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.

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

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)

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)

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)

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.

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

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.

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.

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.)

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...

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)

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.

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

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.

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

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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.

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.

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

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

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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)

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

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...

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 interpretation – digital image processing techniques on satellite data of high spatial resolution.

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.

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...

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.

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

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

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

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.

Digital X-ray Imaging in Dentistry

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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.

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)

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)

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.

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.

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

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

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

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.

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

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....

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

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

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.

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.

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 .

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.

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.

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)

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)

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.

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.

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

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.

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

Diagnostic Efficiency in Digital Pathology: A Comparison of Optical Versus Digital Assessment in 510 Surgical Pathology Cases.

Science.gov (United States)

Mills, Anne M; Gradecki, Sarah E; Horton, Bethany J; Blackwell, Rebecca; Moskaluk, Christopher A; Mandell, James W; Mills, Stacey E; Cathro, Helen P

2018-01-01

Prior work has shown that digital images and microscopic slides can be interpreted with comparable diagnostic accuracy. Although accuracy has been well-validated, the interpretative time for digital images has scarcely been studied and concerns about efficiency remain a major barrier to adoption. We investigated the efficiency of digital pathology when compared with glass slide interpretation in the diagnosis of surgical pathology biopsy and resection specimens. Slides were pulled from 510 surgical pathology cases from 5 organ systems (gastrointestinal, gynecologic, liver, bladder, and brain). Original diagnoses were independently confirmed by 2 validating pathologists. Diagnostic slides were scanned using the Philips IntelliSite Pathology Solution. Each case was assessed independently on digital and optical by 3 reading pathologists, with a ≥6 week washout period between modalities. Reading pathologists recorded assessment times for each modality; digital times included time to load the case. Diagnostic accuracy was determined based on whether a rendered diagnosis differed significantly from the original diagnosis. Statistical analysis was performed to assess for differences in interpretative times across modalities. All 3 reading pathologists showed comparable diagnostic accuracy across optical and digital modalities (mean major discordance rates with original diagnosis: 4.8% vs. 4.4%, respectively). Mean assessment times ranged from 1.2 to 9.1 seconds slower on digital versus optical. The slowest reader showed a significant learning effect during the course of the study so that digital assessment times decreased over time and were comparable with optical times by the end of the series. Organ site and specimen type did not significantly influence differences in interpretative times. In summary, digital image reading times compare favorably relative to glass slides across a variety of organ systems and specimen types. Mean increase in assessment time is 4

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.

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

PENGEMBANGAN PROGRAM PENGOLAHAN CITRA UNTUK RADIOGRAFI DIGITAL

Directory of Open Access Journals (Sweden)

EC Nugroho

2012-09-01

Full Text Available Telah dikembangkan sebuah program pengolahan citra untuk radiografi digital yang disusun menggunakan perangkat lunak Borland C++ Builder 4 Professional. Untuk melakukan pengolahan terhadap citra radiografi digital,dengan pengolahan terhadap pixel-pixel dari citra. Teknik pengolahan citra, meliputi pengaturan kecerahan citra (image brightness, kontras citra (image contras, pelembutan citra (image smoothing, penajaman citra (image sharpening, deteksi tepi (edge detection, citra negatif (negative image, dan histogram. Hasil pengolahan citra dihasilkan citra radiografi digital yang mudah  diinterprestasi  lebih  teliti  oleh  pengamat.  Tujuan penelitian ini adalah mendesain perangkat lunak pengolahan citra radiografi digital. Perangkat yang telah disusun kemudian digunakan untuk melakukan pengolahan terhadap citra radiografi digital. Hasil penelitian menunjukkan adanya peningkatan kualitas citra radiografi digital, sehingga dapat membantu seorang radiographer dalam mendiagnosa atau menginterprestasikan citra radiografi digital lebih teliti. Citra radiografi awal dan citra hasilnya dapat dilihat pada layar monitor sehingga  kualitas  pengolahan  dapat dibandingkan secara langsung. The image processing program has been developed for digital radiography that is designed by using software Borland C++ Builder 4 Professional to process the radiography digital image with image pixels processing. Image processing technique consists of image brightness, image contrast, image smoothing, image sharpening, edge detection, and negative image and histogram. From the result of image processing it produced radiography image that is easier to interpret by the observer. The purpose of this research is to design the software of image processing for digital radiography. Then the software is used as the image processor for digital radiography. The result shows that there is a quality improvement of digital radiography image, so it can help

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.

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

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

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.

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

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

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.

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.)

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.

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

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....

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

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.

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.

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)

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. <

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...

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

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

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.

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

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.

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

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

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)

Evaluation of teleradiology for interpretation of intravenous urograms

International Nuclear Information System (INIS)

Halpern, E.J.; Newhouse, J.H.; Amis, E.S.; Lubetsky, H.W.; Jaffe, R.M.; Esser, P.D.; Alderson, P.O.

1990-01-01

This paper reports on diagnostic yield of urography evaluated following digitization and transmission of the images from a satellite hospital via a commercial teleradiology/picture archiving and communications system (T/PACS) (AT and T-Philips CommView). Following digitization of 100 urograms to 2,048 x 1,684-pixel resolution with a laser scanner (Dupont FD2000), the radiographs were transmitted approximately 3 miles over a dedicated T-1 line to a receiving digital archive. Each digital image was first displayed at half resolution on a 1,024-line monitor and subsequently evaluated at full resolution with a zoom feature. Three radiologists, who had interpreted the original films over 2 years earlier, independently reviewed the digitized images

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.

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…

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

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....

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...

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

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.

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.

A simple method of digitizing analog scintigrams for quantification and digital archiving

International Nuclear Information System (INIS)

Schramm, M.; Kaempfer, B.; Wolf, H.; Clausen, M.; Wendhausen, H.; Henze, E.

1993-01-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on X-ray film were then digitized seecondarily by three different methods: 300 dpi flatbed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification. (orig.) [de

[A simple method of digitizing analog scintigrams for quantification and digital archiving].

Science.gov (United States)

Schramm, M; Kämpfer, B; Wolf, H; Clausen, M; Wendhausen, H; Henze, E

1993-02-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on x-ray film were then digitized secondarily by three different methods: 300 dpi flat-bed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification.

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…

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

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...

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....

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....

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.

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

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.

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

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

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 ...

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

Entraigues, a system dedicated to industrial radiography interpretation

International Nuclear Information System (INIS)

Fleuet, E.; Lavayssiere, B.

1995-01-01

Some inspections including radiography are periodically done among the components of a nuclear power plant in order to check their integrity. Today the operator is in charge of acquiring data, of analysing and of quantifying the produced X-ray films. EDF has built a digital system called ENTRAIGUES which aims to help the processing and the interpretation of radiographic images. The hardware of ENTRAIGUES is composed of a digitizer, a dedicated image processor and a PC. The software has been designed to facilitate the analysis of X-ray images. With the inclusion of compression algorithms and automatic image procedures ENTRAIGUES has become a complete tool dedicated to digitization, processing and archiving of nuclear power plant radiographs. (authors). 2 refs

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.

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.)

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.

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

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

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)

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.

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

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)

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.

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

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.

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

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

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…

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)

Automated quadrilateral mesh generation for digital image structures

Institute of Scientific and Technical Information of China (English)

无

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...

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

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.

Feature Extraction of Weld Defectology in Digital Image of Radiographic Film Using Geometric Invariant Moment and Statistical Texture

International Nuclear Information System (INIS)

Muhtadan

2009-01-01

The purpose of this research is to perform feature extraction in weld defect of digital image of radiographic film using geometric invariant moment and statistical texture method. Feature extraction values can be use as values that used to classify and pattern recognition on interpretation of weld defect in digital image of radiographic film by computer automatically. Weld defectology type that used in this research are longitudinal crack, transversal crack, distributed porosity, clustered porosity, wormhole, and no defect. Research methodology on this research are program development to read digital image, then performing image cropping to localize weld position, and then applying geometric invariant moment and statistical texture formulas to find feature values. The result of this research are feature extraction values that have tested with RST (rotation, scale, transformation) treatment and yield moment values that more invariant there are ϕ 3 , ϕ 4 , ϕ 5 from geometric invariant moment method. Feature values from statistical texture that are average intensity, average contrast, smoothness, 3 rd moment, uniformity, and entropy, they used as feature extraction values. (author)

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

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.

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.

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...

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.

Tolerance of brightness and contrast adjustments on chronic apical abscess and apical granuloma interpretation

Science.gov (United States)

Purnamasari, L.; Iskandar, H. H. B.; Makes, B. N.

2017-08-01

In digitized radiography techniques, adjusting the image enhancement can improve the subjective image quality by optimizing the brightness and contrast for diagnostic needs. To determine the value range of image enhancement (brightness and contrast) on chronic apical abscess and apical granuloma interpretation. 30 periapical radiographs that diagnosed chronic apical abscess and 30 that diagnosed apical granuloma were adjusted by changing brightness and contrast values. The value range of brightness and contrast adjustment that can be tolerated in radiographic interpretations of chronic apical abscess and apical granuloma spans from -10 to +10. Brightness and contrast adjustments on digital radiographs do not affect the radiographic interpretation of chronic apical abscess and apical granuloma if conducted within the value range.

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.

