Accuracy of Bolton analysis measured in laser scanned digital models compared with plaster models (gold standard) and cone-beam computer tomography images.

PubMed

Kim, Jooseong; Lagravére, Manuel O

2016-01-01

The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models. CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC). Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were 0.41 ± 0.305% and 0.45 ± 0.456%, respectively; for anterior Bolton ratios, 0.59 ± 0.520% and 1.01 ± 0.780%, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis. Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis.

Radiologists' preferences for digital mammographic display. The International Digital Mammography Development Group.

PubMed

Pisano, E D; Cole, E B; Major, S; Zong, S; Hemminger, B M; Muller, K E; Johnston, R E; Walsh, R; Conant, E; Fajardo, L L; Feig, S A; Nishikawa, R M; Yaffe, M J; Williams, M B; Aylward, S R

2000-09-01

To determine the preferences of radiologists among eight different image processing algorithms applied to digital mammograms obtained for screening and diagnostic imaging tasks. Twenty-eight images representing histologically proved masses or calcifications were obtained by using three clinically available digital mammographic units. Images were processed and printed on film by using manual intensity windowing, histogram-based intensity windowing, mixture model intensity windowing, peripheral equalization, multiscale image contrast amplification (MUSICA), contrast-limited adaptive histogram equalization, Trex processing, and unsharp masking. Twelve radiologists compared the processed digital images with screen-film mammograms obtained in the same patient for breast cancer screening and breast lesion diagnosis. For the screening task, screen-film mammograms were preferred to all digital presentations, but the acceptability of images processed with Trex and MUSICA algorithms were not significantly different. All printed digital images were preferred to screen-film radiographs in the diagnosis of masses; mammograms processed with unsharp masking were significantly preferred. For the diagnosis of calcifications, no processed digital mammogram was preferred to screen-film mammograms. When digital mammograms were preferred to screen-film mammograms, radiologists selected different digital processing algorithms for each of three mammographic reading tasks and for different lesion types. Soft-copy display will eventually allow radiologists to select among these options more easily.

D Point Cloud Model Colorization by Dense Registration of Digital Images

NASA Astrophysics Data System (ADS)

Crombez, N.; Caron, G.; Mouaddib, E.

2015-02-01

Architectural heritage is a historic and artistic property which has to be protected, preserved, restored and must be shown to the public. Modern tools like 3D laser scanners are more and more used in heritage documentation. Most of the time, the 3D laser scanner is completed by a digital camera which is used to enrich the accurate geometric informations with the scanned objects colors. However, the photometric quality of the acquired point clouds is generally rather low because of several problems presented below. We propose an accurate method for registering digital images acquired from any viewpoints on point clouds which is a crucial step for a good colorization by colors projection. We express this image-to-geometry registration as a pose estimation problem. The camera pose is computed using the entire images intensities under a photometric visual and virtual servoing (VVS) framework. The camera extrinsic and intrinsic parameters are automatically estimated. Because we estimates the intrinsic parameters we do not need any informations about the camera which took the used digital image. Finally, when the point cloud model and the digital image are correctly registered, we project the 3D model in the digital image frame and assign new colors to the visible points. The performance of the approach is proven in simulation and real experiments on indoor and outdoor datasets of the cathedral of Amiens, which highlight the success of our method, leading to point clouds with better photometric quality and resolution.

How to Determine the Centre of Mass of Bodies from Image Modelling

ERIC Educational Resources Information Center

Dias, Marco Adriano; Carvalho, Paulo Simeão; Rodrigues, Marcelo

2016-01-01

Image modelling is a recent technique in physics education that includes digital tools for image treatment and analysis, such as digital stroboscopic photography (DSP) and video analysis software. It is commonly used to analyse the motion of objects. In this work we show how to determine the position of the centre of mass (CM) of objects with…

Digital data registration and differencing compression system

NASA Technical Reports Server (NTRS)

Ransford, Gary A. (Inventor); Cambridge, Vivien J. (Inventor)

1990-01-01

A process is disclosed for x ray registration and differencing which results in more efficient compression. Differencing of registered modeled subject image with a modeled reference image forms a differenced image for compression with conventional compression algorithms. Obtention of a modeled reference image includes modeling a relatively unrelated standard reference image upon a three-dimensional model, which three-dimensional model is also used to model the subject image for obtaining the modeled subject image. The registration process of the modeled subject image and modeled reference image translationally correlates such modeled images for resulting correlation thereof in spatial and spectral dimensions. Prior to compression, a portion of the image falling outside a designated area of interest may be eliminated, for subsequent replenishment with a standard reference image. The compressed differenced image may be subsequently transmitted and/or stored, for subsequent decompression and addition to a standard reference image so as to form a reconstituted or approximated subject image at either a remote location and/or at a later moment in time. Overall effective compression ratios of 100:1 are possible for thoracic x ray digital images.

