorama of the heart with digital images.

    Science.gov (United States)

    Rosebrock, L

    2000-01-01

    Digital imaging offers new opportunities still being discovered by users. This article describes a technique that was created using a digital camera to photograph the entire surface of a rat heart. The technique may have other applications as well.

  13. An experimental study on the readability of digital images in the furcal bone defects

    International Nuclear Information System (INIS)

    Kang, Hyung Wuk; Hwang, Eui Hwan; Lee, Sang Rae

    2003-01-01

    To evaluate and compare the efficacy of digital radiographic images in the detection of bone loss at the bifurcation area of the mandibular first molar with traditional film-based periapical radiographs. One dried human mandible with minimal periodontal bone loss around the first molar was selected and an artificial alveolar bone defect at the bifurcation area was serially prepared over 18 steps. Images were taken using a direct CCD-based system and with F-speed periapical films. The images were evaluated by seven interpreters (3 radiologists, 3 periodontologists, and 1 general dentist) using a 5-point confidence rating scale. The readability of both periapical radiographs and digital image increased as the size of the artificial lesion and exposure time increased (p<0.05). Periapical radiographs offered greater readability of smaller bone defects than digital images, and the coefficient of variation of mean score between periapical radiographs and digital images showed a significant difference. The experimental results indicate that a significant difference in the coefficient of variation of mean score exists between periapical radiographs and digital images, and that traditional film-based periapical images offer greater readability of smaller bone defects than digital images can presently offer.

  14. An experimental study on the readability of digital images in the furcal bone defects

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hyung Wuk; Hwang, Eui Hwan; Lee, Sang Rae [Kyunghee University College of Medicine, Seoul (Korea, Republic of)

    2003-06-15

    To evaluate and compare the efficacy of digital radiographic images in the detection of bone loss at the bifurcation area of the mandibular first molar with traditional film-based periapical radiographs. One dried human mandible with minimal periodontal bone loss around the first molar was selected and an artificial alveolar bone defect at the bifurcation area was serially prepared over 18 steps. Images were taken using a direct CCD-based system and with F-speed periapical films. The images were evaluated by seven interpreters (3 radiologists, 3 periodontologists, and 1 general dentist) using a 5-point confidence rating scale. The readability of both periapical radiographs and digital image increased as the size of the artificial lesion and exposure time increased (p<0.05). Periapical radiographs offered greater readability of smaller bone defects than digital images, and the coefficient of variation of mean score between periapical radiographs and digital images showed a significant difference. The experimental results indicate that a significant difference in the coefficient of variation of mean score exists between periapical radiographs and digital images, and that traditional film-based periapical images offer greater readability of smaller bone defects than digital images can presently offer.

  15. Detecting jaundice by using digital image processing

    Science.gov (United States)

    Castro-Ramos, J.; Toxqui-Quitl, C.; Villa Manriquez, F.; Orozco-Guillen, E.; Padilla-Vivanco, A.; Sánchez-Escobar, JJ.

    2014-03-01

    When strong Jaundice is presented, babies or adults should be subject to clinical exam like "serum bilirubin" which can cause traumas in patients. Often jaundice is presented in liver disease such as hepatitis or liver cancer. In order to avoid additional traumas we propose to detect jaundice (icterus) in newborns or adults by using a not pain method. By acquiring digital images in color, in palm, soles and forehead, we analyze RGB attributes and diffuse reflectance spectra as the parameter to characterize patients with either jaundice or not, and we correlate that parameters with the level of bilirubin. By applying support vector machine we distinguish between healthy and sick patients.

  16. Physiological conditions for the effective interpretation of radiographic images

    International Nuclear Information System (INIS)

    Overington, I.

    1989-01-01

    A wide range of factors influence the ability of the human observer to perceive detail in images. Most of these factors are of some significance in interpretation of one or more types of radiographic image. Human observer performance may be conveniently categorized in terms of multiparametric threshold surfaces, suprathreshold visibility and observer variance. The general multiparametric trends of human threshold performance are discussed, together with the implications for visibility. The importance and implications of observer variance are then explored, with particular reference to their effects on search processes. Finally, attempts are made to highlight the implications of some of the factors on typical radiographic interpretation tasks and on the adequacy of certain types of phantom image used for equipment calibration. (author)

  17. Issues to consider before implementing digital breast tomosynthesis into a breast imaging practice.

    Science.gov (United States)

    Hardesty, Lara A

    2015-03-01

    OBJECTIVE. The purpose of this article is to discuss issues surrounding the implementation of digital breast tomosynthesis (DBT) into a clinical breast imaging practice and assist radiologists, technologists, and administrators who are considering the addition of this new technology to their practices. CONCLUSION. When appropriate attention is given to image acquisition, interpretation, storage, technologist and radiologist training, patient selection, billing, radiation dose, and marketing, implementation of DBT into a breast imaging practice can be successful.

  18. The image-interpretation-workstation of the future: lessons learned

    Science.gov (United States)

    Maier, S.; van de Camp, F.; Hafermann, J.; Wagner, B.; Peinsipp-Byma, E.; Beyerer, J.

    2017-05-01

    In recent years, professionally used workstations got increasingly complex and multi-monitor systems are more and more common. Novel interaction techniques like gesture recognition were developed but used mostly for entertainment and gaming purposes. These human computer interfaces are not yet widely used in professional environments where they could greatly improve the user experience. To approach this problem, we combined existing tools in our imageinterpretation-workstation of the future, a multi-monitor workplace comprised of four screens. Each screen is dedicated to a special task in the image interpreting process: a geo-information system to geo-reference the images and provide a spatial reference for the user, an interactive recognition support tool, an annotation tool and a reporting tool. To further support the complex task of image interpreting, self-developed interaction systems for head-pose estimation and hand tracking were used in addition to more common technologies like touchscreens, face identification and speech recognition. A set of experiments were conducted to evaluate the usability of the different interaction systems. Two typical extensive tasks of image interpreting were devised and approved by military personal. They were then tested with a current setup of an image interpreting workstation using only keyboard and mouse against our image-interpretationworkstation of the future. To get a more detailed look at the usefulness of the interaction techniques in a multi-monitorsetup, the hand tracking, head pose estimation and the face recognition were further evaluated using tests inspired by everyday tasks. The results of the evaluation and the discussion are presented in this paper.

  19. Semiautomatic digital imaging system for cytogenetic analysis

    International Nuclear Information System (INIS)

    Chaubey, R.C.; Chauhan, P.C.; Bannur, S.V.; Kulgod, S.V.; Chadda, V.K.; Nigam, R.K.

    1999-08-01

    The paper describes a digital image processing system, developed indigenously at BARC for size measurement of microscopic biological objects such as cell, nucleus and micronucleus in mouse bone marrow; cytochalasin-B blocked human lymphocytes in-vitro; numerical counting and karyotyping of metaphase chromosomes of human lymphocytes. Errors in karyotyping of chromosomes by the imaging system may creep in due to lack of well-defined position of centromere or extensive bending of chromosomes, which may result due to poor quality of preparation. Good metaphase preparations are mandatory for precise and accurate analysis by the system. Additional new morphological parameters about each chromosome have to be incorporated to improve the accuracy of karyotyping. Though the experienced cytogenetisist is the final judge; however, the system assists him/her to carryout analysis much faster as compared to manual scoring. Further, experimental studies are in progress to validate different software packages developed for various cytogenetic applications. (author)

  20. The Neuro-Image: Alain Resnais's Digital Cinema without the Digits

    NARCIS (Netherlands)

    Pisters, P.

    2011-01-01

    This paper proposes to read cinema in the digital age as a new type of image, the neuroimage. Going back to Gilles Deleuze's cinema books and it is argued that the neuro-image is based in the future. The cinema of Alain Resnais is analyzed as a neuro-image and digital cinema .

  1. From Digital Imaging to Computer Image Analysis of Fine Art

    Science.gov (United States)

    Stork, David G.

    An expanding range of techniques from computer vision, pattern recognition, image analysis, and computer graphics are being applied to problems in the history of art. The success of these efforts is enabled by the growing corpus of high-resolution multi-spectral digital images of art (primarily paintings and drawings), sophisticated computer vision methods, and most importantly the engagement of some art scholars who bring questions that may be addressed through computer methods. This paper outlines some general problem areas and opportunities in this new inter-disciplinary research program.

  2. Digital imaging in diagnostic radiology. Image quality - radiation exposure

    International Nuclear Information System (INIS)

    Schmidt, T.; Stieve, F.E.

    1996-01-01

    The publication contains the 37 lectures of the symposium on digital imaging in diagnostic radiology, held in November 1995 at Kloster Seeon, as well as contributions enhancing the information presented in the lectures. The publication reflects the state of the art in this subject field, discusses future trends and gives recommendations and information relating to current practice in radiology. In-depth information is given about R and D activities for the digitalisation of X-ray pictures and the image quality required to meet the purposes of modern diagnostics. Further aspects encompass radiological protection and dose optimization as well as optimization of examination methods. (vhe) [de

  3. Advanced digital image archival system using MPEG technologies

    Science.gov (United States)

    Chang, Wo

    2009-08-01

    Digital information and records are vital to the human race regardless of the nationalities and eras in which they were produced. Digital image contents are produced at a rapid pace from cultural heritages via digitalization, scientific and experimental data via high speed imaging sensors, national defense satellite images from governments, medical and healthcare imaging records from hospitals, personal collection of photos from digital cameras. With these mass amounts of precious and irreplaceable data and knowledge, what standards technologies can be applied to preserve and yet provide an interoperable framework for accessing the data across varieties of systems and devices? This paper presents an advanced digital image archival system by applying the international standard of MPEG technologies to preserve digital image content.

  4. Integrating Digital Images into the Art and Art History Curriculum.

    Science.gov (United States)

    Pitt, Sharon P.; Updike, Christina B.; Guthrie, Miriam E.

    2002-01-01

    Describes an Internet-based image database system connected to a flexible, in-class teaching and learning tool (the Madison Digital Image Database) developed at James Madison University to bring digital images to the arts and humanities classroom. Discusses content, copyright issues, ensuring system effectiveness, instructional impact, sharing the…

  5. Remote Sensing Digital Image Analysis An Introduction

    CERN Document Server

    Richards, John A

    2013-01-01

    Remote Sensing Digital Image Analysis provides the non-specialist with a treatment of the quantitative analysis of satellite and aircraft derived remotely sensed data. Since the first edition of the book there have been significant developments in the algorithms used for the processing and analysis of remote sensing imagery; nevertheless many of the fundamentals have substantially remained the same.  This new edition presents material that has retained value since those early days, along with new techniques that can be incorporated into an operational framework for the analysis of remote sensing data. The book is designed as a teaching text for the senior undergraduate and postgraduate student, and as a fundamental treatment for those engaged in research using digital image processing in remote sensing.  The presentation level is for the mathematical non-specialist.  Since the very great number of operational users of remote sensing come from the earth sciences communities, the text is pitched at a leve...

  6. Reliability-guided digital image correlation for image deformation measurement

    International Nuclear Information System (INIS)

    Pan Bing

    2009-01-01

    A universally applicable reliability-guided digital image correlation (DIC) method is proposed for reliable image deformation measurement. The zero-mean normalized cross correlation (ZNCC) coefficient is used to identify the reliability of the point computed. The correlation calculation begins with a seed point and is then guided by the ZNCC coefficient. That means the neighbors of the point with the highest ZNCC coefficient in a queue for computed points will be processed first. Thus the calculation path is always along the most reliable direction, and possible error propagation of the conventional DIC method can be avoided. The proposed novel DIC method is universally applicable to the images with shadows, discontinuous areas, and deformation discontinuity. Two image pairs were used to evaluate the performance of the proposed technique, and the successful results clearly demonstrate its robustness and effectiveness

  7. Global manipulation of digital images can lead to variation in cytological diagnosis.

    Science.gov (United States)

    Prasad, H; Wanjari, Sangeeta; Parwani, Rajkumar

    2011-03-31

    With the adoption of a completely electronic workflow by several journals and the advent of telepathology, digital imaging has become an integral part of every scientific research. However, manipulating digital images is very easy, and it can lead to misinterpretations. To analyse the impact of manipulating digital images on their diagnosis. Digital images were obtained from Papanicolaou-stained smears of dysplastic and normal oral epithelium. They were manipulated using GNU Image Manipulation Program (GIMP) to alter their brightness and contrast and color levels. A Power Point presentation composed of slides of these manipulated images along with the unaltered originals arranged randomly was created. The presentation was shown to five observers individually who rated the images as normal, mild, moderate or severe dysplasia. Weighted κ statistics was used to measure and assess the levels of agreement between observers. Levels of agreement between manipulated images and original images varied greatly among observers. Variation in diagnosis was in the form of overdiagnosis or under-diagnosis, usually by one grade. Global manipulations of digital images of cytological slides can significantly affect their interpretation. Such manipulations should therefore be kept to a minimum, and avoided wherever possible.

  8. Global manipulation of digital images can lead to variation in cytological diagnosis

    Directory of Open Access Journals (Sweden)

    H Prasad

    2011-01-01

    Full Text Available Background: With the adoption of a completely electronic workflow by several journals and the advent of telepathology, digital imaging has become an integral part of every scientific research. However, manipulating digital images is very easy, and it can lead to misinterpretations. Aim: To analyse the impact of manipulating digital images on their diagnosis. Design: Digital images were obtained from Papanicolaou-stained smears of dysplastic and normal oral epithelium. They were manipulated using GNU Image Manipulation Program (GIMP to alter their brightness and contrast and color levels. A Power Point presentation composed of slides of these manipulated images along with the unaltered originals arranged randomly was created. The presentation was shown to five observers individually who rated the images as normal, mild, moderate or severe dysplasia. Weighted k statistics was used to measure and assess the levels of agreement between observers. Results: Levels of agreement between manipulated images and original images varied greatly among observers. Variation in diagnosis was in the form of overdiagnosis or under-diagnosis, usually by one grade. Conclusion: Global manipulations of digital images of cytological slides can significantly affect their interpretation. Such manipulations should therefore be kept to a minimum, and avoided wherever possible.

  9. Measuring the effects of image interpretation: An evaluative framework

    International Nuclear Information System (INIS)

    Brealey, Stephen

    2001-01-01

    The relaxing of restrictions on reporting films has resulted in radiographers and other health care professionals becoming increasingly involved in the interpretation of images in areas such as mammography, ultrasound and plain film radiography. However, errors and variation in the interpretation of images now represents the weakest area of clinical imaging. This has been highlighted by the difficulty of establishing standards to measure the film reading performance of radiographers as part of role extension initiatives. Despite a growing literature of studies that evaluate the film reading performance of different health care professionals, there is a paucity of evidence of the subsequent effects on the referring clinician's diagnosis, management plans and patient outcome. This paper proposes an evaluative framework that can be used to measure the chain of events from the initial technical assessment of observers' potential to interpret images using search behaviour techniques, through to the potential costs and benefits to society. Evaluating the wider implications of alternative or complementary reporting policies is essential for generating the evidence base to comprehensively underpin policy and practice and direct future research. Brealey, S. (2001)

  10. Surface Distresses Detection of Pavement Based on Digital Image Processing

    OpenAIRE

    Ouyang , Aiguo; Luo , Chagen; Zhou , Chao

    2010-01-01

    International audience; Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing has been applied to detect the pavement crack for its advantages of large amount of information and automatic detection. The applications of digital image processing in pavement crack detection, distresses classificati...

  11. X-ray images in the digital mode

    International Nuclear Information System (INIS)

    Buchmann, F.; Balter, S.

    1981-01-01

    In addition to computed tomography which presents actually the most important processing and transfer procedure of digital X-ray images, application of real time addition and substraction of X-ray images in a digital mode has found considerable interest. An estimation of the information contents of both digital and analog images is made in close relation to applications. As example of an image processing system on digital base a recently developed system for intravenous arteriography is described: the Philips-DVI. (orig.) [de

  12. Edge-detect interpolation for direct digital periapical images

    International Nuclear Information System (INIS)

    Song, Nam Kyu; Koh, Kwang Joon

    1998-01-01

    The purpose of this study was to aid in the use of the digital images by edge-detect interpolation for direct digital periapical images using edge-deted interpolation. This study was performed by image processing of 20 digital periapical images; pixel replication, linear non-interpolation, linear interpolation, and edge-sensitive interpolation. The obtained results were as follows ; 1. Pixel replication showed blocking artifact and serious image distortion. 2. Linear interpolation showed smoothing effect on the edge. 3. Edge-sensitive interpolation overcame the smoothing effect on the edge and showed better image.

  13. New possibilities of digital luminescence radiography (DLR) and digital image processing for verification and portal imaging

    International Nuclear Information System (INIS)

    Zimmermann, J.S.; Blume, J.; Wendhausen, H.; Hebbinghaus, D.; Kovacs, G.; Eilf, K.; Schultze, J.; Kimmig, B.N.

    1995-01-01

    We developed a method, using digital luminescence radiography (DLR), not only for portal imaging of photon beams in an excellent quality, but also for verification of electron beams. Furtheron, DLR was used as basic instrument for image fusion of portal and verification film and simulation film respectively for image processing in ''beams-eye-view'' verification (BEVV) of rotating beams or conformation therapy. Digital radiographs of an excellent quality are gained for verification of photon and electron beams. In photon beams, quality improvement vs. conventional portal imaging may be dramatic, even more for high energy beams (e.g. 15-MV-photon beams) than for Co-60. In electron beams, excellent results may be easily obtained. By digital image fusion of 1 or more verification films on simulation film or MRI-planning film, more precise judgement even on small differences between simulation and verification films becomes possible. Using BEVV, it is possible to compare computer aided simulation in rotating beams or conformation therapy with the really applied treatment. The basic principle of BEVV is also suitable for dynamic multileaf collimation. (orig.) [de

  14. A note on the physical interpretation of frequency dependent boundary conditions in a digital waveguide mesh

    DEFF Research Database (Denmark)

    Escolano-Carrasco, José; Jacobsen, Finn

    2007-01-01

    Digital waveguide mesh (DWM) is a popular method for time domain modelling of sound fields. DWM consists of a recursive digital filter structure where a D'Alembert solution of the wave equation is propagated. One of the attractive characteristics of this method is related to the simplicity...... model of the boundary does not agree with the behaviour of a locally reacting surface, and this can give rise to contradictions in the physical interpretation of the reflected sound field. This paper analyses the behaviour of frequency dependent boundary conditions in DWM in order to obtain a physical...

  15. Making the Case for Embedded Metadata in Digital Images

    DEFF Research Database (Denmark)

    Smith, Kari R.; Saunders, Sarah; Kejser, U.B.

    2014-01-01

    This paper discusses the standards, methods, use cases, and opportunities for using embedded metadata in digital images. In this paper we explain the past and current work engaged with developing specifications, standards for embedding metadata of different types, and the practicalities of data...... exchange in heritage institutions and the culture sector. Our examples and findings support the case for embedded metadata in digital images and the opportunities for such use more broadly in non-heritage sectors as well. We encourage the adoption of embedded metadata by digital image content creators...... and curators as well as those developing software and hardware that support the creation or re-use of digital images. We conclude that the usability of born digital images as well as physical objects that are digitized can be extended and the files preserved more readily with embedded metadata....

  16. Making the Case for Embedded Metadata in Digital Images

    DEFF Research Database (Denmark)

    Smith, Kari R.; Saunders, Sarah; Kejser, U.B.

    2014-01-01

    exchange in heritage institutions and the culture sector. Our examples and findings support the case for embedded metadata in digital images and the opportunities for such use more broadly in non-heritage sectors as well. We encourage the adoption of embedded metadata by digital image content creators......This paper discusses the standards, methods, use cases, and opportunities for using embedded metadata in digital images. In this paper we explain the past and current work engaged with developing specifications, standards for embedding metadata of different types, and the practicalities of data...... and curators as well as those developing software and hardware that support the creation or re-use of digital images. We conclude that the usability of born digital images as well as physical objects that are digitized can be extended and the files preserved more readily with embedded metadata....

  17. Histological image classification using biologically interpretable shape-based features

    International Nuclear Information System (INIS)

    Kothari, Sonal; Phan, John H; Young, Andrew N; Wang, May D

    2013-01-01

    Automatic cancer diagnostic systems based on histological image classification are important for improving therapeutic decisions. Previous studies propose textural and morphological features for such systems. These features capture patterns in histological images that are useful for both cancer grading and subtyping. However, because many of these features lack a clear biological interpretation, pathologists may be reluctant to adopt these features for clinical diagnosis. We examine the utility of biologically interpretable shape-based features for classification of histological renal tumor images. Using Fourier shape descriptors, we extract shape-based features that capture the distribution of stain-enhanced cellular and tissue structures in each image and evaluate these features using a multi-class prediction model. We compare the predictive performance of the shape-based diagnostic model to that of traditional models, i.e., using textural, morphological and topological features. The shape-based model, with an average accuracy of 77%, outperforms or complements traditional models. We identify the most informative shapes for each renal tumor subtype from the top-selected features. Results suggest that these shapes are not only accurate diagnostic features, but also correlate with known biological characteristics of renal tumors. Shape-based analysis of histological renal tumor images accurately classifies disease subtypes and reveals biologically insightful discriminatory features. This method for shape-based analysis can be extended to other histological datasets to aid pathologists in diagnostic and therapeutic decisions

  18. Digital Particle Image Velocimetry: Partial Image Error (PIE)

    International Nuclear Information System (INIS)

    Anandarajah, K; Hargrave, G K; Halliwell, N A

    2006-01-01

    This paper quantifies the errors due to partial imaging of seeding particles which occur at the edges of interrogation regions in Digital Particle Image Velocimetry (DPIV). Hitherto, in the scientific literature the effect of these partial images has been assumed to be negligible. The results show that the error is significant even at a commonly used interrogation region size of 32 x 32 pixels. If correlation of interrogation region sizes of 16 x 16 pixels and smaller is attempted, the error which occurs can preclude meaningful results being obtained. In order to reduce the error normalisation of the correlation peak values is necessary. The paper introduces Normalisation by Signal Strength (NSS) as the preferred means of normalisation for optimum accuracy. In addition, it is shown that NSS increases the dynamic range of DPIV

  19. Digital image archiving: challenges and choices.

    Science.gov (United States)

    Dumery, Barbara

    2002-01-01

    In the last five years, imaging exam volume has grown rapidly. In addition to increased image acquisition, there is more patient information per study. RIS-PACS integration and information-rich DICOM headers now provide us with more patient information relative to each study. The volume of archived digital images is increasing and will continue to rise at a steeper incline than film-based storage of the past. Many filmless facilities have been caught off guard by this increase, which has been stimulated by many factors. The most significant factor is investment in new digital and DICOM-compliant modalities. A huge volume driver is the increase in images per study from multi-slice technology. Storage requirements also are affected by disaster recovery initiatives and state retention mandates. This burgeoning rate of imaging data volume presents many challenges: cost of ownership, data accessibility, storage media obsolescence, database considerations, physical limitations, reliability and redundancy. There are two basic approaches to archiving--single tier and multi-tier. Each has benefits. With a single-tier approach, all the data is stored on a single media that can be accessed very quickly. A redundant copy of the data is then stored onto another less expensive media. This is usually a removable media. In this approach, the on-line storage is increased incrementally as volume grows. In a multi-tier approach, storage levels are set up based on access speed and cost. In other words, all images are stored at the deepest archiving level, which is also the least expensive. Images are stored on or moved back to the intermediate and on-line levels if they will need to be accessed more quickly. It can be difficult to decide what the best approach is for your organization. The options include RAIDs (redundant array of independent disks), direct attached RAID storage (DAS), network storage using RAIDs (NAS and SAN), removable media such as different types of tape, compact

  20. Digital image processing applied Rock Art tracing

    Directory of Open Access Journals (Sweden)

    Montero Ruiz, Ignacio

    1998-06-01

    Full Text Available Adequate graphic recording has been one of the main objectives of rock art research. Photography has increased its role as a documentary technique. Now, digital image and its treatment allows new ways to observe the details of the figures and to develop a recording procedure which is as, or more, accurate than direct tracing. This technique also avoid deterioration of the rock paintings. The mathematical basis of this method is also presented.

    La correcta documentación del arte rupestre ha sido una preocupación constante por parte de los investigadores. En el desarrollo de nuevas técnicas de registro, directas e indirectas, la fotografía ha ido adquiriendo mayor protagonismo. La imagen digital y su tratamiento permiten nuevas posibilidades de observación de las figuras representadas y, en consecuencia, una lectura mediante la realización de calcos indirectos de tanta o mayor fiabilidad que la observación directa. Este sistema evita los riesgos de deterioro que provocan los calcos directos. Se incluyen las bases matemáticas que sustentan el método.

  1. Image interpretation performance: A longitudinal study from novice to professional

    International Nuclear Information System (INIS)

    Wright, C.; Reeves, P.

    2017-01-01

    Purpose: Universities need to deliver educational programmes that create radiography graduates who are ready and able to participate in abnormality detection schemes, ultimately delivering safe and reliable performance because junior doctors are exposed to the risk of misdiagnosis if unsupported by other healthcare professionals. Radiographers are ideally suited to this role having the responsibility for conducting the actual X-ray examination. Method: The image interpretation performance of one cohort of student radiographers was measured upon enrolment from UCAS in the first week of university education and then again prior to graduation using RadBench (n = 23). Results: The results identified that novices have a range of natural image interpretation skills; accuracy 35–85%, sensitivity 45–100%, specificity 15–85%, mean ROC 0.691. Graduates presented a narrower range; accuracy 60–90%, sensitivity 40–100%, specificity 60–90%, mean ROC 0.841. The positive shift in graduate mean accuracy (+16%) was driven by increases in specificity (+27%) rather than sensitivity (+5%). No statistically significant differences (ANOVA) could be found between age group, gender and previous education however trends were identified. 56.5% of the population (n = 13) met a benchmark accurate standard of 80%, including one graduate who met 90%. Conclusion: Image interpretation testing at the point of UCAS entry is a useful indicator of future performance and is a recommended factor for consideration as part of the selection process. Whilst image interpretation now forms an integral part of undergraduate radiography programmes, new graduates may not necessary possess the reliability in decision making to justify participation in abnormality detection schemes, highlighting the need for continuous professional development. - Highlights: • Some novices appear to have inherent skills in fracture identification. • RadBench testing as part of the UCAS selection process

  2. Feasibility of digital imaging to characterize earth materials : part 1.

    Science.gov (United States)

    2012-06-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  3. Feasibility of digital imaging to characterize earth materials : part 4.

    Science.gov (United States)

    2012-06-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  4. Feasibility of digital imaging to characterize earth materials : part 5.

    Science.gov (United States)

    2012-05-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  5. Feasibility of digital imaging to characterize earth materials : part 3.

    Science.gov (United States)

    2012-06-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  6. Feasibility of digital imaging to characterize earth materials : part 2.

    Science.gov (United States)

    2012-06-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  7. Feasibility of digital imaging to characterize earth materials : part 6.

    Science.gov (United States)

    2012-06-06

    This study demonstrated the feasibility of digital imaging to characterize earth materials. Two rapid, relatively low cost image-based methods were developed for determining the grain size distribution of soils and aggregates. The first method, calle...

  8. Visual Interpretation with Three-Dimensional Annotations (VITA): three-dimensional image interpretation tool for radiological reporting.

    Science.gov (United States)

    Roy, Sharmili; Brown, Michael S; Shih, George L

    2014-02-01

    This paper introduces a software framework called Visual Interpretation with Three-Dimensional Annotations (VITA) that is able to automatically generate three-dimensional (3D) visual summaries based on radiological annotations made during routine exam reporting. VITA summaries are in the form of rotating 3D volumes where radiological annotations are highlighted to place important clinical observations into a 3D context. The rendered volume is produced as a Digital Imaging and Communications in Medicine (DICOM) object and is automatically added to the study for archival in Picture Archiving and Communication System (PACS). In addition, a video summary (e.g., MPEG4) can be generated for sharing with patients and for situations where DICOM viewers are not readily available to referring physicians. The current version of VITA is compatible with ClearCanvas; however, VITA can work with any PACS workstation that has a structured annotation implementation (e.g., Extendible Markup Language, Health Level 7, Annotation and Image Markup) and is able to seamlessly integrate into the existing reporting workflow. In a survey with referring physicians, the vast majority strongly agreed that 3D visual summaries improve the communication of the radiologists' reports and aid communication with patients.

  9. Securing Digital Images Integrity using Artificial Neural Networks

    Science.gov (United States)

    Hajji, Tarik; Itahriouan, Zakaria; Ouazzani Jamil, Mohammed

    2018-05-01

    Digital image signature is a technique used to protect the image integrity. The application of this technique can serve several areas of imaging applied to smart cities. The objective of this work is to propose two methods to protect digital image integrity. We present a description of two approaches using artificial neural networks (ANN) to digitally sign an image. The first one is “Direct Signature without learning” and the second is “Direct Signature with learning”. This paper presents the theory of proposed approaches and an experimental study to test their effectiveness.

  10. X-ray imaging using digital cameras

    Science.gov (United States)

    Winch, Nicola M.; Edgar, Andrew

    2012-03-01

    The possibility of using the combination of a computed radiography (storage phosphor) cassette and a semiprofessional grade digital camera for medical or dental radiography is investigated. We compare the performance of (i) a Canon 5D Mk II single lens reflex camera with f1.4 lens and full-frame CMOS array sensor and (ii) a cooled CCD-based camera with a 1/3 frame sensor and the same lens system. Both systems are tested with 240 x 180 mm cassettes which are based on either powdered europium-doped barium fluoride bromide or needle structure europium-doped cesium bromide. The modulation transfer function for both systems has been determined and falls to a value of 0.2 at around 2 lp/mm, and is limited by light scattering of the emitted light from the storage phosphor rather than the optics or sensor pixelation. The modulation transfer function for the CsBr:Eu2+ plate is bimodal, with a high frequency wing which is attributed to the light-guiding behaviour of the needle structure. The detective quantum efficiency has been determined using a radioisotope source and is comparatively low at 0.017 for the CMOS camera and 0.006 for the CCD camera, attributed to the poor light harvesting by the lens. The primary advantages of the method are portability, robustness, digital imaging and low cost; the limitations are the low detective quantum efficiency and hence signal-to-noise ratio for medical doses, and restricted range of plate sizes. Representative images taken with medical doses are shown and illustrate the potential use for portable basic radiography.

  11. A Comparative Study on Diagnostic Accuracy of Colour Coded Digital Images, Direct Digital Images and Conventional Radiographs for Periapical Lesions – An In Vitro Study

    Science.gov (United States)

    Mubeen; K.R., Vijayalakshmi; Bhuyan, Sanat Kumar; Panigrahi, Rajat G; Priyadarshini, Smita R; Misra, Satyaranjan; Singh, Chandravir

    2014-01-01

    Objectives: The identification and radiographic interpretation of periapical bone lesions is important for accurate diagnosis and treatment. The present study was undertaken to study the feasibility and diagnostic accuracy of colour coded digital radiographs in terms of presence and size of lesion and to compare the diagnostic accuracy of colour coded digital images with direct digital images and conventional radiographs for assessing periapical lesions. Materials and Methods: Sixty human dry cadaver hemimandibles were obtained and periapical lesions were created in first and second premolar teeth at the junction of cancellous and cortical bone using a micromotor handpiece and carbide burs of sizes 2, 4 and 6. After each successive use of round burs, a conventional, RVG and colour coded image was taken for each specimen. All the images were evaluated by three observers. The diagnostic accuracy for each bur and image mode was calculated statistically. Results: Our results showed good interobserver (kappa > 0.61) agreement for the different radiographic techniques and for the different bur sizes. Conventional Radiography outperformed Digital Radiography in diagnosing periapical lesions made with Size two bur. Both were equally diagnostic for lesions made with larger bur sizes. Colour coding method was least accurate among all the techniques. Conclusion: Conventional radiography traditionally forms the backbone in the diagnosis, treatment planning and follow-up of periapical lesions. Direct digital imaging is an efficient technique, in diagnostic sense. Colour coding of digital radiography was feasible but less accurate however, this imaging technique, like any other, needs to be studied continuously with the emphasis on safety of patients and diagnostic quality of images. PMID:25584318

  12. Digital pulse processor for ion beam microprobe imaging

    International Nuclear Information System (INIS)

    Bogovac, M.; Jaksic, M.; Wegrzynek, D.; Markowicz, A.

    2009-01-01

    Capabilities of spectroscopic ion beam analysis (IBA) techniques that are available in ion microprobe facilities can be greatly improved by the use of digital pulse processing. We report here development of a digital multi parameter data acquisition system suitable for IBA imaging applications. Input signals from charge sensitive preamplifier are conditioned by using a simple circuit and digitized with fast ADCs. The digitally converted signals are processed in real time using FPGA. Implementation of several components of the system is presented.

  13. Automated quadrilateral mesh generation for digital image structures

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With the development of advanced imaging technology, digital images are widely used. This paper proposes an automatic quadrilateral mesh generation algorithm for multi-colour imaged structures. It takes an original arbitrary digital image as an input for automatic quadrilateral mesh generation, this includes removing the noise, extracting and smoothing the boundary geometries between different colours, and automatic all-quad mesh generation with the above boundaries as constraints. An application example is...

  14. A kind of video image digitizing circuit based on computer parallel port

    International Nuclear Information System (INIS)

    Wang Yi; Tang Le; Cheng Jianping; Li Yuanjing; Zhang Binquan

    2003-01-01

    A kind of video images digitizing circuit based on parallel port was developed to digitize the flash x ray images in our Multi-Channel Digital Flash X ray Imaging System. The circuit can digitize the video images and store in static memory. The digital images can be transferred to computer through parallel port and can be displayed, processed and stored. (authors)

  15. Mechanical shape correlation : a novel integrated digital image correlation approach

    NARCIS (Netherlands)

    Kleinendorst, S.M.; Hoefnagels, J.P.M.; Geers, M.G.D.; Lamberti, L.; Lin, M.-T.; Furlong, C.; Sciammarella, C.

    2018-01-01

    Mechanical Shape Correlation (MSC) is a novel integrated digital image correlation technique, used to determine the optimal set of constitutive parameters to describe the experimentally observed mechanical behavior of a test specimen, based on digital images taken during the experiment. In contrast

  16. Improving digital image watermarking by means of optimal channel selection

    NARCIS (Netherlands)

    Huynh-The, Thien; Banos Legran, Oresti; Lee, Sungyoung; Yoon, Yongik; Le-Tien, Thuong

    2016-01-01

    Supporting safe and resilient authentication and integrity of digital images is of critical importance in a time of enormous creation and sharing of these contents. This paper presents an improved digital image watermarking model based on a coefficient quantization technique that intelligently

  17. Digital image technology and a measurement tool in physical models

    CSIR Research Space (South Africa)

    Phelp, David

    2006-05-01

    Full Text Available Advances in digital image technology has allowed us to use accurate, but relatively cost effective technology to measure a number of varied activities in physical models. The capturing and manipulation of high resolution digital images can be used...

  18. Losing images in digital radiology: more than you think.

    Science.gov (United States)

    Oglevee, Catherine; Pianykh, Oleg

    2015-06-01

    It is a common belief that the shift to digital imaging some 20 years ago helped medical image exchange and got rid of any potential image loss that was happening with printed image films. Unfortunately, this is not the case: despite the most recent advances in digital imaging, most hospitals still keep losing their imaging data, with these losses going completely unnoticed. As a result, not only does image loss affect the faith in digital imaging but it also affects patient diagnosis and daily quality of clinical work. This paper identifies the origins of invisible image losses, provides methods and procedures to detect image loss, and demonstrates modes of action that can be taken to stop the problem from happening.