The diagnosis of small solitary pulmonary nodule: comparison of standard and inverse digital images on a high resolution monitor using ROC analysis

International Nuclear Information System (INIS)

Choi, Byeong Kyoo; Lee, In Sun; Seo, Joon Beom; Lee, Jin Seong; Song, Koun Sik; Lim, Tae Hwan

2002-01-01

To study the impact of inversion of soft-copy chest radiographs on the detection of small solitary pulmonary nodules using a high-resolution monitor. The study group consisted of 80 patients who had undergone posterior chest radiography; 40 had a solitary noncalcified pulmonary nodule approximately 1 cm in diameter, and 40 were control subjects. Standard and inverse digital images using the inversion tool on a PACS system were displayed on high-resolution monitors (2048x2560x8 bit). Ten radiologists were requested to rank each image using a five-point scale (1=definitely negative, 3=equivocal or indeterminate, 5=definite nodule), and the data were interpreted using receiver operating characteristic (ROC) analysis. The area under the ROC curve for pooled data of standard image sets was significantly larger than that of inverse image sets (0.8893 and 0.8095, respectively; p 0.05). For detecting small solitary pulmonary nodules, inverse digital images were significantly inferior to standard digital images

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

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.

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)

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.

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.

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.

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...

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.

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.

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.

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.

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

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

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

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)

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.

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.)

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...

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

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)

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

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.

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.

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.

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.

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.

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.

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...

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)

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)

Interpretation and mapping of geological features using mobile devices for 3D outcrop modelling

Science.gov (United States)

Buckley, Simon J.; Kehl, Christian; Mullins, James R.; Howell, John A.

2016-04-01

Advances in 3D digital geometric characterisation have resulted in widespread adoption in recent years, with photorealistic models utilised for interpretation, quantitative and qualitative analysis, as well as education, in an increasingly diverse range of geoscience applications. Topographic models created using lidar and photogrammetry, optionally combined with imagery from sensors such as hyperspectral and thermal cameras, are now becoming commonplace in geoscientific research. Mobile devices (tablets and smartphones) are maturing rapidly to become powerful field computers capable of displaying and interpreting 3D models directly in the field. With increasingly high-quality digital image capture, combined with on-board sensor pose estimation, mobile devices are, in addition, a source of primary data, which can be employed to enhance existing geological models. Adding supplementary image textures and 2D annotations to photorealistic models is therefore a desirable next step to complement conventional field geoscience. This contribution reports on research into field-based interpretation and conceptual sketching on images and photorealistic models on mobile devices, motivated by the desire to utilise digital outcrop models to generate high quality training images (TIs) for multipoint statistics (MPS) property modelling. Representative training images define sedimentological concepts and spatial relationships between elements in the system, which are subsequently modelled using artificial learning to populate geocellular models. Photorealistic outcrop models are underused sources of quantitative and qualitative information for generating TIs, explored further in this research by linking field and office workflows through the mobile device. Existing textured models are loaded to the mobile device, allowing rendering in a 3D environment. Because interpretation in 2D is more familiar and comfortable for users, the developed application allows new images to be captured

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.

Endodontic radiography: who is reading the digital radiograph?

Science.gov (United States)

Tewary, Shalini; Luzzo, Joseph; Hartwell, Gary

2011-07-01

Digital radiographic imaging systems have undergone tremendous improvements since their introduction. Advantages of digital radiographs over conventional films include lower radiation doses compared with conventional films, instantaneous images, archiving and sharing images easily, and manipulation of several radiographic properties that might help in diagnosis. A total of 6 observers including 2 endodontic residents, 3 endodontists, and 1 oral radiologist evaluated 150 molar digital periapical radiographs to determine which of the following conditions existed: normal periapical tissue, widened periodontal ligament, or presence of periapical radiolucency. The evaluators had full control over the radiograph's parameters of the Planmeca Dimaxis software program. All images were viewed on the same computer monitor with ideal vie-wing conditions. The same 6 observers evaluated the same 150 digital images 3 months later. The data were analyzed to determine how well the evaluators agreed with each other (interobserver agreement) for 2 rounds of observations and with themselves (intraobserver agreement). Fleiss kappa statistical analysis was used to measure the level of agreement among multiple raters. The overall Fleiss kappa value for interobserver agreement for the first round of interpretation was 0.34 (P value for interobserver agreement for the second round of interpretation was 0.35 (P fair (0.2-0.4) agreement among the 6 raters at both observation periods. A weighted kappa analysis was used to determine intraobserver agreement, which showed on average a moderate agreement. The results indicate that the interpretation of a dental radiograph is subjective, irrespective of whether conventional or digital radiographs are used. The factors that appeared to have the most impact were the years of experience of the examiner and familiarity of the operator with a given digital system. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All

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

Preliminary clinical evaluation of hard- and soft-copy digitized chest radiography

Science.gov (United States)

Rian, Roger L.; Smerud, Michael J.; Guinn, Todd

1994-05-01

The digital applications in radiology are a controversial advanced which potentially will influence all areas of patient imaging. It is utilized and accepted in angiography, computed tomography, magnetic resonance, nuclear imaging and sonography. More recently Computed Radiography has gained credibility in mobile scenarios as well as specific applications from cervical spine radiography to digital fluoroscopy. Usually this acceptance is related to benefits of lesser radiation exposure or an improved presentation with an incorrect radiographic technique. One advantage of interpreting from digital information is the potential manipulation of the image presentation to the observer through windowing, leveling and edge enhancement pre and/or during image review. Additionally this digital data can be transmitted over distance and represented as hard and/or soft copy for primary or consultative review. The number and quality of the images to be viewed, the environment of the review station as well as the observer experience with conventional radiographic as well as digital image evaluation are important aspects of delivering the radiologist's product i.e. the final interpretation. This paper assesses that product, specifically addressing the question `Is the radiologist's report the same whether derived from the original analog image or from its digitized image.' The object of this study is to determine whether a digital system (3M PACS) designed for consultative viewing in a satellite department can also be used directly for primary diagnosis of conventional chest exams.

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.

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.

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

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.

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

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,

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)

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

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

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.

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.

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...

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.

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.

Digital image intensifier radiography. One year's experience with a Polytron system

International Nuclear Information System (INIS)

Busch, H.P.; Lehmann, K.J.; Georgi, M.

1989-01-01

Since January 1988, digital image intensifier radiography has been used in the Clinic in Mannheim for DSA examinations and also in place of conventional screen/film examinations. Measurements have shown that compared with 100 mm and film/screen formats, digital radiography has poorer spatial resolution, but improved contrast resolution. The most common use of digital radiography was for examinations of the gastrointestinal tract. Using the demonstration of the mucosal fine relief pattern as a criterion of image quality, digital image intensifier radiography was able to achieve this satisfactorily. Comparison with film/screen examinations showed no loss of diagnostic information. Advantages of image intensifier radiography are reduced radiation dose, the possibility of postprocessing and economy. On the basis of 399 examinations, digital image intensifier radiography is now firmly established as part of the daily routine of the Mannheim Clinic. (orig.) [de

Digitizing pediatric chest radiographs: comparison of low-cost, commercial off-the-shelf technologies

International Nuclear Information System (INIS)

Ruess, L.; Shiels, K.C.; Cho, K.H.; O'Connor, S.C.; Uyehara, C.F.T.; Person, D.A.; Whitton, R.K.

2001-01-01

Objective: To compare low-cost, off-the-shelf technology for digitizing pediatric chest radiographs. Materials and methods: Forty pediatric chest radiographs (hard copy), each with a single abnormality, were digitized using a commercial film digitizer and two low-cost methods: a digital camera and a flatbed scanner. A stratified, randomized, block design was used where 20 readers evaluated 40 different images to determine the ability to accurately detect the abnormality. Readers then rated all 160 images (40 images x 4 methods) for conspicuity of the abnormality and overall image quality. Results: Abnormalities were correctly identified on 82.3 % of hard copy images, 82.9 % of flatbed scanner images, 74.3 % of film digitizer images, and 69.7 % of digital camera images (p flatbed scanner > film digitizer > digital camera images. Conclusion: A low-cost flatbed scanner yielded digital pediatric chest images which were significantly superior to digital camera images While flatbed scanner images were interpreted with the equivalent diagnostic accuracy of hard copy images, they were rated lower for image quality and lesion conspicuity. (orig.)

Implementation of a dedicated digital projectional radiographic system in thoracic imaging

International Nuclear Information System (INIS)

Aberle, D.R.; Batra, P.; Hayrapetian, A.S.; Brown, K.; Morioka, C.A.; Steckel, R.J.

1988-01-01

An integrated digital radiographic system was evaluated with respect to image quality and impact on diagnosis relative to conventional chest radiographs for a variety of focal and diffuse lung processes. Digital images were acquired with a stimulable phosphor plate detector that was scanned by a semiconductor laser for immediate digitalization to a 2,048 X 2,464 X 10-bit image. Digital images were displayed on a 2,048-line monitor and printed on 14 X 17-inch film with use of a laser film printer (Kodak). Preliminary results with this system, including the effects of user interaction with the display monitor, inverse intensity display, and regional magnification techniques, indicate that it may be successfully implemented for thoracic imaging

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.

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…

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…

Analysis of identification of digital images from a map of cosmic microwaves

Science.gov (United States)

Skeivalas, J.; Turla, V.; Jurevicius, M.; Viselga, G.

2018-04-01

This paper discusses identification of digital images from the cosmic microwave background radiation map formed according to the data of the European Space Agency "Planck" telescope by applying covariance functions and wavelet theory. The estimates of covariance functions of two digital images or single images are calculated according to the random functions formed of the digital images in the form of pixel vectors. The estimates of pixel vectors are formed on expansion of the pixel arrays of the digital images by a single vector. When the scale of a digital image is varied, the frequencies of single-pixel color waves remain constant and the procedure for calculation of covariance functions is not affected. For identification of the images, the RGB format spectrum has been applied. The impact of RGB spectrum components and the color tensor on the estimates of covariance functions was analyzed. The identity of digital images is assessed according to the changes in the values of the correlation coefficients in a certain range of values by applying the developed computer program.

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

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

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

[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.

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.

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.

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.

Benefits and unexpected artifacts of biplanar digital slot-scanning imaging in children

Energy Technology Data Exchange (ETDEWEB)

Blumer, Steven L. [Nemours/A.I duPont Hospital for Children, Department of Medical Imaging, Wilmington, DE (United States); Dinan, David [Nemours Children' s Hospital, Orlando, FL (United States); Grissom, Leslie E. [Nemours/Alfred I. duPont Hospital for Children, Department of Radiology, Wilmington, DE (United States)

2014-07-15

Biplanar digital slot-scanning allows for relatively low-dose orthopedic imaging, an advantage in imaging children given the growing concerns regarding radiosensitivity. We have used this system for approximately 1 year for orthopedic imaging of the spine and lower extremities. We have noted advantages of using the digital slot-scanning system when compared with computed radiographic and standard digital radiographic imaging systems, but we also found unexpected but common imaging artifacts that are the direct result of the imaging method and that have not been reported. This pictorial essay serves to familiarize radiologists with the advantages of the digital slot-scanning system as well as imaging artifacts common with this new technology. (orig.)

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.

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.

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.

Development of an image intensifier-TV digital imaging system with a multiple-slit scanning x-ray beam

International Nuclear Information System (INIS)

Kume, Y.; Doi, K.

1986-01-01

The authors are developing a new digital x-ray imaging system employing a multiple-slit assembly (MSA) and an image intensifier (II)-TV digital system. The final image consisting of primary radiation is digitally reconstructed from multiple slit images obtained with the MSA. This system can significantly reduce the scattered radiation from an object and the veiling glare from II-TV system. The quality of the reconstructed image is related to many parameters, such as slit width, the number of image frames, and the image reconstruction algorithm. They present the effect of these various parameters on basic imaging properties and the practicability of the method in comparison with conventional wide beam imaging

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

Image analysis and machine learning in digital pathology: Challenges and opportunities.

Science.gov (United States)

Madabhushi, Anant; Lee, George

2016-10-01

With the rise in whole slide scanner technology, large numbers of tissue slides are being scanned and represented and archived digitally. While digital pathology has substantial implications for telepathology, second opinions, and education there are also huge research opportunities in image computing with this new source of "big data". It is well known that there is fundamental prognostic data embedded in pathology images. The ability to mine "sub-visual" image features from digital pathology slide images, features that may not be visually discernible by a pathologist, offers the opportunity for better quantitative modeling of disease appearance and hence possibly improved prediction of disease aggressiveness and patient outcome. However the compelling opportunities in precision medicine offered by big digital pathology data come with their own set of computational challenges. Image analysis and computer assisted detection and diagnosis tools previously developed in the context of radiographic images are woefully inadequate to deal with the data density in high resolution digitized whole slide images. Additionally there has been recent substantial interest in combining and fusing radiologic imaging and proteomics and genomics based measurements with features extracted from digital pathology images for better prognostic prediction of disease aggressiveness and patient outcome. Again there is a paucity of powerful tools for combining disease specific features that manifest across multiple different length scales. The purpose of this review is to discuss developments in computational image analysis tools for predictive modeling of digital pathology images from a detection, segmentation, feature extraction, and tissue classification perspective. We discuss the emergence of new handcrafted feature approaches for improved predictive modeling of tissue appearance and also review the emergence of deep learning schemes for both object detection and tissue classification

Digital-image processing improves man-machine communication at a nuclear reactor

International Nuclear Information System (INIS)

Cook, S.A.; Harrington, T.P.; Toffer, H.

1982-01-01

The application of digital image processing to improve man-machine communication in a nuclear reactor control room is illustrated. At the Hanford N Reactor, operated by UNC Nuclear Industries for the United States Department of Energy, in Richland, Washington, digital image processing is applied to flow, temperature, and tube power data. Color displays are used to present the data in a clear and concise fashion. Specific examples are used to demonstrate the capabilities and benefits of digital image processing of reactor data. N Reactor flow and power maps for routine reactor operations and for perturbed reactor conditions are displayed. The advantages of difference mapping are demonstrated. Image processing techniques have also been applied to results of analytical reactor models; two examples are shown. The potential of combining experimental and analytical information with digital image processing to produce predictive and adaptive reactor core models is discussed. The applications demonstrate that digital image processing can provide new more effective ways for control room personnel to assess reactor status, to locate problems and explore corrective actions. 10 figures

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

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…

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)

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.

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...

The establishment of Digital Image Capture System(DICS) using conventional simulator

International Nuclear Information System (INIS)

Oh, Tae Sung; Park, Jong Il; Byun, Young Sik; Shin, Hyun Kyoh

2004-01-01

The simulator is used to determine patient field and ensure the treatment field, which encompasses the required anatomy during patient normal movement such as during breathing. The latest simulator provide real time display of still, fluoroscopic and digitalized image, but conventional simulator is not yet. The purpose of this study is to introduce digital image capture system(DICS) using conventional simulator and clinical case using digital captured still and fluoroscopic image. We connect the video signal cable to the video terminal in the back up of simulator monitor, and connect the video jack to the A/D converter. After connection between the converter jack and computer, We can acquire still image and record fluoroscopic image with operating image capture program. The data created with this system can be used in patient treatment, and modified for verification by using image processing software. (j.e. photoshop, paintshop) DICS was able to establish easy and economical procedure. DCIS image was helpful for simulation. DICS imaging was powerful tool in the evaluation of the department specific patient positioning. Because the commercialized simulator based of digital capture is very expensive, it is not easily to establish DICS simulator in the most hospital. DICS using conventional simulator enable to utilize the practical use of image equal to high cost digitalized simulator and to research many clinical cases in case of using other software program.

Mouse cursor movement and eye tracking data as an indicator of pathologists′ attention when viewing digital whole slide images

Directory of Open Access Journals (Sweden)

Vignesh Raghunath

2012-01-01

Full Text Available Context: Digital pathology has the potential to dramatically alter the way pathologists work, yet little is known about pathologists′ viewing behavior while interpreting digital whole slide images. While tracking pathologist eye movements when viewing digital slides may be the most direct method of capturing pathologists′ viewing strategies, this technique is cumbersome and technically challenging to use in remote settings. Tracking pathologist mouse cursor movements may serve as a practical method of studying digital slide interpretation, and mouse cursor data may illuminate pathologists′ viewing strategies and time expenditures in their interpretive workflow. Aims: To evaluate the utility of mouse cursor movement data, in addition to eye-tracking data, in studying pathologists′ attention and viewing behavior. Settings and Design: Pathologists (N = 7 viewed 10 digital whole slide images of breast tissue that were selected using a random stratified sampling technique to include a range of breast pathology diagnoses (benign/atypia, carcinoma in situ, and invasive breast cancer. A panel of three expert breast pathologists established a consensus diagnosis for each case using a modified Delphi approach. Materials and Methods: Participants′ foveal vision was tracked using SensoMotoric Instruments RED 60 Hz eye-tracking system. Mouse cursor movement was tracked using a custom MATLAB script. Statistical Analysis Used: Data on eye-gaze and mouse cursor position were gathered at fixed intervals and analyzed using distance comparisons and regression analyses by slide diagnosis and pathologist expertise. Pathologists′ accuracy (defined as percent agreement with the expert consensus diagnoses and efficiency (accuracy and speed were also analyzed. Results: Mean viewing time per slide was 75.2 seconds (SD = 38.42. Accuracy (percent agreement with expert consensus by diagnosis type was: 83% (benign/atypia; 48% (carcinoma in situ; and 93% (invasive

Mouse cursor movement and eye tracking data as an indicator of pathologists’ attention when viewing digital whole slide images

Science.gov (United States)

Raghunath, Vignesh; Braxton, Melissa O.; Gagnon, Stephanie A.; Brunyé, Tad T.; Allison, Kimberly H.; Reisch, Lisa M.; Weaver, Donald L.; Elmore, Joann G.; Shapiro, Linda G.

2012-01-01

Context: Digital pathology has the potential to dramatically alter the way pathologists work, yet little is known about pathologists’ viewing behavior while interpreting digital whole slide images. While tracking pathologist eye movements when viewing digital slides may be the most direct method of capturing pathologists’ viewing strategies, this technique is cumbersome and technically challenging to use in remote settings. Tracking pathologist mouse cursor movements may serve as a practical method of studying digital slide interpretation, and mouse cursor data may illuminate pathologists’ viewing strategies and time expenditures in their interpretive workflow. Aims: To evaluate the utility of mouse cursor movement data, in addition to eye-tracking data, in studying pathologists’ attention and viewing behavior. Settings and Design: Pathologists (N = 7) viewed 10 digital whole slide images of breast tissue that were selected using a random stratified sampling technique to include a range of breast pathology diagnoses (benign/atypia, carcinoma in situ, and invasive breast cancer). A panel of three expert breast pathologists established a consensus diagnosis for each case using a modified Delphi approach. Materials and Methods: Participants’ foveal vision was tracked using SensoMotoric Instruments RED 60 Hz eye-tracking system. Mouse cursor movement was tracked using a custom MATLAB script. Statistical Analysis Used: Data on eye-gaze and mouse cursor position were gathered at fixed intervals and analyzed using distance comparisons and regression analyses by slide diagnosis and pathologist expertise. Pathologists’ accuracy (defined as percent agreement with the expert consensus diagnoses) and efficiency (accuracy and speed) were also analyzed. Results: Mean viewing time per slide was 75.2 seconds (SD = 38.42). Accuracy (percent agreement with expert consensus) by diagnosis type was: 83% (benign/atypia); 48% (carcinoma in situ); and 93% (invasive). Spatial

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

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.