  19. Geomorphic Map of Worcester County, Maryland, Interpreted from a LIDAR-Based, Digital Elevation Model

    Science.gov (United States)

    Newell, Wayne L.; Clark, Inga

    2008-01-01

    A recently compiled mosaic of a LIDAR-based digital elevation model (DEM) is presented with geomorphic analysis of new macro-topographic details. The geologic framework of the surficial and near surface late Cenozoic deposits of the central uplands, Pocomoke River valley, and the Atlantic Coast includes Cenozoic to recent sediments from fluvial, estuarine, and littoral depositional environments. Extensive Pleistocene (cold climate) sandy dune fields are deposited over much of the terraced landscape. The macro details from the LIDAR image reveal 2 meter-scale resolution of details of the shapes of individual dunes, and fields of translocated sand sheets. Most terrace surfaces are overprinted with circular to elliptical rimmed basins that represent complex histories of ephemeral ponds that were formed, drained, and overprinted by younger basins. The terrains of composite ephemeral ponds and the dune fields are inter-shingled at their margins indicating contemporaneous erosion, deposition, and re-arrangement and possible internal deformation of the surficial deposits. The aggregate of these landform details and their deposits are interpreted as the products of arid, cold climate processes that were common to the mid-Atlantic region during the Last Glacial Maximum. In the Pocomoke valley and its larger tributaries, erosional remnants of sandy flood plains with anastomosing channels indicate the dynamics of former hydrology and sediment load of the watershed that prevailed at the end of the Pleistocene. As the climate warmed and precipitation increased during the transition from late Pleistocene to Holocene, dune fields were stabilized by vegetation, and the stream discharge increased. The increased discharge and greater local relief of streams graded to lower sea levels stimulated down cutting and created the deeply incised valleys out onto the continental shelf. These incised valleys have been filling with fluvial to intertidal deposits that record the rising sea

  20. Image processing by use of the digital cross-correlator

    International Nuclear Information System (INIS)

    Katou, Yoshinori

    1982-01-01

    We manufactured for trial an instrument which achieved the image processing using digital correlators. A digital correlator perform 64-bit parallel correlation at 20 MH. The output of a digital correlator is a 7-bit word representing. An A-D converter is used to quantize it a precision of six bits. The resulting 6-bit word is fed to six correlators, wired in parallel. The image processing achieved in 12 bits, whose digital outputs converted an analog signal by a D-A converter. This instrument is named the digital cross-correlator. The method which was used in the image processing system calculated the convolution with the digital correlator. It makes various digital filters. In the experiment with the image processing video signals from TV camera were used. The digital image processing time was approximately 5 μs. The contrast was enhanced and smoothed. The digital cross-correlator has the image processing of 16 sorts, and was produced inexpensively. (author)

  1. Elastography of the Breast: Imaging Techniques and Pitfalls in Interpretation

    International Nuclear Information System (INIS)

    Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya

    2011-01-01

    Ultrasound (US) elastography is a tool that indicates the hardness of a lesion. Recent studies using elastography with freehand compression have shown similar diagnostic performance to conventional US in differentiating benign lesions from malignant breast masses. On the other hand, the acquired information is not quantitative, and the reliability of the imaging technique to correctly compress the tissue depends on the skill of the operator, resulting in substantial interobserver variability during data acquisition and interpretation. To overcome this, shear wave elastography was developed to provide quantitative information on the tissue elasticity. The system works by remotely inducing mechanical vibrations through the acoustic radiation force created by a focused US beam. This review discusses the principles and examination techniques of the two types of elastography systems and provides practical points to reduce the interobserver variability or errors during data acquisition and interpretation

  2. Elastography of the Breast: Imaging Techniques and Pitfalls in Interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Woo Kyung; Chang, Jung Min; Cho, Nariya [Seoul National University Hospital, Seoul (Korea, Republic of)

    2011-12-15

    Ultrasound (US) elastography is a tool that indicates the hardness of a lesion. Recent studies using elastography with freehand compression have shown similar diagnostic performance to conventional US in differentiating benign lesions from malignant breast masses. On the other hand, the acquired information is not quantitative, and the reliability of the imaging technique to correctly compress the tissue depends on the skill of the operator, resulting in substantial interobserver variability during data acquisition and interpretation. To overcome this, shear wave elastography was developed to provide quantitative information on the tissue elasticity. The system works by remotely inducing mechanical vibrations through the acoustic radiation force created by a focused US beam. This review discusses the principles and examination techniques of the two types of elastography systems and provides practical points to reduce the interobserver variability or errors during data acquisition and interpretation

  3. System for objective assessment of image differences in digital cinema

    Science.gov (United States)

    Fliegel, Karel; Krasula, Lukáš; Páta, Petr; Myslík, Jiří; Pecák, Josef; Jícha, Marek

    2014-09-01

    There is high demand for quick digitization and subsequent image restoration of archived film records. Digitization is very urgent in many cases because various invaluable pieces of cultural heritage are stored on aging media. Only selected records can be reconstructed perfectly using painstaking manual or semi-automatic procedures. This paper aims to answer the question what are the quality requirements on the restoration process in order to obtain acceptably close visual perception of the digitally restored film in comparison to the original analog film copy. This knowledge is very important to preserve the original artistic intention of the movie producers. Subjective experiment with artificially distorted images has been conducted in order to answer the question what is the visual impact of common image distortions in digital cinema. Typical color and contrast distortions were introduced and test images were presented to viewers using digital projector. Based on the outcome of this subjective evaluation a system for objective assessment of image distortions has been developed and its performance tested. The system utilizes calibrated digital single-lens reflex camera and subsequent analysis of suitable features of images captured from the projection screen. The evaluation of captured image data has been optimized in order to obtain predicted differences between the reference and distorted images while achieving high correlation with the results of subjective assessment. The system can be used to objectively determine the difference between analog film and digital cinema images on the projection screen.

  4. Effects of optimization and image processing in digital chest radiography

    International Nuclear Information System (INIS)

    Kheddache, S.; Maansson, L.G.; Angelhed, J.E.; Denbratt, L.; Gottfridsson, B.; Schlossman, D.

    1991-01-01

    A digital system for chest radiography based on a large image intensifier was compared to a conventional film-screen system. The digital system was optimized with regard to spatial and contrast resolution and dose. The images were digitally processed for contrast and edge enhancement. A simulated pneumothorax and two and two simulated nodules were positioned over the lungs and the mediastinum of an anthro-pomorphic phantom. Observer performance was evaluated with Receiver Operating Characteristic (ROC) analysis. Five observers assessed the processed digital images and the conventional full-size radiographs. The time spent viewing the full-size radiographs and the digital images was recorded. For the simulated pneumothorax, the results showed perfect performance for the full-size radiographs and detectability was high also for the processed digital images. No significant differences in the detectability of the simulated nodules was seen between the two imaging systems. The results for the digital images showed a significantly improved detectability for the nodules in the mediastinum as compared to a previous ROC study where no optimization and image processing was available. No significant difference in detectability was seen between the former and the present ROC study for small nodules in the lung. No difference was seen in the time spent assessing the conventional full-size radiographs and the digital images. The study indicates that processed digital images produced by a large image intensifier are equal in image quality to conventional full-size radiographs for low-contrast objects such as nodules. (author). 38 refs.; 4 figs.; 1 tab

  5. Digital image processing for radiography in nuclear power plants

    International Nuclear Information System (INIS)

    Heidt, H.; Rose, P.; Raabe, P.; Daum, W.

    1985-01-01

    With the help of digital processing of radiographic images from reactor-components it is possible to increase the security and objectiveness of the evaluation. Several examples of image processing procedures (contrast enhancement, density profiles, shading correction, digital filtering, superposition of images etc.) show the advantages for the visualization and evaluation of radiographs. Digital image processing can reduce some of the restrictions of radiography in nuclear power plants. In addition a higher degree of automation can be cost-saving and increase the quality of radiographic evaluation. The aim of the work performed was to to improve the readability of radiographs for the human observer. The main problem is lack of contrast and the presence of disturbing structures like weld seams. Digital image processing of film radiographs starts with the digitization of the image. Conventional systems use TV-cameras or scanners and provide a dynamic range of 1.5. to 3 density units, which are digitized to 256 grey levels. For the enhancement process it is necessary that the grey level range covers the density range of the important regions of the presented film. On the other hand the grey level coverage should not be wider than necessary to minimize the width of digitization steps. Poor digitization makes flaws and cracks invisible and spoils all further image processing

  6. Comparison Between Digital and Synthetic 2D Mammograms in Breast Density Interpretation.

    Science.gov (United States)

    Alshafeiy, Taghreed I; Wadih, Antoine; Nicholson, Brandi T; Rochman, Carrie M; Peppard, Heather R; Patrie, James T; Harvey, Jennifer A

    2017-07-01

    The purpose of this study was to compare assessments of breast density on synthetic 2D images as compared with digital 2D mammograms. This retrospective study included consecutive women undergoing screening with digital 2D mammography and tomosynthesis during May 2015 with a negative or benign outcome. In separate reading sessions, three radiologists with 5-25 years of clinical experience and 1 year of experience with synthetic 2D mammography read digital 2D and synthetic 2D images and assigned breast density categories according to the 5th edition of BI-RADS. Inter- and intrareader agreement was assessed for each BI-RADS density assessment and combined dense and nondense categories using percent agreement and Cohen kappa coefficient for consensus and all reads. A total of 309 patients met study inclusion criteria. Agreement between consensus BI-RADS density categories assigned for digital and synthetic 2D mammography was 80.3% (95% CI, 75.4-84.5%) with κ = 0.73 (95% CI, 0.66-0.79). For combined dense and nondense categories, agreement reached 91.9% (95% CI, 88.2-94.7%). For consensus readings, similar numbers of patients were shifted between nondense and dense categories (11 and 14, respectively) with the synthetic 2D compared with digital 2D mammography. Interreader differences were apparent; assignment to dense categories was greater with digital 2D mammography for reader 1 (odds ratio [OR], 1.26; p = 0.002), the same for reader 2 (OR, 0.91; p = 0.262), and greater with synthetic 2D mammography for reader 3 (OR, 0.86; p = 0.033). Overall, synthetic 2D mammography is comparable with digital 2D mammography in assessment of breast density, though there is some variability by reader. Practices can readily adopt synthetic 2D mammography without concern that it will affect density assessment and subsequent recommendations for supplemental screening.

  7. Digital imaging in conventional diagnostic radiology: status and trends

    International Nuclear Information System (INIS)

    Pfeiler, M.; Marhoff, P.; Schipper, P.

    1984-01-01

    Digital techniques, i.e. techniques using microcomputers of minicomputers, are getting increasingly common in so-called conventional radiography. These nonreconstructive techniques are referred to here as 'digital, direct-imaging radiography' in order to contrast them with the reconstructive techniques of computerized tomography. Digitalisation of imaging and image processing operation and control will change the jobs of the radiologist and radiological assistants in such manner that only X-ray units with film-foil systems or with X-ray image intensification should be classified as conventional systems. Digital and conventional systems differ in that digital techniques imply the possibility of establishing data pools which may eventually be developed into a digital image interconnection and archiving system. The authors first describe the general system in which the digital imaging systems must be integrated on a medium-term and long-term basis and then proceed to discuss digital imaging and image processing in some more detail. (orig./WU) [de

  8. Investigation of physical imaging properties in various digital radiography systems

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hoi Woun [Dept. of Radiological Science, Baekseok Culture University, Cheonan (Korea, Republic of); Min, Jung Hwan [Dept. of Radiological technology, Shingu University, Seongnam (Korea, Republic of); Yoon, Yong Su [Dept. of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Kyushu (Japan); Kim, Jung Min [Dept. of Health and Environmental Science, College of Health Science, Korea University, Seoul (Korea, Republic of)

    2017-09-15

    We aimed to evaluate the physical imaging properties in various digital radiography systems with charged coupled device (CCD), computed radiography (CR), and indirect flat panel detector (FPD). The imaging properties measured in this study were modulation transfer function (MTF) wiener spectrum (WS), and detective quantum efficiency (DQE) to compare the performance of each digital radiography system. The system response of CCD were in a linear relationship with exposure and that of CR and FPD were proportional to the logarithm of exposure. The MTF of both CR and FPD indicated a similar tendency but in case of CCD, it showed lower MTF than that of CR and FPD. FPD showed the lowest WS and also indicated the highest DQE among three systems. According to the results, digital radiography system with different type of image receptor had its own image characteristics. Therefore, it is important to know the physical imaging characteristics of the digital radiography system accurately to obtain proper image quality.

  9. Validation of Diagnostic Imaging Based on Repeat Examinations. An Image Interpretation Model

    International Nuclear Information System (INIS)

    Isberg, B.; Jorulf, H.; Thorstensen, Oe.

    2004-01-01

    Purpose: To develop an interpretation model, based on repeatedly acquired images, aimed at improving assessments of technical efficacy and diagnostic accuracy in the detection of small lesions. Material and Methods: A theoretical model is proposed. The studied population consists of subjects that develop focal lesions which increase in size in organs of interest during the study period. The imaging modality produces images that can be re-interpreted with high precision, e.g. conventional radiography, computed tomography, and magnetic resonance imaging. At least four repeat examinations are carried out. Results: The interpretation is performed in four or five steps: 1. Independent readers interpret the examinations chronologically without access to previous or subsequent films. 2. Lesions found on images at the last examination are included in the analysis, with interpretation in consensus. 3. By concurrent back-reading in consensus, the lesions are identified on previous images until they are so small that even in retrospect they are undetectable. The earliest examination at which included lesions appear is recorded, and the lesions are verified by their growth (imaging reference standard). Lesion size and other characteristics may be recorded. 4. Records made at step 1 are corrected to those of steps 2 and 3. False positives are recorded. 5. (Optional) Lesion type is confirmed by another diagnostic test. Conclusion: Applied on subjects with progressive disease, the proposed image interpretation model may improve assessments of technical efficacy and diagnostic accuracy in the detection of small focal lesions. The model may provide an accurate imaging reference standard as well as repeated detection rates and false-positive rates for tested imaging modalities. However, potential review bias necessitates a strict protocol

  10. Cognitive model of image interpretation for artificial intelligence applications

    International Nuclear Information System (INIS)

    Raju, S.

    1988-01-01

    A cognitive model of imaging diagnosis was devised to aid in the development of expert systems that assist in the interpretation of diagnostic images. In this cognitive model, a small set of observations that are strongly predictive of a particular diagnosis lead to a search for other observations that would support this diagnosis but are not necessarily specific for it. Then a set of alternative diagnoses is considered. This is followed by a search for observations that might allow differentiation of the primary diagnostic consideration from the alternatives. The production rules needed to implement this model can be classified into three major categories, each of which have certain general characteristics. Knowledge of these characteristics simplifies the development of these expert systems

  11. Problems with Permatrace: a note on digital image publication

    Directory of Open Access Journals (Sweden)

    Guy Hopkinson

    2004-01-01

    Full Text Available The methodology presented here developed out of work required to convert the hard-copy illustrations submitted to Internet Archaeology for publication of the 1975 excavations at Cricklade. The publication (and digital image preparatory work was funded by English Heritage and was, in part, an experiment designed to explore some of the possibilities presented by digital image publication. Various challenges in how to transform the drawings on permatrace to a digital format were encountered. While a full exploration of the potential of all areas of digital image preparation and publication was not possible, some interesting technical options were evaluated. This short article explains the processes applied in creating the images that were finally incorporated within the publication. It also examines some other avenues regarding the presentation of archaeological drawings that could be explored in both future Internet Archaeology content and other digital publications.

  12. Digital image processing an algorithmic approach with Matlab

    CERN Document Server

    Qidwai, Uvais

    2009-01-01

    Introduction to Image Processing and the MATLAB EnvironmentIntroduction Digital Image Definitions: Theoretical Account Image Properties MATLAB Algorithmic Account MATLAB CodeImage Acquisition, Types, and File I/OImage Acquisition Image Types and File I/O Basics of Color Images Other Color Spaces Algorithmic Account MATLAB CodeImage ArithmeticIntroduction Operator Basics Theoretical TreatmentAlgorithmic Treatment Coding ExamplesAffine and Logical Operations, Distortions, and Noise in ImagesIntroduction Affine Operations Logical Operators Noise in Images Distortions in ImagesAlgorithmic Account

  13. Digitalization and networking of analog simulators and portal images

    Energy Technology Data Exchange (ETDEWEB)

    Pesznyak, C.; Zarand, P.; Mayer, A. [Uzsoki Hospital, Budapest (Hungary). Inst. of Oncoradiology

    2007-03-15

    Background: Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R and V (Record and Verify) system is required. Material and Methods: Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Results: Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. Conclusion: The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R and V system. (orig.)

  14. Digitalization and networking of analog simulators and portal images.

    Science.gov (United States)

    Pesznyák, Csilla; Zaránd, Pál; Mayer, Arpád

    2007-03-01

    Many departments have analog simulators and irradiation facilities (especially cobalt units) without electronic portal imaging. Import of the images into the R&V (Record & Verify) system is required. Simulator images are grabbed while portal films scanned by using a laser scanner and both converted into DICOM RT (Digital Imaging and Communications in Medicine Radiotherapy) images. Image intensifier output of a simulator and portal films are converted to DICOM RT images and used in clinical practice. The simulator software was developed in cooperation at the authors' hospital. The digitalization of analog simulators is a valuable updating in clinical use replacing screen-film technique. Film scanning and digitalization permit the electronic archiving of films. Conversion into DICOM RT images is a precondition of importing to the R&V system.

  15. What We Do and Do Not Know about Teaching Medical Image Interpretation

    NARCIS (Netherlands)

    Kok, E M; Van Geel, Koos; van Merrienboer, Jeroen J. G.; Robben, S G F

    2017-01-01

    Educators in medical image interpretation have difficulty finding scientific evidence as to how they should design their instruction. We review and comment on 81 papers that investigated instructional design in medical image interpretation. We distinguish between studies that evaluated complete

  16. Assessing Expertise in Radiology : Evaluating and Improving the Assessment of Knowledge and Image Interpretation Skill

    NARCIS (Netherlands)

    Ravesloot, C.J.

    2016-01-01

    Aim: Expert radiologists are excellent image interpreters. Unfortunately, image interpretation errors are frequent even among experienced radiologists and not much is known about which factors lead to expertise. Increasing assessment quality can improve radiological performance. Progress tests can

  17. Topology of digital images visual pattern discovery in proximity spaces

    CERN Document Server

    Peters, James F

    2014-01-01

    This book carries forward recent work on visual patterns and structures in digital images and introduces a near set-based a topology of digital images. Visual patterns arise naturally in digital images viewed as sets of non-abstract points endowed with some form of proximity (nearness) relation. Proximity relations make it possible to construct uniform topolo- gies on the sets of points that constitute a digital image. In keeping with an interest in gaining an understanding of digital images themselves as a rich source of patterns, this book introduces the basics of digital images from a computer vision perspective. In parallel with a computer vision perspective on digital images, this book also introduces the basics of prox- imity spaces. Not only the traditional view of spatial proximity relations but also the more recent descriptive proximity relations are considered. The beauty of the descriptive proximity approach is that it is possible to discover visual set patterns among sets that are non-overlapping ...

  18. Myocardial perfusion imaging by digital subtraction angiography

    International Nuclear Information System (INIS)

    Kadowaki, Hiroyuki; Ishikawa, Kinji; Ogai, Toshihiro; Katori, Ryo

    1986-01-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; 1) at the R wave of the electrocardiogram, 2) 100 msec before the R wave, and 3) 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery. In all patients with anterior myocardial infarction, low perfusion was observed at the infarcted portion compared to the non-infarcted myocardium. In patients with inferior myocardial infarction, this low perfusion area was not observed because right coronary angiography was not subjected to DSA in this study. (J.P.N.)

  19. [Myocardial perfusion imaging by digital subtraction angiography].

    Science.gov (United States)

    Kadowaki, H; Ishikawa, K; Ogai, T; Katori, R

    1986-03-01

    Several methods of digital subtraction angiography (DSA) were compared to determine which could better visualize regional myocardial perfusion using coronary angiography in seven patients with myocardial infarction, two with angina pectoris and five with normal coronary arteries. Satisfactory DSA was judged to be achieved if the shape of the heart on the mask film was identical to that on the live film and if both films were exactly superimposed. To obtain an identical mask film in the shape of each live film, both films were selected from the following three phases of the cardiac cycle; at the R wave of the electrocardiogram, 100 msec before the R wave, and 200 msec before the R wave. The last two were superior for obtaining mask and live films which were similar in shape, because the cardiac motion in these phases was relatively small. Using these mask and live films, DSA was performed either with the continuous image mode (CI mode) or the time interval difference mode (TID mode). The overall perfusion of contrast medium through the artery to the vein was adequately visualized using the CI mode. Passage of contrast medium through the artery, capillary and vein was visualized at each phase using TID mode. Subtracted images were displayed and photographed, and the density of the contrast medium was adequate to display contour lines as in a relief map. Using this DSA, it was found that regional perfusion of the contrast medium was not always uniform in normal subjects, depending on the typography of the coronary artery.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Digital Image Correlation for Performance Monitoring

    Science.gov (United States)

    Palaviccini, Miguel; Turner, Dan; Herzberg, Michael

    2016-01-01

    Evaluating the health of a mechanism requires more than just a binary evaluation of whether an operation was completed. It requires analyzing more comprehensive, full-field data. Health monitoring is a process of non-destructively identifying characteristics that indicate the fitness of an engineered component. In order to monitor unit health in a production setting, an automated test system must be created to capture the motion of mechanism parts in a real-time and non-intrusive manner. One way to accomplish this is by using high-speed video and Digital Image Correlation (DIC). In this approach, individual frames of the video are analyzed to track the motion of mechanism components. The derived performance metrics allow for state-of-health monitoring and improved fidelity of mechanism modeling. The results are in-situ state-of-health identification and performance prediction. This paper introduces basic concepts of this test method, and discusses two main themes: the use of laser marking to add fiducial patterns to mechanism components, and new software developed to track objects with complex shapes, even as they move behind obstructions. Finally, the implementation of these tests into an automated tester is discussed.

  1. 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.

  2. Functions of the digital image in Education: A methodological proposal for reading and writing the digital image on instructional screens

    Directory of Open Access Journals (Sweden)

    Mariella Milagros Azzato

    2011-07-01

    Full Text Available This research goes through the instructional possibilities that reading and writing the digital image have in Education. Along these lines, we are presenting this research that looks for, on one hand, to develop a methodological proposal for reading and writing the digital image, and on the other, to implement these methodologies in a course used as a study case and whose objective was to evaluate students' performance when writing screens for a learning object using the methodologies for reading and writing the digital image. The process for compiling date was based on the questionnaire technique, individual interviews and the analysis of course proposed activities. The application of the first questionnaire allowed us to determine students' knowledge level about the digital image before starting the course. The individual interview allowed us to determine the students' reading criteria gained after using the reading methodology for the digital image to analyse educational materials (Galavis, 2008; Azzato, 2009. The proposed activities for the course permitted us to value students' performance when reading and writing the digital image of a learning object. Finally, after course completion, the second questionnaire was applied in order to determine the students' acquired knowledge level about reading and writing an image on digital screens. The results obtained in each of the analysis allowed us to establish that the proposed methodologies were highly useful to write the educational image for the screens of each one of the learning objects created in the course.

  3. Imaging defined risk factors in neuroblastoma -guidelines for optimising imaging interpretations

    International Nuclear Information System (INIS)

    Valchev, G.; Balev, B.

    2017-01-01

    Neuroblastoma is the most frequent extracranial tumor in children, arising from the primitive sympathetic cells and the adrenal medulla. Two separate mutually complementing staging systems exist - INSS and INRGSS - one is based on post-operative findings, the other - on pre-treatment imaging. INRGSS consists of a list of 20 separate imaging defined risk factors (IDRF), the presence of which could alter the treatment plan. Radiologists need to be aware of certain intricacies in interpreting the individual IDRFs in order to optimise clinical decision-making. Key words: neuroblastoma. imaging defined risk factors (IDRF). interpretation guidelines [bg

  4. Epistemic Function and Ontology of Analog and Digital Images

    Directory of Open Access Journals (Sweden)

    Aleksandra Łukaszewicz Alcaraz

    2016-01-01

    Full Text Available The important epistemic function of photographic images is their active role in construction and reconstruction of our beliefs concerning the world and human identity, since we often consider photographs as presenting reality or even the Real itself. Because photography can convince people of how different social and ethnic groups and even they themselves look, documentary projects and the dissemination of photographic practices supported the transition from disciplinary society to the present-day society of control. While both analog and digital images are formed from the same basic materia, the ways in which this matter appears are distinctive. In the case of analog photography, we deal with physical and chemical matter, whereas with digital images we face electronic matter. Because digital photography allows endless modification of the image, we can no longer believe in the truthfulness of digital images.

  5. [Managing digital medical imaging projects in healthcare services: lessons learned].

    Science.gov (United States)

    Rojas de la Escalera, D

    2013-01-01

    Medical imaging is one of the most important diagnostic instruments in clinical practice. The technological development of digital medical imaging has enabled healthcare services to undertake large scale projects that require the participation and collaboration of many professionals of varied backgrounds and interests as well as substantial investments in infrastructures. Rather than focusing on systems for dealing with digital medical images, this article deals with the management of projects for implementing these systems, reviewing various organizational, technological, and human factors that are critical to ensure the success of these projects and to guarantee the compatibility and integration of digital medical imaging systems with other health information systems. To this end, the author relates several lessons learned from a review of the literature and the author's own experience in the technical coordination of digital medical imaging projects. Copyright © 2012 SERAM. Published by Elsevier Espana. All rights reserved.

  6. Reducing image interpretation errors – Do communication strategies undermine this?

    International Nuclear Information System (INIS)

    Snaith, B.; Hardy, M.; Lewis, E.F.

    2014-01-01

    Introduction: Errors in the interpretation of diagnostic images in the emergency department are a persistent problem internationally. To address this issue, a number of risk reduction strategies have been suggested but only radiographer abnormality detection schemes (RADS) have been widely implemented in the UK. This study considers the variation in RADS operation and communication in light of technological advances and changes in service operation. Methods: A postal survey of all NHS hospitals operating either an Emergency Department or Minor Injury Unit and a diagnostic imaging (radiology) department (n = 510) was undertaken between July and August 2011. The questionnaire was designed to elicit information on emergency service provision and details of RADS. Results: 325 questionnaires were returned (n = 325/510; 63.7%). The majority of sites (n = 288/325; 88.6%) operated a RADS with the majority (n = 227/288; 78.8%) employing a visual ‘flagging’ system as the only method of communication although symbols used were inconsistent and contradictory across sites. 61 sites communicated radiographer findings through a written proforma (paper or electronic) but this was run in conjunction with a flagging system at 50 sites. The majority of sites did not have guidance on the scope or operation of the ‘flagging’ or written communication system in use. Conclusions: RADS is an established clinical intervention to reduce errors in diagnostic image interpretation within the emergency setting. The lack of standardisation in communication processes and practices alongside the rapid adoption of technology has increased the potential for error and miscommunication

  7. Advanced human machine interaction for an image interpretation workstation

    Science.gov (United States)

    Maier, S.; Martin, M.; van de Camp, F.; Peinsipp-Byma, E.; Beyerer, J.

    2016-05-01

    In recent years, many new interaction technologies have been developed that enhance the usability of computer systems and allow for novel types of interaction. The areas of application for these technologies have mostly been in gaming and entertainment. However, in professional environments, there are especially demanding tasks that would greatly benefit from improved human machine interfaces as well as an overall improved user experience. We, therefore, envisioned and built an image-interpretation-workstation of the future, a multi-monitor workplace comprised of four screens. Each screen is dedicated to a complex software product such as a geo-information system to provide geographic context, an image annotation tool, software to generate standardized reports and a tool to aid in the identification of objects. Using self-developed systems for hand tracking, pointing gestures and head pose estimation in addition to touchscreens, face identification, and speech recognition systems we created a novel approach to this complex task. For example, head pose information is used to save the position of the mouse cursor on the currently focused screen and to restore it as soon as the same screen is focused again while hand gestures allow for intuitive manipulation of 3d objects in mid-air. While the primary focus is on the task of image interpretation, all of the technologies involved provide generic ways of efficiently interacting with a multi-screen setup and could be utilized in other fields as well. In preliminary experiments, we received promising feedback from users in the military and started to tailor the functionality to their needs

  8. A radiographic image archive system on digital optical disks

    International Nuclear Information System (INIS)

    Mankovich, N.J.; Taira, R.K.; Cho, P.S.; Wong, W.K.; Stewart, B.K.; Huang, H.K.

    1986-01-01

    The recent introduction of projection computed radiography (CR) systems allows radiology departments to consider digital operation in over 90% of performed procedures. Ideally, current patient procedures from CT, CT, and MR along with laser-digitized historical films should be centrally stored at their full digital resolution. Magnetic disks, because of their limited storage capacity and expense, can only retain these data on a limited basis. The author devised an optical disk archive system which automatically stores images directly onto 2.6-gigabyte optical cartridges without recourse to film. This system is in full clinical operation in the UCLA Pediatric Radiology Section of the authors' department. From this experience they present (a) an analysis of the digital archiving requirements of the Pediatric Radiology Section based on CR, CT, MR, and laser digitized films; (b) the archive and retrieval methods along with performance statistics; and (c) the procedure for assuring digital image integrity

  9. Dynamic imaging through turbid media based on digital holography.

    Science.gov (United States)

    Li, Shiping; Zhong, Jingang

    2014-03-01

    Imaging through turbid media using visible or IR light instead of harmful x ray is still a challenging problem, especially in dynamic imaging. A method of dynamic imaging through turbid media using digital holography is presented. In order to match the coherence length between the dynamic object wave and the reference wave, a cw laser is used. To solve the problem of difficult focusing in imaging through turbid media, an autofocus technology is applied. To further enhance the image contrast, a spatial filtering technique is used. A description of digital holography and experiments of imaging the objects hidden in turbid media are presented. The experimental result shows that dynamic images of the objects can be achieved by the use of digital holography.

  10. Digital Correlation based on Wavelet Transform for Image Detection

    International Nuclear Information System (INIS)

    Barba, L; Vargas, L; Torres, C; Mattos, L

    2011-01-01

    In this work is presented a method for the optimization of digital correlators to improve the characteristic detection on images using wavelet transform as well as subband filtering. It is proposed an approach of wavelet-based image contrast enhancement in order to increase the performance of digital correlators. The multiresolution representation is employed to improve the high frequency content of images taken into account the input contrast measured for the original image. The energy of correlation peaks and discrimination level of several objects are improved with this technique. To demonstrate the potentiality in extracting characteristics using the wavelet transform, small objects inside reference images are detected successfully.

  11. Evaluation of display on CRT by various processing digital images

    International Nuclear Information System (INIS)

    Toyama, Yasuhiko; Akagi, Naoki; Ohara, Shuichi; Maeda, Tomoho; Kitazoe, Yasuhiro; Yamamoto, Kouji

    1986-01-01

    In this study, we digitized three sheets of thin line chart X-ray photographs altered the photographic density. By selecting the width of the photographic density at displaying the images on the CRT, We could augment the contrast of images and more easily recognize line images compared with original X-ray photos. This characteristic was clearly observed within the region of low wave length. Though the easy recognition was got by adjusting the contrast, the sharpness of line images was not in accordance with it. As mentioned above, we discussed the relation between the contrast and the sharpness of digitized images obtained with a multi-format camera. (author)

  12. Evaluation of display on CRT by various processing digital images

    Energy Technology Data Exchange (ETDEWEB)

    Toyama, Yasuhiko; Akagi, Naoki; Ohara, Shuichi; Maeda, Tomoho; Kitazoe, Yasuhiro; Yamamoto, Kouji

    1986-12-01

    In this study, we digitized three sheets of thin line chart X-ray photographs altered the photographic density. By selecting the width of the photographic density at displaying the images on the CRT, We could augment the contrast of images and more easily recognize line images compared with original X-ray photos. This characteristic was clearly observed within the region of low wave length. Though the easy recognition was got by adjusting the contrast, the sharpness of line images was not in accordance with it. As mentioned above, we discussed the relation between the contrast and the sharpness of digitized images obtained with a multi-format camera.

  13. Stellar Image Interpretation System using Artificial Neural Networks: Unipolar Function Case

    Directory of Open Access Journals (Sweden)

    F. I. Younis

    2001-01-01

    Full Text Available An artificial neural network based system for interpreting astronomical images has been developed. The system is based on feed-forward Artificial Neural Networks (ANNs with error back-propagation learning. Knowledge about images of stars, cosmic ray events and noise found in images is used to prepare two sets of input patterns to train and test our approach. The system has been developed and implemented to scan astronomical digital images in order to segregate stellar images from other entities. It has been coded in C language for users of personal computers. An astronomical image of a star cluster from other objects is undertaken as a test case. The obtained results are found to be in very good agreement with those derived from the DAOPHOTII package, which is widely used in the astronomical community. It is proved that our system is simpler, much faster and more reliable. Moreover, no prior knowledge, or initial data from the frame to be analysed is required.

  14. The clinical application of the digital imaging in urography

    International Nuclear Information System (INIS)

    Zhu Yuelong; Xie Sumin; Zhang Li; Li Huayu

    2003-01-01

    Objective: To evaluate the clinical application of the digital imaging in the urography. Methods: In total 112 patients underwent digital urography, including intravenous pyelography (IVP) in 38 cases and retrograde pyelography in 74 cases. Results: the entire urinary tract was better shown on digital imaging, which was accurate in locating the obstruction of urinary tract and helped the qualitative diagnosis. Digital urography was especially valuable in detecting urinary calculus. In 38 cases of IVP, the results were normal in 5 patients, renal stone in 12, ureteral stone in 13, ureteral stenosis in 6 and nephroblastom in 2. In the 74 cases of retrograde pyelography, benign ureteral stenosis was found in 31 patients, ureteral stone in 27, ureteral polyp in 2, urethral stone in 8 and benign urethral stenosis in 6. Conclusion: Digital imaging technique is of big value in the diagnosis of urinary tract lesions

  15. Improving image quality of parallel phase-shifting digital holography

    International Nuclear Information System (INIS)

    Awatsuji, Yasuhiro; Tahara, Tatsuki; Kaneko, Atsushi; Koyama, Takamasa; Nishio, Kenzo; Ura, Shogo; Kubota, Toshihiro; Matoba, Osamu

    2008-01-01

    The authors propose parallel two-step phase-shifting digital holography to improve the image quality of parallel phase-shifting digital holography. The proposed technique can increase the effective number of pixels of hologram twice in comparison to the conventional parallel four-step technique. The increase of the number of pixels makes it possible to improve the image quality of the reconstructed image of the parallel phase-shifting digital holography. Numerical simulation and preliminary experiment of the proposed technique were conducted and the effectiveness of the technique was confirmed. The proposed technique is more practical than the conventional parallel phase-shifting digital holography, because the composition of the digital holographic system based on the proposed technique is simpler.

  16. Digitalization of the radiological image. A new philosophy of the radiological imagery: the high resolution of the contrasts

    International Nuclear Information System (INIS)

    Schmidt, R.

    1983-01-01

    Three cases of digitalization are to be considered: static digitalization of the conventional radiographic image; static digitalization of the calculated image, like tomodensitometric images; dynamic digitalization of television images [fr

  17. Simple and robust image-based autofocusing for digital microscopy.

    Science.gov (United States)

    Yazdanfar, Siavash; Kenny, Kevin B; Tasimi, Krenar; Corwin, Alex D; Dixon, Elizabeth L; Filkins, Robert J

    2008-06-09

    A simple image-based autofocusing scheme for digital microscopy is demonstrated that uses as few as two intermediate images to bring the sample into focus. The algorithm is adapted to a commercial inverted microscope and used to automate brightfield and fluorescence imaging of histopathology tissue sections.

  18. Factors to consider in the transition to digital radiological imaging.

    LENUS (Irish Health Repository)

    MacDonald, David

    2009-02-01

    The dentist considering adopting digital radiological technology should consider more than the type of detector with which to capture the image. He\\/she should also consider the mode of display, image enhancement, radiation dose reduction, how the image can be stored long term, and infection control.

  19. Self-adaptive isogeometric global digital image correlation and digital height correlation

    NARCIS (Netherlands)

    Hoefnagels, J. P M; Kleinendorst, S. M.; Ruybalid, A. P.; Verhoosel, C. V.; Geers, M. G D; Yoshida, S.; Lamberti, L.; Sciammarella, C.

    2017-01-01

    This work explores the full potential of isogeometric shape functions for global digital image correlation. To this end, a novel DIC and DHC (digital height correlation) methodology have been developed based on adaptive refinement of isogeometric shape functions. Non-Uniform Rational B-Spline

  20. Affordable, Accessible, Immediate: Capture Stunning Images with Digital Infrared Photography

    Science.gov (United States)

    Snyder, Mark

    2011-01-01

    Technology educators who teach digital photography should consider incorporating an infrared (IR) photography component into their program. This is an area where digital photography offers significant benefits. Either type of IR imaging is very interesting to explore, but traditional film-based IR photography is difficult and expensive. In…

  1. Information Seeking Behavior in Digital Image Collections: A Cognitive Approach

    Science.gov (United States)

    Matusiak, Krystyna K.

    2006-01-01

    Presents the results of a qualitative study that focuses on search patterns of college students and community users interacting with a digital image collection. The study finds a distinct difference between the two groups of users and examines the role of mental models in information seeking behavior in digital libraries.

  2. The Digital Microscope and Its Image Processing Utility

    Directory of Open Access Journals (Sweden)

    Tri Wahyu Supardi

    2011-12-01

    Full Text Available Many institutions, including high schools, own a large number of analog or ordinary microscopes. These microscopes are used to observe small objects. Unfortunately, object observations on the ordinary microscope require precision and visual acuity of the user. This paper discusses the development of a high-resolution digital microscope from an analog microscope, including the image processing utility, which allows the digital microscope users to capture, store and process the digital images of the object being observed. The proposed microscope is constructed from hardware components that can be easily found in Indonesia. The image processing software is capable of performing brightness adjustment, contrast enhancement, histogram equalization, scaling and cropping. The proposed digital microscope has a maximum magnification of 1600x, and image resolution can be varied from 320x240 pixels up to 2592x1944 pixels. The microscope was tested with various objects with a variety of magnification, and image processing was carried out on the image of the object. The results showed that the digital microscope and its image processing system were capable of enhancing the observed object and other operations in accordance with the user need. The digital microscope has eliminated the need for direct observation by human eye as with the traditional microscope.

  3. Integrated global digital image correlation for interface delamination characterization

    KAUST Repository

    Hoefnagels, Johan P.M.; Blaysat, Benoî t; Lubineau, Gilles; Geers, Marc G D

    2013-01-01

    , but require accurate interface models to capture (irreversible) crack initiation and propagation behavior observed in experiments. Therefore, an Integrated Global Digital Image Correlation (I-GDIC) strategy is developed for accurate determination of mechanical

  4. Development of digital image correlation method to analyse crack ...

    Indian Academy of Sciences (India)

    samples were performed to verify the performance of the digital image correlation method. ... development cannot be measured accurately. ..... Mendelson A 1983 Plasticity: Theory and application (USA: Krieger Publishing company Malabar,.