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.

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

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

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

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.

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.

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

[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.

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.

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)

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.

The comparison between SVD-DCT and SVD-DWT digital image watermarking

Science.gov (United States)

Wira Handito, Kurniawan; Fauzi, Zulfikar; Aminy Ma’ruf, Firda; Widyaningrum, Tanti; Muslim Lhaksmana, Kemas

2018-03-01

With internet, anyone can publish their creation into digital data simply, inexpensively, and absolutely easy to be accessed by everyone. However, the problem appears when anyone else claims that the creation is their property or modifies some part of that creation. It causes necessary protection of copyrights; one of the examples is with watermarking method in digital image. The application of watermarking technique on digital data, especially on image, enables total invisibility if inserted in carrier image. Carrier image will not undergo any decrease of quality and also the inserted image will not be affected by attack. In this paper, watermarking will be implemented on digital image using Singular Value Decomposition based on Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT) by expectation in good performance of watermarking result. In this case, trade-off happen between invisibility and robustness of image watermarking. In embedding process, image watermarking has a good quality for scaling factor < 0.1. The quality of image watermarking in decomposition level 3 is better than level 2 and level 1. Embedding watermark in low-frequency is robust to Gaussian blur attack, rescale, and JPEG compression, but in high-frequency is robust to Gaussian noise.

Effects of image enhancement on reliability of landmark identification in digital cephalometry

Directory of Open Access Journals (Sweden)

M Oshagh

2013-01-01

Full Text Available Introduction: Although digital cephalometric radiography is gaining popularity in orthodontic practice, the most important source of error in its tracing is uncertainty in landmark identification. Therefore, efforts to improve accuracy in landmark identification were directed primarily toward the improvement in image quality. One of the more useful techniques of this process involves digital image enhancement which can increase overall visual quality of image, but this does not necessarily mean a better identification of landmarks. The purpose of this study was to evaluate the effectiveness of digital image enhancements on reliability of landmark identification. Materials and Methods: Fifteen common landmarks including 10 skeletal and 5 soft tissues were selected on the cephalograms of 20 randomly selected patients, prepared in Natural Head Position (NHP. Two observers (orthodontists identified landmarks on the 20 original photostimulable phosphor (PSP digital cephalogram images and 20 enhanced digital images twice with an intervening time interval of at least 4 weeks. The x and y coordinates were further analyzed to evaluate the pattern of recording differences in horizontal and vertical directions. Reliability of landmarks identification was analyzed by paired t test. Results: There was a significant difference between original and enhanced digital images in terms of reliability of points Ar and N in vertical and horizontal dimensions, and enhanced images were significantly more reliable than original images. Identification of A point, Pogonion and Pronasal points, in vertical dimension of enhanced images was significantly more reliable than original ones. Reliability of Menton point identification in horizontal dimension was significantly more in enhanced images than original ones. Conclusion: Direct digital image enhancement by altering brightness and contrast can increase reliability of some landmark identification and this may lead to more

Digital atlas of fetal brain MRI

Energy Technology Data Exchange (ETDEWEB)

Chapman, Teresa; Weinberger, E. [Department of Radiology, Seattle Children' s Hospital, Seattle, WA (United States); Matesan, Manuela [University of Washington, Department of Radiology, Seattle, WA (United States); Bulas, Dorothy I. [Division of Diagnostic Imaging and Radiology, Children' s National Medical Center, Washington, DC (United States)

2010-02-15

Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download. Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development. (orig.)

Digital atlas of fetal brain MRI

International Nuclear Information System (INIS)

Chapman, Teresa; Weinberger, E.; Matesan, Manuela; Bulas, Dorothy I.

2010-01-01

Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download. Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development. (orig.)

Digital cytology: current state of the art and prospects for the future.

Science.gov (United States)

Wilbur, David C

2011-01-01

The growth of digital methods in pathology is accelerating. Digital images can be used for a variety of applications in cytology, including rapid interpretations, primary diagnosis and second opinions, continuing education and proficiency testing. All of these functions can be performed using small static digital images, real-time dynamic digital microscopy, or whole-slide images. This review will discuss the general principles of digital pathology, its methods and applications to cytologic specimens. As cytologic specimens have unique features compared to histopathology specimens, the key differences will be discussed. Technical and administrative issues in digital pathology applications and the outlook for the future of the field will be presented. Copyright © 2011 S. Karger AG, Basel.

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.

Are digital images good enough? A comparative study of conventional film-screen vs digital radiographs on printed images of total hip replacement

International Nuclear Information System (INIS)

Eklund, K.; Jonsson, K.; Lindblom, G.; Lundin, B.; Sanfridsson, J.; Sloth, M.; Sivberg, B.

2004-01-01

The aim of this study was to evaluate the inter- and intra-observer variability and to find differences in diagnostic safety between digital and analog technique in diagnostic zones around hip prostheses. In 80 patients who had had a total hip replacement (THR) for more than 2 years, a conventional image and a digital image were taken. Gruen's model of seven distinct regions of interest was used for evaluations. Five experienced radiologists observed the seven regions and noted in a protocol the following distances: stem-cement; cement-bone; and stem-bone. All images were printed on hard copies and were read twice. Weighted kappa, κ w , analyses were used. The two most frequently loosening regions, stem-cement region 1 and cement-bone region 7, were closely analyzed. In region 1 the five observers had an agreement of 86.75-97.92% between analog and digital images in stem-cement, which is a varied κ w 0.29-0.71. For cement-bone region 7 an agreement of 87.21-90.45% was found, which is a varied κ w of 0.48-0.58. All the kappa values differ significantly from nil. The result shows that digital technique is as good as analog radiographs for diagnosing possible loosening of hip prostheses. (orig.)

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.

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

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.

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.

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

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...

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

Comparative study of digital laser film and analog paper image recordings

International Nuclear Information System (INIS)

Lee, K.R.; Cox, G.G.; Templeton, A.W.; Preston, D.F.; Anderson, W.H.; Hensley, K.S.; Dwyer, S.J.

1987-01-01

The increase in the use of various imaging modalities demands higher quality and more efficacious analog image recordings. Laser electronic recordings with digital array prints of 4,000 x 5,000 x 12 bits obtained using laser-sensitive film or paper are being evaluated. Dry silver paper recordings are being improved and evaluated. High-resolution paper dot printers are being studied to determine their gray-scale capabilities. The authors evaluated the image quality, costs, clinical utilization, and acceptability of CT scans, MR images, digital subtraction angiograms, digital radiographs, and radionuclide scans recorded by seven different printers (three laser, three silver paper, and one dot) and compared the same features in conventional film recording. This exhibit outlines the technical developments and instrumentation of digital laser film and analog paper recorders and presents the results of the study

The application of digital image plane holography technology to identify Chinese herbal medicine

Science.gov (United States)

Wang, Huaying; Guo, Zhongjia; Liao, Wei; Zhang, Zhihui

2012-03-01

In this paper, the imaging technology of digital image plane holography to identify the Chinese herbal medicine is studied. The optical experiment system of digital image plane holography which is the special case of pre-magnification digital holography was built. In the record system, one is an object light by using plane waves which illuminates the object, and the other one is recording hologram by using spherical light wave as reference light. There is a Micro objective lens behind the object. The second phase factor which caus ed by the Micro objective lens can be eliminated by choosing the proper position of the reference point source when digital image plane holography is recorded by spherical light. In this experiment, we use the Lygodium cells and Onion cells as the object. The experiment results with Lygodium cells and Onion cells show that digital image plane holography avoid the process of finding recording distance by using auto-focusing approach, and the phase information of the object can be reconstructed more accurately. The digital image plane holography is applied to the microscopic imaging of cells more effectively, and it is suit to apply for the identify of Chinese Herbal Medicine. And it promotes the application of digital holographic in practice.

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.)

A simple method of digitizing analog scintigrams for quantification and digital archiving. Eine einfache Methode der Digitalisierung von Analogszintigrammen zur Quantifizierung und digitalen Archivierung

Energy Technology Data Exchange (ETDEWEB)

Schramm, M. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Kaempfer, B. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Wolf, H. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Clausen, M. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Wendhausen, H. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany)); Henze, E. (Klinik fuer Nuklearmedizin, Kiel Univ. (Germany))

1993-02-01

This study was undertaken to evaluate a quick, reliable and cheap method of digitizing analog scintigrams. 40 whole-body bone scintigrams were obtained simultaneously in analog and genuine digital format. The analog scans on X-ray film were then digitized seecondarily by three different methods: 300 dpi flatbed scanning, high-resolution camera scanning and camcorder recording. A simple exposure approach using a light box, a cheap camcorder, a PC and image grabber hard- and software proved to be optimal. Visual interpretation showed no differences in clinical findings when comparing the analog images with their secondarily digitized counterparts. To test the possibility of quantification, 126 equivalent ROIs were drawn both in the genuine digital and the secondarily digitized images. Comparing the ROI count to whole-body count percentage of the corresponding ROIs showed the correlation to be linear. The evaluation of phantom studies showed the linear correlation to be true within a wide activity range. Thus, secondary digitalization of analog scintigrams is an easy, cheap and reliable method of archiving images and allows secondary digital quantification. (orig.)