  5. Digital Imaging of Pipeline Mechanical Damage and Residual Stress

    Science.gov (United States)

    2010-02-19

    The purpose of this program was to enhance characterization of mechanical damage in pipelines through application of digital eddy current imaging. Lift-off maps can be used to develop quantitative representations of mechanical damage and magnetic per...

  6. Finite element formulation for a digital image correlation method

    International Nuclear Information System (INIS)

    Sun Yaofeng; Pang, John H. L.; Wong, Chee Khuen; Su Fei

    2005-01-01

    A finite element formulation for a digital image correlation method is presented that will determine directly the complete, two-dimensional displacement field during the image correlation process on digital images. The entire interested image area is discretized into finite elements that are involved in the common image correlation process by use of our algorithms. This image correlation method with finite element formulation has an advantage over subset-based image correlation methods because it satisfies the requirements of displacement continuity and derivative continuity among elements on images. Numerical studies and a real experiment are used to verify the proposed formulation. Results have shown that the image correlation with the finite element formulation is computationally efficient, accurate, and robust

  7. Micro-Structure Measurement and Imaging Based on Digital Holography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyeong Suk; Jung, Hyun Chul; Chang, Ho Seob; Akhter, Naseem [Chosun University, Gwangju (Korea, Republic of); Kee, Chang Doo [Chonnam National University, Gwangju (Korea, Republic of)

    2010-06-15

    Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated

  8. Micro-Structure Measurement and Imaging Based on Digital Holography

    International Nuclear Information System (INIS)

    Kim, Kyeong Suk; Jung, Hyun Chul; Chang, Ho Seob; Akhter, Naseem; Kee, Chang Doo

    2010-01-01

    Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated

  9. Camac interface for digitally recording infrared camera images

    International Nuclear Information System (INIS)

    Dyer, G.R.

    1986-01-01

    An instrument has been built to store the digital signals from a modified imaging infrared scanner directly in a digital memory. This procedure avoids the signal-to-noise degradation and dynamic range limitations associated with successive analog-to-digital and digital-to-analog conversions and the analog recording method normally used to store data from the scanner. This technique also allows digital data processing methods to be applied directly to recorded data and permits processing and image reconstruction to be done using either a mainframe or a microcomputer. If a suitable computer and CAMAC-based data collection system are already available, digital storage of up to 12 scanner images can be implemented for less than $1750 in materials cost. Each image is stored as a frame of 60 x 80 eight-bit pixels, with an acquisition rate of one frame every 16.7 ms. The number of frames stored is limited only by the available memory. Initially, data processing for this equipment was done on a VAX 11-780, but images may also be displayed on the screen of a microcomputer. Software for setting the displayed gray scale, generating contour plots and false-color displays, and subtracting one image from another (e.g., background suppression) has been developed for IBM-compatible personal computers

  10. Topology-Preserving Rigid Transformation of 2D Digital Images.

    Science.gov (United States)

    Ngo, Phuc; Passat, Nicolas; Kenmochi, Yukiko; Talbot, Hugues

    2014-02-01

    We provide conditions under which 2D digital images preserve their topological properties under rigid transformations. We consider the two most common digital topology models, namely dual adjacency and well-composedness. This paper leads to the proposal of optimal preprocessing strategies that ensure the topological invariance of images under arbitrary rigid transformations. These results and methods are proved to be valid for various kinds of images (binary, gray-level, label), thus providing generic and efficient tools, which can be used in particular in the context of image registration and warping.

  11. Selected annotated bibliographies for adaptive filtering of digital image data

    Science.gov (United States)

    Mayers, Margaret; Wood, Lynnette

    1988-01-01

    Digital spatial filtering is an important tool both for enhancing the information content of satellite image data and for implementing cosmetic effects which make the imagery more interpretable and appealing to the eye. Spatial filtering is a context-dependent operation that alters the gray level of a pixel by computing a weighted average formed from the gray level values of other pixels in the immediate vicinity.Traditional spatial filtering involves passing a particular filter or set of filters over an entire image. This assumes that the filter parameter values are appropriate for the entire image, which in turn is based on the assumption that the statistics of the image are constant over the image. However, the statistics of an image may vary widely over the image, requiring an adaptive or "smart" filter whose parameters change as a function of the local statistical properties of the image. Then a pixel would be averaged only with more typical members of the same population. This annotated bibliography cites some of the work done in the area of adaptive filtering. The methods usually fall into two categories, (a) those that segment the image into subregions, each assumed to have stationary statistics, and use a different filter on each subregion, and (b) those that use a two-dimensional "sliding window" to continuously estimate the filter either the spatial or frequency domain, or may utilize both domains. They may be used to deal with images degraded by space variant noise, to suppress undesirable local radiometric statistics while enforcing desirable (user-defined) statistics, to treat problems where space-variant point spread functions are involved, to segment images into regions of constant value for classification, or to "tune" images in order to remove (nonstationary) variations in illumination, noise, contrast, shadows, or haze.Since adpative filtering, like nonadaptive filtering, is used in image processing to accomplish various goals, this bibliography

  12. An expert system for the interpretation of cranial CTSCAN images

    International Nuclear Information System (INIS)

    Kumar, R.; Srihari, S.N.

    1985-01-01

    An experimental system for Interpretation of Cranial CT SCAN Images has been developed. Given a Cranial CT SCAN slice of a patient the system (which is an artificial intelligence (AI) based computer program) finds and labels neuroanatomical landmarks e.g. skull bone, CSF cavities, tissue and distinct abnormalities, present within the CT slice. If abnormalities are found, the system determines the kind of abnormality present e.g. hematoma, tumor, edema, etc., and where the abnormality was detected. The system described is a rule-based one. The rules are knowledge engineered from the radiologist. The system can be viewed as a series of mappings beginning from the matrix of ct numbers, representing a ct slice of a patient, to a symbolic description of the image in terms of black and white regions and their properties. The rules operate on this symbolic description and diagnose each region to be normal or abnormal, and if abnormal then the kind of abnormality present. The system developed so far is an experimental one and far from routine clinical applications. Essentially, the report presents a frame-work for labeling regions in each ct slice

  13. The influence of software filtering in digital mammography image quality

    Science.gov (United States)

    Michail, C.; Spyropoulou, V.; Kalyvas, N.; Valais, I.; Dimitropoulos, N.; Fountos, G.; Kandarakis, I.; Panayiotakis, G.

    2009-05-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  14. The influence of software filtering in digital mammography image quality

    International Nuclear Information System (INIS)

    Michail, C; Spyropoulou, V; Valais, I; Panayiotakis, G; Kalyvas, N; Fountos, G; Kandarakis, I; Dimitropoulos, N

    2009-01-01

    Breast cancer is one of the most frequently diagnosed cancers among women. Several techniques have been developed to help in the early detection of breast cancer such as conventional and digital x-ray mammography, positron and single-photon emission mammography, etc. A key advantage in digital mammography is that images can be manipulated as simple computer image files. Thus non-dedicated commercially available image manipulation software can be employed to process and store the images. The image processing tools of the Photoshop (CS 2) software usually incorporate digital filters which may be used to reduce image noise, enhance contrast and increase spatial resolution. However, improving an image quality parameter may result in degradation of another. The aim of this work was to investigate the influence of three sharpening filters, named hereafter sharpen, sharpen more and sharpen edges on image resolution and noise. Image resolution was assessed by means of the Modulation Transfer Function (MTF).In conclusion it was found that the correct use of commercial non-dedicated software on digital mammograms may improve some aspects of image quality.

  15. NAIP Digital Ortho Photo Image 2010

    Data.gov (United States)

    Kansas Data Access and Support Center — This data set contains imagery from the National Agriculture Imagery Program (NAIP). NAIP acquires digital ortho imagery during the agricultural growing seasons in...

  16. Digital Image Quantitative Evaluations for Low Cost Film Digitizers Height Determination

    International Nuclear Information System (INIS)

    Khairul Anuar Mohd Salleh; Arshad Yassin; Ahmad Nasir Yusof; Noorhazleena Azaman

    2016-01-01

    Non Destructive Testing (NDT) technology contributes significant improvement to the quality of industrial products, and the integrity of equipment and plants. Introduction of powerful computers and reliable imaging technology has had significant impact on the traditional nuclear based NDT technology. Demand for faster, reliable, low cost, and flexible technology is rapidly increased. With the growing demand for more efficient digital archiving, digital image analysis, and reporting results with a low cost technology, one cannot deny the importance of having another cheaper solution. This project will apply fundamental principle of image digitization to be used in building up a low cost film digitization solution. The height of the film digitization was carefully determined by examining each digital images produced. Three (3) repetitive quantitative evaluations (Modulation Transfer Function [MTF], Characteristic Transfer Curve [CTC], and Contrast to Noise Ratio [CNR]) were performed at different condition to assist with the determination of the low cost film digitizers height. All 3 evaluations were successfully applied and the most appropriate height was successfully determined. (author)

  17. Digital image processing in NDT : Application to industrial radiography

    International Nuclear Information System (INIS)

    Aguirre, J.; Gonzales, C.; Pereira, D.

    1988-01-01

    Digital image processing techniques are applied to image enhancement discontinuity detection and characterization is radiographic test. Processing is performed mainly by image histogram modification, edge enhancement, texture and user interactive segmentation. Implementation was achieved in a microcomputer with video image capture system. Results are compared with those obtained through more specialized equipment main frame computers and high precision mechanical scanning digitisers. Procedures are intended as a precious stage for automatic defect detection

  18. A report on digital image processing and analysis

    International Nuclear Information System (INIS)

    Singh, B.; Alex, J.; Haridasan, G.

    1989-01-01

    This report presents developments in software, connected with digital image processing and analysis in the Centre. In image processing, one resorts to either alteration of grey level values so as to enhance features in the image or resorts to transform domain operations for restoration or filtering. Typical transform domain operations like Karhunen-Loeve transforms are statistical in nature and are used for a good registration of images or template - matching. Image analysis procedures segment grey level images into images contained within selectable windows, for the purpose of estimating geometrical features in the image, like area, perimeter, projections etc. In short, in image processing both the input and output are images, whereas in image analyses, the input is an image whereas the output is a set of numbers and graphs. (author). 19 refs

  19. Image quality of digital mammography images produced using wet and dry laser imaging systems

    International Nuclear Information System (INIS)

    Al Khalifah, K.; Brindhaban, A.; AlArfaj, R.; Jassim, O.

    2006-01-01

    Introduction: A study was carried out to compare the quality of digital mammographic images printed or processed by a wet laser imaging system and a dedicated mammographic dry laser imaging system. Material and methods: Digital images of a tissue equivalent breast phantom were obtained using a GE Senographe 2000D digital mammography system and different target/filter combinations of the X-ray tube. These images were printed on films using the Fuji FL-IM D wet laser imaging system and the Kodak DryView 8600 dry laser imaging system. The quality of images was assessed in terms of detectability of microcalcifications and simulated tumour masses by five radiologists. In addition, the contrast index and speed index of the two systems were measured using the step wedge in the phantom. The unpaired, unequal variance t-test was used to test any statistically significant differences. Results: There were no significant (p < 0.05) differences between the images printed using the two systems in terms of microcalcification and tumour mass detectability. The wet system resulted in slightly higher contrast index while the dry system showed significantly higher speed index. Conclusion: Both wet and dry laser imaging systems can produce mammography images of good quality on which 0.2 mm microcalcifications and 2 mm tumour masses can be detected. Dry systems are preferable due to the absence of wet chemical processing and solid or liquid chemical waste. The wet laser imaging systems, however, still represent a useful alternative to dry laser imaging systems for mammography studies

  20. Digital archives, big data and image-based culturomics for social impact assessment: Opportunities and challenges

    International Nuclear Information System (INIS)

    Sherren, Kate; Parkins, John R.; Smit, Michael; Holmlund, Mona; Chen, Yan

    2017-01-01

    Social impact assessment (SIA) is well-established but uses conventional approaches that have become less effective in recent decades, particularly in relation to declining survey response rates and a lack of youth engagement. Images from digital archives and social media sources are poised to advance the research and practice of SIA by transcending text-based methods with insights into changing landscapes, and human engagement with them. This viewpoint describes progress, challenges and cautions toward the development of such tools (defined as culturomics), using hydroelectricity cases to illustrate potential approaches. These tools build on foundational work in a range of disciplines, including the humanities and computer science. We describe necessary advances in machine learning, image digitization, and data aggregation and visualization techniques, as well as ways to ensure that such tools are carefully tested, applied and interpreted. Challenges include the automation, acquisition and management of datasets, and using these tools appropriately and equitably. Critically, culturomics of any kind must not be used as a replacement for engagement with people, but as complementary to inclusive stakeholder engagement. - Highlights: •Image-based digital archives and social media present opportunities for new SIA tools. •Application-ready big data approaches are emerging across many fields. •SIA scholars, practitioners and stakeholders should engage with culturomics. •Challenges include automation, digitization, interpretation and justice. •Culturomics of any kind must not replace engagement with people.

  1. Database application of digital medical X-rays and labs: computerization, storage, retrieval, interpretation, and distribution.

    Science.gov (United States)

    Hatcher, Myron; Tabriziani, Hossein; Heetebry, Irene

    2005-08-01

    Stenter lets the health care worker order an X-ray that is produced as a computer image rather than on flat film. The health care provider can be in any location with the correct equipment, and view the digital image. The dimensions of this discussion are extensive. The cost savings because of reduced media and storage cost is substantial. Health care quality can be improved because of the ability to obtain consultation via telemedicine and the enhanced ability to track medical problems over time via trends. The major downside is the limited cost imbursement system to pay for technology. Unfortunately, this may impact on the improved quality of care. In simple terms someone needs to pay for the technology and the quality of health care needs to be maintained or improved. The real cost to the health care systems needs to be correctly calculated and inappropriate charging kept to a minimum. Specific costs need to be kept in mind and the first is the cost for new staff or staff training. The number of health care providers that are able to read the X-ray can be enlarged remembering that only American Board Certified Radiologists are allowed to give the final recommendation. How do we view the cost of missing something? It could be argued that this risk will be reduced because of improved technology for obtaining the digital X-ray and improved enhancement software. One way to view this situation is to include technology, management, and organization. The cost and benefits occur through the interplay of all three dimensions. The development of digital imaging hardware and artificial intelligence software will demand change in the management and organization. The organization will require changes in its design to accommodate the technology as to support and resources. Management will evolve to include methods for control and monitoring this technology. Business processes and standard operating procedures will change to integrate the technology into the organization in

  2. Optimal image resolution for digital storage of radiotherapy-planning images

    International Nuclear Information System (INIS)

    Baba, Yuji; Furusawa, Mitsuhiro; Murakami, Ryuji; Baba, Takashi; Yokoyama, Toshimi; Nishimura, Ryuichi; Takahashi, Mutsumasa

    1998-01-01

    Purpose: To evaluate the quality of digitized radiation-planning images at different resolution and to determine the optimal resolution for digital storage. Methods and Materials: Twenty-five planning films were scanned and digitized using a film scanner at a resolution of 72 dots per inch (dpi) with 8-bit depth. The resolution of scanned images was reduced to 48, 36, 24, and 18 dpi using computer software. Image qualities of these five images (72, 48, 36, 24, and 18 dpi) were evaluated and given scores (4 = excellent; 3 = good; 2 = fair; and 1 = poor) by three radiation oncologists. An image data compression algorithm by the Joint Photographic Experts Group (JPEG) (not reversible and some information will be lost) was also evaluated. Results: The scores of digitized images with 72, 48, 36, 24, and 17 dpi resolution were 3.8 ± 0.3, 3.5 ± 0.3, 3.3 ± 0.5, 2.7 ± 0.5, and 1.6 ± 0.3, respectively. The quality of 36-dpi images were definitely worse compared to 72-dpi images, but were good enough as planning films. Digitized planning images with 72- and 36-dpi resolution requires about 800 and 200 KBytes, respectively. The JPEG compression algorithm produces little degradation in 36-dpi images at compression ratios of 5:1. Conclusion: The quality of digitized images with 36-dpi resolution was good enough as radiation-planning images and required 200 KBytes/image

  3. New modified map for digital image encryption and its performance

    Science.gov (United States)

    Suryadi, MT; Yus Trinity Irsan, Maria; Satria, Yudi

    2017-10-01

    Protection to classified digital data becomes so important in avoiding data manipulation and alteration. The focus of this paper is in data and information protection of digital images form. Protection is provided in the form of encrypted digital image. The encryption process uses a new map, {x}n+1=\\frac{rλ {x}n}{1+λ {(1-{x}n)}2}\\quad ({mod} 1), which is called MS map. This paper will show: the results of digital image encryption using MS map and how the performance is regarding the average time needed for encryption/decryption process; randomness of key stream sequence with NIST test, histogram analysis and goodness of fit test, quality of the decrypted image by PSNR, initial value sensitivity level, and key space. The results show that the average time of the encryption process is relatively same as the decryption process and it depends to types and sizes of the image. Cipherimage (encrypted image) is uniformly distributed since: it passes the goodness of fit test and also the histogram of the cipherimage is flat; key stream, that are generated by MS map, passes frequency (monobit) test, and runs test, which means the key stream is a random sequence; the decrypted image has same quality as the original image; and initial value sensitivity reaches 10-17, and key space reaches 3.24 × 10634. So, that encryption algorithm generated by MS map is more resistant to brute-force attack and known plaintext attack.

  4. The study of image processing of parallel digital signal processor

    International Nuclear Information System (INIS)

    Liu Jie

    2000-01-01

    The author analyzes the basic characteristic of parallel DSP (digital signal processor) TMS320C80 and proposes related optimized image algorithm and the parallel processing method based on parallel DSP. The realtime for many image processing can be achieved in this way

  5. Digital Data Processing of Images | Lotter | South African Medical ...

    African Journals Online (AJOL)

    Digital data processing was investigated to perform image processing. Image smoothing and restoration were explored and promising results obtained. The use of the computer, not only as a data management device, but as an important tool to render quantitative information, was illustrated by lung function determination.

  6. Quantification of image persistence in a digital angiography system

    International Nuclear Information System (INIS)

    Okkalides, D.P.; Raptou, P.D.

    1993-01-01

    Image persistence, as a characteristic of video imaging systems affecting the quality of fast moving fluoroscopic images, is shown to vary considerably. A simple quantitative method for measuring image persistence in a digital angiography system is presented, together with a series of image intensifier exposure-response curves. For the Saticon tube, used with the Siemens 3VA Digitron, it was found that persistence increased for low exposure rates and may increase to 31% at a 120 ms interval. In addition, a sharp increase in image persistence, from 8.3% to 33%, was observed within 18 months from installation of the system. (author)

  7. The FBI compression standard for digitized fingerprint images

    Energy Technology Data Exchange (ETDEWEB)

    Brislawn, C.M.; Bradley, J.N. [Los Alamos National Lab., NM (United States); Onyshczak, R.J. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Hopper, T. [Federal Bureau of Investigation, Washington, DC (United States)

    1996-10-01

    The FBI has formulated national standards for digitization and compression of gray-scale fingerprint images. The compression algorithm for the digitized images is based on adaptive uniform scalar quantization of a discrete wavelet transform subband decomposition, a technique referred to as the wavelet/scalar quantization method. The algorithm produces archival-quality images at compression ratios of around 15 to 1 and will allow the current database of paper fingerprint cards to be replaced by digital imagery. A compliance testing program is also being implemented to ensure high standards of image quality and interchangeability of data between different implementations. We will review the current status of the FBI standard, including the compliance testing process and the details of the first-generation encoder.

  8. The task of control digital image compression

    OpenAIRE

    TASHMANOV E.B.; МАМАTOV М.S.

    2014-01-01

    In this paper we consider the relationship of control tasks and image compression losses. The main idea of this approach is to allocate structural lines simplified image and further compress the selected data

  9. Conceptualising engagement with digital behaviour change interventions: a systematic review using principles from critical interpretive synthesis.

    Science.gov (United States)

    Perski, Olga; Blandford, Ann; West, Robert; Michie, Susan

    2017-06-01

    "Engagement" with digital behaviour change interventions (DBCIs) is considered important for their effectiveness. Evaluating engagement is therefore a priority; however, a shared understanding of how to usefully conceptualise engagement is lacking. This review aimed to synthesise literature on engagement to identify key conceptualisations and to develop an integrative conceptual framework involving potential direct and indirect influences on engagement and relationships between engagement and intervention effectiveness. Four electronic databases (Ovid MEDLINE, PsycINFO, ISI Web of Knowledge, ScienceDirect) were searched in November 2015. We identified 117 articles that met the inclusion criteria: studies employing experimental or non-experimental designs with adult participants explicitly or implicitly referring to engagement with DBCIs, digital games or technology. Data were synthesised using principles from critical interpretive synthesis. Engagement with DBCIs is conceptualised in terms of both experiential and behavioural aspects. A conceptual framework is proposed in which engagement with a DBCI is influenced by the DBCI itself (content and delivery), the context (the setting in which the DBCI is used and the population using it) and the behaviour that the DBCI is targeting. The context and "mechanisms of action" may moderate the influence of the DBCI on engagement. Engagement, in turn, moderates the influence of the DBCI on those mechanisms of action. In the research literature, engagement with DBCIs has been conceptualised in terms of both experience and behaviour and sits within a complex system involving the DBCI, the context of use, the mechanisms of action of the DBCI and the target behaviour.

  10. Interpretation of Radiological Images: Towards a Framework of Knowledge and Skills

    Science.gov (United States)

    van der Gijp, A.; van der Schaaf, M. F.; van der Schaaf, I. C.; Huige, J. C. B. M.; Ravesloot, C. J.; van Schaik, J. P. J.; ten Cate, Th. J.

    2014-01-01

    The knowledge and skills that are required for radiological image interpretation are not well documented, even though medical imaging is gaining importance. This study aims to develop a comprehensive framework of knowledge and skills, required for two-dimensional and multiplanar image interpretation in radiology. A mixed-method study approach was…

  11. Assembly and evaluation of a training module and dataset with feedback for improved interpretation of digital breast tomosynthesis examinations

    Science.gov (United States)

    Gur, David; Zuley, Margarita L.; Sumkin, Jules H.; Hakim, Christiane M.; Chough, Denise M.; Lovy, Linda; Sobran, Cynthia; Logue, Durwin; Zheng, Bin; Klym, Amy H.

    2012-02-01

    The FDA recently approved Digital Breast Tomosynthesis (DBT) for use in screening for the early detection of breast cancer. However, MQSA qualification for interpreting DBT through training was noted as important. Performance issues related to training are largely unknown. Therefore, we assembled a unique computerized training module to assess radiologists' performances before and after using the training module. Seventy-one actual baseline mammograms (no priors) with FFDM and DBT images were assembled to be read before and after training with the developed module. Fifty examinations of FFDM and DBT images enriched with positive findings were assembled for the training module. Depicted findings were carefully reviewed, summarized, and entered into a specially designed training database where findings were identified by case number and synchronized to the display of the related FFDM plus DBT examinations on a clinical workstation. Readers reported any findings using screening BIRADS (0, 1, or 2) followed by instantaneous feedback of the verified truth. Six radiologists participated in the study and reader average sensitivity and specificity were compared before and after training. Average sensitivity improved and specificity remained relatively the same after training. Performance changes may be affected by disease prevalence in the training set.

  12. The role of key image notes in CT imaging study interpretation.

    Science.gov (United States)

    Fan, Shu-Feng; Xu, Zhe; He, Hai-Qing; Ding, Jian-Rong; Teng, Gao-Jun

    2011-04-01

    The objective of the study was to investigate the clinical effects of CT key image notes (KIN) in the interpretation of a CT image study. All experiments were approved by the ethics committee of the local district. Six experienced radiologists were equally divided into routine reporting (RR) group and KIN reporting (KIN) group. CT scans of each 100 consecutive cases before and after using KIN technique were randomly selected, and the reports were made by group RR and KIN, respectively. All the reports were again reviewed 3 months later by both groups. All the results with using or not using KIN were interpreted and reinterpreted after 3 months by six clinicians, who were experienced in picture archiving and communication system (PACS) applications and were equally divided into the clinical routine report group and the clinical KIN report group, respectively. The results were statistically analyzed; the time used in making a report, the re-reading time 3 months later, and the consistency of imaging interpretation were determined and compared between groups. After using KIN technique, the time used in making a report was significantly increased (8.77 ± 5.27 vs. 10.53 ± 5.71 min, P < 0.05), the re-reading time was decreased (5.23 ± 2.54 vs. 4.99 ± 1.70 min, P < 0.05), the clinical interpretation and reinterpretation time after 3 months were decreased, and the consistency of the interpretation, reinterpretation between different doctors in different time was markedly improved (P < 0.01). CT report with KIN technique in PACS can significantly improve the consistency of the interpretation and efficiency in routine clinical work.

  13. Comparison of the automated evaluation of phantom mama in digital and digitalized images

    International Nuclear Information System (INIS)

    Santana, Priscila do Carmo

    2011-01-01

    Mammography is an essential tool for diagnosis and early detection of breast cancer if it is provided as a very good quality service. The process of evaluating the quality of radiographic images in general, and mammography in particular, can be much more accurate, practical and fast with the help of computer analysis tools. This work compare the automated methodology for the evaluation of scanned digital images the phantom mama. By applied the DIP method techniques was possible determine geometrical and radiometric images evaluated. The evaluated parameters include circular details of low contrast, contrast ratio, spatial resolution, tumor masses, optical density and background in Phantom Mama scanned and digitized images. The both results of images were evaluated. Through this comparison was possible to demonstrate that this automated methodology is presented as a promising alternative for the reduction or elimination of subjectivity in both types of images, but the Phantom Mama present insufficient parameters for spatial resolution evaluation. (author)

  14. Low-Light Image Enhancement Using Adaptive Digital Pixel Binning

    Directory of Open Access Journals (Sweden)

    Yoonjong Yoo

    2015-06-01

    Full Text Available This paper presents an image enhancement algorithm for low-light scenes in an environment with insufficient illumination. Simple amplification of intensity exhibits various undesired artifacts: noise amplification, intensity saturation, and loss of resolution. In order to enhance low-light images without undesired artifacts, a novel digital binning algorithm is proposed that considers brightness, context, noise level, and anti-saturation of a local region in the image. The proposed algorithm does not require any modification of the image sensor or additional frame-memory; it needs only two line-memories in the image signal processor (ISP. Since the proposed algorithm does not use an iterative computation, it can be easily embedded in an existing digital camera ISP pipeline containing a high-resolution image sensor.

  15. Image enhancement of digital periapical radiographs according to diagnostic tasks

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung [Dept. of Oral and Maxillofacial Radiology, Dankook University College of Dentistry, Cheonan (Korea, Republic of)

    2014-03-15

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  16. Image enhancement of digital periapical radiographs according to diagnostic tasks

    International Nuclear Information System (INIS)

    Choi, Jin Woo; Han, Won Jeong; Kim, Eun Kyung

    2014-01-01

    his study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task. Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale. There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01). Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

  17. Information quantity in a pixel of digital image

    OpenAIRE

    Kharinov, M.

    2014-01-01

    The paper is devoted to the problem of integer-valued estimating of information quantity in a pixel of digital image. The definition of an integer estimation of information quantity based on constructing of the certain binary hierarchy of pixel clusters is proposed. The methods for constructing hierarchies of clusters and generating of hierarchical sequences of image approximations that minimally differ from the image by a standard deviation are developed. Experimental results on integer-valu...

  18. Digital image processing as an aid in forensic medicine

    International Nuclear Information System (INIS)

    Buitrago-Tellez, C.; Wenz, W.; Friedrich, G.

    1992-01-01

    Radiology plays an important role in the identification of unknown corpses. Positive radiographic identification by comparison with antemortem films is an established technique in this setting. Technical defects together with non-well-preserved films make it sometimes difficult or even impossible to establish a confident comparison. Digital image processing after secondary digitalization of ante- and postmortem films represents an important development and aid in forensic medicine. The application of this method is demonstrated on a single case. (orig.) [de

  19. The role of moving images in the conference interpreting classroom

    OpenAIRE

    Susi Septaviana Rakhmawati

    2016-01-01

    This paper reports on the study of the student interpreters’ performance in conference interpreting classes in an Indonesian university when multimodal texts were provided as part of the teaching methods. It aims to answer how multimodal texts can influence interpreting performance among students. A case study design was used to allow an in-depth analysis of the students’ interpreting performance as the phenomenon described (Yin, 2003) using triangulation of data analysis. Observation, interv...

  20. Dual Level Digital Watermarking for Images

    Science.gov (United States)

    Singh, V. K.; Singh, A. K.

    2010-11-01

    More than 700 years ago, watermarks were used in Italy to indicate the paper brand and the mill that produced it. By the 18th century watermarks began to be used as anti counterfeiting measures on money and other documents.The term watermark was introduced near the end of the 18th century. It was probably given because the marks resemble the effects of water on paper. The first example of a technology similar to digital watermarking is a patent filed in 1954 by Emil Hembrooke for identifying music works. In 1988, Komatsu and Tominaga appear to be the first to use the term "digital watermarking". Consider the following hypothetical situations. You go to a shop, buy some goods and at the counter you are given a currency note you have never come across before. How do you verify that it is not counterfeit? Or say you go to a stationery shop and ask for a ream of bond paper. How do you verify that you have actually been given what you asked for? How does a philatelist verify the authenticity of a stamp? In all these cases, the watermark is used to authenticate. Watermarks have been in existence almost from the time paper has been in use. The impression created by the mesh moulds on the slurry of fibre and water remains on the paper. It serves to identify the manufacturer and thus authenticate the product without actually degrading the aesthetics and utility of the stock. It also makes forgery significantly tougher. Even today, important government and legal documents are watermarked. But what is watermarking, when it comes to digital data? Information is no longer present on a physical material but is represented as a series of zeros and ones. Duplication of information is achieved easily by just reproducing that combination of zeros and ones. How then can one protect ownership rights and authenticate data? The digital watermark is the same as that of conventional watermarks.

  1. Forensic Analysis of Digital Image Tampering

    Science.gov (United States)

    2004-12-01

    analysis of when each method fails, which Chapter 4 discusses. Finally, a test image containing an invisible watermark using LSB steganography is...2.2 – Example of invisible watermark using Steganography Software F5 ............. 8 Figure 2.3 – Example of copy-move image forgery [12...used to embed the hidden watermark is Steganography Software F5 version 11+ discussed in Section 2.2. Original JPEG Image – 580 x 435 – 17.4

  2. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

    1982-01-01

    A method of producing visible difference images derived from an x-ray image of an anatomical subject is described. X-rays are directed through the subject, and the image is converted into television fields comprising trains of analog video signals. The analog signals are converted into digital signals, which are then integrated over a predetermined time corresponding to several television fields. Difference video signals are produced by performing a subtraction between the ongoing video signals and the corresponding integrated signals, and are converted into visible television difference images representing changes in the x-ray image

  3. Experience with CANDID: Comparison algorithm for navigating digital image databases

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.; Cannon, M.

    1994-10-01

    This paper presents results from the authors experience with CANDID (Comparison Algorithm for Navigating Digital Image Databases), which was designed to facilitate image retrieval by content using a query-by-example methodology. A global signature describing the texture, shape, or color content is first computed for every image stored in a database, and a normalized similarity measure between probability density functions of feature vectors is used to match signatures. This method can be used to retrieve images from a database that are similar to a user-provided example image. Results for three test applications are included.

  4. Gastrointestinal digital fluoroscopy: Comparison of digital pulsed progressive readout images with 100-mm spot films

    International Nuclear Information System (INIS)

    Steiner, E.; Ferrucci, J.T.; Mueller, P.R.; Hahn, P.F.

    1987-01-01

    New developments in pulsed progressive readout (PPR) techniques allow short, extremely intense pulses of radiation to be used to produce a latent image which is then progressively read off the video camera and placed in 1,024 x 1,024-pixel digital storage. The resulting image is produced by a 10-20-msec pulse, reducing motion artifact to below that achievable with conventional spot film techniques, with a potential for 50%-95% dose reduction. This technique of reducing motion artifact is ideal for digital applications in gastrointestinal radiology. The authors compared 10-mm spot films and PPR digital radiographs of 86 anatomic regions in 43 patients undergoing routine barium enema and cholangiographic examinations. Parameters evaluated included display of normal and pathologic features, image contrast, and resolution. The benefits of the PPR technique include postprocessing to evaluate low contrast region and the potential for significant dose reduction

  5. Latin American image quality survey in digital mammography studies

    International Nuclear Information System (INIS)

    Mora, Patricia; Khoury, Helen; Bitelli, Regina; Quintero, Ana Rosa; Garay, Fernando; Garcia Aguilar, Juan; Gamarra, Mirtha; Ubeda, Carlos

    2017-01-01

    Under International Atomic Energy Agency regional programme TSA3 Radiological Protection of Patients in Medical Exposures, Latin American countries evaluated the image quality and glandular doses for digital mammography equipment with the purpose of seeing the performance and compliance with international recommendations. Totally, 24 institutions participated from Brazil, Chile, Costa Rica, El Salvador, Mexico, Paraguay and Venezuela. Signal difference noise ratio results showed for CR poor compliance with tolerances; better results were obtained for full-field digital mammography equipment. Mean glandular dose results showed that the majority of units have values below the acceptable dose levels. This joint Latin American project identified common problems: difficulty in working with digital images and lack of specific training by medical physicists from the region. Image quality is a main issue not being satisfied in accordance with international recommendations; optimisation processes in which the doses are increased should be very carefully done in order to improve early detection of any cancer signs. (authors)

  6. Application of Super-Resolution Image Reconstruction to Digital Holography

    Directory of Open Access Journals (Sweden)

    Zhang Shuqun

    2006-01-01

    Full Text Available We describe a new application of super-resolution image reconstruction to digital holography which is a technique for three-dimensional information recording and reconstruction. Digital holography has suffered from the low resolution of CCD sensors, which significantly limits the size of objects that can be recorded. The existing solution to this problem is to use optics to bandlimit the object to be recorded, which can cause the loss of details. Here super-resolution image reconstruction is proposed to be applied in enhancing the spatial resolution of digital holograms. By introducing a global camera translation before sampling, a high-resolution hologram can be reconstructed from a set of undersampled hologram images. This permits the recording of larger objects and reduces the distance between the object and the hologram. Practical results from real and simulated holograms are presented to demonstrate the feasibility of the proposed technique.

  7. Moiré Effect: Index and the Digital Image

    Directory of Open Access Journals (Sweden)

    Stella Baraklianou

    2014-10-01

    Full Text Available The moiré effect and phenomena are natural occurring geometric formations that appear during the super-position of grid structures. Most widely recognisable in colour printing practices, generally viewed on screens (computer and TV they are in most cases examples of interference within a signal or a code, unwanted visual mis-alignment. Especially in digital image capture, moiré patternings appear when a geometrically even pattern, like a fabric or close-up of fine texture, has an appearance of rippled water with blue or red hues of concentric circle formations. The intriguing pattern formation in this case points back not only to the mis-alignment of frequencies, but can be further seen as the intersection point of a speculative ontology for the index of the digital image. Moiré not only as a visually reproducible phenomenon or effect, but a field of vision that blurs the boundaries between analogue and digital, perception and affect, manifesting the photographic as a constant site of becoming, a site of immanence. The philosophy of Henri Bergson, Brian Massumi and Francois Laruelle will be explored alongside the moiré image and phenomenon, to see if there is such a speculative site underlining the becoming of the digital image and its repercussions in contemporary digital culture.

  8. Digital structural interpretation of mountain-scale photogrammetric 3D models (Kamnik Alps, Slovenia)

    Science.gov (United States)

    Dolžan, Erazem; Vrabec, Marko

    2015-04-01

    From the earliest days of geological science, mountainous terrains with their extreme topographic relief and sparse to non-existent vegetation were utilized to a great advantage for gaining 3D insight into geological structure. But whereas Alpine vistas may offer perfect panoramic views of geology, the steep mountain slopes and vertical cliffs make it very time-consuming and difficult (if not impossible) to acquire quantitative mapping data such as precisely georeferenced traces of geological boundaries and attitudes of structural planes. We faced this problem in mapping the central Kamnik Alps of northern Slovenia, which are built up from Mid to Late Triassic succession of carbonate rocks. Polyphase brittle tectonic evolution, monotonous lithology and the presence of temporally and spatially irregular facies boundary between bedded platform carbonates and massive reef limestones considerably complicate the structural interpretation of otherwise perfectly exposed, but hardly accessible massif. We used Agisoft Photoscan Structure-from-Motion photogrammetric software to process a series of overlapping high-resolution (~0.25 m ground resolution) vertical aerial photographs originally acquired by the Geodetic Authority of the Republic of Slovenia for surveying purposes, to derive very detailed 3D triangular mesh models of terrain and associated photographic textures. Phototextures are crucial for geological interpretation of the models as they provide additional levels of detail and lithological information which is not resolvable from geometrical mesh models alone. We then exported the models to Paradigm Gocad software to refine and optimize the meshing. Structural interpretation of the models, including mapping of traces and surfaces of faults and stratigraphic boundaries and determining dips of structural planes, was performed in MVE Move suite which offers a range of useful tools for digital mapping and interpretation. Photogrammetric model was complemented by

  9. Fisheye image rectification using spherical and digital distortion models

    Science.gov (United States)

    Li, Xin; Pi, Yingdong; Jia, Yanling; Yang, Yuhui; Chen, Zhiyong; Hou, Wenguang

    2018-02-01

    Fisheye cameras have been widely used in many applications including close range visual navigation and observation and cyber city reconstruction because its field of view is much larger than that of a common pinhole camera. This means that a fisheye camera can capture more information than a pinhole camera in the same scenario. However, the fisheye image contains serious distortion, which may cause trouble for human observers in recognizing the objects within. Therefore, in most practical applications, the fisheye image should be rectified to a pinhole perspective projection image to conform to human cognitive habits. The traditional mathematical model-based methods cannot effectively remove the distortion, but the digital distortion model can reduce the image resolution to some extent. Considering these defects, this paper proposes a new method that combines the physical spherical model and the digital distortion model. The distortion of fisheye images can be effectively removed according to the proposed approach. Many experiments validate its feasibility and effectiveness.