Extraction of Urban Trees from Integrated Airborne Based Digital Image and LIDAR Point Cloud Datasets - Initial Results

Science.gov (United States)

Dogon-yaro, M. A.; Kumar, P.; Rahman, A. Abdul; Buyuksalih, G.

2016-10-01

Timely and accurate acquisition of information on the condition and structural changes of urban trees serves as a tool for decision makers to better appreciate urban ecosystems and their numerous values which are critical to building up strategies for sustainable development. The conventional techniques used for extracting tree features include; ground surveying and interpretation of the aerial photography. However, these techniques are associated with some constraint, such as labour intensive field work, a lot of financial requirement, influences by weather condition and topographical covers which can be overcome by means of integrated airborne based LiDAR and very high resolution digital image datasets. This study presented a semi-automated approach for extracting urban trees from integrated airborne based LIDAR and multispectral digital image datasets over Istanbul city of Turkey. The above scheme includes detection and extraction of shadow free vegetation features based on spectral properties of digital images using shadow index and NDVI techniques and automated extraction of 3D information about vegetation features from the integrated processing of shadow free vegetation image and LiDAR point cloud datasets. The ability of the developed algorithms shows a promising result as an automated and cost effective approach to estimating and delineated 3D information of urban trees. The research also proved that integrated datasets is a suitable technology and a viable source of information for city managers to be used in urban trees management.

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)

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).

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.

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

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.

A High-Dynamic-Range Optical Remote Sensing Imaging Method for Digital TDI CMOS

Directory of Open Access Journals (Sweden)

Taiji Lan

2017-10-01

Full Text Available The digital time delay integration (digital TDI technology of the complementary metal-oxide-semiconductor (CMOS image sensor has been widely adopted and developed in the optical remote sensing field. However, the details of targets that have low illumination or low contrast in scenarios of high contrast are often drowned out because of the superposition of multi-stage images in digital domain multiplies the read noise and the dark noise, thus limiting the imaging dynamic range. Through an in-depth analysis of the information transfer model of digital TDI, this paper attempts to explore effective ways to overcome this issue. Based on the evaluation and analysis of multi-stage images, the entropy-maximized adaptive histogram equalization (EMAHE algorithm is proposed to improve the ability of images to express the details of dark or low-contrast targets. Furthermore, in this paper, an image fusion method is utilized based on gradient pyramid decomposition and entropy weighting of different TDI stage images, which can improve the detection ability of the digital TDI CMOS for complex scenes with high contrast, and obtain images that are suitable for recognition by the human eye. The experimental results show that the proposed methods can effectively improve the high-dynamic-range imaging (HDRI capability of the digital TDI CMOS. The obtained images have greater entropy and average gradients.

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.

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.)

Digital image processing for real-time neutron radiography and its applications

International Nuclear Information System (INIS)

Fujine, Shigenori

1989-01-01

The present paper describes several digital image processing approaches for the real-time neutron radiography (neutron television-NTV), such as image integration, adaptive smoothing and image enhancement, which have beneficial effects on image improvements, and also describes how to use these techniques for applications. Details invisible in direct images of NTV are able to be revealed by digital image processing, such as reversed image, gray level correction, gray scale transformation, contoured image, subtraction technique, pseudo color display and so on. For real-time application a contouring operation and an averaging approach can also be utilized effectively. (author)

An overview of digital image processing in the field of nuclear medicine

International Nuclear Information System (INIS)

Okuyama, Yasuo

1992-01-01

The current status and remaining problems of digital image processing in nuclear medicine were discussed. Digitalization of nuclear medicine images has made it possible, in conjunction with computers, to obtain new information (Fourier analysis, Factor analysis, etc.) with added value from images, in place of the fixed concepts that had formerly been drawn only from images. However, the basis of this technology is the special QC and QA of nuclear medicine examinations, and those techniques have not yet been adequately established. The advantage of digitalization is the flexibility that comes from the programs, but the element of the subjectivity of each individual plays a large role, and it can be said that there is also the risk that the logic of image diagnosis established to date will be destroyed. Accordingly, the creation of digital image processing technique with specifications will give birth to standardized digital nuclear medicine images, and these development will certainly lead to progress in nuclear medicine diagnosis. In addition, in comparison with other modalities, the field of nuclear medicine involves a lesser amount of information, and this simplifiers the digitalization of images. At present, equipment is being designed and developed with incorporation of the concept of a work station. A serious problem that remains in this field is the standardization of image transmission. In summary, the main problem that must be solved in the field of nuclear medicine examinations is the establishment of QC and QA methods and practical algorithms for the software. It is hoped that there will be open access to information, etc., related to the software. (author)

Diagnostic ability of the periapical radiographs and digital image in the detection of the artificial proximal caries

International Nuclear Information System (INIS)

Heo, Min Suk; You, Dong Soo

1994-01-01

Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC (Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquired: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference (p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

Are digital images good enough? A comparative study of conventional film-screen vs digital radiographs on printed images of total hip replacement

Energy Technology Data Exchange (ETDEWEB)

Eklund, K.; Jonsson, K.; Lindblom, G.; Lundin, B.; Sanfridsson, J.; Sloth, M. [Department of Radiology, Center for Medical Imaging and Physiology, Lund University Hospital, 22185, Lund (Sweden); Sivberg, B. [Department of Nursing, Faculty of Medicine, Lund University, P.O. Box 157, 22100, Lund (Sweden)

2004-05-01

The aim of this study was to evaluate the inter- and intra-observer variability and to find differences in diagnostic safety between digital and analog technique in diagnostic zones around hip prostheses. In 80 patients who had had a total hip replacement (THR) for more than 2 years, a conventional image and a digital image were taken. Gruen's model of seven distinct regions of interest was used for evaluations. Five experienced radiologists observed the seven regions and noted in a protocol the following distances: stem-cement; cement-bone; and stem-bone. All images were printed on hard copies and were read twice. Weighted kappa, {kappa}{sub w}, analyses were used. The two most frequently loosening regions, stem-cement region 1 and cement-bone region 7, were closely analyzed. In region 1 the five observers had an agreement of 86.75-97.92% between analog and digital images in stem-cement, which is a varied {kappa}{sub w} 0.29-0.71. For cement-bone region 7 an agreement of 87.21-90.45% was found, which is a varied {kappa}{sub w} of 0.48-0.58. All the kappa values differ significantly from nil. The result shows that digital technique is as good as analog radiographs for diagnosing possible loosening of hip prostheses. (orig.)

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 ...

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...

Enhancement of digital radiography image quality using a convolutional neural network.

Science.gov (United States)

Sun, Yuewen; Li, Litao; Cong, Peng; Wang, Zhentao; Guo, Xiaojing

2017-01-01

Digital radiography system is widely used for noninvasive security check and medical imaging examination. However, the system has a limitation of lower image quality in spatial resolution and signal to noise ratio. In this study, we explored whether the image quality acquired by the digital radiography system can be improved with a modified convolutional neural network to generate high-resolution images with reduced noise from the original low-quality images. The experiment evaluated on a test dataset, which contains 5 X-ray images, showed that the proposed method outperformed the traditional methods (i.e., bicubic interpolation and 3D block-matching approach) as measured by peak signal to noise ratio (PSNR) about 1.3 dB while kept highly efficient processing time within one second. Experimental results demonstrated that a residual to residual (RTR) convolutional neural network remarkably improved the image quality of object structural details by increasing the image resolution and reducing image noise. Thus, this study indicated that applying this RTR convolutional neural network system was useful to improve image quality acquired by the digital radiography system.

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

Feed particle size evaluation: conventional approach versus digital holography based image analysis

Directory of Open Access Journals (Sweden)

Vittorio Dell’Orto

2010-01-01

Full Text Available The aim of this study was to evaluate the application of image analysis approach based on digital holography in defining particle size in comparison with the sieve shaker method (sieving method as reference method. For this purpose ground corn meal was analyzed by a sieve shaker Retsch VS 1000 and by image analysis approach based on digital holography. Particle size from digital holography were compared with results obtained by screen (sieving analysis for each of size classes by a cumulative distribution plot. Comparison between particle size values obtained by sieving method and image analysis indicated that values were comparable in term of particle size information, introducing a potential application for digital holography and image analysis in feed industry.

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)

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.

Digital atlas of fetal brain MRI.

Science.gov (United States)

Chapman, Teresa; Matesan, Manuela; Weinberger, Ed; Bulas, Dorothy I

2010-02-01

Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C#, permits linked scrolling and resizing the images. Simultaneous comparison of varying gestational ages is permissible. Fetal brain images across gestational ages 18 to 37 weeks are provided as an interactive digital atlas and are available for free download from http://radiology.seattlechildrens.org/teaching/fetal_brain . Improved interpretation of fetal brain abnormalities can be facilitated by the use of digital atlas cataloging of the normal changes throughout fetal development. Here we provide a description of the atlas and a discussion of normal fetal brain development.