  10. Thinning an object boundary on digital image using pipelined algorithm

    International Nuclear Information System (INIS)

    Dewanto, S.; Aliyanta, B.

    1997-01-01

    In digital image processing, the thinning process to an object boundary is required to analyze the image structure with a measurement of parameter such as area, circumference of the image object. The process needs a sufficient large memory and time consuming if all the image pixels stored in the memory and the following process is done after all the pixels has ben transformed. pipelined algorithm can reduce the time used in the process. This algorithm uses buffer memory where its size can be adjusted. the next thinning process doesn't need to wait all the transformation of pixels. This paper described pipelined algorithm with some result on the use of the algorithm to digital image

  11. The role of camera-bundled image management software in the consumer digital imaging value chain

    Science.gov (United States)

    Mueller, Milton; Mundkur, Anuradha; Balasubramanian, Ashok; Chirania, Virat

    2005-02-01

    This research was undertaken by the Convergence Center at the Syracuse University School of Information Studies (www.digital-convergence.info). Project ICONICA, the name for the research, focuses on the strategic implications of digital Images and the CONvergence of Image management and image CApture. Consumer imaging - the activity that we once called "photography" - is now recognized as in the throes of a digital transformation. At the end of 2003, market researchers estimated that about 30% of the households in the U.S. and 40% of the households in Japan owned digital cameras. In 2004, of the 86 million new cameras sold (excluding one-time use cameras), a majority (56%) were estimated to be digital cameras. Sales of photographic film, while still profitable, are declining precipitously.

  12. Fluorescence Image Segmentation by using Digitally Reconstructed Fluorescence Images

    OpenAIRE

    Blumer, Clemens; Vivien, Cyprien; Oertner, Thomas G; Vetter, Thomas

    2011-01-01

    In biological experiments fluorescence imaging is used to image living and stimulated neurons. But the analysis of fluorescence images is a difficult task. It is not possible to conclude the shape of an object from fluorescence images alone. Therefore, it is not feasible to get good manual segmented nor ground truth data from fluorescence images. Supervised learning approaches are not possible without training data. To overcome this issues we propose to synthesize fluorescence images and call...

  13. A digital library for medical imaging activities

    Science.gov (United States)

    dos Santos, Marcelo; Furuie, Sérgio S.

    2007-03-01

    This work presents the development of an electronic infrastructure to make available a free, online, multipurpose and multimodality medical image database. The proposed infrastructure implements a distributed architecture for medical image database, authoring tools, and a repository for multimedia documents. Also it includes a peer-reviewed model that assures quality of dataset. This public repository provides a single point of access for medical images and related information to facilitate retrieval tasks. The proposed approach has been used as an electronic teaching system in Radiology as well.

  14. Digital image processing and analysis human and computer vision applications with CVIPtools

    CERN Document Server

    Umbaugh, Scott E

    2010-01-01

    Section I Introduction to Digital Image Processing and AnalysisDigital Image Processing and AnalysisOverviewImage Analysis and Computer VisionImage Processing and Human VisionKey PointsExercisesReferencesFurther ReadingComputer Imaging SystemsImaging Systems OverviewImage Formation and SensingCVIPtools SoftwareImage RepresentationKey PointsExercisesSupplementary ExercisesReferencesFurther ReadingSection II Digital Image Analysis and Computer VisionIntroduction to Digital Image AnalysisIntroductionPreprocessingBinary Image AnalysisKey PointsExercisesSupplementary ExercisesReferencesFurther Read

  15. Comprehensive evaluation of a digital imaging network

    International Nuclear Information System (INIS)

    Mun, S.K.; Benson, H.; Elliott, L.P.; Horii, S.

    1988-01-01

    The authors' institution has installed a comprehensive PACS network involving a dozen work stations and ten imaging systems with electronic archiving and teleradiology capability based on the CommView (AT and T) system and its fiberoptic network. Diagnostic reporting stations are placed in neuroradiology, abdominal imaging, general radiology, and ultrasound service. Other review stations are located in intensive care units, radiation medicine, the emergency room, and other sites. Clinical acceptance of such technology varies depending on a number of factors: image quality, image data volume, service style, and personal preference. The general acceptance depends on the work station performance, network response time, and work station environment. Clinical acceptance by radiologists and referring physicians was evaluated. The evaluation project included work-station performance, network performance, system interface, RIS interface, and development of training methods and implementation strategy for other sites. A cost analysis and a study of administrative impact are integral parts of the comprehensive evaluation project

  16. Digital tomosynthesis with an on-board kilovoltage imaging device

    International Nuclear Information System (INIS)

    Godfrey, Devon J.; Yin, F.-F.; Oldham, Mark; Yoo, Sua; Willett, Christopher

    2006-01-01

    Purpose: To generate on-board digital tomosynthesis (DTS) and reference DTS images for three-dimensional image-guided radiation therapy (IGRT) as an alternative to conventional portal imaging or on-board cone-beam computed tomography (CBCT). Methods and Materials: Three clinical cases (prostate, head-and-neck, and liver) were selected to illustrate the capabilities of on-board DTS for IGRT. Corresponding reference DTS images were reconstructed from digitally reconstructed radiographs computed from planning CT image sets. The effect of scan angle on DTS slice thickness was examined by computing the mutual information between coincident CBCT and DTS images, as the DTS scan angle was varied from 0 o to 165 o . A breath-hold DTS acquisition strategy was implemented to remove respiratory motion artifacts. Results: Digital tomosynthesis slices appeared similar to coincident CBCT planes and yielded substantially more anatomic information than either kilovoltage or megavoltage radiographs. Breath-hold DTS acquisition improved soft-tissue visibility by suppressing respiratory motion. Conclusions: Improved bony and soft-tissue visibility in DTS images is likely to improve target localization compared with radiographic verification techniques and might allow for daily localization of a soft-tissue target. Breath-hold DTS is a potential alternative to on-board CBCT for sites prone to respiratory motion

  17. Computing eye gaze metrics for the automatic assessment of radiographer performance during X-ray image interpretation.

    Science.gov (United States)

    McLaughlin, Laura; Bond, Raymond; Hughes, Ciara; McConnell, Jonathan; McFadden, Sonyia

    2017-09-01

    To investigate image interpretation performance by diagnostic radiography students, diagnostic radiographers and reporting radiographers by computing eye gaze metrics using eye tracking technology. Three groups of participants were studied during their interpretation of 8 digital radiographic images including the axial and appendicular skeleton, and chest (prevalence of normal images was 12.5%). A total of 464 image interpretations were collected. Participants consisted of 21 radiography students, 19 qualified radiographers and 18 qualified reporting radiographers who were further qualified to report on the musculoskeletal (MSK) system. Eye tracking data was collected using the Tobii X60 eye tracker and subsequently eye gaze metrics were computed. Voice recordings, confidence levels and diagnoses provided a clear demonstration of the image interpretation and the cognitive processes undertaken by each participant. A questionnaire afforded the participants an opportunity to offer information on their experience in image interpretation and their opinion on the eye tracking technology. Reporting radiographers demonstrated a 15% greater accuracy rate (p≤0.001), were more confident (p≤0.001) and took a mean of 2.4s longer to clinically decide on all features compared to students. Reporting radiographers also had a 15% greater accuracy rate (p≤0.001), were more confident (p≤0.001) and took longer to clinically decide on an image diagnosis (p=0.02) than radiographers. Reporting radiographers had a greater mean fixation duration (p=0.01), mean fixation count (p=0.04) and mean visit count (p=0.04) within the areas of pathology compared to students. Eye tracking patterns, presented within heat maps, were a good reflection of group expertise and search strategies. Eye gaze metrics such as time to first fixate, fixation count, fixation duration and visit count within the areas of pathology were indicative of the radiographer's competency. The accuracy and confidence of

  18. Digital imaging improves upright stereotactic core biopsy of mammographic microcalcifications

    International Nuclear Information System (INIS)

    Whitlock, J.P.L.; Evans, A.J.; Burrell, H.C.; Pinder, S.E.; Ellis, I.O.; Blamey, R.W.; Wilson, A.R.M.

    2000-01-01

    AIM: This comparative study was carried out to assess the effect of using digital images compared to conventional film-screen mammography on the accuracy of core biopsy of microcalcifications using upright stereotactic equipment. MATERIALS AND METHODS: The biopsy results from a consecutive series of 104 upright stereotactic 14-gauge core biopsies performed with conventional X-ray (Group A) were compared with 40 biopsies carried out using stereotaxis with digital imaging (Group B). In all cases specimen radiography was performed and analysed for the presence of calcifications. Pathological correlation was then carried out with needle and surgical histology. RESULTS: The use of digital add-on equipment increased the radiographic calcification retrieval rate from 55 to 85% (P < 0.005). The absolute sensitivity of core biopsy in pure ductal carcinoma in situ (DCIS) cases rose from 34 to 69% (P < 0.03), with the complete sensitivity increasing from 52 to 94% (P < 0.005). For DCIS with or without an invasive component the absolute sensitivity rose from 41 to 67% (P = 0.052), while the complete sensitivity was 59% before and 86% after the introduction of digital imaging (P < 0.04). CONCLUSION: Digital equipment improves the performance of upright stereotactic core biopsy of microcalcifications, giving a significantly increased success rate in accurately obtaining calcifications. This leads to an improvement in absolute and complete sensitivity of core biopsy when diagnosing DCIS. Whitlock, J.P.L. (2000)

  19. Computer processing of the scintigraphic image using digital filtering techniques

    International Nuclear Information System (INIS)

    Matsuo, Michimasa

    1976-01-01

    The theory of digital filtering was studied as a method for the computer processing of scintigraphic images. The characteristics and design techniques of finite impulse response (FIR) digital filters with linear phases were examined using the z-transform. The conventional data processing method, smoothing, could be recognized as one kind of linear phase FIR low-pass digital filtering. Ten representatives of FIR low-pass digital filters with various cut-off frequencies were scrutinized from the frequency domain in one-dimension and two-dimensions. These filters were applied to phantom studies with cold targets, using a Scinticamera-Minicomputer on-line System. These studies revealed that the resultant images had a direct connection with the magnitude response of the filter, that is, they could be estimated fairly well from the frequency response of the digital filter used. The filter, which was estimated from phantom studies as optimal for liver scintigrams using 198 Au-colloid, was successfully applied in clinical use for detecting true cold lesions and, at the same time, for eliminating spurious images. (J.P.N.)

  20. CANDID: Comparison algorithm for navigating digital image databases

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, P.M.; Cannon, T.M.

    1994-02-21

    In this paper, we propose a method for calculating the similarity between two digital images. A global signature describing the texture, shape, or color content is first computed for every image stored in a database, and a normalized distance between probability density functions of feature vectors is used to match signatures. This method can be used to retrieve images from a database that are similar to an example target image. This algorithm is applied to the problem of search and retrieval for database containing pulmonary CT imagery, and experimental results are provided.

  1. Uses of software in digital image analysis: a forensic report

    Science.gov (United States)

    Sharma, Mukesh; Jha, Shailendra

    2010-02-01

    Forensic image analysis is required an expertise to interpret the content of an image or the image itself in legal matters. Major sub-disciplines of forensic image analysis with law enforcement applications include photo-grammetry, photographic comparison, content analysis and image authentication. It has wide applications in forensic science range from documenting crime scenes to enhancing faint or indistinct patterns such as partial fingerprints. The process of forensic image analysis can involve several different tasks, regardless of the type of image analysis performed. Through this paper authors have tried to explain these tasks, which are described in to three categories: Image Compression, Image Enhancement & Restoration and Measurement Extraction. With the help of examples like signature comparison, counterfeit currency comparison and foot-wear sole impression using the software Canvas and Corel Draw.

  2. Integrating digital topology in image-processing libraries.

    Science.gov (United States)

    Lamy, Julien

    2007-01-01

    This paper describes a method to integrate digital topology informations in image-processing libraries. This additional information allows a library user to write algorithms respecting topological constraints, for example, a seed fill or a skeletonization algorithm. As digital topology is absent from most image-processing libraries, such constraints cannot be fulfilled. We describe and give code samples for all the structures necessary for this integration, and show a use case in the form of a homotopic thinning filter inside ITK. The obtained filter can be up to a hundred times as fast as ITK's thinning filter and works for any image dimension. This paper mainly deals of integration within ITK, but can be adapted with only minor modifications to other image-processing libraries.

  3. Post-processing of digital images.

    Science.gov (United States)

    Perrone, Luca; Politi, Marco; Foschi, Raffaella; Masini, Valentina; Reale, Francesca; Costantini, Alessandro Maria; Marano, Pasquale

    2003-01-01

    Post-processing of bi- and three-dimensional images plays a major role for clinicians and surgeons in both diagnosis and therapy. The new spiral (single and multislice) CT and MRI machines have allowed better quality of images. With the associated development of hardware and software, post-processing has become indispensable in many radiologic applications in order to address precise clinical questions. In particular, in CT the acquisition technique is fundamental and should be targeted and optimized to obtain good image reconstruction. Multiplanar reconstructions ensure simple, immediate display of sections along different planes. Three-dimensional reconstructions include numerous procedures: multiplanar techniques as maximum intensity projections (MIP); surface rendering techniques as the Shaded Surface Display (SSD); volume techniques as the Volume Rendering Technique; techniques of virtual endoscopy. In surgery computer-aided techniques as the neuronavigator, which with information provided by neuroimaging helps the neurosurgeon in simulating and performing the operation, are extremely interesting.

  4. Matching rendered and real world images by digital image processing

    Science.gov (United States)

    Mitjà, Carles; Bover, Toni; Bigas, Miquel; Escofet, Jaume

    2010-05-01

    Recent advances in computer-generated images (CGI) have been used in commercial and industrial photography providing a broad scope in product advertising. Mixing real world images with those rendered from virtual space software shows a more or less visible mismatching between corresponding image quality performance. Rendered images are produced by software which quality performance is only limited by the resolution output. Real world images are taken with cameras with some amount of image degradation factors as lens residual aberrations, diffraction, sensor low pass anti aliasing filters, color pattern demosaicing, etc. The effect of all those image quality degradation factors can be characterized by the system Point Spread Function (PSF). Because the image is the convolution of the object by the system PSF, its characterization shows the amount of image degradation added to any taken picture. This work explores the use of image processing to degrade the rendered images following the parameters indicated by the real system PSF, attempting to match both virtual and real world image qualities. The system MTF is determined by the slanted edge method both in laboratory conditions and in the real picture environment in order to compare the influence of the working conditions on the device performance; an approximation to the system PSF is derived from the two measurements. The rendered images are filtered through a Gaussian filter obtained from the taking system PSF. Results with and without filtering are shown and compared measuring the contrast achieved in different final image regions.

  5. Operational digital image processing within the Bureau of Land Management

    International Nuclear Information System (INIS)

    Work, E.A.; Story, M.

    1991-01-01

    An overview of the use of operational digital image processing at the U.S. Bureau of Land Management (BLM) is presented. The BLM digital image analysis facility for the processing and analysis of aerial photography and satellite data is described, and its role within the Bureau's operational structure is explained. Attention is given to examples of BLM digital data analysis projects that have utilized Landsat (MSS and TM), NOAA-AVHRR, or SPOT data. These projects include: landcover mapping to assist land use planning or special projects; monitoring of wilderness units to detect unauthorized activities; stratification aid for detailed field inventories; identification/quantification of unauthorized use (agricultural and mineral trespass); and fire fuels mapping and updates. 3 refs

  6. Digital image comparison by subtracting contextual transformations—percentile rank order differentiation

    Science.gov (United States)

    Wehde, M. E.

    1995-01-01

    The common method of digital image comparison by subtraction imposes various constraints on the image contents. Precise registration of images is required to assure proper evaluation of surface locations. The attribute being measured and the calibration and scaling of the sensor are also important to the validity and interpretability of the subtraction result. Influences of sensor gains and offsets complicate the subtraction process. The presence of any uniform systematic transformation component in one of two images to be compared distorts the subtraction results and requires analyst intervention to interpret or remove it. A new technique has been developed to overcome these constraints. Images to be compared are first transformed using the cumulative relative frequency as a transfer function. The transformed images represent the contextual relationship of each surface location with respect to all others within the image. The process of differentiating between the transformed images results in a percentile rank ordered difference. This process produces consistent terrain-change information even when the above requirements necessary for subtraction are relaxed. This technique may be valuable to an appropriately designed hierarchical terrain-monitoring methodology because it does not require human participation in the process.

  7. Digital image intensifier radiography: A new diagnostic procedure in traumatology?

    International Nuclear Information System (INIS)

    Schmidt, C.; Deininger, H.K.; Staedtische Kliniken Darmstadt

    1990-01-01

    Digital image intensifier radiography visualises all traumatological changes of clinical relevance and can therefore be used in traumatology. However, the quality of conventional radiographs cannot be attained as yet. Radiation exposure is markedly reduced, and radiographs are obtained directly after exposure, so that this is an extremely rapid radiographic procedure. Images can be quickly transmitted by video cable to the relevant departments and working places. (orig.) [de

  8. Medical students' cognitive load in volumetric image interpretation : Insights from human-computer interaction and eye movements

    NARCIS (Netherlands)

    Stuijfzand, Bobby G.; Van Der Schaaf, Marieke F.; Kirschner, Femke C.; Ravesloot, Cécile J.; Van Der Gijp, Anouk; Vincken, Koen L.

    2016-01-01

    Medical image interpretation is moving from using 2D- to volumetric images, thereby changing the cognitive and perceptual processes involved. This is expected to affect medical students' experienced cognitive load, while learning image interpretation skills. With two studies this explorative

  9. Compression of the digitized X-ray images

    International Nuclear Information System (INIS)

    Terae, Satoshi; Miyasaka, Kazuo; Fujita, Nobuyuki; Takamura, Akio; Irie, Goro; Inamura, Kiyonari.

    1987-01-01

    Medical images are using an increased amount of space in the hospitals, while they are not accessed easily. Thus, suitable data filing system and precise data compression will be necessitated. Image quality was evaluated before and after image data compression, using local filing system (MediFile 1000, NEC Co.) and forty-seven modes of compression parameter. For this study X-ray images of 10 plain radiographs and 7 contrast examinations were digitized using a film reader of CCD sensor in MediFile 1000. Those images were compressed into forty-seven kinds of image data to save in an optical disc and then the compressed images were reconstructed. Each reconstructed image was compared with non-compressed images in respect to several regions of our interest by four radiologists. Compression and extension of radiological images were promptly made by employing the local filing system. Image quality was much more affected by the ratio of data compression than by the mode of parameter itself. In another word, the higher compression ratio became, the worse the image quality were. However, image quality was not significantly degraded until the compression ratio was about 15: 1 on plain radiographs and about 8: 1 on contrast studies. Image compression by this technique will be admitted by diagnostic radiology. (author)

  10. Aliasing effects in digital images of line-pair phantoms

    International Nuclear Information System (INIS)

    Albert, Michael; Beideck, Daniel J.; Bakic, Predrag R.; Maidment, Andrew D.A.

    2002-01-01

    Line-pair phantoms are commonly used for evaluating screen-film systems. When imaged digitally, aliasing effects give rise to additional periodic patterns. This paper examines one such effect that medical physicists are likely to encounter, and which can be used as an indicator of super-resolution

  11. Application of digital image correlation method for analysing crack ...

    Indian Academy of Sciences (India)

    centrated strain by imitating the treatment of micro-cracks using the finite element ... water and moisture to penetrate the concrete leading to serious rust of the ... The correlations among various grey values of digital images are analysed for ...

  12. Evaluating fracture healing using digital x-ray image analysis

    African Journals Online (AJOL)

    2011-03-02

    Mar 2, 2011 ... with intensive imaging and modelling.6 dual energy X-ray ... techniques due to their high-quality digital output in ... the bone in the loaded X-ray is at an angular offset due to .... The research described in this article was carried ...

  13. A computer program for planimetric analysis of digitized images

    DEFF Research Database (Denmark)

    Lynnerup, N; Lynnerup, O; Homøe, P

    1992-01-01

    bones as seen on X-rays. By placing the X-rays on a digitizer tablet and tracing the outline of the cell system, the area was calculated by the program. The calculated data and traced images could be stored and printed. The program is written in BASIC; necessary hardware is an IBM-compatible personal...

  14. Application of digital-image-correlation techniques in analysing ...

    Indian Academy of Sciences (India)

    Basis theory of strain analysis using the digital image correlation method .... Type 304N Stainless Steel (Modulus of Elasticity = 193 MPa, Tensile Yield .... also proves the accuracy of the qualitative analyses by using the DIC ... We thank the National Science Council of Taiwan for supporting this research through grant. No.

  15. Digital image monitoring to optimise safe port operation

    CSIR Research Space (South Africa)

    Phelp, D

    2008-11-01

    Full Text Available This paper describes a low cost video system ‘Harbour Watch’, which can be used to support safe port operations, especially in developing countries. Preset digital images are geo-referenced and then archived for later analysis to improve...

  16. Determining storage related egg quality changes via digital image ...

    African Journals Online (AJOL)

    Area and length measurements related to exterior and interior egg quality were determined by digital image analysis. In general, excluding the outer thin albumen area, all of the area measurements such as total egg content area and inner thick albumen area were larger in stored eggs than in fresh eggs (52.28 vs.

  17. Problems and image processing in X-ray film digitization

    International Nuclear Information System (INIS)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru

    1992-01-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author)

  18. Problems and image processing in X-ray film digitization

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Syousuke; Yoshita, Hisashi; Kuranishi, Makoto; Itoh, Hajime; Mori, Kouichi; Konishi, Minoru (Toyama Medical and Pharmaceutical Univ. (Japan). Hospital)

    1992-11-01

    Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but could not understand the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a high density grid and adoption of a low-pass filter were useful in impending the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future-prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described. (author).

  19. Digital image processing of mandibular trabeculae on radiographs

    Energy Technology Data Exchange (ETDEWEB)

    Ogino, Toshi

    1987-06-01

    The present study was aimed to reveal the texture patterns of the radiographs of the mandibular trabeculae by digital image processing. The 32 cases of normal subjects and the 13 cases of patients with mandibular diseases of ameloblastoma, primordial cysts, squamous cell carcinoma and odontoma were analyzed by their intra-oral radiographs in the right premolar regions. The radiograms were digitized by the use of a drum scanner densitometry method. The input radiographic images were processed by a histogram equalization method. The result are as follows : First, the histogram equalization method enhances the image contrast of the textures. Second, the output images of the textures for normal mandible-trabeculae radiograms are of network pattern in nature. Third, the output images for the patients are characterized by the non-network pattern and replaced by the patterns of the fabric texture, intertwined plants (karakusa-pattern), scattered small masses and amorphous texture. Thus, these results indicates that the present digital image system is expected to be useful for revealing the texture patterns of the radiographs and in the future for the texture analysis of the clinical radiographs to obtain quantitative diagnostic findings.

  20. A survey of passive technology for digital image forensics

    Institute of Scientific and Technical Information of China (English)

    LUO Weiqi; QU Zhenhua; PAN Feng; HUANG Jiwu

    2007-01-01

    Over the past years,digital images have been widely used in the Internet and other applications.Whilst image processing techniques are developing at a rapid speed,tampering with digital images without leaving any obvious traces becomes easier and easier.This may give rise to some problems such as image authentication.A new passive technology for image forensics has evolved quickly during the last few years.Unlike the signature-based or watermark-based methods,the new technology does not need any signature generated or watermark embedded in advance,it assumes that different imaging devices or processing would introduce different inherent patterns into the output images.These underlying patterns are consistent in the original untampered images and would be altered after some kind of manipulations.Thus,they can be used as evidence for image source identification and alteration detection.In this paper,we will discuss this new forensics technology and give an overview of the prior literatures.Some concluding remarks are made about the state of the art and the challenges in this novel technology.

  1. Ultrasonic imaging in LMFBRs using digital techniques

    International Nuclear Information System (INIS)

    Fothergill, J.R.; McKnight, J.A.; Barrett, L.M.

    Ultrasonic technology for providing images of components immersed in the opaque sodium of LMFBRs is being developed at RNL. For many years the application has been restricted by the unavailability of convenient ultrasonic sources and receivers capable of withstanding the reactor environment. Until recently, for example, important ultrasonic instrument design, such as for future sweep arms, had to be based on waveguided ultrasonics. RNL have developed an economic immersible transducer that can be deployed during reactor shut-down, when many demands for ultrasonic imaging are made. The transducer design is not suited at present to the sophisticated techniques of phased arrays; consequently image formation must depend on the physical scanning of a target using one or more transducers in pulse-echo mode. The difficulties of access into a fast reactor impose further restrictions. Some applications may involve easy scanning sequences, thus the sweep arm requires only a rotation to provide a map of the reactor core area. For a more detailed examination of the same area, however, special engineering solutions are needed to provide a more satisfactory scanning sequence. A compromise solution involving the rotating shield movement is being used for a PFR experiment to examine a limited area of the core. (author)

  2. Digital Intraoral Imaging Re-Exposure Rates of Dental Students.

    Science.gov (United States)

    Senior, Anthea; Winand, Curtis; Ganatra, Seema; Lai, Hollis; Alsulfyani, Noura; Pachêco-Pereira, Camila

    2018-01-01

    A guiding principle of radiation safety is ensuring that radiation dosage is as low as possible while yielding the necessary diagnostic information. Intraoral images taken with conventional dental film have a higher re-exposure rate when taken by dental students compared to experienced staff. The aim of this study was to examine the prevalence of and reasons for re-exposure of digital intraoral images taken by third- and fourth-year dental students in a dental school clinic. At one dental school in Canada, the total number of intraoral images taken by third- and fourth-year dental students, re-exposures, and error descriptions were extracted from patient clinical records for an eight-month period (September 2015 to April 2016). The data were categorized to distinguish between digital images taken with solid-state sensors or photostimulable phosphor plates (PSP). The results showed that 9,397 intraoral images were made, and 1,064 required re-exposure. The most common error requiring re-exposure for bitewing images was an error in placement of the receptor too far mesially or distally (29% for sensors and 18% for PSP). The most common error requiring re-exposure for periapical images was inadequate capture of the periapical area (37% for sensors and 6% for PSP). A retake rate of 11% was calculated, and the common technique errors causing image deficiencies were identified. Educational intervention can now be specifically designed to reduce the retake rate and radiation dose for future patients.

  3. The Digital Image Processing And Quantitative Analysis In Microscopic Image Characterization

    International Nuclear Information System (INIS)

    Ardisasmita, M. Syamsa

    2000-01-01

    Many electron microscopes although have produced digital images, but not all of them are equipped with a supporting unit to process and analyse image data quantitatively. Generally the analysis of image has to be made visually and the measurement is realized manually. The development of mathematical method for geometric analysis and pattern recognition, allows automatic microscopic image analysis with computer. Image processing program can be used for image texture and structure periodic analysis by the application of Fourier transform. Because the development of composite materials. Fourier analysis in frequency domain become important for measure the crystallography orientation. The periodic structure analysis and crystal orientation are the key to understand many material properties like mechanical strength. stress, heat conductivity, resistance, capacitance and other material electric and magnetic properties. In this paper will be shown the application of digital image processing in microscopic image characterization and analysis in microscopic image

  4. Optimization of digital image processing to determine quantum dots' height and density from atomic force microscopy.

    Science.gov (United States)

    Ruiz, J E; Paciornik, S; Pinto, L D; Ptak, F; Pires, M P; Souza, P L

    2018-01-01

    An optimized method of digital image processing to interpret quantum dots' height measurements obtained by atomic force microscopy is presented. The method was developed by combining well-known digital image processing techniques and particle recognition algorithms. The properties of quantum dot structures strongly depend on dots' height, among other features. Determination of their height is sensitive to small variations in their digital image processing parameters, which can generate misleading results. Comparing the results obtained with two image processing techniques - a conventional method and the new method proposed herein - with the data obtained by determining the height of quantum dots one by one within a fixed area, showed that the optimized method leads to more accurate results. Moreover, the log-normal distribution, which is often used to represent natural processes, shows a better fit to the quantum dots' height histogram obtained with the proposed method. Finally, the quantum dots' height obtained were used to calculate the predicted photoluminescence peak energies which were compared with the experimental data. Again, a better match was observed when using the proposed method to evaluate the quantum dots' height. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Digital image correlation based on a fast convolution strategy

    Science.gov (United States)

    Yuan, Yuan; Zhan, Qin; Xiong, Chunyang; Huang, Jianyong

    2017-10-01

    In recent years, the efficiency of digital image correlation (DIC) methods has attracted increasing attention because of its increasing importance for many engineering applications. Based on the classical affine optical flow (AOF) algorithm and the well-established inverse compositional Gauss-Newton algorithm, which is essentially a natural extension of the AOF algorithm under a nonlinear iterative framework, this paper develops a set of fast convolution-based DIC algorithms for high-efficiency subpixel image registration. Using a well-developed fast convolution technique, the set of algorithms establishes a series of global data tables (GDTs) over the digital images, which allows the reduction of the computational complexity of DIC significantly. Using the pre-calculated GDTs, the subpixel registration calculations can be implemented efficiently in a look-up-table fashion. Both numerical simulation and experimental verification indicate that the set of algorithms significantly enhances the computational efficiency of DIC, especially in the case of a dense data sampling for the digital images. Because the GDTs need to be computed only once, the algorithms are also suitable for efficiently coping with image sequences that record the time-varying dynamics of specimen deformations.

  6. Real-time digital X-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.; Kruger, R.A.; Houk, T.L.

    1979-01-01

    A diagnostic anatomical X-ray apparatus comprising a converter and a television camera for converting an X-ray image of a subject into a series of television fields of video signals is described in detail. A digital memory system stores and integrates the video signals over a time interval corresponding to a plurality of successive television fields. The integrated video signals are recovered from storage and fed to a digital or analogue subtractor, the resulting output being displayed on a television monitor. Thus the display represents on-going changes in the anatomical X-ray image. In a modification, successive groups of fields are stored and integrated in three memories, cyclically, and subtractions are performed between successive pieces of integrated signals to provide a display of successive alterations in the X-ray image. For investigations of the heart, the integrating interval should be of the order of one cardiac cycle. (author)

  7. Smartphone based scalable reverse engineering by digital image correlation

    Science.gov (United States)

    Vidvans, Amey; Basu, Saurabh

    2018-03-01

    There is a need for scalable open source 3D reconstruction systems for reverse engineering. This is because most commercially available reconstruction systems are capital and resource intensive. To address this, a novel reconstruction technique is proposed. The technique involves digital image correlation based characterization of surface speeds followed by normalization with respect to angular speed during rigid body rotational motion of the specimen. Proof of concept of the same is demonstrated and validated using simulation and empirical characterization. Towards this, smart-phone imaging and inexpensive off the shelf components along with those fabricated additively using poly-lactic acid polymer with a standard 3D printer are used. Some sources of error in this reconstruction methodology are discussed. It is seen that high curvatures on the surface suppress accuracy of reconstruction. Reasons behind this are delineated in the nature of the correlation function. Theoretically achievable resolution during smart-phone based 3D reconstruction by digital image correlation is derived.

  8. Chest imaging with dual-energy substraction digital tomosynthesis

    International Nuclear Information System (INIS)

    Sone, S.; Kasuga, T.; Sakai, F.; Hirano, H.; Kubo, K.; Morimoto, M.; Takemura, K.; Hosoba, M.

    1993-01-01

    Dual-energy subtraction digital tomosynthesis with pulsed X-ray and rapid kV switching was used to examine calcifications in pulmonary lesions. The digital tomosynthesis system used included a conventional fluororadiographic TV unit with linear tomographic capabilities, a high resolution videocamera, and an image processing unit. Low-voltage, high voltage, and soft tissue subtracted or bone subtracted tomograms of any desired layer height were reconstructed from the image data acquired during a single tomographic swing. Calcifications, as well as their characteristics and distribution in pulmonary lesions, were clearly shown. The images also permitted discrimination of calcifications from dense fibrotic lesions. This technique was effective in demonstrating calcifications together with a solitary mass or disseminated nodules. (orig.)

  9. An automated digital imaging system for environmental monitoring applications

    Science.gov (United States)

    Bogle, Rian; Velasco, Miguel; Vogel, John

    2013-01-01

    Recent improvements in the affordability and availability of high-resolution digital cameras, data loggers, embedded computers, and radio/cellular modems have advanced the development of sophisticated automated systems for remote imaging. Researchers have successfully placed and operated automated digital cameras in remote locations and in extremes of temperature and humidity, ranging from the islands of the South Pacific to the Mojave Desert and the Grand Canyon. With the integration of environmental sensors, these automated systems are able to respond to local conditions and modify their imaging regimes as needed. In this report we describe in detail the design of one type of automated imaging system developed by our group. It is easily replicated, low-cost, highly robust, and is a stand-alone automated camera designed to be placed in remote locations, without wireless connectivity.

  10. Longitudinal and transverse digital image reconstruction with a tomographic scanner

    International Nuclear Information System (INIS)

    Pickens, D.R.; Price, R.R.; Erickson, J.J.; Patton, J.A.; Partain, C.L.; Rollo, F.D.

    1981-01-01

    A Siemens Gammasonics PHO/CON-192 Multiplane Imager is interfaced to a digital computer for the purpose of performing tomographic reconstructions from the data collected during a single scan. Data from the two moving gamma cameras as well as camera position information are sent to the computer by an interface designed in the authors' laboratory. Backprojection reconstruction is implemented by the computer. Longitudinal images in whole-body format as well as smaller formats are reconstructed for up to six planes simultaneously from the list mode data. Transverse reconstructions are demonstrated for 201 T1 myocardial scans. Post-reconstruction deconvolution processing to remove the blur artifact (characteristic of focal plane tomography) is applied to a multiplane phantom. Digital data acquisition of data and reconstruction of images are practical, and can extend the usefulness of the machine when compared with the film output (author)

  11. Real-time digital x-ray subtraction imaging

    International Nuclear Information System (INIS)

    Mistretta, C.A.

    1982-01-01

    The invention provides a method of producing visible difference images derived from an X-ray image of an anatomical subject, comprising the steps of directing X-rays through the anatomical subject for producing an image, converting the image into television fields comprising trains of on-going video signals, digitally storing and integrating the on-going video signals over a time interval corresponding to several successive television fields and thereby producing stored and integrated video signals, recovering the video signals from storage and producing integrated video signals, producing video difference signals by performing a subtraction between the integrated video signals and the on-going video signals outside the time interval, and converting the difference signals into visible television difference images representing on-going changes in the X-ray image

  12. A study of transverse image reconstruction with digital subtraction angiography

    International Nuclear Information System (INIS)

    Sakamoto, Kiyoshi; Kotoura, Noriko; Terasawa, Yuuji; Oda, Masahiko; Gotou, Hiroshi; Nasada, Toshiya; Tanooka, Masao

    1995-01-01

    For digital subtraction angiography (DSA) with C-type equipment, it is possible to radiate an X-ray during rotation and to collect data at different angular settings. We tried to reconstruct transverse image from data obtained by scanning DSA images at different angular settings. 88 projection data were obtained by rotating the object at 180deg during radiation. Reconstruction was made using the convolution method with pixel value distribution for each projection. Similarly, the image quality of the reconstructed images were compared with the unsubtracted and subtracted ones. In case a part object was outside the calculating region, artifacts were generally produced. However, the artifacts were reduced by subtracting the background from the image. In addition, the cupping phenomenon caused by beam hardening was relaxed and high-quality imaging could be achieved. This method will become even more effective, if we will use it with selective angiography in which the limited area is enhanced. (author)

  13. Digital signal and image processing using Matlab

    CERN Document Server

    Blanchet , Gérard

    2015-01-01

    The most important theoretical aspects of Image and Signal Processing (ISP) for both deterministic and random signals, the theory being supported by exercises and computer simulations relating to real applications.   More than 200 programs and functions are provided in the MATLAB® language, with useful comments and guidance, to enable numerical experiments to be carried out, thus allowing readers to develop a deeper understanding of both the theoretical and practical aspects of this subject.  Following on from the first volume, this second installation takes a more practical stance, provi

  14. On the detection of pornographic digital images

    Science.gov (United States)

    Schettini, Raimondo; Brambilla, Carla; Cusano, Claudio; Ciocca, Gianluigi

    2003-06-01

    The paper addresses the problem of distinguishing between pornographic and non-pornographic photographs, for the design of semantic filters for the web. Both, decision forests of trees built according to CART (Classification And Regression Trees) methodology and Support Vectors Machines (SVM), have been used to perform the classification. The photographs are described by a set of low-level features, features that can be automatically computed simply on gray-level and color representation of the image. The database used in our experiments contained 1500 photographs, 750 of which labeled as pornographic on the basis of the independent judgement of several viewers.

  15. Digital signal and image processing using MATLAB

    CERN Document Server

    Blanchet , Gérard

    2014-01-01

    This fully revised and updated second edition presents the most important theoretical aspects of Image and Signal Processing (ISP) for both deterministic and random signals. The theory is supported by exercises and computer simulations relating to real applications. More than 200 programs and functions are provided in the MATLABÒ language, with useful comments and guidance, to enable numerical experiments to be carried out, thus allowing readers to develop a deeper understanding of both the theoretical and practical aspects of this subject. This fully revised new edition updates : - the

  16. A generic, time-resolved, integrated digital image correlation, identification approach

    NARCIS (Netherlands)

    Hoefnagels, J.P.M.; Neggers, J.; Blaysat, Benoît; Hild, François; Geers, M.G.D.; Jin, H.; Sciammarella, C.; Yoshida, S.; Lamberti, L.

    2015-01-01

    A generic one-step Integrated Digital Image Correlation (I-DIC) inverse parameter identification approach is introduced that enables direct identification of constitutive model parameters by intimately integrating a Finite Elements Method (FEM) with Digital Image Correlation (DIC), directly

  17. Towards A Colorimetric Digital Image Archive For The Visual Arts

    Science.gov (United States)

    Martinez, Kirk; Hamber, Anthony

    1989-04-01

    The aim of this project is to produce a high-resolution, colorimetric and permanent digital archive of images taken directly from works of art. The proposed system is designed for use in education, research, galleries and museums. Tentative user requirements are examined with particular reference to resolution, image access and colorimetry. Existing technology and projects are considered. Some 3000x3000 pel images of paintings are used to illustrate the interrelationship between dimensions of the original, its inherent detail, scan resolution and display.

  18. Free digital image analysis software helps to resolve equivocal scores in HER2 immunohistochemistry.

    Science.gov (United States)

    Helin, Henrik O; Tuominen, Vilppu J; Ylinen, Onni; Helin, Heikki J; Isola, Jorma

    2016-02-01

    Evaluation of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) is subject to interobserver variation and lack of reproducibility. Digital image analysis (DIA) has been shown to improve the consistency and accuracy of the evaluation and its use is encouraged in current testing guidelines. We studied whether digital image analysis using a free software application (ImmunoMembrane) can assist in interpreting HER2 IHC in equivocal 2+ cases. We also compared digital photomicrographs with whole-slide images (WSI) as material for ImmunoMembrane DIA. We stained 750 surgical resection specimens of invasive breast cancers immunohistochemically for HER2 and analysed staining with ImmunoMembrane. The ImmunoMembrane DIA scores were compared with the originally responsible pathologists' visual scores, a researcher's visual scores and in situ hybridisation (ISH) results. The originally responsible pathologists reported 9.1 % positive 3+ IHC scores, for the researcher this was 8.4 % and for ImmunoMembrane 9.5 %. Equivocal 2+ scores were 34 % for the pathologists, 43.7 % for the researcher and 10.1 % for ImmunoMembrane. Negative 0/1+ scores were 57.6 % for the pathologists, 46.8 % for the researcher and 80.8 % for ImmunoMembrane. There were six false positive cases, which were classified as 3+ by ImmunoMembrane and negative by ISH. Six cases were false negative defined as 0/1+ by IHC and positive by ISH. ImmunoMembrane DIA using digital photomicrographs and WSI showed almost perfect agreement. In conclusion, digital image analysis by ImmunoMembrane can help to resolve a majority of equivocal 2+ cases in HER2 IHC, which reduces the need for ISH testing.

  19. Contribution to the study of integrated system design in digital imaging. Application to digital radiology

    International Nuclear Information System (INIS)

    Boy, M.

    1987-02-01

    In the first part of this work, we describe the hardware and software used to design integrated systems able to acquire, memorize, process and visualize 1024 x 1024 x 8 bits images. In the second part, we present and analyse the first realised prototype system which is a digital radiology one. After a technical and economical digital radiology study, we present the angiographic and tomographic results. In the third part, we indicate possible evolution of this system and we show how the adopted structure and developed hardware allow applications in various fields [fr

  20. Applications of digital image analysis capability in Idaho

    Science.gov (United States)

    Johnson, K. A.

    1981-01-01

    The use of digital image analysis of LANDSAT imagery in water resource assessment is discussed. The data processing systems employed are described. The determination of urban land use conversion of agricultural land in two southwestern Idaho counties involving estimation and mapping of crop types and of irrigated land is described. The system was also applied to an inventory of irrigated cropland in the Snake River basin and establishment of a digital irrigation water source/service area data base for the basin. Application of the system to a determination of irrigation development in the Big Lost River basin as part of a hydrologic survey of the basin is also described.

  1. Non-invasive cardiac imaging. Spectrum, methodology, indication and interpretation

    International Nuclear Information System (INIS)

    Schaefers, Michael; Flachskampf, Frank; Sechtem, Udo; Achenbach, Stephan; Krause, Bernd J.; Schwaiger, Markus; Breithardt, Guenter

    2008-01-01

    The book contains 13 contributions concerning the following chapters: (1)methodology: echo cardiography; NMR imaging; nuclear medicine; computer tomography, (2) clinical protocols: contraction; cardiac valve function; perfusion and perfusion reserve; vitality; corona imaging; transmitters, receptors, enzymes; (3) clinic: coronary heart diseases; non-ischemic heart diseases. The appendix contains two contributions on future developments and certification/standardization

  2. Effects of scanning resolution and digital image magnification on photostimulable phosphor imaging system

    International Nuclear Information System (INIS)

    Sakurai, Takashi; Inagaki, Masafumi; Asai, Hideomi; Koyama, Atsushi; Kashima, Isamu

    2000-01-01

    The purpose of this study is to examine the effects of changes in scanning resolution and digital magnification on the image quality and diagnostic ability of the photostimulable phosphor imaging system. Using a photostimulable phosphor imaging system, images of a human adult dried mandible phantom embedded in a 25 mm-thick epoxy resin block were made. The latent images on the photostimulable phosphor imaging plate were scanned using four different pixel sizes as follows: 25 μm x 25 μm, 50 μm x 50 μm, 100 μm x 100 μm and 200 μm x 200 μm. A primary image was produced for each pixel size. These images were also digitally magnified at powers of 2, 4 and 8 times. The gradient range, brightness and contrast of each image were adjusted to optimum levels on a cathode ray tube display, and hard copies were produced with a writing pixel size of 60 μm x 60 μm. The granularity, sharpness and anatomical diagnostic ability of the images were assessed subjectively by eight dentists. Increasing the scanning resolution tended to generally improve image quality and diagnostic ability. Visual image quality was maintained up to a pixel size of 50 μm, and diagnostic ability was maintained up to a pixel size of 100 μm. Digital image magnification degraded image quality, and more than 2-times magnification degraded diagnostic ability. Under the present experimental conditions, increasing the scanning resolution did not always lead to an improvement in image quality or diagnostic ability, and digital image magnification degraded image quality and diagnostic ability. (author)

  3. Some computer applications and digital image processing in nuclear medicine

    International Nuclear Information System (INIS)

    Lowinger, T.

    1981-01-01

    Methods of digital image processing are applied to problems in nuclear medicine imaging. The symmetry properties of central nervous system lesions are exploited in an attempt to determine the three-dimensional radioisotope density distribution within the lesions. An algorithm developed by astronomers at the end of the 19th century to determine the distribution of matter in globular clusters is applied to tumors. This algorithm permits the emission-computed-tomographic reconstruction of spherical lesions from a single view. The three-dimensional radioisotope distribution derived by the application of the algorithm can be used to characterize the lesions. The applicability to nuclear medicine images of ten edge detection methods in general usage in digital image processing were evaluated. A general model of image formation by scintillation cameras is developed. The model assumes that objects to be imaged are composed of a finite set of points. The validity of the model has been verified by its ability to duplicate experimental results. Practical applications of this work involve quantitative assessment of the distribution of radipharmaceuticals under clinical situations and the study of image processing algorithms

  4. Automatic registration of fused lidar/digital imagery (texel images) for three-dimensional image creation

    Science.gov (United States)

    Budge, Scott E.; Badamikar, Neeraj S.; Xie, Xuan

    2015-03-01

    Several photogrammetry-based methods have been proposed that the derive three-dimensional (3-D) information from digital images from different perspectives, and lidar-based methods have been proposed that merge lidar point clouds and texture the merged point clouds with digital imagery. Image registration alone has difficulty with smooth regions with low contrast, whereas point cloud merging alone has difficulty with outliers and a lack of proper convergence in the merging process. This paper presents a method to create 3-D images that uses the unique properties of texel images (pixel-fused lidar and digital imagery) to improve the quality and robustness of fused 3-D images. The proposed method uses both image processing and point-cloud merging to combine texel images in an iterative technique. Since the digital image pixels and the lidar 3-D points are fused at the sensor level, more accurate 3-D images are generated because registration of image data automatically improves the merging of the point clouds, and vice versa. Examples illustrate the value of this method over other methods. The proposed method also includes modifications for the situation where an estimate of position and attitude of the sensor is known, when obtained from low-cost global positioning systems and inertial measurement units sensors.

  5. Evaluation of clinical image processing algorithms used in digital mammography.

    Science.gov (United States)

    Zanca, Federica; Jacobs, Jurgen; Van Ongeval, Chantal; Claus, Filip; Celis, Valerie; Geniets, Catherine; Provost, Veerle; Pauwels, Herman; Marchal, Guy; Bosmans, Hilde

    2009-03-01

    Screening is the only proven approach to reduce the mortality of breast cancer, but significant numbers of breast cancers remain undetected even when all quality assurance guidelines are implemented. With the increasing adoption of digital mammography systems, image processing may be a key factor in the imaging chain. Although to our knowledge statistically significant effects of manufacturer-recommended image processings have not been previously demonstrated, the subjective experience of our radiologists, that the apparent image quality can vary considerably between different algorithms, motivated this study. This article addresses the impact of five such algorithms on the detection of clusters of microcalcifications. A database of unprocessed (raw) images of 200 normal digital mammograms, acquired with the Siemens Novation DR, was collected retrospectively. Realistic simulated microcalcification clusters were inserted in half of the unprocessed images. All unprocessed images were subsequently processed with five manufacturer-recommended image processing algorithms (Agfa Musica 1, IMS Raffaello Mammo 1.2, Sectra Mamea AB Sigmoid, Siemens OPVIEW v2, and Siemens OPVIEW v1). Four breast imaging radiologists were asked to locate and score the clusters in each image on a five point rating scale. The free-response data were analyzed by the jackknife free-response receiver operating characteristic (JAFROC) method and, for comparison, also with the receiver operating characteristic (ROC) method. JAFROC analysis revealed highly significant differences between the image processings (F = 8.51, p < 0.0001), suggesting that image processing strongly impacts the detectability of clusters. Siemens OPVIEW2 and Siemens OPVIEW1 yielded the highest and lowest performances, respectively. ROC analysis of the data also revealed significant differences between the processing but at lower significance (F = 3.47, p = 0.0305) than JAFROC. Both statistical analysis methods revealed that the

  6. Lossy image compression for digital medical imaging systems

    Science.gov (United States)

    Wilhelm, Paul S.; Haynor, David R.; Kim, Yongmin; Nelson, Alan C.; Riskin, Eve A.

    1990-07-01

    Image compression at rates of 10:1 or greater could make PACS much more responsive and economically attractive. This paper describes a protocol for subjective and objective evaluation of the fidelity of compressed/decompressed images to the originals and presents the results ofits application to four representative and promising compression methods. The methods examined are predictive pruned tree-structured vector quantization, fractal compression, the discrete cosine transform with equal weighting of block bit allocation, and the discrete cosine transform with human visual system weighting of block bit allocation. Vector quantization is theoretically capable of producing the best compressed images, but has proven to be difficult to effectively implement. It has the advantage that it can reconstruct images quickly through a simple lookup table. Disadvantages are that codebook training is required, the method is computationally intensive, and achieving the optimum performance would require prohibitively long vector dimensions. Fractal compression is a relatively new compression technique, but has produced satisfactory results while being computationally simple. It is fast at both image compression and image reconstruction. Discrete cosine iransform techniques reproduce images well, but have traditionally been hampered by the need for intensive computing to compress and decompress images. A protocol was developed for side-by-side observer comparison of reconstructed images with originals. Three 1024 X 1024 CR (Computed Radiography) images and two 512 X 512 X-ray CT images were viewed at six bit rates (0.2, 0.4, 0.6, 0.9, 1.2, and 1.5 bpp for CR, and 1.0, 1.3, 1.6, 1.9, 2.2, 2.5 bpp for X-ray CT) by nine radiologists at the University of Washington Medical Center. The CR images were viewed on a Pixar II Megascan (2560 X 2048) monitor and the CT images on a Sony (1280 X 1024) monitor. The radiologists' subjective evaluations of image fidelity were compared to

  7. 78 FR 32427 - Notice of Issuance of Final Determination Concerning Multifunctional Digital Imaging Systems

    Science.gov (United States)

    2013-05-30

    ... multifunctional digital imaging systems for purposes of U.S. Government procurement. DATES: The final... Determination Concerning Multifunctional Digital Imaging Systems AGENCY: U.S. Customs and Border Protection... country of origin of certain multifunctional digital imaging systems. Based upon the facts presented, CBP...

  8. Digital implementation of a neural network for imaging

    Science.gov (United States)

    Wood, Richard; McGlashan, Alex; Yatulis, Jay; Mascher, Peter; Bruce, Ian

    2012-10-01

    This paper outlines the design and testing of a digital imaging system that utilizes an artificial neural network with unsupervised and supervised learning to convert streaming input (real time) image space into parameter space. The primary objective of this work is to investigate the effectiveness of using a neural network to significantly reduce the information density of streaming images so that objects can be readily identified by a limited set of primary parameters and act as an enhanced human machine interface (HMI). Many applications are envisioned including use in biomedical imaging, anomaly detection and as an assistive device for the visually impaired. A digital circuit was designed and tested using a Field Programmable Gate Array (FPGA) and an off the shelf digital camera. Our results indicate that the networks can be readily trained when subject to limited sets of objects such as the alphabet. We can also separate limited object sets with rotational and positional invariance. The results also show that limited visual fields form with only local connectivity.

  9. Use of digital images to estimate soil moisture

    Directory of Open Access Journals (Sweden)

    João F. C. dos Santos

    Full Text Available ABSTRACT The objective of this study was to analyze the relation between the moisture and the spectral response of the soil to generate prediction models. Samples with different moisture contents were prepared and photographed. The photographs were taken under homogeneous light condition and with previous correction for the white balance of the digital photograph camera. The images were processed for extraction of the median values in the Red, Green and Blue bands of the RGB color space; Hue, Saturation and Value of the HSV color space; and values of the digital numbers of a panchromatic image obtained from the RGB bands. The moisture of the samples was determined with the thermogravimetric method. Regression models were evaluated for each image type: RGB, HSV and panchromatic. It was observed the darkening of the soil with the increase of moisture. For each type of soil, a model with best fit was observed and to use these models for prediction purposes, it is necessary to choose the model with best fit in advance, according to the soil characteristics. Soil moisture estimation as a function of its spectral response by digital image processing proves promising.

  10. Preliminary study of lateral cerebral angiography with reverse rotation in the digital image registration and subtraction

    International Nuclear Information System (INIS)

    Shen Zhenglin; Liu Dongyang; Shen Zhenghai; Li Shuping; Zhang Ziyan; Wu Yongjuan; Liu Peijun

    2012-01-01

    Objective: Investigate the value and feasibility of image registration with reverse rotation in lateral cerebral DSA. Methods: (1) Experimental study: the target images were subtracted directly, and subtracted again after reverse rotation. Software of registration and subtraction with reverse rotation edited by the author utilizing Visual Basic. The function of the automatic angle detection by the software were evaluated to see whether it detected the angle of line. The subtraction function of DSA by the software was evaluated. (2) Clinical retrospective study: the untreated mask and target images of 15 patients with motion along vertical axis during lateral cerebral DSA were uploaded to the software. The target images were processed with and without the software to get two sets of images. (3) Evaluation: four experienced radiologists read and compared the two sets of the images,and graded their findings. Results: (1) The automatic detection by the software suggested that the target images should be rotated counterclockwise 1.3°. The subtraction result of the software was satisfactory. (2) In the 15 sets of images, there were only three sets of images deemed optimal after traditional subtraction. After reverse rotation, artifacts were significantly reduced and the image sharper. There were ten cases with significant artifacts after traditional subtraction, and those images were sharper and showed more peripheral vessels after reverse rotation. The traditional subtraction images of two sets could not be interpreted,the reverse rotation registration images reached the diagnostic quality. (3) Subjective evaluation: there were more information and less noise and distortion in the registration images with reverse rotation than in the traditional subtraction. But the image resolution decreased slightly after reverse rotation registration. Conclusion: The registration of digital angiography with reverse rotation can improve the image quality in lateral cerebral DSA

  11. Image and Issue Political Information: Message Content or Interpretation?

    Science.gov (United States)

    Johnston, Deirdre D.

    1989-01-01

    Explores the existence of a cognitive bias that affects an individual's processing of political advertisements. Finds that whether voters see messages as issue or image material depends on their predisposition. (RS)

  12. Monuments deterioration evaluation, using digited images. A methodology

    Directory of Open Access Journals (Sweden)

    Ángel, María C.

    1995-12-01

    Full Text Available In this work a methodology is proposed for data processing, integrating the techniques of digital images processing and the analytical capacity of graphical referencing systems and relational databases, in relation with the monuments. The images are generated using the digital image processing and they are included into a graphical data processing systems associated with a database containing the characteristics of the ashars or constituent elements. By combination of the images with the database induced properties the information is processed. The results are thematic maps that we save such as images. These maps are layers of new information (deduced levels. The elaboration of these maps allows attacking the problems of the restoration, renovation or treatment of the different monumental spaces on a global way, paying special attention on the most gravely affected areas.

    En este trabajo se propone una metodología para el tratamiento de la información, integrando las técnicas de proceso digital de imágenes, la capacidad de análisis de los sistemas de referenciación gráfica y las bases de datos relacionales, referidas a monumentos. Para ello se elaboran las imágenes base por algoritmos propios del proceso digital, incluyendo aquellas en una aplicación especifica que asocia cada capa a una base de datos con las propiedades petrofísicas, hídricas, etc., o bien entre si, dando lugar a mapas temáticos. La generación de estos mapas permite abordar los problemas de restauración, rehabilitación o tratamiento de los diferentes espacios monumentales de forma global, con incidencia especial en las zonas más afectadas.

  13. Interpretation of the method of images in estimating superconducting levitation

    International Nuclear Information System (INIS)

    Perez-Diaz, Jose Luis; Garcia-Prada, Juan Carlos

    2007-01-01

    Among different papers devoted to superconducting levitation of a permanent magnet over a superconductor using the method of images, there is a discrepancy of a factor of two when estimating the lift force. This is not a minor matter but an interesting fundamental question that contributes to understanding the physical phenomena of 'imaging' on a superconductor surface. We solve it, make clear the physical behavior underlying it, and suggest the reinterpretation of some previous experiments

  14. Practical evaluation of clinical image quality (4). Determination of image quality in digital radiography system

    International Nuclear Information System (INIS)

    Katayama, Reiji

    2016-01-01

    Recently, for medical imaging, digital radiography systems are widely used in clinical practices. However, a study in the past reported that a patient radiation exposure level by digital radiography is in fact not lower than that by analog radiography system. High level of attention needs to be paid for over-exposure when using the conventional analog radiography with a screen and a film, as it results in high density of the film. However, for digital radiography systems, since the automatic adjusting function of image density is equipped with them, no attention for radiation dose need to be paid. Thus technologists tend to be careless and results in higher chance for over-exposure. Current digital radiography systems are high-performance in the image properties and capable of patient dose reduction. Especially, the image quality of the flat panel detector system is recognized, higher than that of the computed radiography system by imaging plates, in both objective and subjective evaluations. Therefore, we technologists are responsible for optimizing the balance between the image quality of the digital radiogram and the radiation dose required for each case. Moreover, it is also required for us as medical technologists to make effective use of such evaluation result of medical images for patients. (author)

  15. A Multiresolution Image Completion Algorithm for Compressing Digital Color Images

    Directory of Open Access Journals (Sweden)

    R. Gomathi

    2014-01-01

    Full Text Available This paper introduces a new framework for image coding that uses image inpainting method. In the proposed algorithm, the input image is subjected to image analysis to remove some of the portions purposefully. At the same time, edges are extracted from the input image and they are passed to the decoder in the compressed manner. The edges which are transmitted to decoder act as assistant information and they help inpainting process fill the missing regions at the decoder. Textural synthesis and a new shearlet inpainting scheme based on the theory of p-Laplacian operator are proposed for image restoration at the decoder. Shearlets have been mathematically proven to represent distributed discontinuities such as edges better than traditional wavelets and are a suitable tool for edge characterization. This novel shearlet p-Laplacian inpainting model can effectively reduce the staircase effect in Total Variation (TV inpainting model whereas it can still keep edges as well as TV model. In the proposed scheme, neural network is employed to enhance the value of compression ratio for image coding. Test results are compared with JPEG 2000 and H.264 Intracoding algorithms. The results show that the proposed algorithm works well.

  16. Imaging of cystic fibrosis lung disease and clinical interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Wielpuetz, M.O.; Eichinger, M.; Kauczor, H.U. [Heidelberg University Hospital (Germany). Dept. of Diagnostic and Interventional Radiology; Translational Lung Research Center Heidelberg (TLRC) (Germany); Heidelberg University Hospital (Germany). Dept. of Diagnostic and Interventional Radiology with Nuclear Medicine; Biederer, J. [Heidelberg University Hospital (Germany). Dept. of Diagnostic and Interventional Radiology; Translational Lung Research Center Heidelberg (TLRC) (Germany); Gross-Gerau Community Hospital (Germany). Radiologie Darmstadt; Wege, S. [Heidelberg University Hospital (Germany). Dept. of Pulmonology and Respiratory Medicine; Stahl, M.; Sommerburg, O. [Translational Lung Research Center Heidelberg (TLRC) (Germany); Heidelberg University Hospital (Germany). Div. of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center; Mall, M.A. [Translational Lung Research Center Heidelberg (TLRC) (Germany); Heidelberg University Hospital (Germany). Div. of Pediatric Pulmonology and Allergy and Cystic Fibrosis Center; Heidelberg University Hospital (Germany). Dept. of Translational Pulmonology; Puderbach, M. [Heidelberg University Hospital (Germany). Dept. of Diagnostic and Interventional Radiology; Translational Lung Research Center Heidelberg (TLRC) (Germany); Heidelberg University Hospital (Germany). Dept. of Diagnostic and Interventional Radiology with Nuclear Medicine; Hufeland Hospital, Bad Langensalza (Germany). Dept. of Diagnostic and Interventional Radiology

    2016-09-15

    Progressive lung disease in cystic fibrosis (CF) is the life-limiting factor of this autosomal recessive genetic disorder. Increasing implementation of CF newborn screening allows for a diagnosis even in pre-symptomatic stages. Improvements in therapy have led to a significant improvement in survival, the majority now being of adult age. Imaging provides detailed information on the regional distribution of CF lung disease, hence longitudinal imaging is recommended for disease monitoring in the clinical routine. Chest X-ray (CXR), computed tomography (CT) and magnetic resonance imaging (MRI) are now available as routine modalities, each with individual strengths and drawbacks, which need to be considered when choosing the optimal modality adapted to the clinical situation of the patient. CT stands out with the highest morphological detail and has often been a substitute for CXR for regular severity monitoring at specialized centers. Multidetector CT data can be post-processed with dedicated software for a detailed measurement of airway dimensions and bronchiectasis and potentially a more objective and precise grading of disease severity. However, changing to CT was inseparably accompanied by an increase in radiation exposure of CF patients, a young population with high sensitivity to ionizing radiation and lifetime accumulation of dose. MRI as a cross-sectional imaging modality free of ionizing radiation can depict morphological hallmarks of CF lung disease at lower spatial resolution but excels with comprehensive functional lung imaging, with time-resolved perfusion imaging currently being most valuable.

  17. PACS and the digital storage of medical images

    International Nuclear Information System (INIS)

    Perry, J.R.; Johnston, R.E.; Pizer, S.M.; Lowendorf, D.D.; Rogers, D.C.; Thompson, B.C.; Parrish, D.M.; Brenton, B.C.; Staab, E.V.

    1986-01-01

    An application of computers in medicine is developing wherein large amounts of digital information in the form of images must be stored, retrieved, and displayed quickly. In radiology this application most commonly goes by the acronym PACS which stands for picture archival and communications system. Estimates of the storage requirements for radiologic images strongly suggest that we should think in terms of terabytes per year for a 150,000 procedure/year, 600 bed hospital. Transmission of patient image data files (a single X-ray image pair may be 12.6 Mbytes) arouses concern over transmission speeds, user waiting tolerances and a communications standard. An important accord is being reached between users and equipment manufacturers in radiology for a standard communications protocol, called the proposed ACR-NEMA standard. Features of PACS which require high speed computational abilities include a lexicon for report generation and image reconstruction, compression, enhancement and 3D display

  18. Digital Image Processing Overview For Helmet Mounted Displays

    Science.gov (United States)

    Parise, Michael J.

    1989-09-01

    Digital image processing provides a means to manipulate an image and presents a user with a variety of display formats that are not available in the analog image processing environment. When performed in real time and presented on a Helmet Mounted Display, system capability and flexibility are greatly enhanced. The information content of a display can be increased by the addition of real time insets and static windows from secondary sensor sources, near real time 3-D imaging from a single sensor can be achieved, graphical information can be added, and enhancement techniques can be employed. Such increased functionality is generating a considerable amount of interest in the military and commercial markets. This paper discusses some of these image processing techniques and their applications.

  19. Dissimilarity Application in Digitized Mammographic Images Classification

    Directory of Open Access Journals (Sweden)

    Ubaldo Bottigli

    2006-06-01

    Full Text Available Purpose of this work is the development of an automatic classification system which could be useful for radiologists in the investigation of breast cancer. The software has been designed in the framework of the MAGIC-5 collaboration. In the traditional way of learning from examples of objects the classifiers are built in a feature space. However, an alternative ways can be found by constructing decision rules on dissimilarity (distance representations. In such a recognition process a new object is described by its distances to (a subset of the training samples. The use of the dissimilarities is especially of interest when features are difficult to obtain or when they have a little discriminative power. In the automatic classification system the suspicious regions with high probability to include a lesion are extracted from the image as regions of interest (ROIs. Each ROI is characterized by some features extracted from co-occurrence matrix containing spatial statistics information on ROI pixel grey tones. A dissimilarity representation of these features is made before the classification. A feed-forward neural network is employed to distinguish pathological records, from non-pathological ones by the new features. The results obtained in terms of sensitivity and specificity will be presented.

  20. Integrated optical 3D digital imaging based on DSP scheme

    Science.gov (United States)

    Wang, Xiaodong; Peng, Xiang; Gao, Bruce Z.

    2008-03-01

    We present a scheme of integrated optical 3-D digital imaging (IO3DI) based on digital signal processor (DSP), which can acquire range images independently without PC support. This scheme is based on a parallel hardware structure with aid of DSP and field programmable gate array (FPGA) to realize 3-D imaging. In this integrated scheme of 3-D imaging, the phase measurement profilometry is adopted. To realize the pipeline processing of the fringe projection, image acquisition and fringe pattern analysis, we present a multi-threads application program that is developed under the environment of DSP/BIOS RTOS (real-time operating system). Since RTOS provides a preemptive kernel and powerful configuration tool, with which we are able to achieve a real-time scheduling and synchronization. To accelerate automatic fringe analysis and phase unwrapping, we make use of the technique of software optimization. The proposed scheme can reach a performance of 39.5 f/s (frames per second), so it may well fit into real-time fringe-pattern analysis and can implement fast 3-D imaging. Experiment results are also presented to show the validity of proposed scheme.

  1. IMAGEP - A FORTRAN ALGORITHM FOR DIGITAL IMAGE PROCESSING

    Science.gov (United States)

    Roth, D. J.

    1994-01-01

    IMAGEP is a FORTRAN computer algorithm containing various image processing, analysis, and enhancement functions. It is a keyboard-driven program organized into nine subroutines. Within the subroutines are other routines, also, selected via keyboard. Some of the functions performed by IMAGEP include digitization, storage and retrieval of images; image enhancement by contrast expansion, addition and subtraction, magnification, inversion, and bit shifting; display and movement of cursor; display of grey level histogram of image; and display of the variation of grey level intensity as a function of image position. This algorithm has possible scientific, industrial, and biomedical applications in material flaw studies, steel and ore analysis, and pathology, respectively. IMAGEP is written in VAX FORTRAN for DEC VAX series computers running VMS. The program requires the use of a Grinnell 274 image processor which can be obtained from Mark McCloud Associates, Campbell, CA. An object library of the required GMR series software is included on the distribution media. IMAGEP requires 1Mb of RAM for execution. The standard distribution medium for this program is a 1600 BPI 9track magnetic tape in VAX FILES-11 format. It is also available on a TK50 tape cartridge in VAX FILES-11 format. This program was developed in 1991. DEC, VAX, VMS, and TK50 are trademarks of Digital Equipment Corporation.

  2. Digital Signal Processing for Medical Imaging Using Matlab

    CERN Document Server

    Gopi, E S

    2013-01-01

    This book describes medical imaging systems, such as X-ray, Computed tomography, MRI, etc. from the point of view of digital signal processing. Readers will see techniques applied to medical imaging such as Radon transformation, image reconstruction, image rendering, image enhancement and restoration, and more. This book also outlines the physics behind medical imaging required to understand the techniques being described. The presentation is designed to be accessible to beginners who are doing research in DSP for medical imaging. Matlab programs and illustrations are used wherever possible to reinforce the concepts being discussed.  ·         Acts as a “starter kit” for beginners doing research in DSP for medical imaging; ·         Uses Matlab programs and illustrations throughout to make content accessible, particularly with techniques such as Radon transformation and image rendering; ·         Includes discussion of the basic principles behind the various medical imaging tec...

  3. A review of peer-assisted learning to deliver interprofessional supplementary image interpretation skills

    International Nuclear Information System (INIS)

    Bain, P.; Wareing, A.; Henderson, I.

    2017-01-01

    Background: Peer-assisted learning provides a means through which individuals can learn from one another through a reciprocal process. Radiographic image interpretation skills are fundamental to both diagnostic radiography students and medical students due to their shared role in preliminary evaluation of conventional radiographic images. Medical students on graduation, may not be well prepared to carry out image interpretation, since evidence suggests that they perform less well than radiographers in e.g. Accident and Emergency situations. Method: A review of literature was conducted exploring the application of peer-assisted learning within diagnostic radiography and health education more widely as well as the practice of initial image interpretation. An extensive and systematic search strategy was developed which provided a range of material related to the areas. Findings: An overview was obtained of the effectiveness of peer-assisted learning and the issues associated with development of image interpretation skills and a degree of discrepancy was identified between the two cohorts regarding their interpretative competence and confidence. This inconsistency may create an opportunity to apply peer-assisted learning, better preparing both disciplines for the practical application of image interpretation skills. Conclusion: The review identified the lack of a substantial evidence base relating to peer-assisted learning in radiography. Peer-assisted learning is not widely embraced in an interprofessional context. Multiple positive factors of such an intervention are identified which outweigh perceived negative issues. Student teacher and learner may benefit as should the clinical service from enhanced practitioner performance. The findings justify further research to develop the evidence base. - Highlights: • Many diagnostic radiographers and medics are involved in image interpretation. • Evidence indicates an imbalance in image interpretation competence and

  4. Performances of different digital mammography imaging systems: Evaluation and comparison

    Energy Technology Data Exchange (ETDEWEB)

    Bisogni, M.G. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)]. E-mail: giuseppina.bisogni@pi.infn.it; Bulajic, D. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); International Centre for Theoretical Physics, Trieste (Italy); Delogu, P. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Fantacci, M.E. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Novelli, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Quattrocchi, M. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Rosso, V. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy); Stefanini, A. [Dipartimento di Fisica ' E. Fermi' , Universita di Pisa, e Sezione INFN di Pisa, Pisa (Italy)

    2005-07-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems.

  5. Performances of different digital mammography imaging systems: Evaluation and comparison

    International Nuclear Information System (INIS)

    Bisogni, M.G.; Bulajic, D.; Delogu, P.; Fantacci, M.E.; Novelli, M.; Quattrocchi, M.; Rosso, V.; Stefanini, A.

    2005-01-01

    Digital mammography is entering routine clinical use and many commercial systems are now in use in the radiological units for screening and diagnostic mammography. At the same time, the research in the digital mammography field is very active in the development of more and more performing devices. In this paper we present the performance of single photon counting pixel detectors (MedipixI) tailored for digital mammographic applications. These devices are based on semiconductor (Si and GaAs) pixel detectors of different thickness, read-out by custom designed integrated circuits. To assess the imaging capability of such systems, the images of a mammographic phantom have been acquired in standard conditions for a clinical examination. The signal-to-noise ratio (SNR) of details simulating tumor masses has been evaluated. The same phantom has been also radiographed by three different commercial digital mammographic systems in the same reference conditions and a comparison in terms of SNR has been carried out. The spatial resolution of the single photon counting systems has also been evaluated by measuring the line spread function with the edge technique and then calculating the Modulation Transfer Function (MTF). The MTFs of the single photon counting systems have been compared with the MTFs of the commercial systems

  6. Case study on the results of image interpretation

    International Nuclear Information System (INIS)

    Fukuda, Morimichi; Fukuhisa, Kenjiro; Tateno, Yukio; Nair, Gopinathan; Sharma, S.M.; Padhy, Ajit Kumar; Shishido, Fumio

    1996-01-01

    Hepatocellular carcinoma (HCC) most commonly produces a focal mass lesion which is initially hypoechoic, but becomes more echogenic with increasing size. Texture pattern characteristically produces mosaic appearance and is often accompanied by posterior echo enhancement. In some cases, the tumor infiltrates widely through the liver substance, giving rise to an irregular pattern, invasion of veins, hepatic and portal, is common. The incidence of intra and extrahepatic dissemination is high in HCC with diffuse infiltration. Liver scintigraphy, sonographic findings, clinical history and laboratory investigation were analysed and interpreted

  7. Osteoporosis: a new approach of digital processing of radiological images

    International Nuclear Information System (INIS)

    Salles, Adilson Dias; Braz, Valeria Silva

    1998-01-01

    The authors applied a method based on digital processing of radiological images (fast Fourier transform) to analyze the radius distal epiphysis and calcaneus spongy bone architecture. The study revealed distinct patterns of trabecular distribution. Prior studies about osteoporosis have focused on bone density quantification and its role on fracture prediction. However, resistance to fractures (mechanical strength) is also determined by structural arrangement of bone. THe digital processing (spectral analysis) was applied to radiological images of the radius and calcaneus from 15 normal and osteopenic individuals. Normal bone trabeculae showed an individualized behavior (stress lines). On the other hand, porotic bone trabeculae revealed a diffuse pattern (honey comb). The scattered frequency components showed that the porotic bone trabeculae were remodeled. This process would be responsible for the maintenance of its physical properties. (author)

  8. Test Targets 2.0 and Digital Imaging

    Directory of Open Access Journals (Sweden)

    Robert Chung

    2003-04-01

    Full Text Available Current color management systems, based on a modular approach, enable color portability and mass customization of digital images for print. Because of the non-specific nature of the workflow, implementation of ICC-based color management becomes the responsibility of the user. As such the performance of ICC-based CMS is often unknown and has caused much confusion and slow adoption in the printing and publishing industries. To demonstrate how ICC-based color management can be implemented in a number of workflows, this paper describes a project, called Test Targets 2.0. A description of the test targets and how they were used for device calibration, device profiling, and color imaging applications under different workflows, e.g., from scanner to press, or digital camera to press, are introduced. Color management should work equally well for color matching applications. Thus, a continuation of the project focuses on device gamut and profile accuracy assessment.

  9. Digital optical tomography system for dynamic breast imaging

    Science.gov (United States)

    Flexman, Molly L.; Khalil, Michael A.; Al Abdi, Rabah; Kim, Hyun K.; Fong, Christopher J.; Desperito, Elise; Hershman, Dawn L.; Barbour, Randall L.; Hielscher, Andreas H.

    2011-07-01

    Diffuse optical tomography has shown promising results as a tool for breast cancer screening and monitoring response to chemotherapy. Dynamic imaging of the transient response of the breast to an external stimulus, such as pressure or a respiratory maneuver, can provide additional information that can be used to detect tumors. We present a new digital continuous-wave optical tomography system designed to simultaneously image both breasts at fast frame rates and with a large number of sources and detectors. The system uses a master-slave digital signal processor-based detection architecture to achieve a dynamic range of 160 dB and a frame rate of 1.7 Hz with 32 sources, 64 detectors, and 4 wavelengths per breast. Included is a preliminary study of one healthy patient and two breast cancer patients showing the ability to identify an invasive carcinoma based on the hemodynamic response to a breath hold.