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)

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.

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.

Iso-precision scaling of digitized mammograms to facilitate image analysis

International Nuclear Information System (INIS)

Karssmeijer, N.; van Erning, L.

1991-01-01

This paper reports on a 12 bit CCD camera equipped with a linear sensor of 4096 photodiodes which is used to digitize conventional mammographic films. An iso-precision conversion of the pixel values is preformed to transform the image data to a scale on which the image noise is equal at each level. For this purpose film noise and digitization noise have been determined as a function of optical density and pixel size. It appears that only at high optical densities digitization noise is comparable to or larger than film noise. The quantization error caused by compression of images recorded with 12 bits per pixel to 8 bit images by an iso-precision conversion has been calculated as a function of the number of quantization levels. For mammograms digitized in a 4096 2 matrix the additional error caused by such a scale transform is only about 1.5 percent. An iso-precision scale transform can be advantageous when automated procedures for quantitative image analysis are developed. Especially when detection of signals in noise is aimed at, a constant noise level over the whole pixel value range is very convenient. This is demonstrated by applying local thresholding to detect small microcalcifications. Results are compared to those obtained by using logarithmic or linearized scales

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)

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.

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

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.

Twin-image reduction in inline digital holography using an object segmentation heuristic

International Nuclear Information System (INIS)

McElhinney, Conor P; Hennelly, Bryan M; Naughton, Thomas J

2008-01-01

We present a digital image processing heuristic for the removal of the twin-image in inline digital holograms. Typically, the unwanted twin manifests itself as visible corruptive noise in the reconstruction plane. We reconstruct the unwanted twin-image at its in-focus plane and suppress it by first finding the boundary of the object, and then removing the optical energy within this boundary. In this plane, the wanted twin-image optical energy is largely dispersed outside this boundary and so it is retained. The heuristic's effectiveness is demonstrated using a digital hologram of a real-world object.

Twin-image reduction in inline digital holography using an object segmentation heuristic

Energy Technology Data Exchange (ETDEWEB)

McElhinney, Conor P; Hennelly, Bryan M [Department of Computer Science, National University of Ireland, Maynooth, County Kildare (Ireland); Naughton, Thomas J [University of Oulu, RFMedia Laboratory, Oulu Southern Institute, Vierimaantie 5, 84100 Ylivieska (Finland)], E-mail: conormce@cs.nuim.ie, E-mail: tomn@cs.nuim.ie

2008-11-01

We present a digital image processing heuristic for the removal of the twin-image in inline digital holograms. Typically, the unwanted twin manifests itself as visible corruptive noise in the reconstruction plane. We reconstruct the unwanted twin-image at its in-focus plane and suppress it by first finding the boundary of the object, and then removing the optical energy within this boundary. In this plane, the wanted twin-image optical energy is largely dispersed outside this boundary and so it is retained. The heuristic's effectiveness is demonstrated using a digital hologram of a real-world object.

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

Network based multi-channel digital flash X-ray imaging system

International Nuclear Information System (INIS)

Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin; Zhang Qi; Zheng Futang

2000-01-01

A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images are presented. The software for object separating, mass calculating, 3D positioning, speed determining and cavity reconstruction are described

Network based multi-channel digital flash X-ray imaging system

International Nuclear Information System (INIS)

Wang Jingjin; Yuan Jie; Liu Yaqiang; Lin Yong; Song Zheng; Liu Keyin

2003-01-01

A network based multi-channel digital flash X-ray imaging system has been developed. It can be used to acquire and digitize orthogonal flash X-ray images in multi-interval, and to distribute the images on the network. There is no need of films and chemical process, no anxiety of waiting and no trouble of film archiving. This system is useful for testing ballistics, jet, explode, armour-piercing and fast running machines. The system composing and acquired images of terminal ballistics are presented. The software for object separating, profile calculating and 3D cavity reconstruction are described

How to optimize radiological images captured from digital cameras, using the Adobe Photoshop 6.0 program.

Science.gov (United States)

Chalazonitis, A N; Koumarianos, D; Tzovara, J; Chronopoulos, P

2003-06-01

Over the past decade, the technology that permits images to be digitized and the reduction in the cost of digital equipment allows quick digital transfer of any conventional radiological film. Images then can be transferred to a personal computer, and several software programs are available that can manipulate their digital appearance. In this article, the fundamentals of digital imaging are discussed, as well as the wide variety of optional adjustments that the Adobe Photoshop 6.0 (Adobe Systems, San Jose, CA) program can offer to present radiological images with satisfactory digital imaging quality.

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

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.

Digital color image encoding and decoding using a novel chaotic random generator

International Nuclear Information System (INIS)

Nien, H.H.; Huang, C.K.; Changchien, S.K.; Shieh, H.W.; Chen, C.T.; Tuan, Y.Y.

2007-01-01

This paper proposes a novel chaotic system, in which variables are treated as encryption keys in order to achieve secure transmission of digital color images. Since the dynamic response of chaotic system is highly sensitive to the initial values of a system and to the variation of a parameter, and chaotic trajectory is so unpredictable, we use elements of variables as encryption keys and apply these to computer internet communication of digital color images. As a result, we obtain much higher communication security. We adopt one statistic method involving correlation coefficient γ and FIPS PUB 140-1 to test on the distribution of distinguished elements of variables for continuous-time chaotic system, and accordingly select optimal encryption keys to use in secure communication of digital color images. At the transmitter end, we conduct RGB level decomposition on digital color images, and encrypt them with chaotic keys, and finally transmit them through computer internet. The same encryption keys are used to decrypt and recover the original images at the receiver end. Even if the encrypted images are stolen in the public channel, an intruder is not able to decrypt and recover the original images because of the lack of adequate encryption keys. Empirical example shows that the chaotic system and encryption keys applied in the encryption, transmission, decryption, and recovery of digital color images can achieve higher communication security and best recovered images

Digital image processing of periapical radiographs with low dose of radiation

International Nuclear Information System (INIS)

Kerbauy, Warley David; Moraes, Luiz Cesar de

1996-01-01

The aim of the study was to evaluate whether digitized images obtained from peri apical radiographs taken with low dose of radiation could be improved with the aid of a computer software (Photo Styler) for digital treatment. Serial and standardized radiographs of molar and pre molar areas were studied. A total of 57 images equivalent to the radiographs taken with reduced exposure time (60 and 80% of the time considered normal), digitized and treated, were submitted to the evaluation of seven examiners which compared them with those images without treatment. It was verified that about 80% of the images equivalent to the radiographs taken with 60% reduction of ordinary exposure time were considered to having quality for supporting diagnosis. As for the images taken with 80% reduction of ordinary exposure time, about 50% of them were considered suitable for the same purpose. (author)

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. 

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.

Digital Humanities and networked digital media

DEFF Research Database (Denmark)

Finnemann, Niels Ole

2014-01-01

This article discusses digital humanities and the growing diversity of digital media, digital materials and digital methods. The first section describes the humanities computing tradition formed around the interpretation of computation as a rule-based process connected to a concept of digital...... materials centred on the digitisation of non-digital, finite works, corpora and oeuvres. The second section discusses “the big tent” of contemporary digital humanities. It is argued that there can be no unifying interpretation of digital humanities above the level of studying digital materials with the help...... of software-supported methods. This is so, in part, because of the complexity of the world and, in part, because digital media remain open to the projection of new epistemologies onto the functional architecture of these media. The third section discusses the heterogeneous character of digital materials...

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.

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)

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...

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

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)

Survey of best practices in digital image collection management, 2016 edition

CERN Document Server

2016-01-01

The study presents data and commentary from 55 institutions that manage digital image collections, including museums, historical societies, botanic gardens, churches colleges and universities, government agencies and others. The study looks at a broad range of issues in cataloging, findability, marketing, revenue generation, technology use, rights, digitization, staffing, budgets, access, preservation, image collection building and many other issues of interest to administrators of large digital image collections. Just a few of the report's many findings are that: Only 9.1% of the institutions sampled acquire images from imaging vendors; mostly this was done by college and university collections in the United States; 10% of the institutions sampled had annual revenues from image sales and licensing that exceeded 50,000; No organization in the sample chose outsourced vendor scanning as their primary means of building their collections though 14.55% chose it second and 12.73% ranked it third; 43.64% of those s...

Screening for diabetic retinopathy in rural area using single-field, digital fundus images.

Science.gov (United States)

Ruamviboonsuk, Paisan; Wongcumchang, Nattapon; Surawongsin, Pattamaporn; Panyawatananukul, Ekchai; Tiensuwan, Montip

2005-02-01

To evaluate the practicability of using single-field, 2.3 million-pixel, digital fundus images for screening of diabetic retinopathy in rural areas. All diabetic patients who regularly attended the diabetic clinic at Kabcheang Community Hospital, located at 15 kilometers from the Thailand-Cambodia border, were appointed to the hospital for a 3-day diabetic retinopathy screening programme. The fundi of all patients were captured in single-field, 45 degrees, 2.3 million-pixel images using nonmydriatic digital fundus camera and then sent to a reading center in Bangkok. The fundi were also examined through dilated pupils by a retinal specialist at this hospital. The grading of diabetic retinopathy from two methods was compared for an exact agreement. The average duration of single digital fundus image capture was 2 minutes. The average file size of each image was 750 kilobytes. The average duration of single image transmission to a reading center in Bangkok via satellite was 3 minutes; via a conventional telephone line was 8 minutes. Of all 150 patients, 130 were assessed for an agreement between dilated fundus examination and digital fundus images in diagnosis of diabetic retinopathy. The exact agreement was 0.87, the weighted kappa statistics was 0.74. The sensitivity of digital fundus images in detecting diabetic retinopathy was 80%, the specificity was 96%. For diabetic macular edema the exact agreement was 0.97, the weighted kappa was 0.43, the sensitivity was 43%, and the specificity was 100%. The image capture of the nonmydriatic digital fundus camera is suitable for screening of diabetic retinopathy and single-field digital fundus images are potentially acceptable tools for the screening. The real-time image transmission via telephone lines to remote reading center, however, may not be practical for routine diabetic retinopathy screening in rural areas.