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

    Energy Technology Data Exchange (ETDEWEB)

    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. [National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH (United Kingdom); Jarvis Breast Screening and Diagnostic Centre, Guildford GU1 1LJ (United Kingdom); Department of Radiology, St. George' s Healthcare NHS Trust, Tooting, London SW17 0QT (United Kingdom); Cambridge Breast Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, United Kingdom and NIHR Cambridge Biomedical Research Centre, Cambridge CB2 0QQ (United Kingdom); Department of Radiology, University of Pittsburgh, Pittsburgh, Pennsylvania 15210 (United States); National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom); University Hospitals Leuven, Herestraat 49, 3000 Leuven (Belgium); National Co-ordinating Centre for the Physics of Mammography, Royal Surrey County Hospital NHS Foundation Trust, Guildford GU2 7XX, United Kingdom and Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH (United Kingdom)

    2012-06-15

    Purpose: 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. Methods: 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. Results: There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC

  11. Intravenous dipyridamole thallium-201 SPECT imaging methodology, applications, and interpretations

    International Nuclear Information System (INIS)

    Rockett, J.F.; Magill, H.L.; Loveless, V.S.; Murray, G.L.

    1990-01-01

    Dipyridamole TI-201 imaging is an ideal alternative to exercise TI-201 scintigraphy in patients who are unwilling or unable to perform maximum exercise stress. The use of intravenous dipyridamole, alone or in combination with exercise, has not been approved for clinical practice by the Food and Drug Administration. Once approval is granted, the test will become a widely used and important component of the cardiac work-up. The indications, methodology, side effects, and utility of dipyridamole cardiac imaging in the clinical setting are discussed and a variety of examples presented.59 references

  12. Interpretation of archaeological small-scale features in spectral images

    DEFF Research Database (Denmark)

    Grøn, Ole; Palmer, Susanna; Stylegar, Frans-Arne

    2011-01-01

    The paper's focus is the use of spectral images for the distinction of small archaeological anomalies on the basis of the authors work. Special attention is given to the ground-truthing perspective in the discussion of a number of cases from Norway. Different approaches to pattern-recognition are......The paper's focus is the use of spectral images for the distinction of small archaeological anomalies on the basis of the authors work. Special attention is given to the ground-truthing perspective in the discussion of a number of cases from Norway. Different approaches to pattern...

  13. Panoramic radiology. Seminars on maxillofacial imaging and interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Farman, Allan G. (ed.) [Louisville Univ., KY (United States). Dept. of Surgical and Hospital Dentistry

    2007-07-01

    Complete up-to-date collection of information on panoramic radiography usage. Up-to-date terminology validated by representatives of individual special disciplines within dentistry. Each chapter with educational objectives and review questions. Panoramic radiology systems are currently being used in more practices than at other any time in the past. The practitioner now has decisions to make regarding detector technology selection for image acquisition and must remain informed about appropriate usage. This book is applicable to all panoramic dental images and equipment. It approaches panoramic radiology usage in the context of general and specialty applications. (orig.)

  14. God image and happiness in chronic pain patients: the mediating role of disease interpretation.

    Science.gov (United States)

    Dezutter, Jessie; Luyckx, Koen; Schaap-Jonker, Hanneke; Büssing, Arndt; Corveleyn, Jozef; Hutsebaut, Dirk

    2010-05-01

    The present study explored the role of the emotional experience of God (i.e., positive and negative God images) in the happiness of chronic pain (CP) patients. Framed in the transactional model of stress, we tested a model in which God images would influence happiness partially through its influence on disease interpretation as a mediating mechanism. We expected God images to have both a direct and an indirect (through the interpretation of disease) effect on happiness. A cross-sectional questionnaire design was adopted in order to measure demographics, pain condition, God images, disease interpretation, and happiness. One hundred thirty-six CP patients, all members of a national patients' association, completed the questionnaires. Correlational analyses showed meaningful associations among God images, disease interpretation, and happiness. Path analyses from a structural equation modeling approach indicated that positive God images seemed to influence happiness, both directly and indirectly through the pathway of positive interpretation of the disease. Ancillary analyses showed that the negative influence of angry God images on happiness disappeared after controlling for pain severity. The results indicated that one's emotional experience of God has an influence on happiness in CP patients, both directly and indirectly through the pathway of positive disease interpretation. These findings can be framed within the transactional theory of stress and can stimulate further pain research investigating the possible effects of religion in the adaptation to CP.

  15. [The point-digital interpretation and the choice of the dermatoglyphic patterns on human fingers for diagnostics of consanguineous relationship].

    Science.gov (United States)

    Zvyagin, V N; Rakitin, V A; Fomina, E E

    The objective of the present study was the development of the point-digital model for the scaless interpretation of the dermatoglyphic papillary patterns on human fingers that would allow to comprehensively describe, in digital terms, the main characteristics of the traits and perform the quantitative assessment of the frequency of their inheritance. A specially developed computer program, D.glyphic. 7-14 was used to mark the dermatoglyphic patterns on the fingerprints obtained from 30 familial triplets (father + mother + child).The values of all the studied traits for kinship diagnostics were found by calculating the ratios of the sums of differences between the traits in the parent-parent pairs to those in the respective parent-child pairs. The algorithms for the point marking of the traits and reading out the digital information about them have been developed. The traditional dermatoglyphic patterns were selected and the novel ones applied for the use in the framework of the point-digital model for the interpretation of the for diagnostics of consanguineous relationship. The present experimental study has demonstrated the high level of inheritance of the selected traits and the possibility to develop the algorithms and computation techniques for the calculation of consanguineous relationship coefficients based on these traits.

  16. A Low Power Digital Accumulation Technique for Digital-Domain CMOS TDI Image Sensor.

    Science.gov (United States)

    Yu, Changwei; Nie, Kaiming; Xu, Jiangtao; Gao, Jing

    2016-09-23

    In this paper, an accumulation technique suitable for digital domain CMOS time delay integration (TDI) image sensors is proposed to reduce power consumption without degrading the rate of imaging. In terms of the slight variations of quantization codes among different pixel exposures towards the same object, the pixel array is divided into two groups: one is for coarse quantization of high bits only, and the other one is for fine quantization of low bits. Then, the complete quantization codes are composed of both results from the coarse-and-fine quantization. The equivalent operation comparably reduces the total required bit numbers of the quantization. In the 0.18 µm CMOS process, two versions of 16-stage digital domain CMOS TDI image sensor chains based on a 10-bit successive approximate register (SAR) analog-to-digital converter (ADC), with and without the proposed technique, are designed. The simulation results show that the average power consumption of slices of the two versions are 6 . 47 × 10 - 8 J/line and 7 . 4 × 10 - 8 J/line, respectively. Meanwhile, the linearity of the two versions are 99.74% and 99.99%, respectively.

  17. 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

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

    International Nuclear Information System (INIS)

    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.

    2012-01-01

    Purpose: 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. Methods: 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. Results: There was a significant reduction in calcification detection using CR compared with DR: the alternative FROC

  19. GrinLine identification using digital imaging and Adobe Photoshop.

    Science.gov (United States)

    Bollinger, Susan A; Brumit, Paula C; Schrader, Bruce A; Senn, David R

    2009-03-01

    The purpose of this study was to outline a method by which an antemortem photograph of a victim can be critically compared with a postmortem photograph in an effort to facilitate the identification process. Ten subjects, between 27 and 55 years old provided historical pictures of themselves exhibiting a broad smile showing anterior teeth to some extent (a grin). These photos were termed "antemortem" for the purpose of the study. A digital camera was used to take a current photo of each subject's grin. These photos represented the "postmortem" images. A single subject's "postmortem" photo set was randomly selected to be the "unknown victim." These combined data of the unknown and the 10 antemortem subjects were digitally stored and, using Adobe Photoshop software, the images were sized and oriented for comparative analysis. The goal was to devise a technique that could facilitate the accurate determination of which "antemortem" subject was the "unknown." The generation of antemortem digital overlays of the teeth visible in a grin and the comparison of those overlays to the images of the postmortem dentition is the foundation of the technique. The comparisons made using the GrinLine Identification Technique may assist medical examiners and coroners in making identifications or exclusions.

  20. Freezing effect on bread appearance evaluated by digital imaging

    Science.gov (United States)

    Zayas, Inna Y.

    1999-01-01

    In marketing channels, bread is sometimes delivered in a frozen sate for distribution. Changes occur in physical dimensions, crumb grain and appearance of slices. Ten loaves, twelve bread slices per loaf were scanned for digital image analysis and then frozen in a commercial refrigerator. The bread slices were stored for four weeks scanned again, permitted to thaw and scanned a third time. Image features were extracted, to determine shape, size and image texture of the slices. Different thresholds of grey levels were set to detect changes that occurred in crumb, images were binarized at these settings. The number of pixels falling into these gray level settings were determined for each slice. Image texture features of subimages of each slice were calculated to quantify slice crumb grain. The image features of the slice size showed shrinking of bread slices, as a results of freezing and storage, although shape of slices did not change markedly. Visible crumb texture changes occurred and these changes were depicted by changes in image texture features. Image texture features showed that slice crumb changed differently at the center of a slice compared to a peripheral area close to the crust. Image texture and slice features were sufficient for discrimination of slices before and after freezing and after thawing.

  1. Virtual setting for training in interpreting mammography images

    Science.gov (United States)

    Pezzuol, J. L.; Abreu, F. D. L.; Silva, S. M.; Tendolini, A.; Bissaco, M. A. Se; Rodrigues, S. C. M.

    2017-03-01

    This work presents a web system for the training of students or residents (users) interested in the detection of breast density in mammography images. The system consists of a breast imaging database with breast density types classified and demarcated by the specialist (tutor) or online database. The planning was based on ISO / IEC 12207. Through the browser (desktop or notebook), the user will visualize the breast images and in them will realize the markings of the density region and even classify them per the BI-RADS protocol. After marking, this will be compared to the gold standard already existing in the image base, and then the system will inform if the area demarcation has been set or not. The shape of this marking is similar to the paint brush. The evaluation was based on ISO / IEC 1926 or 25010: 2011 by 3 software development specialists and 3 in mammary radiology, evaluating usability, configuration, performance and System interface through the Likert scale-based questionnaire. Where they have totally agreed on usability, configuration, performance and partially on the interface. And as a good thing: the system is able to be accessed anywhere and at any time, the hit or error response is in real time, it can be used in the educational area, the limit of the amount of images will depend on the size of the computer memory, At the end the system sends the results achieved by e-mail to the user, reproduction of the system on any type of screen, complementation of the system with other types of breast structures. Negative points are the need for internet.

  2. Interpreting Interfacial Structure in Cross-Sectional STM Images of III-V Semiconductor Heterostructures

    National Research Council Canada - National Science Library

    Nosho, B. Z; Barvosa-Carter, W; Yang, M. J; Bennett, B. R; Whitman, L. J

    2000-01-01

    ...) can be used for the study of III-V heterostructure interfaces. The interpretation of interfacial structure in XSTM images is impeded by the fact that only every other III or V plane as grown on the (001...

  3. System for digitalization of medical images based on DICOM standard

    Directory of Open Access Journals (Sweden)

    Čabarkapa Slobodan

    2009-01-01

    Full Text Available According to DICOM standard, which defines both medical image information and user information, a new system for digitalizing medical images is involved as a part of the main system for archiving and retrieving medical databases. The basic characteristics of this system are described in this paper. Furthermore, the analysis of some important DICOM header's tags which are used in this system, are presented, too. Having chosen the appropriate tags in order to preserve important information, the efficient system has been created. .

  4. Radiography and digital image processing for detection of internal breakdown in fruits of mango tree (Mangifera indica L.)

    International Nuclear Information System (INIS)

    Ferreira, Rubemar de Souza

    2004-01-01

    This work proposes a methodology aimed to be an adviser system for detection of internal breakdown in mangoes during the post-harvest phase to packinghouses. It was arranged a set-up to product digital images from X-ray spectrum in the range of 18 and 20 keV, where the primary images acquired were tested by a digital image processing routine for differentiation of seed, pulp, peel and injured zones. The analysis ROC applied to a only cut on a sample of 114 primary images generated, showed that digital image processing routine was able to identify 88% of true-positive injuries and 7% of false-negatives. When tested against the absence of injuries, the DIP routine had identified 22 % of false-positives and 88% of true-negatives. Besides, a cognitive analysis was applied to a sample of 76 digital images of mangoes. Results showed that the images offer enough information for dichotomic interpretation about the main injuries in the fruit, including those of difficult diagnosis under destructive assay. Measurements of observer agreement, performed on the same group of readers showed themselves in the range of fair and substantial strength of agreement. (author)

  5. Inverse transformation algorithm of transient electromagnetic field and its high-resolution continuous imaging interpretation method

    International Nuclear Information System (INIS)

    Qi, Zhipeng; Li, Xiu; Lu, Xushan; Zhang, Yingying; Yao, Weihua

    2015-01-01

    We introduce a new and potentially useful method for wave field inverse transformation and its application in transient electromagnetic method (TEM) 3D interpretation. The diffusive EM field is known to have a unique integral representation in terms of a fictitious wave field that satisfies a wave equation. The continuous imaging of TEM can be accomplished using the imaging methods in seismic interpretation after the diffusion equation is transformed into a fictitious wave equation. The interpretation method based on the imaging of a fictitious wave field could be used as a fast 3D inversion method. Moreover, the fictitious wave field possesses some wave field features making it possible for the application of a wave field interpretation method in TEM to improve the prospecting resolution.Wave field transformation is a key issue in the migration imaging of a fictitious wave field. The equation in the wave field transformation belongs to the first class Fredholm integration equation, which is a typical ill-posed equation. Additionally, TEM has a large dynamic time range, which also facilitates the weakness of this ill-posed problem. The wave field transformation is implemented by using pre-conditioned regularized conjugate gradient method. The continuous imaging of a fictitious wave field is implemented by using Kirchhoff integration. A synthetic aperture and deconvolution algorithm is also introduced to improve the interpretation resolution. We interpreted field data by the method proposed in this paper, and obtained a satisfying interpretation result. (paper)

  6. 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.

  7. Orthoscopic real-image display of digital holograms.

    Science.gov (United States)

    Makowski, P L; Kozacki, T; Zaperty, W

    2017-10-01

    We present a practical solution for the long-standing problem of depth inversion in real-image holographic display of digital holograms. It relies on a field lens inserted in front of the spatial light modulator device addressed by a properly processed hologram. The processing algorithm accounts for pixel size and wavelength mismatch between capture and display devices in a way that prevents image deformation. Complete images of large dimensions are observable from one position with a naked eye. We demonstrate the method experimentally on a 10-cm-long 3D object using a single full-HD spatial light modulator, but it can supplement most holographic displays designed to form a real image, including circular wide angle configurations.

  8. Infective endocarditis detection through SPECT/CT images digital processing

    Science.gov (United States)

    Moreno, Albino; Valdés, Raquel; Jiménez, Luis; Vallejo, Enrique; Hernández, Salvador; Soto, Gabriel

    2014-03-01

    Infective endocarditis (IE) is a difficult-to-diagnose pathology, since its manifestation in patients is highly variable. In this work, it was proposed a semiautomatic algorithm based on SPECT images digital processing for the detection of IE using a CT images volume as a spatial reference. The heart/lung rate was calculated using the SPECT images information. There were no statistically significant differences between the heart/lung rates values of a group of patients diagnosed with IE (2.62+/-0.47) and a group of healthy or control subjects (2.84+/-0.68). However, it is necessary to increase the study sample of both the individuals diagnosed with IE and the control group subjects, as well as to improve the images quality.

  9. Digital Imaging and Communications in Medicine Whole Slide Imaging Connectathon at Digital Pathology Association Pathology Visions 2017.

    Science.gov (United States)

    Clunie, David; Hosseinzadeh, Dan; Wintell, Mikael; De Mena, David; Lajara, Nieves; Garcia-Rojo, Marcial; Bueno, Gloria; Saligrama, Kiran; Stearrett, Aaron; Toomey, David; Abels, Esther; Apeldoorn, Frank Van; Langevin, Stephane; Nichols, Sean; Schmid, Joachim; Horchner, Uwe; Beckwith, Bruce; Parwani, Anil; Pantanowitz, Liron

    2018-01-01

    As digital pathology systems for clinical diagnostic work applications become mainstream, interoperability between these systems from different vendors becomes critical. For the first time, multiple digital pathology vendors have publicly revealed the use of the digital imaging and communications in medicine (DICOM) standard file format and network protocol to communicate between separate whole slide acquisition, storage, and viewing components. Note the use of DICOM for clinical diagnostic applications is still to be validated in the United States. The successful demonstration shows that the DICOM standard is fundamentally sound, though many lessons were learned. These lessons will be incorporated as incremental improvements in the standard, provide more detailed profiles to constrain variation for specific use cases, and offer educational material for implementers. Future Connectathon events will expand the scope to include more devices and vendors, as well as more ambitious use cases including laboratory information system integration and annotation for image analysis, as well as more geographic diversity. Users should request DICOM features in all purchases and contracts. It is anticipated that the growth of DICOM-compliant manufacturers will likely also ease DICOM for pathology becoming a recognized standard and as such the regulatory pathway for digital pathology products.

  10. [Evaluation of dental plaque by quantitative digital image analysis system].

    Science.gov (United States)

    Huang, Z; Luan, Q X

    2016-04-18

    To analyze the plaque staining image by using image analysis software, to verify the maneuverability, practicability and repeatability of this technique, and to evaluate the influence of different plaque stains. In the study, 30 volunteers were enrolled from the new dental students of Peking University Health Science Center in accordance with the inclusion criteria. The digital images of the anterior teeth were acquired after plaque stained according to filming standardization.The image analysis was performed using Image Pro Plus 7.0, and the Quigley-Hein plaque indexes of the anterior teeth were evaluated. The plaque stain area percentage and the corresponding dental plaque index were highly correlated,and the Spearman correlation coefficient was 0.776 (Pchart showed only a few spots outside the 95% consistency boundaries. The different plaque stains image analysis results showed that the difference of the tooth area measurements was not significant, while the difference of the plaque area measurements significant (P<0.01). This method is easy in operation and control,highly related to the calculated percentage of plaque area and traditional plaque index, and has good reproducibility.The different plaque staining method has little effect on image segmentation results.The sensitive plaque stain for image analysis is suggested.

  11. Hard copies for digital medical images: an overview

    Science.gov (United States)

    Blume, Hartwig R.; Muka, Edward

    1995-04-01

    This paper is a condensed version of an invited overview on the technology of film hard-copies used in radiology. Because the overview was given to an essentially nonmedical audience, the reliance on film hard-copies in radiology is outlined in greater detail. The overview is concerned with laser image recorders generating monochrome prints on silver-halide films. The basic components of laser image recorders are sketched. The paper concentrates on the physical parameters - characteristic function, dynamic range, digitization resolution, modulation transfer function, and noise power spectrum - which define image quality and information transfer capability of the printed image. A preliminary approach is presented to compare the printed image quality with noise in the acquired image as well as with the noise of state-of- the-art cathode-ray-tube display systems. High-performance laser-image- recorder/silver-halide-film/light-box systems are well capable of reproducing acquired radiologic information. Most recently development was begun toward a display function standard for soft-copy display systems to facilitate similarity of image presentation between different soft-copy displays as well as between soft- and hard-copy displays. The standard display function is based on perceptional linearization. The standard is briefly reviewed to encourage the printer industry to adopt it, too.

  12. Rethinking Over Textuality of Digital Image: A Methodological Proposal for Pleasant Reading on Digital Screens

    Directory of Open Access Journals (Sweden)

    Cristian Álvarez

    2009-12-01

    Full Text Available It sets out the necessity about thinking over the instructional function of image in digital world under the light of the new opportunities of a methodological proposal to read as a game. First, for this reason it exams the perceptions of García Canclini about the reading of university students, and its problems on the context of new technologies: accumulation of information versus weakening of reflection. To this situation it adds the no appreciation of visual images. Faced with this problematic situation, and with the aim of sketching out options, it analyzes two experiences about books: the “tasty” reading of texts (the “good reading”, and the potentialities presented in the essential characteristics of playing. So, it proposes a methodology shaped for five steps to read images on digital screen. Its aim is seizing the possibilities of “good reading” to expand the comprehension of the visual information perceived through the screen. The proposal puts the accent in the textuality of representational surface of an image. Also it brings the attentive visual route about in order to enable to identify both significant forms and spaces. This proposal is illustrated with examples.

  13. Digital filtering and reconstruction of coded aperture images

    International Nuclear Information System (INIS)

    Tobin, K.W. Jr.

    1987-01-01

    The real-time neutron radiography facility at the University of Virginia has been used for both transmission radiography and computed tomography. Recently, a coded aperture system has been developed to permit the extraction of three dimensional information from a low intensity field of radiation scattered by an extended object. Short wave-length radiations (e.g. neutrons) are not easily image because of the difficulties in achieving diffraction and refraction with a conventional lens imaging system. By using a coded aperture approach, an imaging system has been developed that records and reconstructs an object from an intensity distribution. This system has a signal-to-noise ratio that is proportional to the total open area of the aperture making it ideal for imaging with a limiting intensity radiation field. The main goal of this research was to develope and implement the digital methods and theory necessary for the reconstruction process. Several real-time video systems, attached to an Intellect-100 image processor, a DEC PDP-11 micro-computer, and a Convex-1 parallel processing mainframe were employed. This system, coupled with theoretical extensions and improvements, allowed for retrieval of information previously unobtainable by earlier optical methods. The effect of thermal noise, shot noise, and aperture related artifacts were examined so that new digital filtering techniques could be constructed and implemented. Results of image data filtering prior to and following the reconstruction process are reported. Improvements related to the different signal processing methods are emphasized. The application and advantages of this imaging technique to the field of non-destructive testing are also discussed

  14. Trustworthiness of digital government services : deriving a comprehensive theory through interpretive structural modelling

    NARCIS (Netherlands)

    Janssen, M.F.W.H.A.; Rana, Nripendra P.; Slade, Emma L.; Dwivedi, Yogesh K.

    2017-01-01

    Having its origin in public administration, trustworthiness is a significant concept in digital government research, influencing the relationships between citizens and governments. However, the interrelationships between the facets of trustworthiness are given inadequate attention. Therefore, the

  15. [Evaluating the maturity of IT-supported clinical imaging and diagnosis using the Digital Imaging Adoption Model : Are your clinical imaging processes ready for the digital era?

    Science.gov (United States)

    Studzinski, J

    2017-06-01

    The Digital Imaging Adoption Model (DIAM) has been jointly developed by HIMSS Analytics and the European Society of Radiology (ESR). It helps evaluate the maturity of IT-supported processes in medical imaging, particularly in radiology. This eight-stage maturity model drives your organisational, strategic and tactical alignment towards imaging-IT planning. The key audience for the model comprises hospitals with imaging centers, as well as external imaging centers that collaborate with hospitals. The assessment focuses on different dimensions relevant to digital imaging, such as software infrastructure and usage, workflow security, clinical documentation and decision support, data exchange and analytical capabilities. With its standardised approach, it enables regional, national and international benchmarking. All DIAM participants receive a structured report that can be used as a basis for presenting, e.g. budget planning and investment decisions at management level.

  16. Independent transmission of sign language interpreter in DVB: assessment of image compression

    Science.gov (United States)

    Zatloukal, Petr; Bernas, Martin; Dvořák, LukáÅ.¡

    2015-02-01

    Sign language on television provides information to deaf that they cannot get from the audio content. If we consider the transmission of the sign language interpreter over an independent data stream, the aim is to ensure sufficient intelligibility and subjective image quality of the interpreter with minimum bit rate. The work deals with the ROI-based video compression of Czech sign language interpreter implemented to the x264 open source library. The results of this approach are verified in subjective tests with the deaf. They examine the intelligibility of sign language expressions containing minimal pairs for different levels of compression and various resolution of image with interpreter and evaluate the subjective quality of the final image for a good viewing experience.

  17. Textured digital elevation model formation from low-cost UAV LADAR/digital image data

    Science.gov (United States)

    Bybee, Taylor C.; Budge, Scott E.

    2015-05-01

    Textured digital elevation models (TDEMs) have valuable use in precision agriculture, situational awareness, and disaster response. However, scientific-quality models are expensive to obtain using conventional aircraft-based methods. The cost of creating an accurate textured terrain model can be reduced by using a low-cost (processing step and enables both 2D- and 3D-image registration techniques to be used. This paper describes formation of TDEMs using simulated data from a small UAV gathering swaths of texel images of the terrain below. Being a low-cost UAV, only a coarse knowledge of position and attitude is known, and thus both 2D- and 3D-image registration techniques must be used to register adjacent swaths of texel imagery to create a TDEM. The process of creating an aggregate texel image (a TDEM) from many smaller texel image swaths is described. The algorithm is seeded with the rough estimate of position and attitude of each capture. Details such as the required amount of texel image overlap, registration models, simulated flight patterns (level and turbulent), and texture image formation are presented. In addition, examples of such TDEMs are shown and analyzed for accuracy.

  18. Effectiveness of an e-Learning Platform for Image Interpretation Education of Medical Staff and Students.

    Science.gov (United States)

    Ogura, Akio; Hayashi, Norio; Negishi, Tohru; Watanabe, Haruyuki

    2018-05-09

    Medical staff must be able to perform accurate initial interpretations of radiography to prevent diagnostic errors. Education in medical image interpretation is an ongoing need that is addressed by text-based and e-learning platforms. The effectiveness of these methods has been previously reported. Here, we describe the effectiveness of an e-learning platform used for medical image interpretation education. Ten third-year medical students without previous experience in chest radiography interpretation were provided with e-learning instructions. Accuracy of diagnosis using chest radiography was provided before and after e-learning education. We measured detection accuracy for two image groups: nodular shadow and ground-glass shadow. We also distributed the e-learning system to the two groups and analyzed the effectiveness of education for both types of image shadow. The mean correct answer rate after the 2-week e-learning period increased from 34.5 to 72.7%. Diagnosis of the ground glass shadow improved significantly more than that of the mass shadow. Education using the e-leaning platform is effective for interpretation of chest radiography results. E-learning is particularly effective for the interpretation of chest radiography images containing ground glass shadow.

  19. Image noise reduction algorithm for digital subtraction angiography: clinical results.

    Science.gov (United States)

    Söderman, Michael; Holmin, Staffan; Andersson, Tommy; Palmgren, Charlotta; Babic, Draženko; Hoornaert, Bart

    2013-11-01

    To test the hypothesis that an image noise reduction algorithm designed for digital subtraction angiography (DSA) in interventional neuroradiology enables a reduction in the patient entrance dose by a factor of 4 while maintaining image quality. This clinical prospective study was approved by the local ethics committee, and all 20 adult patients provided informed consent. DSA was performed with the default reference DSA program, a quarter-dose DSA program with modified acquisition parameters (to reduce patient radiation dose exposure), and a real-time noise-reduction algorithm. Two consecutive biplane DSA data sets were acquired in each patient. The dose-area product (DAP) was calculated for each image and compared. A randomized, blinded, offline reading study was conducted to show noninferiority of the quarter-dose image sets. Overall, 40 samples per treatment group were necessary to acquire 80% power, which was calculated by using a one-sided α level of 2.5%. The mean DAP with the quarter-dose program was 25.3% ± 0.8 of that with the reference program. The median overall image quality scores with the reference program were 9, 13, and 12 for readers 1, 2, and 3, respectively. These scores increased slightly to 12, 15, and 12, respectively, with the quarter-dose program imaging chain. In DSA, a change in technique factors combined with a real-time noise-reduction algorithm will reduce the patient entrance dose by 75%, without a loss of image quality. RSNA, 2013

  20. Effect of image scaling and segmentation in digital rock characterisation

    Science.gov (United States)

    Jones, B. D.; Feng, Y. T.

    2016-04-01

    Digital material characterisation from microstructural geometry is an emerging field in computer simulation. For permeability characterisation, a variety of studies exist where the lattice Boltzmann method (LBM) has been used in conjunction with computed tomography (CT) imaging to simulate fluid flow through microscopic rock pores. While these previous works show that the technique is applicable, the use of binary image segmentation and the bounceback boundary condition results in a loss of grain surface definition when the modelled geometry is compared to the original CT image. We apply the immersed moving boundary (IMB) condition of Noble and Torczynski as a partial bounceback boundary condition which may be used to better represent the geometric definition provided by a CT image. The IMB condition is validated against published work on idealised porous geometries in both 2D and 3D. Following this, greyscale image segmentation is applied to a CT image of Diemelstadt sandstone. By varying the mapping of CT voxel densities to lattice sites, it is shown that binary image segmentation may underestimate the true permeability of the sample. A CUDA-C-based code, LBM-C, was developed specifically for this work and leverages GPU hardware in order to carry out computations.

  1. Coherent imaging with incoherent light in digital holographic microscopy

    Science.gov (United States)

    Chmelik, Radim

    2012-01-01

    Digital holographic microscope (DHM) allows for imaging with a quantitative phase contrast. In this way it becomes an important instrument, a completely non-invasive tool for a contrast intravital observation of living cells and a cell drymass density distribution measurement. A serious drawback of current DHMs is highly coherent illumination which makes the lateral resolution worse and impairs the image quality by a coherence noise and a parasitic interference. An uncompromising solution to this problem can be found in the Leith concept of incoherent holography. An off-axis hologram can be formed with arbitrary degree of light coherence in systems equipped with an achromatic interferometer and thus the resolution and the image quality typical for an incoherent-light wide-field microscopy can be achieved. In addition, advanced imaging modes based on limited coherence can be utilized. The typical example is a coherence-gating effect which provides a finite axial resolution and makes DHM image similar to that of a confocal microscope. These possibilities were described theoretically using the formalism of three-dimensional coherent transfer functions and proved experimentally by the coherence-controlled holographic microscope which is DHM based on the Leith achromatic interferometer. Quantitative-phase-contrast imaging is demonstrated with incoherent light by the living cancer cells observation and their motility evaluation. The coherence-gating effect was proved by imaging of model samples through a scattering layer and living cells inside an opalescent medium.

  2. Fingerprint Image Enhancement Based on Second Directional Derivative of the Digital Image

    Directory of Open Access Journals (Sweden)

    Onnia Vesa

    2002-01-01

    Full Text Available This paper presents a novel approach of fingerprint image enhancement that relies on detecting the fingerprint ridges as image regions where the second directional derivative of the digital image is positive. A facet model is used in order to approximate the derivatives at each image pixel based on the intensity values of pixels located in a certain neighborhood. We note that the size of this neighborhood has a critical role in achieving accurate enhancement results. Using neighborhoods of various sizes, the proposed algorithm determines several candidate binary representations of the input fingerprint pattern. Subsequently, an output binary ridge-map image is created by selecting image zones, from the available binary image candidates, according to a MAP selection rule. Two public domain collections of fingerprint images are used in order to objectively assess the performance of the proposed fingerprint image enhancement approach.

  3. A Versatile Image Processor For Digital Diagnostic Imaging And Its Application In Computed Radiography

    Science.gov (United States)

    Blume, H.; Alexandru, R.; Applegate, R.; Giordano, T.; Kamiya, K.; Kresina, R.

    1986-06-01

    In a digital diagnostic imaging department, the majority of operations for handling and processing of images can be grouped into a small set of basic operations, such as image data buffering and storage, image processing and analysis, image display, image data transmission and image data compression. These operations occur in almost all nodes of the diagnostic imaging communications network of the department. An image processor architecture was developed in which each of these functions has been mapped into hardware and software modules. The modular approach has advantages in terms of economics, service, expandability and upgradeability. The architectural design is based on the principles of hierarchical functionality, distributed and parallel processing and aims at real time response. Parallel processing and real time response is facilitated in part by a dual bus system: a VME control bus and a high speed image data bus, consisting of 8 independent parallel 16-bit busses, capable of handling combined up to 144 MBytes/sec. The presented image processor is versatile enough to meet the video rate processing needs of digital subtraction angiography, the large pixel matrix processing requirements of static projection radiography, or the broad range of manipulation and display needs of a multi-modality diagnostic work station. Several hardware modules are described in detail. For illustrating the capabilities of the image processor, processed 2000 x 2000 pixel computed radiographs are shown and estimated computation times for executing the processing opera-tions are presented.

  4. High Res at High Speed: Automated Delivery of High-Resolution Images from Digital Library Collections

    Science.gov (United States)

    Westbrook, R. Niccole; Watkins, Sean

    2012-01-01

    As primary source materials in the library are digitized and made available online, the focus of related library services is shifting to include new and innovative methods of digital delivery via social media, digital storytelling, and community-based and consortial image repositories. Most images on the Web are not of sufficient quality for most…

  5. Using x-ray mammograms to assist in microwave breast image interpretation.

    Science.gov (United States)

    Curtis, Charlotte; Frayne, Richard; Fear, Elise

    2012-01-01

    Current clinical breast imaging modalities include ultrasound, magnetic resonance (MR) imaging, and the ubiquitous X-ray mammography. Microwave imaging, which takes advantage of differing electromagnetic properties to obtain image contrast, shows potential as a complementary imaging technique. As an emerging modality, interpretation of 3D microwave images poses a significant challenge. MR images are often used to assist in this task, and X-ray mammograms are readily available. However, X-ray mammograms provide 2D images of a breast under compression, resulting in significant geometric distortion. This paper presents a method to estimate the 3D shape of the breast and locations of regions of interest from standard clinical mammograms. The technique was developed using MR images as the reference 3D shape with the future intention of using microwave images. Twelve breast shapes were estimated and compared to ground truth MR images, resulting in a skin surface estimation accurate to within an average Euclidean distance of 10 mm. The 3D locations of regions of interest were estimated to be within the same clinical area of the breast as corresponding regions seen on MR imaging. These results encourage investigation into the use of mammography as a source of information to assist with microwave image interpretation as well as validation of microwave imaging techniques.

  6. Using X-Ray Mammograms to Assist in Microwave Breast Image Interpretation

    Directory of Open Access Journals (Sweden)

    Charlotte Curtis

    2012-01-01

    Full Text Available Current clinical breast imaging modalities include ultrasound, magnetic resonance (MR imaging, and the ubiquitous X-ray mammography. Microwave imaging, which takes advantage of differing electromagnetic properties to obtain image contrast, shows potential as a complementary imaging technique. As an emerging modality, interpretation of 3D microwave images poses a significant challenge. MR images are often used to assist in this task, and X-ray mammograms are readily available. However, X-ray mammograms provide 2D images of a breast under compression, resulting in significant geometric distortion. This paper presents a method to estimate the 3D shape of the breast and locations of regions of interest from standard clinical mammograms. The technique was developed using MR images as the reference 3D shape with the future intention of using microwave images. Twelve breast shapes were estimated and compared to ground truth MR images, resulting in a skin surface estimation accurate to within an average Euclidean distance of 10 mm. The 3D locations of regions of interest were estimated to be within the same clinical area of the breast as corresponding regions seen on MR imaging. These results encourage investigation into the use of mammography as a source of information to assist with microwave image interpretation as well as validation of microwave imaging techniques.

  7. Imaging of the digital arteries: Digital subtraction angiography versus conventional angiography

    International Nuclear Information System (INIS)

    Menanteau, B.P.; Treutenaere, J.M.; Marcus, C.; Ladam, V.; Gausserand, F.

    1986-01-01

    The authors report their experience with the use of digital subtraction angiography (DSA) and conventional angiography of the hand. Of the 95 patients in the study group, 80 underwent conventional angiography and 15 underwent DSA. They analyzed the studies with regard to the type and amount of contrast agent used, the number of radiographs needed, and the diagnostic quality of the images. Conventional angiography often requires general anesthesia, magnification, and pharmaco-angiographic techniques to improve the image-based diagnosis. In comparison with conventional angiography, intraarterial DSA is characterized by improved contrast sensitivity and inferior spatial resolution. However, DSA provides images as acceptable as those of conventional angiography. Smaller catheters can be used, and the examination is performed under local anesthesia. The authors conclude that intraarterial DSA is now the technique of choice for examining patients with chronic ischemia of the hand

  8. Automatic Microaneurysm Detection and Characterization Through Digital Color Fundus Images

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Charles; Veras, Rodrigo; Ramalho, Geraldo; Medeiros, Fatima; Ushizima, Daniela

    2008-08-29

    Ocular fundus images can provide information about retinal, ophthalmic, and even systemic diseases such as diabetes. Microaneurysms (MAs) are the earliest sign of Diabetic Retinopathy, a frequently observed complication in both type 1 and type 2 diabetes. Robust detection of MAs in digital color fundus images is critical in the development of automated screening systems for this kind of disease. Automatic grading of these images is being considered by health boards so that the human grading task is reduced. In this paper we describe segmentation and the feature extraction methods for candidate MAs detection.We show that the candidate MAs detected with the methodology have been successfully classified by a MLP neural network (correct classification of 84percent).

  9. Digital processing methodology applied to exploring of radiological images

    International Nuclear Information System (INIS)

    Oliveira, Cristiane de Queiroz

    2004-01-01

    In this work, digital image processing is applied as a automatic computational method, aimed for exploring of radiological images. It was developed an automatic routine, from the segmentation and post-processing techniques to the radiology images acquired from an arrangement, consisting of a X-ray tube, target and filter of molybdenum, of 0.4 mm and 0.03 mm, respectively, and CCD detector. The efficiency of the methodology developed is showed in this work, through a case study, where internal injuries in mangoes are automatically detected and monitored. This methodology is a possible tool to be introduced in the post-harvest process in packing houses. A dichotomic test was applied to evaluate a efficiency of the method. The results show a success of 87.7% to correct diagnosis and 12.3% to failures to correct diagnosis with a sensibility of 93% and specificity of 80%. (author)

  10. Imaging and computational considerations for image computed permeability: Operating envelope of Digital Rock Physics

    Science.gov (United States)

    Saxena, Nishank; Hows, Amie; Hofmann, Ronny; Alpak, Faruk O.; Freeman, Justin; Hunter, Sander; Appel, Matthias

    2018-06-01

    This study defines the optimal operating envelope of the Digital Rock technology from the perspective of imaging and numerical simulations of transport properties. Imaging larger volumes of rocks for Digital Rock Physics (DRP) analysis improves the chances of achieving a Representative Elementary Volume (REV) at which flow-based simulations (1) do not vary with change in rock volume, and (2) is insensitive to the choice of boundary conditions. However, this often comes at the expense of image resolution. This trade-off exists due to the finiteness of current state-of-the-art imaging detectors. Imaging and analyzing digital rocks that sample the REV and still sufficiently resolve pore throats is critical to ensure simulation quality and robustness of rock property trends for further analysis. We find that at least 10 voxels are needed to sufficiently resolve pore throats for single phase fluid flow simulations. If this condition is not met, additional analyses and corrections may allow for meaningful comparisons between simulation results and laboratory measurements of permeability, but some cases may fall outside the current technical feasibility of DRP. On the other hand, we find that the ratio of field of view and effective grain size provides a reliable measure of the REV for siliciclastic rocks. If this ratio is greater than 5, the coefficient of variation for single-phase permeability simulations drops below 15%. These imaging considerations are crucial when comparing digitally computed rock flow properties with those measured in the laboratory. We find that the current imaging methods are sufficient to achieve both REV (with respect to numerical boundary conditions) and required image resolution to perform digital core analysis for coarse to fine-grained sandstones.

  11. Quantifying biodiversity using digital cameras and automated image analysis.

    Science.gov (United States)

    Roadknight, C. M.; Rose, R. J.; Barber, M. L.; Price, M. C.; Marshall, I. W.

    2009-04-01

    Monitoring the effects on biodiversity of extensive grazing in complex semi-natural habitats is labour intensive. There are also concerns about the standardization of semi-quantitative data collection. We have chosen to focus initially on automating the most time consuming aspect - the image analysis. The advent of cheaper and more sophisticated digital camera technology has lead to a sudden increase in the number of habitat monitoring images and information that is being collected. We report on the use of automated trail cameras (designed for the game hunting market) to continuously capture images of grazer activity in a variety of habitats at Moor House National Nature Reserve, which is situated in the North of England at an average altitude of over 600m. Rainfall is high, and in most areas the soil consists of deep peat (1m to 3m), populated by a mix of heather, mosses and sedges. The cameras have been continuously in operation over a 6 month period, daylight images are in full colour and night images (IR flash) are black and white. We have developed artificial intelligence based methods to assist in the analysis of the large number of images collected, generating alert states for new or unusual image conditions. This paper describes the data collection techniques, outlines the quantitative and qualitative data collected and proposes online and offline systems that can reduce the manpower overheads and increase focus on important subsets in the collected data. By converting digital image data into statistical composite data it can be handled in a similar way to other biodiversity statistics thus improving the scalability of monitoring experiments. Unsupervised feature detection methods and supervised neural methods were tested and offered solutions to simplifying the process. Accurate (85 to 95%) categorization of faunal content can be obtained, requiring human intervention for only those images containing rare animals or unusual (undecidable) conditions, and

  12. USRC: a new strategy for adding digital images to the medical school curriculum.

    Science.gov (United States)

    Pinelle, David; Burbridge, Brent; Kalra, Neil

    2012-10-01

    Many medical schools use learning management systems (LMSs) to give students access to online lecture notes, assignments, quizzes, and other learning resources. LMSs can also be used to provide access to digital radiology images, potentially improving preclinical teaching in anatomy, physiology, and pathology while also allowing students to develop interpretation skills that are important in clinical practice. However, it is unclear how radiology images can best be stored, imported, and displayed in an LMS. We developed University of Saskatchewan Radiology Courseware (USRC), a new web application that allows course designers to import images into pages linked to BlackBoard Learn, a popular LMS. Page content, including images, annotations, captions, and supporting text, are stored as teaching cases on a MIRC (Medical Imaging Resource Center) server. Course designers create cases in MIRC, and then create a corresponding page in BlackBoard by modifying an HTML template so that it holds the URL of a MIRC case. When a user visits the page in BlackBoard, the page requests content from the MIRC case, reformats the text for display in BlackBoard, and loads an image viewer plug-in that allows students to view and interact with the images stored in the case. The USRC technology can be used to reformat MIRC cases for presentation in any website or in any learning management system that supports custom pages written in HTML with embedded JavaScript.

  13. improvement of digital image watermarking techniques based on FPGA implementation

    International Nuclear Information System (INIS)

    EL-Hadedy, M.E

    2006-01-01

    digital watermarking provides the ownership of a piece of digital data by marking the considered data invisibly or visibly. this can be used to protect several types of multimedia objects such as audio, text, image and video. this thesis demonstrates the different types of watermarking techniques such as (discrete cosine transform (DCT) and discrete wavelet transform (DWT) and their characteristics. then, it classifies these techniques declaring their advantages and disadvantages. an improved technique with distinguished features, such as peak signal to noise ratio ( PSNR) and similarity ratio (SR) has been introduced. the modified technique has been compared with the other techniques by measuring heir robustness against differ attacks. finally, field programmable gate arrays (FPGA) based implementation and comparison, for the proposed watermarking technique have been presented and discussed

  14. The Cultural Interpretation of Food Images in the Joy luck Club

    Institute of Scientific and Technical Information of China (English)

    童安剑

    2014-01-01

    The Joy Luck Club employs a wide range of images, which embody the complicated and profound Chinese culture and eastern philosophy, to highlight the cultural conflicts and fusion within and beyond the narrations. Foods, an important image to interpret Chinese culture, have been discussed to show the cultural conflicts and the final reconciliation.

  15. Cultural Interpretations of the Visual Meaning of Icons and Images Used in North American Web Design

    Science.gov (United States)

    Knight, Eliot; Gunawardena, Charlotte N.; Aydin, Cengiz Hakan

    2009-01-01

    This study examines cross-cultural interpretations of icons and images drawn from US academic websites. Participants from Morocco, Sri Lanka, Turkey, and the USA responded to an online questionnaire containing 18 icons and images representing online functions and information types common on US academic websites. Participants supplied meanings for…

  16. The wavelet/scalar quantization compression standard for digital fingerprint images

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, J.N.; Brislawn, C.M.

    1994-04-01

    A new digital image compression standard has been adopted by the US Federal Bureau of Investigation for use on digitized gray-scale fingerprint images. The algorithm is based on adaptive uniform scalar quantization of a discrete wavelet transform image decomposition and is referred to as the wavelet/scalar quantization standard. The standard produces archival quality images at compression ratios of around 20:1 and will allow the FBI to replace their current database of paper fingerprint cards with digital imagery.

  17. Report from the research committee of digital imaging standardization in nuclear medicine

    International Nuclear Information System (INIS)

    Nakamura, Yutaka; Ise, Toshihide; Isetani, Osamu; Ichihara, Takashi; Ohya, Nobuyoshi; Kanaya, Shinichi; Fukuda, Toshio; Horii, Hitoshi.

    1994-01-01

    Since digital scintillation camera systems were developed in 1982, digital imaging is rapidly replacing analog imaging. During the first year, the research committee of digital imaging standardization has collected and analyzed basic data concerning digital examination equipment systems, display equipments, films, and hardware and software techniques to determine items required for the standardization of digital imaging. During the second year, it has done basic phantom studies to assess digital images and analyzed the results from both physical and visual viewpoints. On the basis of the outcome of the research committee's activities and the nationwide survey, the draft of digital imaging standardization in nuclear medicine has been presented. In this paper. the analytical data of the two-year survey, made by the research committee of digital imaging standardization, are presented. The descriptions are given under the following four items: (1) standardization digital examination techniques, (2) standardization of display techniques, (3) the count and pixel of digital images, and (4) standardization of digital imaging techniques. (N.K.)

  18. On the technique of digital X-ray image processing, especially of digital substraction angiography

    International Nuclear Information System (INIS)

    Pfeiler, M.; Marhoff, P.

    1983-01-01

    Digital radiography, especially in the form of subtraction angiography, has found special consideration during the last two years as could be noted at many radiological conventions. Also a series of symposia was especially devoted to this subject. The extensive picture material shown at these conventions does not only document an important extension of the fields of application, but also an important increment in clinical and technical experience. Two pictures may represent many other examples: with a time lag of less than one year the improvement of objective and subjective image quality is easy to recognize. The principle and the technology of digital radiography were demonstrated at these conventions as well as in this magazine, and they also were discussed in detail; therefore a comprehensive review with only a few concepts necessary for defining the topic is sufficient here. Of the different imaging techniques, the fluorographic and the pulsed operation techniques are discussed, especially with regard to the storage method used. The definition of these concepts follows later. Special emphasis is put on some considerations of the signal-to-noise ratio that represents an essential criterion of the image quality. (orig.) [de

  19. Comparison of different phantoms used in digital diagnostic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bor, Dogan, E-mail: bor@eng.ankara.edu.tr [Ankara University, Faculty of Engineering, Department of Engineering Physics. Tandogan, 06100 Ankara (Turkey); Unal, Elif, E-mail: elf.unall@gmail.com [Radat Dosimetry Laboratory Services, 06830, Golbasi, Ankara (Turkey); Uslu, Anil, E-mail: m.aniluslu@gmail.com [Radat Dosimetry Laboratory Services, 06830, Golbasi, Ankara (Turkey)

    2015-09-21

    The organs of extremity, chest, skull and lumbar were physically simulated using uniform PMMA slabs with different thicknesses alone and using these slabs together with aluminum plates and air gaps (ANSI Phantoms). The variation of entrance surface air kerma and scatter fraction with X-ray beam qualities was investigated for these phantoms and the results were compared with those measured from anthropomorphic phantoms. A flat panel digital radiographic system was used for all the experiments. Considerable variations of entrance surface air kermas were found for the same organs of different designs, and highest doses were measured for the PMMA slabs. A low contrast test tool and a contrast detail test object (CDRAD) were used together with each organ simulation of PMMA slabs and ANSI phantoms in order to test the clinical image qualities. Digital images of these phantom combinations and anthropomorphic phantoms were acquired in raw and clinically processed formats. Variation of image quality with kVp and post processing was evaluated using the numerical metrics of these test tools and measured contrast values from the anthropomorphic phantoms. Our results indicated that design of some phantoms may not be efficient enough to reveal the expected performance of the post processing algorithms.

  20. HD Photo: a new image coding technology for digital photography

    Science.gov (United States)

    Srinivasan, Sridhar; Tu, Chengjie; Regunathan, Shankar L.; Sullivan, Gary J.

    2007-09-01

    This paper introduces the HD Photo coding technology developed by Microsoft Corporation. The storage format for this technology is now under consideration in the ITU-T/ISO/IEC JPEG committee as a candidate for standardization under the name JPEG XR. The technology was developed to address end-to-end digital imaging application requirements, particularly including the needs of digital photography. HD Photo includes features such as good compression capability, high dynamic range support, high image quality capability, lossless coding support, full-format 4:4:4 color sampling, simple thumbnail extraction, embedded bitstream scalability of resolution and fidelity, and degradation-free compressed domain support of key manipulations such as cropping, flipping and rotation. HD Photo has been designed to optimize image quality and compression efficiency while also enabling low-complexity encoding and decoding implementations. To ensure low complexity for implementations, the design features have been incorporated in a way that not only minimizes the computational requirements of the individual components (including consideration of such aspects as memory footprint, cache effects, and parallelization opportunities) but results in a self-consistent design that maximizes the commonality of functional processing components.

  1. Medical image digital archive: a comparison of storage technologies

    Science.gov (United States)

    Chunn, Timothy; Hutchings, Matt

    1998-07-01

    A cost effective, high capacity digital archive system is one of the remaining key factors that will enable a radiology department to eliminate film as an archive medium. The ever increasing amount of digital image data is creating the need for huge archive systems that can reliably store and retrieve millions of images and hold from a few terabytes of data to possibly hundreds of terabytes. Selecting the right archive solution depends on a number of factors: capacity requirements, write and retrieval performance requirements, scaleability in capacity and performance, conformance to open standards, archive availability and reliability, security, cost, achievable benefits and cost savings, investment protection, and more. This paper addresses many of these issues. It compares and positions optical disk and magnetic tape technologies, which are the predominant archive mediums today. New technologies will be discussed, such as DVD and high performance tape. Price and performance comparisons will be made at different archive capacities, plus the effect of file size on random and pre-fetch retrieval time will be analyzed. The concept of automated migration of images from high performance, RAID disk storage devices to high capacity, NearlineR storage devices will be introduced as a viable way to minimize overall storage costs for an archive.

  2. Radiographer involvement in mammography image interpretation: A survey of United Kingdom practice

    International Nuclear Information System (INIS)

    Culpan, A.M.

    2016-01-01

    Breast cancer is most often diagnosed using x-ray mammography. Traditionally mammography images have been interpreted and reported by medically qualified practitioners – radiologists. Due to radiologist workforce shortages in recent years some non-medical practitioners, radiographers, now interpret and report mammography images. The aims of this survey were to describe the characteristics and practices of radiographers who interpret and report mammography images in NHS hospitals in the UK, and in particular to establish the extent of their practice beyond low-risk asymptomatic screening cases. This service evaluation demonstrated that UK radiographers are interpreting and reporting images across the full spectrum of clinical indications for mammography including: low-risk population screening, symptomatic, annual surveillance, family history and biopsy/surgical cases. The survey revealed that radiographers are involved in a diverse range of single and double reading practices where responsibility for diagnostic decision making is shared or transferred between radiologists and/or other radiographers. Comparative analysis of sub-group data suggested that there might be differences in the characteristics and practices of radiographers who interpret only low-risk screening mammograms and those who interpret and report a wider range of cases. The findings of this survey provide a platform for further research to investigate how and why the roles and responsibilities of radiographers who interpret and report mammograms vary between organisations, between practitioners and across different examinations. Further research is also needed to explore the implications of variation in practice for patients, practitioners and service providers. - Highlights: • UK radiographers interpret mammograms across the full spectrum of clinical indications. • UK radiographers are involved in a wide range of single/double mammography reading practices. • Characteristics required for

  3. Distribution of normal superficial ocular vessels in digital images.

    Science.gov (United States)

    Banaee, Touka; Ehsaei, Asieh; Pourreza, Hamidreza; Khajedaluee, Mohammad; Abrishami, Mojtaba; Basiri, Mohsen; Daneshvar Kakhki, Ramin; Pourreza, Reza

    2014-02-01

    To investigate the distribution of different-sized vessels in the digital images of the ocular surface, an endeavor which may provide useful information for future studies. This study included 295 healthy individuals. From each participant, four digital photographs of the superior and inferior conjunctivae of both eyes, with a fixed succession of photography (right upper, right lower, left upper, left lower), were taken with a slit lamp mounted camera. Photographs were then analyzed by a previously described algorithm for vessel detection in the digital images. The area (of the image) occupied by vessels (AOV) of different sizes was measured. Height, weight, fasting blood sugar (FBS) and hemoglobin levels were also measured and the relationship between these parameters and the AOV was investigated. These findings indicated a statistically significant difference in the distribution of the AOV among the four conjunctival areas. No significant correlations were noted between the AOV of each conjunctival area and the different demographic and biometric factors. Medium-sized vessels were the most abundant vessels in the photographs of the four investigated conjunctival areas. The AOV of the different sizes of vessels follows a normal distribution curve in the four areas of the conjunctiva. The distribution of the vessels in successive photographs changes in a specific manner, with the mean AOV becoming larger as the photos were taken from the right upper to the left lower area. The AOV of vessel sizes has a normal distribution curve and medium-sized vessels occupy the largest area of the photograph. Copyright © 2013 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  4. Automated extraction of chemical structure information from digital raster images

    Directory of Open Access Journals (Sweden)

    Shedden Kerby A

    2009-02-01

    Full Text Available Abstract Background To search for chemical structures in research articles, diagrams or text representing molecules need to be translated to a standard chemical file format compatible with cheminformatic search engines. Nevertheless, chemical information contained in research articles is often referenced as analog diagrams of chemical structures embedded in digital raster images. To automate analog-to-digital conversion of chemical structure diagrams in scientific research articles, several software systems have been developed. But their algorithmic performance and utility in cheminformatic research have not been investigated. Results This paper aims to provide critical reviews for these systems and also report our recent development of ChemReader – a fully automated tool for extracting chemical structure diagrams in research articles and converting them into standard, searchable chemical file formats. Basic algorithms for recognizing lines and letters representing bonds and atoms in chemical structure diagrams can be independently run in sequence from a graphical user interface-and the algorithm parameters can be readily changed-to facilitate additional development specifically tailored to a chemical database annotation scheme. Compared with existing software programs such as OSRA, Kekule, and CLiDE, our results indicate that ChemReader outperforms other software systems on several sets of sample images from diverse sources in terms of the rate of correct outputs and the accuracy on extracting molecular substructure patterns. Conclusion The availability of ChemReader as a cheminformatic tool for extracting chemical structure information from digital raster images allows research and development groups to enrich their chemical structure databases by annotating the entries with published research articles. Based on its stable performance and high accuracy, ChemReader may be sufficiently accurate for annotating the chemical database with links

  5. Radar image enhancement and simulation as an aid to interpretation and training

    Science.gov (United States)

    Frost, V. S.; Stiles, J. A.; Holtzman, J. C.; Dellwig, L. F.; Held, D. N.

    1980-01-01

    Greatly increased activity in the field of radar image applications in the coming years demands that techniques of radar image analysis, enhancement, and simulation be developed now. Since the statistical nature of radar imagery differs from that of photographic imagery, one finds that the required digital image processing algorithms (e.g., for improved viewing and feature extraction) differ from those currently existing. This paper addresses these problems and discusses work at the Remote Sensing Laboratory in image simulation and processing, especially for systems comparable to the formerly operational SEASAT synthetic aperture radar.

  6. An Experience of Forest Inventory by Photo Interpretation Method Based on Advanced Firmware and Digital Aerial Photographs of New Generation

    Directory of Open Access Journals (Sweden)

    V. I. Arkhipov

    2014-10-01

    Full Text Available The main stages of the developed technology of forest inventory by interpretation method, named «From survey – to project», with the use of modern aerial survey data, special software and hardware are discussed in the paper. A need for development of high-end technology of forest inventory is due to increasing demands of state, business, and civil community for actual and correct information about forests. The tasks of research were: integration software and hardware into single technology, testing on the real object, and development of recommendations for introduction into production and forming of system of preparing specialists for forest interpretation. Positive results of experimental works by measurement and analytical forest interpretation in stereo regime on base of photogrammetric software were obtained by specialists from Russia, Croatia, Belarus, and Sweden. In the technology «From survey – to project», the following instruments are used: photogrammetric complex Vision Map A3, digital photogrammetric system Photomod, program «ESAUL», GIS ArcGIS, special hardware for stereo visualization. Results of testing this technology are shown on example of model territory. Comparison of results of forest inventory obtained by interpretation method and results of control inventory obtained by enumeration method demonstrated that errors of determination of main forest inventory characteristics do not exceed the norms. The advantages of practical use of the technology are shown. It has been noted that forest inventory by interpretation method is a complex psychophysiological process and it requires an attraction of specialists with high qualification on base of special training. It is indicated the necessity of forming system for training forest inventory specialists on interpretation method. The designed and prepared curriculums and training manuals for interpretation method in forestry are listed.

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

    International Nuclear Information System (INIS)

    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. - Highlights: • Radiation dose in CR digital mammography (CRDM) systems was determined. • Image quality related with dose in CR digital mammography (CRDM) systems was analysed. • Image processing artefacts were observed and correlated with dose. • Measured entrance dose by TL phosphors could be good parameter for radiation protection optimization in patient

  8. Monitoring of civil engineering structures using Digital Image Correlation technique

    Science.gov (United States)

    Malesa, M.; Szczepanek, D.; Kujawińska, M.; Świercz, A.; Kołakowski, P.

    2010-06-01

    The Digital Image Correlation (DIC) technique enables full field, noncontact measurements of displacements and strains of a wide variety of objects. An adaptation of the DIC technique for monitoring of civil-engineering structures is presented in the paper. A general concept of the complex, automatic monitoring system, in which the DIC sensor plays an important role is described. Some new software features, which aim to facilitate outdoor measurements and speed up the correlation analysis, is also introduced. As an example of application, measurements of a railway bridge in Nieporet (Poland) are presented. The experimental results are compared with displacements of a FEM model of the bridge.

  9. Multiframe digitization of x-ray (TV) images (abstract)

    Science.gov (United States)

    Karpenko, V. A.; Khil'chenko, A. D.; Lysenko, A. P.; Panchenko, V. E.

    1989-07-01

    The work in progress deals with the experimental search for a technique of digitizing x-ray TV images. The small volume of the buffer memory of the analog-to-digital (A/D) converter (ADC) we have previously used to detect TV signals made it necessary to digitize only one line at a time of the television raster and also to make use of gating to gain the video information contained in the whole frame. This paper is devoted to multiframe digitizing. The recorder of video signals comprises a broadband 8-bit A/D converter, a buffer memory having 128K words and a control circuit which forms a necessary sequence of advance pulses for the A/D converter and the memory relative to the input frame and line sync pulses (FSP and LSP). The device provides recording of video signals corresponding to one or a few frames following one after another, or to their fragments. The control circuit is responsible for the separation of the required fragment of the TV image. When loading the limit registers, the following input parameters of the control circuit are set: the skipping of a definite number of lines after the next FSP, the number of the lines of recording inside a fragment, the frequency of the information lines inside a fragment, the delay in the start of the ADC conversion relative to the arrival of the LSP, the length of the information section of a line, and the frequency of taking the readouts in a line. In addition, among the instructions given are the number of frames of recording and the frequency of their sequence. Thus, the A/D converter operates only inside a given fragment of the TV image. The information is introduced into the memory in sequence, fragment by fragment, without skipping and is then extracted as samples according to the addresses needed for representation in the required form, and processing. The video signal recorder governs the shortest time of the ADC conversion per point of 250 ns. As before, among the apparatus used were an image vidicon with

  10. Systems of imaging digital systems in case of glaucoma

    International Nuclear Information System (INIS)

    Fernandez Argones, Liamet; Piloto Diaz, Ibrain; Coba Penna, Maria Josefa; Perez Tamayo, Bertila; Dominguez Randulfe, Marerneda; Trujillo Fonseca, Katia

    2009-01-01

    Now a day we can't consider the strict follow up in Glaucoma without the use of the digital analysis of image system of the optic nerve head and the retinal nerve fiber layer. This is a review about some contributions of Scanning Laser Polarimetry (GDx VCC, Carl Zeiss Meditec, Dublin, CA), Confocal Scanning Laser (Heidelberg Retina Tomograph HRT, Heidelberg Engineering Inc.) and Optical Coherence Tomography (Stratus OCT, Carl Zeiss Meditec, Alemania) in the diagnosis and follow up of Glaucoma. It's considered that objective measurement giving by them must be incorporate in the rigorous analysis of each glaucomatous patient

  11. Reevaluation of JPEG image compression to digitalized gastrointestinal endoscopic color images: a pilot study

    Science.gov (United States)

    Kim, Christopher Y.

    1999-05-01

    Endoscopic images p lay an important role in describing many gastrointestinal (GI) disorders. The field of radiology has been on the leading edge of creating, archiving and transmitting digital images. With the advent of digital videoendoscopy, endoscopists now have the ability to generate images for storage and transmission. X-rays can be compressed 30-40X without appreciable decline in quality. We reported results of a pilot study using JPEG compression of 24-bit color endoscopic images. For that study, the result indicated that adequate compression ratios vary according to the lesion and that images could be compressed to between 31- and 99-fold smaller than the original size without an appreciable decline in quality. The purpose of this study was to expand upon the methodology of the previous sty with an eye towards application for the WWW, a medium which would expand both clinical and educational purposes of color medical imags. The results indicate that endoscopists are able to tolerate very significant compression of endoscopic images without loss of clinical image quality. This finding suggests that even 1 MB color images can be compressed to well under 30KB, which is considered a maximal tolerable image size for downloading on the WWW.

  12. Desktop publishing and medical imaging: paper as hardcopy medium for digital images.

    Science.gov (United States)

    Denslow, S

    1994-08-01

    Desktop-publishing software and hardware has progressed to the point that many widely used word-processing programs are capable of printing high-quality digital images with many shades of gray from black to white. Accordingly, it should be relatively easy to print digital medical images on paper for reports, instructional materials, and in research notes. Components were assembled that were necessary for extracting image data from medical imaging devices and converting the data to a form usable by word-processing software. A system incorporating these components was implemented in a medical setting and has been operating for 18 months. The use of this system by medical staff has been monitored.

  13. Recent developments at JPL in the application of digital image processing techniques to astronomical images

    Science.gov (United States)

    Lorre, J. J.; Lynn, D. J.; Benton, W. D.

    1976-01-01

    Several techniques of a digital image-processing nature are illustrated which have proved useful in visual analysis of astronomical pictorial data. Processed digital scans of photographic plates of Stephans Quintet and NGC 4151 are used as examples to show how faint nebulosity is enhanced by high-pass filtering, how foreground stars are suppressed by linear interpolation, and how relative color differences between two images recorded on plates with different spectral sensitivities can be revealed by generating ratio images. Analyses are outlined which are intended to compensate partially for the blurring effects of the atmosphere on images of Stephans Quintet and to obtain more detailed information about Saturn's ring structure from low- and high-resolution scans of the planet and its ring system. The employment of a correlation picture to determine the tilt angle of an average spectral line in a low-quality spectrum is demonstrated for a section of the spectrum of Uranus.

  14. Robust digital image inpainting algorithm in the wireless environment

    Science.gov (United States)

    Karapetyan, G.; Sarukhanyan, H. G.; Agaian, S. S.

    2014-05-01

    Image or video inpainting is the process/art of retrieving missing portions of an image without introducing undesirable artifacts that are undetectable by an ordinary observer. An image/video can be damaged due to a variety of factors, such as deterioration due to scratches, laser dazzling effects, wear and tear, dust spots, loss of data when transmitted through a channel, etc. Applications of inpainting include image restoration (removing laser dazzling effects, dust spots, date, text, time, etc.), image synthesis (texture synthesis), completing panoramas, image coding, wireless transmission (recovery of the missing blocks), digital culture protection, image de-noising, fingerprint recognition, and film special effects and production. Most inpainting methods can be classified in two key groups: global and local methods. Global methods are used for generating large image regions from samples while local methods are used for filling in small image gaps. Each method has its own advantages and limitations. For example, the global inpainting methods perform well on textured image retrieval, whereas the classical local methods perform poorly. In addition, some of the techniques are computationally intensive; exceeding the capabilities of most currently used mobile devices. In general, the inpainting algorithms are not suitable for the wireless environment. This paper presents a new and efficient scheme that combines the advantages of both local and global methods into a single algorithm. Particularly, it introduces a blind inpainting model to solve the above problems by adaptively selecting support area for the inpainting scheme. The proposed method is applied to various challenging image restoration tasks, including recovering old photos, recovering missing data on real and synthetic images, and recovering the specular reflections in endoscopic images. A number of computer simulations demonstrate the effectiveness of our scheme and also illustrate the main properties

  15. Monitoring of the periodontal disease using digital image analyses

    International Nuclear Information System (INIS)

    Taba Junior, Mario.

    1995-01-01

    The radiographs play an important role in the diagnosis and management of periodontal disease although the most appropriate form of assessment vary. The great technologic advance and the easily accessible systems of digital image analyses, specify digitized radiographs, improve the diagnostic power. The studied group was 29 adults (14 female and 15 male) ranging in age from 18 to 45 years. They all had evidence of alveolar bone loss and established periodontitis. They were studied, without treatment, over a six month period with four posterior standardized vertical bite wings radiographs, electronic probing of attachment loss, and bacteriological and temperature analysis of periodontal pocket. The aim of this investigation was to determine the relationship between the loss of radiographic crestal bone height and probing attachment loss in digitized radiographs and show a standardization method for periodontal radiographs. Radiographic and probing attachment change at all sites, dichotomously classified as to not changing or loosing indicated 20.42% of sites were loosing by measurement of radiographic change and 5.29% were loosing by measurement of attachment change. There was concordance between the presence or absence of probing attachment loss and bone loss in 72% to 86% depending on the area. The results, admitting methodological limitations, indicate that when these two methods for the assessment of progressive periodontitis were used they represents measure degrees of different features of periodontitis and that the period of periodontal disease activity was detected in the either the soft tissue attachment or bone. (author)

  16. A dual-view digital tomosynthesis imaging technique for improved chest imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuncheng; Lai, Chao-Jen; Wang, Tianpeng; Shaw, Chris C., E-mail: cshaw@mdanderson.org [Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77054 (United States)

    2015-09-15

    Purpose: Digital tomosynthesis (DTS) has been shown to be useful for reducing the overlapping of abnormalities with anatomical structures at various depth levels along the posterior–anterior (PA) direction in chest radiography. However, DTS provides crude three-dimensional (3D) images that have poor resolution in the lateral view and can only be displayed with reasonable quality in the PA view. Furthermore, the spillover of high-contrast objects from off-fulcrum planes generates artifacts that may impede the diagnostic use of the DTS images. In this paper, the authors describe and demonstrate the use of a dual-view DTS technique to improve the accuracy of the reconstructed volume image data for more accurate rendition of the anatomy and slice images with improved resolution and reduced artifacts, thus allowing the 3D image data to be viewed in views other than the PA view. Methods: With the dual-view DTS technique, limited angle scans are performed and projection images are acquired in two orthogonal views: PA and lateral. The dual-view projection data are used together to reconstruct 3D images using the maximum likelihood expectation maximization iterative algorithm. In this study, projection images were simulated or experimentally acquired over 360° using the scanning geometry for cone beam computed tomography (CBCT). While all projections were used to reconstruct CBCT images, selected projections were extracted and used to reconstruct single- and dual-view DTS images for comparison with the CBCT images. For realistic demonstration and comparison, a digital chest phantom derived from clinical CT images was used for the simulation study. An anthropomorphic chest phantom was imaged for the experimental study. The resultant dual-view DTS images were visually compared with the single-view DTS images and CBCT images for the presence of image artifacts and accuracy of CT numbers and anatomy and quantitatively compared with root-mean-square-deviation (RMSD) values

  17. Fuzzy logic and image processing techniques for the interpretation of seismic data

    International Nuclear Information System (INIS)

    Orozco-del-Castillo, M G; Ortiz-Alemán, C; Rodríguez-Castellanos, A; Urrutia-Fucugauchi, J

    2011-01-01

    Since interpretation of seismic data is usually a tedious and repetitive task, the ability to do so automatically or semi-automatically has become an important objective of recent research. We believe that the vagueness and uncertainty in the interpretation process makes fuzzy logic an appropriate tool to deal with seismic data. In this work we developed a semi-automated fuzzy inference system to detect the internal architecture of a mass transport complex (MTC) in seismic images. We propose that the observed characteristics of a MTC can be expressed as fuzzy if-then rules consisting of linguistic values associated with fuzzy membership functions. The constructions of the fuzzy inference system and various image processing techniques are presented. We conclude that this is a well-suited problem for fuzzy logic since the application of the proposed methodology yields a semi-automatically interpreted MTC which closely resembles the MTC from expert manual interpretation

  18. Image analysis of microsialograms of the mouse parotid gland using digital image processing

    International Nuclear Information System (INIS)

    Yoshiura, K.; Ohki, M.; Yamada, N.

    1991-01-01

    The authors compared two digital-image feature-extraction methods for the analysis of microsialograms of the mouse parotid gland following either overfilling, experimentally induced acute sialoadenitis or irradiation. Microsialograms were digitized using a drum-scanning microdensitometer. The grey levels were then partitioned into four bands representing soft tissue, peripheral minor, middle-sized and major ducts, and run-length and histogram analysis of the digital images performed. Serial analysis of microsialograms during progressive filling showed that both methods depicted the structural characteristics of the ducts at each grey level. However, in the experimental groups, run-length analysis showed slight changes in the peripheral duct system more clearly. This method was therefore considered more effective than histogram analysis

  19. Influence of Digital Camera Errors on the Photogrammetric Image Processing

    Science.gov (United States)

    Sužiedelytė-Visockienė, Jūratė; Bručas, Domantas

    2009-01-01

    The paper deals with the calibration of digital camera Canon EOS 350D, often used for the photogrammetric 3D digitalisation and measurements of industrial and construction site objects. During the calibration data on the optical and electronic parameters, influencing the distortion of images, such as correction of the principal point, focal length of the objective, radial symmetrical and non-symmetrical distortions were obtained. The calibration was performed by means of the Tcc software implementing the polynomial of Chebichev and using a special test-field with the marks, coordinates of which are precisely known. The main task of the research - to determine how parameters of the camera calibration influence the processing of images, i. e. the creation of geometric model, the results of triangulation calculations and stereo-digitalisation. Two photogrammetric projects were created for this task. In first project the non-corrected and in the second the corrected ones, considering the optical errors of the camera obtained during the calibration, images were used. The results of analysis of the images processing is shown in the images and tables. The conclusions are given.

  20. Establishing imaging sensor specifications for digital still cameras

    Science.gov (United States)

    Kriss, Michael A.

    2007-02-01

    Digital Still Cameras, DSCs, have now displaced conventional still cameras in most markets. The heart of a DSC is thought to be the imaging sensor, be it Full Frame CCD, and Interline CCD, a CMOS sensor or the newer Foveon buried photodiode sensors. There is a strong tendency by consumers to consider only the number of mega-pixels in a camera and not to consider the overall performance of the imaging system, including sharpness, artifact control, noise, color reproduction, exposure latitude and dynamic range. This paper will provide a systematic method to characterize the physical requirements of an imaging sensor and supporting system components based on the desired usage. The analysis is based on two software programs that determine the "sharpness", potential for artifacts, sensor "photographic speed", dynamic range and exposure latitude based on the physical nature of the imaging optics, sensor characteristics (including size of pixels, sensor architecture, noise characteristics, surface states that cause dark current, quantum efficiency, effective MTF, and the intrinsic full well capacity in terms of electrons per square centimeter). Examples will be given for consumer, pro-consumer, and professional camera systems. Where possible, these results will be compared to imaging system currently on the market.

  1. Acquired image quality in digital industrial radiographic equipments

    International Nuclear Information System (INIS)

    Oliveira, Cristiane de Queiroz; Lopes, Ricardo Tadeu; Oliveira, Davi F.

    2008-01-01

    The computerized radiographic application in the industrial area is a recent event. The imaging plate is the equipment used as imaging receiver during the exposition radiographic technique, which consists of a flexible photostimulable phosphor screen, capable of storing the photons energy of the incident X and γ rays and of a reading unit which uses a laser device to stimulate a visible light. As two types of phosphor screen are manufactured, one for general use (General Plate - GP) and another one for specific using (High Resolution-HR), one of the objectives of this study was to evaluate the spatial resolution capability in both plates using the Kodak equipment. Furthermore, equipment from different makers, Kodak and General Electric Company - GE, were compared. Two phosphor screen HR were used as the main objective of this study. Imaging Quality Indicators - IQI were used to evaluate the spatial resolution of the images in accordance with ASME and DIN standard. The results show that after evaluating the GP and HR Kodak plates, the HR plate was capable of showing a larger resolution of details. However, after evaluating the performance of the HR Kodak plate and GE plate, over the same acquisition condition and with the same size of the laser focal set of 87 μm, the results show a superiority in the GE equipment used for industrial radiographic, mainly for processed images in each specific ambient of digital processing and its performance in meeting satisfactorily the ASME code and the DIN standard. (author)

  2. Quantitative vs. subjective portal verification using digital portal images.

    Science.gov (United States)

    Bissett, R; Leszczynski, K; Loose, S; Boyko, S; Dunscombe, P

    1996-01-15

    Off-line, computer-aided prescription (simulator) and treatment (portal) image registration using chamfer matching has been implemented on PC based viewing station. The purposes of this study were (a) to evaluate the performance of interactive anatomy and field edge extraction and subsequent registration, and (b) to compare observer's perceptions of field accuracy with measured discrepancies following anatomical registration. Prescription-treatment image pairs for 48 different patients were examined in this study. Digital prescription images were produced with the aid of a television camera and a digital frame grabber, while the treatment images were obtained directly from an on-line portal imaging system. To facilitate perception of low contrast anatomical detail, on-line portal images were enhanced with selective adaptive histogram equalization prior to extraction of anatomical edges. Following interactive extraction of anatomical and field border information by an experienced observer, the identified anatomy was registered using chamfer matching. The degree of conformity between the prescription and treatment fields was quantified using several parameters, which included relative prescription field coverage and overcoverage, as well as the translational and rotational displacements as measured by chamfer matching applied to the boundaries of the two fields. These quantitative measures were compared with subjective evaluations made by four radiation oncologists. All the images in this series that included a range of the most commonly seen treatment sites were registered and the conformity parameters were found. The mean treatment/prescription field coverage and overcoverage were approximately 95 and 7%, respectively before registration. The mean translational displacement in the transverse and cranio-caudal directions were 2.9 and 3.4 mm, respectively. The mean rotational displacement was approximately 2 degrees. For all four oncologists, the portals classified

  3. Fourier transform digital holographic adaptive optics imaging system

    Science.gov (United States)

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects. PMID:23262541

  4. A Recursive Fuzzy System for Efficient Digital Image Stabilization

    Directory of Open Access Journals (Sweden)

    Nikolaos Kyriakoulis

    2008-01-01

    Full Text Available A novel digital image stabilization technique is proposed in this paper. It is based on a fuzzy Kalman compensation of the global motion vector (GMV, which is estimated in the log-polar plane. The GMV is extracted using four local motion vectors (LMVs computed on respective subimages in the logpolar plane. The fuzzy Kalman system consists of a fuzzy system with the Kalman filter's discrete time-invariant definition. Due to this inherited recursiveness, the output results into smoothed image sequences. The proposed stabilization system aims to compensate any oscillations of the frame absolute positions, based on the motion estimation in the log-polar domain, filtered by the fuzzy Kalman system, and thus the advantages of both the fuzzy Kalman system and the log-polar transformation are exploited. The described technique produces optimal results in terms of the output quality and the level of compensation.