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

Automatic analysis of quality of images from X-ray digital flat detectors

International Nuclear Information System (INIS)

Le Meur, Y.

2009-04-01

Since last decade, medical imaging has grown up with the development of new digital imaging techniques. In the field of X-ray radiography, new detectors replace progressively older techniques, based on film or x-ray intensifiers. These digital detectors offer a higher sensibility and reduced overall dimensions. This work has been prepared with Trixell, the world leading company in flat detectors for medical radiography. It deals with quality control on digital images stemming from these detectors. High quality standards of medical imaging impose a close analysis of the defects that can appear on the images. This work describes a complete process for quality analysis of such images. A particular focus is given on the detection task of the defects, thanks to methods well adapted to our context of spatially correlated defects in noise background. (author)

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.

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

Incidence of ischemic lesions in diffusion-weighted imaging after transbrachial digital subtraction angiography

International Nuclear Information System (INIS)

Aschenbach, R.; Majeed, A.; Eger, C.; Basche, S.; Kerl, J.M.; Vogl, T.J.

2008-01-01

Purpose: to evaluate the frequency of ischemia after transbrachial digital subtraction angiography under ambulant conditions using diffusion-weighted imaging. Materials and methods: 200 patients were included in a prospective study design and received transbrachial digital subtraction angiography under ambulant conditions. Before and after digital subtraction angiography, diffusion-weighted imaging of the brain was performed. Results: in our study population no new lesions were found in diffusion-weighted imaging after digital subtraction angiography during the 3-hour window after angiography. One new lesion was found 3 days after angiography as a late onset complication. Therefore, the frequency of neurological complications is at the level of the confidence interval of 0 - 1.5%. Conclusion: the transbrachial approach under ambulant conditions is a safe method for digital subtraction angiography resulting in a low rate of ischemic lesions in diffusion-weighted imaging. (orig.)

[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).

Two digital X-ray imaging systems for applications in X-ray diffraction

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Flesher, A.C.; Bryant, C.J.; Lincoln, A.D.; Tucker, P.A.; Swanton, S.W.

1986-08-01

Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described:- the Mark I and the Mark II. Both use a bidimensionally sensitive Multiwire proportional counter as the basic X-ray image transducer coupled to a digital microcomputer system. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multi-frame exposures. (author)

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.

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.

Digital gastrointestinal imaging: Effect of pixel size of subtle mucosal abnormalities on observer performance

International Nuclear Information System (INIS)

Kastan, D.J.; Ackerman, L.V.; Feczko, P.J.

1986-01-01

Radiographs from double-contrast colon examinations demonstrating subtle mucosal changes of inflammatory bowel disease and radiographs showing normal colon were digitized (0.1-mm, 0.2-mm, 0.4-mm and 0.8-mm pixel sizes). Ten radiologists interpreted the laser-printed images. Receiver operating characteristic analysis was performed. The results indicated that (1) the sensitivity of radiography in detecting subtle mucosal abnormalities improved as resolution improved; (2) more experience readers performed remarkably well even at the poorer levels of resolution; (3) the resolution necessary for evaluating the colonic mucosa was less than expected; and (4) at low noise levels, conventional television fluoroscopy may have sufficient resolution for mucosal evaluation

A Study on the Improvement of Digital Periapical Images using Image Interpolation Methods

International Nuclear Information System (INIS)

Song, Nam Kyu; Koh, Kwang Joon

1998-01-01

Image resampling is of particular interest in digital radiology. When resampling an image to a new set of coordinate, there appears blocking artifacts and image changes. To enhance image quality, interpolation algorithms have been used. Resampling is used to increase the number of points in an image to improve its appearance for display. The process of interpolation is fitting a continuous function to the discrete points in the digital image. The purpose of this study was to determine the effects of the seven interpolation functions when image resampling in digital periapical images. The images were obtained by Digora, CDR and scanning of Ektaspeed plus periapical radiograms on the dry skull and human subject. The subjects were exposed to intraoral X-ray machine at 60 kVp and 70 kVp with exposure time varying between 0.01 and 0.50 second. To determine which interpolation method would provide the better image, seven functions were compared ; (1) nearest neighbor (2) linear (3) non-linear (4) facet model (5) cubic convolution (6) cubic spline (7) gray segment expansion. And resampled images were compared in terms of SNR (Signal to Noise Ratio) and MTF (Modulation Transfer Function) coefficient value. The obtained results were as follows ; 1. The highest SNR value (75.96 dB) was obtained with cubic convolution method and the lowest SNR value (72.44 dB) was obtained with facet model method among seven interpolation methods. 2. There were significant differences of SNR values among CDR, Digora and film scan (P 0.05). 4. There were significant differences of MTF coefficient values between linear interpolation method and the other six interpolation methods (P<0.05). 5. The speed of computation time was the fastest with nearest neighbor method and the slowest with non-linear method. 6. The better image was obtained with cubic convolution, cubic spline and gray segment method in ROC analysis. 7. The better sharpness of edge was obtained with gray segment expansion method

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

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

[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.

Minimal requirements of ACR-NEMA digital imaging and communication standards

International Nuclear Information System (INIS)

Wang, Y.; Horrii, S.; Lehr, J.

1986-01-01

The American College of Radiology-National Electrical Manufacturers Association (ACR-NEMA) Digital Imaging and Communication Standards were formally adopted in December 1985. They are intended to facilitate management and communication of digital image information regardless of source, format, or device manufacturer; to promote the development and expansion of radiologic imaging and communication systems that can also interface with other systems of hospital information; and to allow the creation of diagnostic information databases that can be interrogated by a wide variety of devices distributed geographically. The Standards specify the hardware interface, a minimum set of software commands, and a consistent set of data formats for communication across the interface between an imaging device and a network interface unit or another imaging device

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

Image Format Conversion to DICOM and Lookup Table Conversion to Presentation Value of the Japanese Society of Radiological Technology (JSRT) Standard Digital Image Database.

Science.gov (United States)

Yanagita, Satoshi; Imahana, Masato; Suwa, Kazuaki; Sugimura, Hitomi; Nishiki, Masayuki

2016-01-01

Japanese Society of Radiological Technology (JSRT) standard digital image database contains many useful cases of chest X-ray images, and has been used in many state-of-the-art researches. However, the pixel values of all the images are simply digitized as relative density values by utilizing a scanned film digitizer. As a result, the pixel values are completely different from the standardized display system input value of digital imaging and communications in medicine (DICOM), called presentation value (P-value), which can maintain a visual consistency when observing images using different display luminance. Therefore, we converted all the images from JSRT standard digital image database to DICOM format followed by the conversion of the pixel values to P-value using an original program developed by ourselves. Consequently, JSRT standard digital image database has been modified so that the visual consistency of images is maintained among different luminance displays.

Digital contrast subtraction radiography for proximal caries diagnosis

International Nuclear Information System (INIS)

Kang, Byung Cheol; Yoon, Suk Ja

2002-01-01

To determine whether subtraction images utilizing contrast media can improve the diagnostic performance of proximal caries diagnosis compared to conventional periapical radiographic images. Thirty-six teeth with 57 proximal surfaces were radiographied using a size no.2 RVG-ui sensor (Trophy Radiology, Marne-la-Vallee, France). The teeth immersed in water-soluble contrast media and subtraction images were taken. Each tooth was then sectioned for histologic examination. The digital radiographic images and subtraction images were examined and interpreted by three dentists for proximal caries. The results of the proximal caries diagnosis were then verified with the results of the histologic examination. The proximal caries sensitivity using digital subtraction radiography was significantly higher than simply examining a single digital radiograph. The sensitivity of the proximal dentinal carious lesion when analyzed with the subtraction radiograph and the radiograph together was higher than with the subtraction radiograph or the radiograph alone. The use of subtraction radiography with contrast media may be useful for detecting proximal dentinal carious lesions.

A Non-symmetric Digital Image Secure Communication Scheme Based on Generalized Chaos Synchronization System

International Nuclear Information System (INIS)

Zhang Xiaohong; Min Lequan

2005-01-01

Based on a generalized chaos synchronization system and a discrete Sinai map, a non-symmetric true color (RGB) digital image secure communication scheme is proposed. The scheme first changes an ordinary RGB digital image with 8 bits into unrecognizable disorder codes and then transforms the disorder codes into an RGB digital image with 16 bits for transmitting. A receiver uses a non-symmetric key to verify the authentication of the received data origin, and decrypts the ciphertext. The scheme can encrypt and decrypt most formatted digital RGB images recognized by computers, and recover the plaintext almost without any errors. The scheme is suitable to be applied in network image communications. The analysis of the key space, sensitivity of key parameters, and correlation of encrypted images imply that this scheme has sound security.