  5. Application of digital techniques to the restoration of radiographic images

    International Nuclear Information System (INIS)

    Burch, S.F.

    1980-09-01

    The methods of constrained least squares and maximum entropy have been used to restore digital X and γ-ray radiographs. Both methods require the blurring of the image to be a linear, spatially invariant process. Although the blurring processes in radiography can be complex, situations have been identified where these simplifying assumptions are valid. Algorithms for deriving the point-spread function of each image are discussed. These include a pinhole method for X-ray radiographs, and reconstruction from edge profiles for γ-ray radiographs. The results from the restoration of geometrically blurred radiographs of sparking plugs are given. Maximum entropy gives results superior to those obtained by constrained least squares. The resolution is improved by a factor of about three when maximum entropy is used, and by a factor of about two for constrained least squares. (author)

  6. Automatic anatomically selective image enhancement in digital chest radiography

    International Nuclear Information System (INIS)

    Sezan, M.I.; Minerbo, G.N.; Schaetzing, R.

    1989-01-01

    The authors develop a technique for automatic anatomically selective enhancement of digital chest radiographs. Anatomically selective enhancement is motivated by the desire to simultaneously meet the different enhancement requirements of the lung field and the mediastinum. A recent peak detection algorithm and a set of rules are applied to the image histogram to determine automatically a gray-level threshold between the lung field and mediastinum. The gray-level threshold facilitates anatomically selective gray-scale modification and/or unsharp masking. Further, in an attempt to suppress possible white-band or black-band artifacts due to unsharp masking at sharp edges, local-contrast adaptivity is incorporated into anatomically selective unsharp masking by designing an anatomy-sensitive emphasis parameter which varies asymmetrically with positive and negative values of the local image contrast

  7. Advances in digital printing and quality considerations of digitally printed images

    Science.gov (United States)

    Waes, Walter C.

    1997-02-01

    The traditional 'graphic arts' market has changed very rapidly. It has been only ten years now since Aldus introduced its 'PageMaker' software for text and layout. The platform used was Apple-Mac, which became also the standard for many other graphic applications. The so-called high-end workstations disappeared. This was the start for what later was called: the desk top publishing revolution. At the same time, image scanning became also user-friendly and heavy duty scanners were reduced to desktop-size. Color- reproduction became a commodity product. Since then, the pre-press industry has been going through a technical nightmare, trying to keep up with the digital explosion. One after another, tasks and crafts of pre-press were being transformed by digital technologies. New technologies in this field came almost too fast for many people to adapt. The next digital revolution will be for the commercial printers. All the reasons are explained later in this document. There is now a definite need for a different business-strategy and a new positioning in the electronic media-world. Niches have to be located for new graphic arts- applications. Electronic services to-and-from originators' and executors environments became a requirement. Data can now flow on-line between the printer and the originator of the job. It is no longer the pre-press shop who is controlling this. In many cases, electronic data goes between the print-buyer or agency and the printer. High power communication-systems with accepted standard color- management are transforming the printer, and more particularly, the pre-press shop fatally. The new digital printing market, now in the beginning of its expected full expansion, has to do with growing requests coming from agencies and other print-buyers for: (1) short-run printing; (2) print-on-demand approximately in-time; (3) personalization or other forms of customization; (4) quick turnaround.

  8. An instructional guide for leaf color analysis using digital imaging software

    Science.gov (United States)

    Paula F. Murakami; Michelle R. Turner; Abby K. van den Berg; Paul G. Schaberg

    2005-01-01

    Digital color analysis has become an increasingly popular and cost-effective method utilized by resource managers and scientists for evaluating foliar nutrition and health in response to environmental stresses. We developed and tested a new method of digital image analysis that uses Scion Image or NIH image public domain software to quantify leaf color. This...

  9. Optimized digital speckle patterns for digital image correlation by consideration of both accuracy and efficiency.

    Science.gov (United States)

    Chen, Zhenning; Shao, Xinxing; Xu, Xiangyang; He, Xiaoyuan

    2018-02-01

    The technique of digital image correlation (DIC), which has been widely used for noncontact deformation measurements in both the scientific and engineering fields, is greatly affected by the quality of speckle patterns in terms of its performance. This study was concerned with the optimization of the digital speckle pattern (DSP) for DIC in consideration of both the accuracy and efficiency. The root-mean-square error of the inverse compositional Gauss-Newton algorithm and the average number of iterations were used as quality metrics. Moreover, the influence of subset sizes and the noise level of images, which are the basic parameters in the quality assessment formulations, were also considered. The simulated binary speckle patterns were first compared with the Gaussian speckle patterns and captured DSPs. Both the single-radius and multi-radius DSPs were optimized. Experimental tests and analyses were conducted to obtain the optimized and recommended DSP. The vector diagram of the optimized speckle pattern was also uploaded as reference.

  10. Modeling digital breast tomosynthesis imaging systems for optimization studies

    Science.gov (United States)

    Lau, Beverly Amy

    Digital breast tomosynthesis (DBT) is a new imaging modality for breast imaging. In tomosynthesis, multiple images of the compressed breast are acquired at different angles, and the projection view images are reconstructed to yield images of slices through the breast. One of the main problems to be addressed in the development of DBT is the optimal parameter settings to obtain images ideal for detection of cancer. Since it would be unethical to irradiate women multiple times to explore potentially optimum geometries for tomosynthesis, it is ideal to use a computer simulation to generate projection images. Existing tomosynthesis models have modeled scatter and detector without accounting for oblique angles of incidence that tomosynthesis introduces. Moreover, these models frequently use geometry-specific physical factors measured from real systems, which severely limits the robustness of their algorithms for optimization. The goal of this dissertation was to design the framework for a computer simulation of tomosynthesis that would produce images that are sensitive to changes in acquisition parameters, so an optimization study would be feasible. A computer physics simulation of the tomosynthesis system was developed. The x-ray source was modeled as a polychromatic spectrum based on published spectral data, and inverse-square law was applied. Scatter was applied using a convolution method with angle-dependent scatter point spread functions (sPSFs), followed by scaling using an angle-dependent scatter-to-primary ratio (SPR). Monte Carlo simulations were used to generate sPSFs for a 5-cm breast with a 1-cm air gap. Detector effects were included through geometric propagation of the image onto layers of the detector, which were blurred using depth-dependent detector point-spread functions (PRFs). Depth-dependent PRFs were calculated every 5-microns through a 200-micron thick CsI detector using Monte Carlo simulations. Electronic noise was added as Gaussian noise as a

  11. Implementation of real-time digital endoscopic image processing system

    Science.gov (United States)

    Song, Chul Gyu; Lee, Young Mook; Lee, Sang Min; Kim, Won Ky; Lee, Jae Ho; Lee, Myoung Ho

    1997-10-01

    Endoscopy has become a crucial diagnostic and therapeutic procedure in clinical areas. Over the past four years, we have developed a computerized system to record and store clinical data pertaining to endoscopic surgery of laparascopic cholecystectomy, pelviscopic endometriosis, and surgical arthroscopy. In this study, we developed a computer system, which is composed of a frame grabber, a sound board, a VCR control board, a LAN card and EDMS. Also, computer system controls peripheral instruments such as a color video printer, a video cassette recorder, and endoscopic input/output signals. Digital endoscopic data management system is based on open architecture and a set of widely available industry standards; namely Microsoft Windows as an operating system, TCP/IP as a network protocol and a time sequential database that handles both images and speech. For the purpose of data storage, we used MOD and CD- R. Digital endoscopic system was designed to be able to store, recreate, change, and compress signals and medical images. Computerized endoscopy enables us to generate and manipulate the original visual document, making it accessible to a virtually unlimited number of physicians.

  12. Filmless reading and digital imaging distribution with refering to physicians

    International Nuclear Information System (INIS)

    Matzko, M.; Nissen-Meyer, S.; Sprenger, D.

    1999-01-01

    In healthcare, cost effectiveness as well as the quality of examinations and procedures are subjected to quickly increasing expectations and demands: We like to demonstrate how the resulting challenges and problems can be met with implementation of modern information technology. Analysing the respective demands (pattern of quantities) and choosing the adequate technical solution/ technical approach, we found filmless reading and the usage of digital image distribution to communicate with referring physicians to be cost effective as well as of higher quality. Special attention should be paid to the rigorous maintenance of data security and access. Today's information technology allows individual adjustment to the respective size and requirements of a radiological department or practice for filmless reading and digital image distribution. Working with the systems as a matter of routine and using all of the expanding technological possibilities, an important improvement of service and quality can be achieved. Amortisation will be obtained despite high investments, due to the subsequent savings in personal- and enterprise costs. (orig.) [de

  13. Standard digital reference images for inspection of aluminum castings

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 These digital reference images illustrate the types and degrees of discontinuities that may be found in aluminum-alloy castings. The castings illustrated are in thicknesses of 1/ 4 in. [6.35 mm] and 3/4 in. [19.1mm]. 1.2 All areas of this standard may be open to agreement between the cognizant engineering organization and the supplier, or specific direction from the cognizant engineering organization. These items should be addressed in the purchase order or the contract. 1.3 The values stated in inch-pound units are to be regarded as standard. 1.4 These digital reference images are not intended to illustrate the types and degrees of discontinuities found in aluminum-alloy castings when performing film radiography. If performing film radiography of aluminum-alloy castings, refer to Reference Radiographs E 155. 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 he...

  14. A review of peer-assisted learning to deliver interprofessional supplementary image interpretation skills.

    Science.gov (United States)

    Bain, P; Wareing, A; Henderson, I

    2017-09-01

    Peer-assisted learning provides a means through which individuals can learn from one another through a reciprocal process. Radiographic image interpretation skills are fundamental to both diagnostic radiography students and medical students due to their shared role in preliminary evaluation of conventional radiographic images. Medical students on graduation, may not be well prepared to carry out image interpretation, since evidence suggests that they perform less well than radiographers in e.g. Accident and Emergency situations. A review of literature was conducted exploring the application of peer-assisted learning within diagnostic radiography and health education more widely as well as the practice of initial image interpretation. An extensive and systematic search strategy was developed which provided a range of material related to the areas. An overview was obtained of the effectiveness of peer-assisted learning and the issues associated with development of image interpretation skills and a degree of discrepancy was identified between the two cohorts regarding their interpretative competence and confidence. This inconsistency may create an opportunity to apply peer-assisted learning, better preparing both disciplines for the practical application of image interpretation skills. The review identified the lack of a substantial evidence base relating to peer-assisted learning in radiography. Peer-assisted learning is not widely embraced in an interprofessional context. Multiple positive factors of such an intervention are identified which outweigh perceived negative issues. Student teacher and learner may benefit as should the clinical service from enhanced practitioner performance. The findings justify further research to develop the evidence base. Copyright © 2017 The College of Radiographers. Published by Elsevier Ltd. All rights reserved.

  15. Quality assessment of the digitalization process of analog x-ray images

    International Nuclear Information System (INIS)

    Georgieva, D.

    2014-01-01

    Computer-assisted diagnosis enabled doctors for a second point-of-view on the test results. This improves the diseases' early detection and significantly reduces the chance of errors. These methods very nicely complemented the possibilities of digital medical imaging apparatus, but in analog images their applicability and results entirely depend on the quality of analog images digitalisation. Today many standards and remarks for good practices discuss the digital apparatus image quality but the digitalisation process of analog medical images is not a part of them. Medical imaging apparatus have become digital, but within an entirely digital medical environment is necessary for their ability to blend with the old analog medical imaging carriers. The life of patients doesn't start with the beginning of digital era and for the aim of tracking diseases it is necessary to use the new digital images as well as older analog ones. For the generation of 40-50 years a large archive of images is piled up, which should be accounted of in the diagnosis process. This article is the author's study of the digitalized image quality problem. It offers a new approach to the x-ray image digitalisation - getting the HDR-image by optical sensor. After the HDR-image generation method offers to be used a digital signal processing to improve the quality of the final 16 bit gray scale medical image. The new method for medical image enhancement is proposed - it improves the image contrast, it increases or preserves the dynamic range and it doesn't lead to the loss of small low contrast structures in the image. Key words: Quality of Digital X-Rays Images

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  17. Digital Insights

    DEFF Research Database (Denmark)

    Knudsen, Gry Høngsmark

    , by incorporating media as both channel, frame, and apparatus for advertising response, the dissertation brings into attention that more aspects than the text-reader relationship influence ad response. Finally, the dissertation proposes the assemblage approach for exploring big data in consumer culture research...... and practices with digital media, when they meet and interpret advertising. Through studies of advertising response on YouTube and experiments with consumers’ response to digitally manipulated images, the dissertation shows how digital media practices facilitate polysemic and socially embedded advertising......This dissertation forwards the theory of digital consumer-response as a perspective to examine how digital media practices influence consumers’ response to advertising. Digital consumer-response is a development of advertising theory that encompasses how consumers employ their knowledge...

  18. Standard practice for digital imaging and communication in nondestructive evaluation (DICONDE) for digital radiographic (DR) test methods

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice facilitates the interoperability of digital X-ray imaging equipment by specifying image data transfer and archival methods in commonly accepted terms. This document is intended to be used in conjunction with Practice E2339 on Digital Imaging and Communication in Nondestructive Evaluation (DICONDE). Practice E2339 defines an industrial adaptation of the NEMA Standards Publication titled Digital Imaging and Communications in Medicine (DICOM, see http://medical.nema.org), an international standard for image data acquisition, review, storage and archival storage. The goal of Practice E2339, commonly referred to as DICONDE, is to provide a standard that facilitates the display and analysis of NDE results on any system conforming to the DICONDE standard. Toward that end, Practice E2339 provides a data dictionary and a set of information modules that are applicable to all NDE modalities. This practice supplements Practice E2339 by providing information object definitions, information modules and a ...

  19. Interaction of image noise, spatial resolution, and low contrast fine detail preservation in digital image processing

    Science.gov (United States)

    Artmann, Uwe; Wueller, Dietmar

    2009-01-01

    We present a method to improve the validity of noise and resolution measurements on digital cameras. If non-linear adaptive noise reduction is part of the signal processing in the camera, the measurement results for image noise and spatial resolution can be good, while the image quality is low due to the loss of fine details and a watercolor like appearance of the image. To improve the correlation between objective measurement and subjective image quality we propose to supplement the standard test methods with an additional measurement of the texture preserving capabilities of the camera. The proposed method uses a test target showing white Gaussian noise. The camera under test reproduces this target and the image is analyzed. We propose to use the kurtosis of the derivative of the image as a metric for the texture preservation of the camera. Kurtosis is a statistical measure for the closeness of a distribution compared to the Gaussian distribution. It can be shown, that the distribution of digital values in the derivative of the image showing the chart becomes the more leptokurtic (increased kurtosis) the stronger the noise reduction has an impact on the image.

  20. Workflow Dynamics and the Imaging Value Chain: Quantifying the Effect of Designating a Nonimage-Interpretive Task Workflow.

    Science.gov (United States)

    Lee, Matthew H; Schemmel, Andrew J; Pooler, B Dustin; Hanley, Taylor; Kennedy, Tabassum A; Field, Aaron S; Wiegmann, Douglas; Yu, John-Paul J

    To assess the impact of separate non-image interpretive task and image-interpretive task workflows in an academic neuroradiology practice. A prospective, randomized, observational investigation of a centralized academic neuroradiology reading room was performed. The primary reading room fellow was observed over a one-month period using a time-and-motion methodology, recording frequency and duration of tasks performed. Tasks were categorized into separate image interpretive and non-image interpretive workflows. Post-intervention observation of the primary fellow was repeated following the implementation of a consult assistant responsible for non-image interpretive tasks. Pre- and post-intervention data were compared. Following separation of image-interpretive and non-image interpretive workflows, time spent on image-interpretive tasks by the primary fellow increased from 53.8% to 73.2% while non-image interpretive tasks decreased from 20.4% to 4.4%. Mean time duration of image interpretation nearly doubled, from 05:44 to 11:01 (p = 0.002). Decreases in specific non-image interpretive tasks, including phone calls/paging (2.86/hr versus 0.80/hr), in-room consultations (1.36/hr versus 0.80/hr), and protocoling (0.99/hr versus 0.10/hr), were observed. The consult assistant experienced 29.4 task switching events per hour. Rates of specific non-image interpretive tasks for the CA were 6.41/hr for phone calls/paging, 3.60/hr for in-room consultations, and 3.83/hr for protocoling. Separating responsibilities into NIT and IIT workflows substantially increased image interpretation time and decreased TSEs for the primary fellow. Consolidation of NITs into a separate workflow may allow for more efficient task completion. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Predictors of Knowledge and Image Interpretation Skill Development in Radiology Residents.

    Science.gov (United States)

    Ravesloot, Cécile J; van der Schaaf, Marieke F; Kruitwagen, Cas L J J; van der Gijp, Anouk; Rutgers, Dirk R; Haaring, Cees; Ten Cate, Olle; van Schaik, Jan P J

    2017-09-01

    Purpose To investigate knowledge and image interpretation skill development in residency by studying scores on knowledge and image questions on radiology tests, mediated by the training environment. Materials and Methods Ethical approval for the study was obtained from the ethical review board of the Netherlands Association for Medical Education. Longitudinal test data of 577 of 2884 radiology residents who took semiannual progress tests during 5 years were retrospectively analyzed by using a nonlinear mixed-effects model taking training length as input variable. Tests included nonimage and image questions that assessed knowledge and image interpretation skill. Hypothesized predictors were hospital type (academic or nonacademic), training hospital, enrollment age, sex, and test date. Results Scores showed a curvilinear growth during residency. Image scores increased faster during the first 3 years of residency and reached a higher maximum than knowledge scores (55.8% vs 45.1%). The slope of image score development versus knowledge question scores of 1st-year residents was 16.8% versus 12.4%, respectively. Training hospital environment appeared to be an important predictor in both knowledge and image interpretation skill development (maximum score difference between training hospitals was 23.2%; P radiology residency and leveled off in the 3rd and 4th training year. The shape of the curve was mainly influenced by the specific training hospital. © RSNA, 2017 Online supplemental material is available for this article.

  2. The impact of image test bank construction on radiographic interpretation outcomes: A comparison study

    International Nuclear Information System (INIS)

    Hardy, M.; Flintham, K.; Snaith, B.; Lewis, E.F.

    2016-01-01

    Introduction: Assessment of image interpretation competency is commonly undertaken through review of a defined image test bank. Content of these image banks has been criticised for the high percentage of abnormal examinations which contrasts with lower reported incidences of abnormal radiographs in clinical practice. As a result, questions have been raised regarding the influence of prevalence bias on the accuracy of interpretive decision making. This article describes a new and novel approach to the design of musculoskeletal image test banks. Methods: Three manufactured image banks were compiled following a standard academic menu in keeping with previous studies. Three further image test banks were constructed to reflect local clinical workload within a single NHS Trust. Eighteen radiographers, blinded to the method of test bank composition, were randomly assigned 2 test banks to review (1 manufactured, 1 clinical workload). Comparison of interpretive accuracy was undertaken. Results: Inter-rater agreement was moderate to good for all image banks (manufactured: range k = 0.45–0.68; clinical workload: k = 0.49–0.62). A significant difference in mean radiographer sensitivity was noted between test bank designs (manufactured 87.1%; clinical workload 78.5%; p = 0.040, 95% CI = 0.4–16.8; t = 2.223). Relative parity in radiographer specificity and overall accuracy was observed. Conclusion: This study confirms the findings of previous research that high abnormality prevalence image banks over-estimate the ability of observers to identify abnormalities. Assessment of interpretive competency using an image bank that reflects local clinical practice is a better approach to accurately establish interpretive competency and the learning development needs of individual practitioners. - Highlights: • High prevalence image test banks over-estimate the ability of observers. • Clinical workload test banks may better reflect image interpretation competency.

  3. Integrated global digital image correlation for interface delamination characterization

    KAUST Repository

    Hoefnagels, Johan P.M.

    2013-07-23

    Interfacial delamination is a key reliability challenge in composites and micro-electronic systems due to (high-density) integration of dissimilar materials. Predictive finite element models are used to minimize delamination failures during design, but require accurate interface models to capture (irreversible) crack initiation and propagation behavior observed in experiments. Therefore, an Integrated Global Digital Image Correlation (I-GDIC) strategy is developed for accurate determination of mechanical interface behavior from in-situ delamination experiments. Recently, a novel miniature delamination setup was presented that enables in-situ microscopic characterization of interface delamination while sensitively measuring global load-displacement curves for all mode mixities. Nevertheless, extraction of detailed mechanical interface behavior from measured images is challenging, because deformations are tiny and measurement noise large. Therefore, an advanced I-GDIC methodology is developed which correlates the image patterns by only deforming the images using kinematically-admissible \\'eigenmodes\\' that correspond to the few parameters controlling the interface tractions in an analytic description of the crack tip deformation field, thereby greatly enhancing accuracy and robustness. This method is validated on virtual delamination experiments, simulated using a recently developed self-adaptive cohesive zone (CZ) finite element framework. © The Society for Experimental Mechanics, Inc. 2014.

  4. Accuracy evaluation of optical distortion calibration by digital image correlation

    Science.gov (United States)

    Gao, Zeren; Zhang, Qingchuan; Su, Yong; Wu, Shangquan

    2017-11-01

    Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera distortion calibrations. This paper presents an experimental method for evaluating camera distortion calibration accuracy, which is easy to implement, has high precision, and is suitable for a variety of commonly used lens. First, we use the digital image correlation method to calculate the in-plane rigid body displacement field of an image displayed on a liquid crystal display before and after translation, as captured with a camera. Next, we use a calibration board to calibrate the camera to obtain calibration parameters which are used to correct calculation points of the image before and after deformation. The displacement field before and after correction is compared to analyze the distortion calibration results. Experiments were carried out to evaluate the performance of two commonly used industrial camera lenses for four commonly used distortion models.

  5. Watermarking Techniques Using Least Significant Bit Algorithm for Digital Image Security Standard Solution- Based Android

    Directory of Open Access Journals (Sweden)

    Ari Muzakir

    2017-05-01

    Full Text Available Ease of deployment of digital image through the internet has positive and negative sides, especially for owners of the original digital image. The positive side of the ease of rapid deployment is the owner of that image deploys digital image files to various sites in the world address. While the downside is that if there is no copyright that serves as protector of the image it will be very easily recognized ownership by other parties. Watermarking is one solution to protect the copyright and know the results of the digital image. With Digital Image Watermarking, copyright resulting digital image will be protected through the insertion of additional information such as owner information and the authenticity of the digital image. The least significant bit (LSB is one of the algorithm is simple and easy to understand. The results of the simulations carried out using android smartphone shows that the LSB watermarking technique is not able to be seen by naked human eye, meaning there is no significant difference in the image of the original files with images that have been inserted watermarking. The resulting image has dimensions of 640x480 with a bit depth of 32 bits. In addition, to determine the function of the ability of the device (smartphone in processing the image using this application used black box testing. 

  6. Optimisation of the digital radiographic imaging of suspected non-accidental injury

    Science.gov (United States)

    Offiah, Amaka

    Aim: To optimise the digital (radiographic) imaging of children presenting with suspected non-accidental injury (NAI). Objectives: (i) To evaluate existing radiographic quality criteria, and to develop a more suitable system if these are found to be inapplicable to skeletal surveys obtained in suspected NAI. (ii) To document differences in image quality between conventional film-screen and the recently installed Fuji5000R computed radiography (CR) system at Great Ormond Street Hospital for Children, (iii) To document the extent of variability in the standard of skeletal surveys obtained in the UK for suspected NAI. (iv) To determine those radiographic parameters which yield the highest diagnostic accuracy, while still maintaining acceptable radiation dose to the child, (v) To determine how varying degrees of edge-enhancement affect diagnostic accuracy. (vi) To establish the accuracy of soft compared to hard copy interpretation of images in suspected NAI. Materials and Methods: (i) and (ii) Retrospective analysis of 286 paediatric lateral spine radiographs by two observers based on the Commission of European Communities (CEC) quality criteria, (iii) Review of the skeletal surveys of 50 consecutive infants referred from hospitals throughout the United Kingdom (UK) with suspected NAI. (iv) Phantom studies. Leeds TO. 10 and TO. 16 test objects were used to compare the relationship between film density, exposure parameters and visualisation of object details, (iv) Clinical study. Anteroposterior and lateral post mortem skull radiographs of six consecutive infants were obtained at various exposures. Six observers independently scored the images based on visualisation of five criteria, (v) and (vi) A study of diagnostic accuracy in which six observers independently interpreted 50 radiographs from printed copies (with varying degrees of edge-enhancement) and from a monitor. Results: The CEC criteria are useful for optimisation of imaging parameters and allow the detection

  7. 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.

  8. Computerized follow-up of discrepancies in image interpretation between emergency and radiology departments

    OpenAIRE

    Siegel, Eliot; Groleau, Georgina; Reiner, Bruce; Stair, Thomas

    1998-01-01

    Radiographs are ordered and interpreted for immediate clinical decisions 24 hours a day by emergency physicians (EP’s). The Joint Commission for Accreditation of Health Care Organizations requires that all these images be reviewed by radiologists and that there be some mechanism for quality improvement (QI) for discrepant readings. There must be a log of discrepancies and documentation of follow up activities, but this alone does not guarantee effective Q.I. Radiologists reviewing images from...

  9. Specters in the Archive: Faculty Digital Image Collections and the Problems of Invisibility

    Science.gov (United States)

    Beaudoin, Joan E.

    2011-01-01

    This paper presents the findings of a research study which investigated the digital preservation practices among two faculty user groups, archeologists and art historians. This faculty's knowledge of digital preservation practices and their perceptions and emotions concerning the digital images they had created and, or collected to support their…

  10. Low-Power Low-Noise CMOS Imager Design : In Micro-Digital Sun Sensor Application

    NARCIS (Netherlands)

    Xie, N.

    2012-01-01

    A digital sun sensor is superior to an analog sun sensor in aspects of resolution, albedo immunity, and integration. The proposed Micro-Digital Sun Sensor (µDSS) is an autonomous digital sun sensor which is implemented by means of a CMOS image sensor, which is named APS+. The µDSS is designed

  11. Comparison of image quality and radiation exposure from digital and 105-mm film images in pediatric fluoroscopy

    International Nuclear Information System (INIS)

    Drake, D.G.; Day, D.L.; Alford, B.A.; Geise, R.; Thompson, W.M.

    1987-01-01

    This study was designed to compare image quality of digitally acquired films compared with conventional 105-mm films in pediatric gastrointestinal and genitourinary fluoroscopic studies. Films were acquired digitally in 1,024 x 1,024 matrix, 512 x 512 matrix, and 105-mm film. Based on the observers' median scoring, the 1,024 x 1,024 reduced to 512 x 512 matrix provided similar overall image quality to the 105-mm films. The digital images produced a patient radiation exposure of 25% to 30% that of the 105-mm images on their equipment. The authors conclude that digital images provide similar image quality to 105-mm images with a significant reduction in patient radiation exposure

  12. Statistical analysis and interpretation of prenatal diagnostic imaging studies, Part 2: descriptive and inferential statistical methods.

    Science.gov (United States)

    Tuuli, Methodius G; Odibo, Anthony O

    2011-08-01

    The objective of this article is to discuss the rationale for common statistical tests used for the analysis and interpretation of prenatal diagnostic imaging studies. Examples from the literature are used to illustrate descriptive and inferential statistics. The uses and limitations of linear and logistic regression analyses are discussed in detail.

  13. Agreement in the Interpretation of Magnetic Resonance Images of the Lumbar Spine

    DEFF Research Database (Denmark)

    Kovacs, F M; Royuela, A; Jensen, Tue Secher

    2009-01-01

    Background: Correlation between clinical features and magnetic resonance imaging (MRI) findings is essential in low-back-pain patients. Most previous studies have analyzed concordance in the interpretation of lumbar MRI among a few radiologists who worked together. This may have overestimated...

  14. What We Do and Do Not Know about Teaching Medical Image Interpretation.

    Science.gov (United States)

    Kok, Ellen M; van Geel, Koos; van Merriënboer, Jeroen J G; Robben, Simon G F

    2017-01-01

    Educators in medical image interpretation have difficulty finding scientific evidence as to how they should design their instruction. We review and comment on 81 papers that investigated instructional design in medical image interpretation. We distinguish between studies that evaluated complete offline courses and curricula, studies that evaluated e-learning modules, and studies that evaluated specific educational interventions. Twenty-three percent of all studies evaluated the implementation of complete courses or curricula, and 44% of the studies evaluated the implementation of e-learning modules. We argue that these studies have encouraging results but provide little information for educators: too many differences exist between conditions to unambiguously attribute the learning effects to specific instructional techniques. Moreover, concepts are not uniformly defined and methodological weaknesses further limit the usefulness of evidence provided by these studies. Thirty-two percent of the studies evaluated a specific interventional technique. We discuss three theoretical frameworks that informed these studies: diagnostic reasoning, cognitive schemas and study strategies. Research on diagnostic reasoning suggests teaching students to start with non-analytic reasoning and subsequently applying analytic reasoning, but little is known on how to train non-analytic reasoning. Research on cognitive schemas investigated activities that help the development of appropriate cognitive schemas. Finally, research on study strategies supports the effectiveness of practice testing, but more study strategies could be applicable to learning medical image interpretation. Our commentary highlights the value of evaluating specific instructional techniques, but further evidence is required to optimally inform educators in medical image interpretation.

  15. Digital all-sky polarization imaging of partly cloudy skies.

    Science.gov (United States)

    Pust, Nathan J; Shaw, Joseph A

    2008-12-01

    Clouds reduce the degree of linear polarization (DOLP) of skylight relative to that of a clear sky. Even thin subvisual clouds in the "twilight zone" between clouds and aerosols produce a drop in skylight DOLP long before clouds become visible in the sky. In contrast, the angle of polarization (AOP) of light scattered by a cloud in a partly cloudy sky remains the same as in the clear sky for most cases. In unique instances, though, select clouds display AOP signatures that are oriented 90 degrees from the clear-sky AOP. For these clouds, scattered light oriented parallel to the scattering plane dominates the perpendicularly polarized Rayleigh-scattered light between the instrument and the cloud. For liquid clouds, this effect may assist cloud particle size identification because it occurs only over a relatively limited range of particle radii that will scatter parallel polarized light. Images are shown from a digital all-sky-polarization imager to illustrate these effects. Images are also shown that provide validation of previously published theories for weak (approximately 2%) polarization parallel to the scattering plane for a 22 degrees halo.

  16. BUILDING DETECTION USING AERIAL IMAGES AND DIGITAL SURFACE MODELS

    Directory of Open Access Journals (Sweden)

    J. Mu

    2017-05-01

    Full Text Available In this paper a method for building detection in aerial images based on variational inference of logistic regression is proposed. It consists of three steps. In order to characterize the appearances of buildings in aerial images, an effective bag-of-Words (BoW method is applied for feature extraction in the first step. In the second step, a classifier of logistic regression is learned using these local features. The logistic regression can be trained using different methods. In this paper we adopt a fully Bayesian treatment for learning the classifier, which has a number of obvious advantages over other learning methods. Due to the presence of hyper prior in the probabilistic model of logistic regression, approximate inference methods have to be applied for prediction. In order to speed up the inference, a variational inference method based on mean field instead of stochastic approximation such as Markov Chain Monte Carlo is applied. After the prediction, a probabilistic map is obtained. In the third step, a fully connected conditional random field model is formulated and the probabilistic map is used as the data term in the model. A mean field inference is utilized in order to obtain a binary building mask. A benchmark data set consisting of aerial images and digital surfaced model (DSM released by ISPRS for 2D semantic labeling is used for performance evaluation. The results demonstrate the effectiveness of the proposed method.

  17. Digital Path Approach Despeckle Filter for Ultrasound Imaging and Video

    Directory of Open Access Journals (Sweden)

    Marek Szczepański

    2017-01-01

    Full Text Available We propose a novel filtering technique capable of reducing the multiplicative noise in ultrasound images that is an extension of the denoising algorithms based on the concept of digital paths. In this approach, the filter weights are calculated taking into account the similarity between pixel intensities that belongs to the local neighborhood of the processed pixel, which is called a path. The output of the filter is estimated as the weighted average of pixels connected by the paths. The way of creating paths is pivotal and determines the effectiveness and computational complexity of the proposed filtering design. Such procedure can be effective for different types of noise but fail in the presence of multiplicative noise. To increase the filtering efficiency for this type of disturbances, we introduce some improvements of the basic concept and new classes of similarity functions and finally extend our techniques to a spatiotemporal domain. The experimental results prove that the proposed algorithm provides the comparable results with the state-of-the-art techniques for multiplicative noise removal in ultrasound images and it can be applied for real-time image enhancement of video streams.

  18. Practical steganalysis of digital images: state of the art

    Science.gov (United States)

    Fridrich, Jessica; Goljan, Miroslav

    2002-04-01

    Steganography is the art of hiding the very presence of communication by embedding secret messages into innocuous looking cover documents, such as digital images. Detection of steganography, estimation of message length, and its extraction belong to the field of steganalysis. Steganalysis has recently received a great deal of attention both from law enforcement and the media. In our paper, we classify and review current stego-detection algorithms that can be used to trace popular steganographic products. We recognize several qualitatively different approaches to practical steganalysis - visual detection, detection based on first order statistics (histogram analysis), dual statistics methods that use spatial correlations in images and higher-order statistics (RS steganalysis), universal blind detection schemes, and special cases, such as JPEG compatibility steganalysis. We also present some new results regarding our previously proposed detection of LSB embedding using sensitive dual statistics. The recent steganalytic methods indicate that the most common paradigm in image steganography - the bit-replacement or bit substitution - is inherently insecure with safe capacities far smaller than previously thought.

  19. IMPROVED BACKGROUND SUBTRACTION FOR THE SLOAN DIGITAL SKY SURVEY IMAGES

    International Nuclear Information System (INIS)

    Blanton, Michael R.; Kazin, Eyal; Muna, Demitri; Weaver, Benjamin A.; Price-Whelan, Adrian

    2011-01-01

    We describe a procedure for background subtracting Sloan Digital Sky Survey (SDSS) imaging that improves the resulting detection and photometry of large galaxies on the sky. Within each SDSS drift scan run, we mask out detected sources and then fit a smooth function to the variation of the sky background. This procedure has been applied to all SDSS-III Data Release 8 images, and the results are available as part of that data set. We have tested the effect of our background subtraction on the photometry of large galaxies by inserting fake galaxies into the raw pixels, reanalyzing the data, and measuring them after background subtraction. Our technique results in no size-dependent bias in galaxy fluxes up to half-light radii r 50 ∼ 100 arcsec; in contrast, for galaxies of that size the standard SDSS photometric catalog underestimates fluxes by about 1.5 mag. Our results represent a substantial improvement over the standard SDSS catalog results and should form the basis of any analysis of nearby galaxies using the SDSS imaging data.

  20. Skeletonization and Partitioning of Digital Images Using Discrete Morse Theory.

    Science.gov (United States)

    Delgado-Friedrichs, Olaf; Robins, Vanessa; Sheppard, Adrian

    2015-03-01

    We show how discrete Morse theory provides a rigorous and unifying foundation for defining skeletons and partitions of grayscale digital images. We model a grayscale image as a cubical complex with a real-valued function defined on its vertices (the voxel values). This function is extended to a discrete gradient vector field using the algorithm presented in Robins, Wood, Sheppard TPAMI 33:1646 (2011). In the current paper we define basins (the building blocks of a partition) and segments of the skeleton using the stable and unstable sets associated with critical cells. The natural connection between Morse theory and homology allows us to prove the topological validity of these constructions; for example, that the skeleton is homotopic to the initial object. We simplify the basins and skeletons via Morse-theoretic cancellation of critical cells in the discrete gradient vector field using a strategy informed by persistent homology. Simple working Python code for our algorithms for efficient vector field traversal is included. Example data are taken from micro-CT images of porous materials, an application area where accurate topological models of pore connectivity are vital for fluid-flow modelling.