Noise equalization for detection of microcalcification clusters in direct digital mammogram images.

NARCIS (Netherlands)

McLoughlin, K.J.; Bones, P.J.; Karssemeijer, N.

2004-01-01

Equalizing image noise is shown to be an important step in the automatic detection of microcalcifications in digital mammography. This study extends a well established film-screen noise equalization scheme developed by Veldkamp et al. for application to full-field digital mammogram (FFDM) images. A

Improvement of viewing-zone angle and image quality of digital holograms

Energy Technology Data Exchange (ETDEWEB)

Nomura, Takanori, E-mail: nom@sys.wakayama-u.ac.j [Faculty of Systems Enigneering, Wakayama Univesity, 930 Sakaedani, Wakayama, 640-8510 (Japan)

2010-02-01

The method to improve of a viewing-zone angle and an image quality of a digital hologram is presented. A number of digital holograms of a central object are recorded from the position on the circumference. The holograms are used for a hologram synthesis to improve the image quality from whole viewing-zone angle. The synthesis is achieved by a correlation between a hologram and numerically propagated holograms. The large-sized synthesized digital hologram has a wide viewing-zone angle and less speckles. Some experimental results are shown to confirm the proposed method.

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.

FOOT ROT DISEASE IDENTIFICATION FOR VELLAIKODI VARIETY OF BETELVINE PLANTS USING DIGITAL IMAGE PROCESSING

Directory of Open Access Journals (Sweden)

J. Vijayakumar

2012-11-01

Full Text Available Betelvine plants are infected variety of diseases in the complete plantation without any premature warning of the diseases. The aim of this paper is to detection of foot rot disease in the vellaikodi variety of betelvine plants using digital image processing techniques. The digital images of the uninfected or normal betelvine leaves and the digital images of the infected in foot rot diseased betelvine leaves at different stages are collected from different Betelvine plants using a high resolution digital camera and collected betelvine images are stored with JPEG format. The digital images of the betelvine leaves analyses are done using the image processing toolbox in MATLAB which gives the normal patterns of the digital images. Using RGB encoding process, the RGB components of the betelvine leaves are separated. The mean and median values for all sample leaves are computed and calculated values are stored in the system. The mean and median values of test leaves are computed and compared with the stored values. As the result of this comparison, it is identified whether test leaves are affected by foot rot disease or not. Finally this analysis helps to recognize the foot rot disease can be identified before it spreads to entire crop.

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.

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

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.

[Standard chest x-ray: from film to all digital!].

Science.gov (United States)

Ducou Le Pointe, H

2000-04-01

Conventional imaging will be totally replaced by digital imaging because of the lower exposure dosage and the clear advantages in terms of image processing, transfer and storage. Reports in the literature have demonstrated that a 2.5 pl/mm spatial resolution is satisfactory to detect a pneumothorax, a parenchymal nodule or a mediastinal mass. For most authors, this resolution is also sufficient to detect an interstitial syndrome. Digitalization by amplification or by particle detectors using wire chambers are not, for the time being, acceptable for interpretation of a simple chest image because of the low spatial resolution. The selenium cylinder is an adapted technology dedicated to chest imaging. Memory display screens can be used to digitalize the entire radiology unit. They are perfectly adapted for bedside imaging. Flat detectors are based on direct or indirect conversion of the X photons into an electrical signal during the clinical evaluation. The early results appear most promising.

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

Two digital X-ray imaging systems for applications in X-ray diffraction

International Nuclear Information System (INIS)

Bateman, J.E.; Connolly, J.F.; Stephenson, R.; Flesher, A.C.; Tucker, P.A.; Swanton, S.W.

1987-01-01

Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described: the Mark I and the Mark II. Both use a bidimensionally sensitive multiwire proportional counter (MWPC) as the basic X-ray image transducer coupled, in the case of the Mark I to a Digital LSI 11-23 microcomputer system via CAMAC, and in the case of the Mark II to a Digital LSI 11-73 microcomputer system via custom-built data acquisition hardware mounted directly on the Q-bus of the microcomputer. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multiframe exposures. The dedicated digital memories have a resolution of 512x512 pixels of 16 bits, matching well to the spatial resolution of the xenon-filled MWPC (0.5 mm fwhm over an aperture of 200 mm x 200 mm). A 512x512x4 bit video graphics system displays the images in grey scales or colour. (orig.)

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

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.

Comparative study on mammographic findings between conventional mammography and digital mammography

International Nuclear Information System (INIS)

Gonzalez Calle, Aurelio; Saldarriaga Jaramillo, Ximena; Zapata Walliser, Luz Estela; Mejia Restrepo, Jorge Hernando; Arango Martinez, Adriana; Velez Arango, Jorge Mario

2007-01-01

We performed conventional-film mammograms in 180 patients between 35 and 6 years and additionally, we added 2 digital CR technique images to each patient, either craneocaudal (90 patients) or oblique (90 patients). All images were interpreted independently by four radiologists for a total of 720 evaluations, who compared film versus digital images through a 5 mega pixel monitor (soft-copy), using a score scale using the following parameters: mass visualization, detection of micro-calcifications, architectural distortion, visibility of the skin line, and image sharpness and noise. Additionally the tissue density was classified as well as the BIRADS score. The data was processed with the Teleform program and analyzed by de SPSSS program. Results: 52.6% of the micro-calcifications were equally visualized with both systems, in 13.5% of the cases they were better visualized with digital mammography. Similarly, in 50% of the cases, the skin line was better visualized with the digital CR modality. Conclusion: the sharpness of the image was also better seen with the digital CR technique in 48.2%. On the contrary, more noise was seen in digital CR images (63%). digital mammography is a diagnostic alternative that can improve mammographic findings detection and finally become a useful tool in breast cancer diagnosis

The digital subtraction technique in lateral urethrocystography. Die laterale Urethrozystographie in digitaler Subtraktionstechnik

Energy Technology Data Exchange (ETDEWEB)

Wolf, K. (Radiologische Abt., Caritas-Krankenhaus, Bad Mergentheim (Germany)); Peterseim, H. (Frauenklinik, Caritas-Krankenhaus, Bad Mergentheim (Germany)); Grehn, S. (Radiologische Abt., Caritas-Krankenhaus, Bad Mergentheim (Germany))

1994-09-01

The first application of the digital subtraction technique to lateral urethrocystography is described. This methodology facilitates gynecological-urological operations by providing reliable investigation results and an unambiguous image interpretation. Methods and first experiences with the digital subtraction technique in gynecological-urological diagnosis are reported. (orig.)

Development of a digital panoramic X-ray imaging system of adaptive image layers for dental applications

International Nuclear Information System (INIS)

Choi, S.I.; Park, Y.O.; Cho, H.S.; Oh, J.E.; Cho, H.M.; Hong, D.K.; Lee, M.S.; Yang, Y.J.; Je, U.K.; Kim, D.S.; Lee, H.K.

2011-01-01

As a continuation of our digital radiographic sensor R and D, we have developed a prototyped digital panoramic X-ray imaging system for dental applications. The imaging system consists of a slit-collimated X-ray generator with a 0.4 mm focal spot size and a 3.5 mm Al filtration, a linear-array typed CMOS imager with a 48x48 μm 2 pixel size and a 128 (in the scan direction)x3072 (in the vertical direction) pixel format, a series of microstep motors for the precise motion control of the imaging system, and the designed sequences for the motion control and pixel readout required to make a specific plane of interest (POI) to be focused. With the several test phantoms we designed, we obtained useful digital panoramic X-ray images by moving the X-ray generator and the CMOS imager along a continuously sliding rotational center. In this study, we demonstrated that the prototype system can be applicable to any shaped POI or multi-POIs simultaneously to be focused, provided that adequate sequences for motion control and pixel readout are designed. We expect that the imaging system will be useful for our ongoing applications of dental panoramic radiography and nondestructive testing.

Comparison of JPEG and wavelet compression on intraoral digital radiographic images

International Nuclear Information System (INIS)

Kim, Eun Kyung

2004-01-01

To determine the proper image compression method and ratio without image quality degradation in intraoral digital radiographic images, comparing the discrete cosine transform (DCT)-based JPEG with the wavelet-based JPEG 2000 algorithm. Thirty extracted sound teeth and thirty extracted teeth with occlusal caries were used for this study. Twenty plaster blocks were made with three teeth each. They were radiographically exposed using CDR sensors (Schick Inc., Long Island, USA). Digital images were compressed to JPEG format, using Adobe Photoshop v. 7.0 and JPEG 2000 format using Jasper program with compression ratios of 5 : 1, 9 : 1, 14 : 1, 28 : 1 each. To evaluate the lesion detectability, receiver operating characteristic (ROC) analysis was performed by the three oral and maxillofacial radiologists. To evaluate the image quality, all the compressed images were assessed subjectively using 5 grades, in comparison to the original uncompressed images. Compressed images up to compression ratio of 14: 1 in JPEG and 28 : 1 in JPEG 2000 showed nearly the same the lesion detectability as the original images. In the subjective assessment of image quality, images up to compression ratio of 9 : 1 in JPEG and 14 : 1 in JPEG 2000 showed minute mean paired differences from the original images. The results showed that the clinically acceptable compression ratios were up to 9 : 1 for JPEG and 14 : 1 for JPEG 2000. The wavelet-based JPEG 2000 is a better compression method, comparing to DCT-based JPEG for intraoral digital radiographic images.