Digital Data Registration and Differencing Compression System

NASA Technical Reports Server (NTRS)

Ransford, Gary A. (Inventor); Cambridge, Vivien J. (Inventor)

1996-01-01

A process for X-ray registration and differencing results in more efficient compression. Differencing of registered modeled subject image with a modeled reference image forms a differenced image for compression with conventional compression algorithms. Obtention of a modeled reference image includes modeling a relatively unrelated standard reference image upon a three-dimensional model, which three-dimensional model is also used to model the subject image for obtaining the modeled subject image. The registration process of the modeled subject image and modeled reference image translationally correlates such modeled images for resulting correlation thereof in spatial and spectral dimensions. Prior to compression, a portion of the image falling outside a designated area of interest may be eliminated, for subsequent replenishment with a standard reference image. The compressed differenced image may be subsequently transmitted and/or stored, for subsequent decompression and addition to a standard reference image so as to form a reconstituted or approximated subject image at either a remote location and/or at a later moment in time. Overall effective compression ratios of 100:1 are possible for thoracic X-ray digital images.

Digital data registration and differencing compression system

NASA Technical Reports Server (NTRS)

Ransford, Gary A. (Inventor); Cambridge, Vivien J. (Inventor)

1992-01-01

A process for x ray registration and differencing results in more efficient compression is discussed. Differencing of registered modeled subject image with a modeled reference image forms a differential image for compression with conventional compression algorithms. Obtention of a modeled reference image includes modeling a relatively unrelated standard reference image upon a three dimensional model, which three dimensional model is also used to model the subject image for obtaining the modeled subject image. The registration process of the modeled subject image and modeled reference image translationally correlates such modeled images for resulting correlation thereof in spatial and spectral dimensions. Prior to compression, a portion of the image falling outside a designated area of interest may be eliminated, for subsequent replenishment with a standard reference image. The compressed differenced image may be subsequently transmitted and/or stored, for subsequent decompression and addition to a standard reference image so as to form a reconstituted or approximated subject image at either remote location and/or at a later moment in time. Overall effective compression ratios of 100:1 are possible for thoracic x ray digital images.

Digital Biomass Accumulation Using High-Throughput Plant Phenotype Data Analysis.

PubMed

Rahaman, Md Matiur; Ahsan, Md Asif; Gillani, Zeeshan; Chen, Ming

2017-09-01

Biomass is an important phenotypic trait in functional ecology and growth analysis. The typical methods for measuring biomass are destructive, and they require numerous individuals to be cultivated for repeated measurements. With the advent of image-based high-throughput plant phenotyping facilities, non-destructive biomass measuring methods have attempted to overcome this problem. Thus, the estimation of plant biomass of individual plants from their digital images is becoming more important. In this paper, we propose an approach to biomass estimation based on image derived phenotypic traits. Several image-based biomass studies state that the estimation of plant biomass is only a linear function of the projected plant area in images. However, we modeled the plant volume as a function of plant area, plant compactness, and plant age to generalize the linear biomass model. The obtained results confirm the proposed model and can explain most of the observed variance during image-derived biomass estimation. Moreover, a small difference was observed between actual and estimated digital biomass, which indicates that our proposed approach can be used to estimate digital biomass accurately.

[Precision of digital impressions with TRIOS under simulated intraoral impression taking conditions].

PubMed

Yang, Xin; Sun, Yi-fei; Tian, Lei; Si, Wen-jie; Feng, Hai-lan; Liu, Yi-hong

2015-02-18

To evaluate the precision of digital impressions taken under simulated clinical impression taking conditions with TRIOS and to compare with the precision of extraoral digitalizations. Six #14-#17 epoxy resin dentitions with extracted #16 tooth preparations embedded were made. For each artificial dentition, (1)a silicone rubber impression was taken with individual tray, poured with type IV plaster,and digitalized with 3Shape D700 model scanner for 10 times; (2) fastened to a dental simulator, 10 digital impressions for each were taken with 3Shape TRIOS intraoral scanner. To assess the precision, best-fit algorithm and 3D comparison were conducted between repeated scan models pairwise by Geomagic Qualify 12.0, exported as averaged errors (AE) and color-coded diagrams. Non-parametric analysis was performed to compare the precisions of digital impressions and model images. The color-coded diagrams were used to show the deviations distributions. The mean of AE for digital impressions was 7.058 281 μm, which was greater than that of 4.092 363 μm for the model images (P<0.05). However, the means and medians of AE for digital impressions were no more than 10 μm, which meant that the consistency between the digital impressions was good. The deviations distribution was uniform in the model images,while nonuniform in the digital impressions with greater deviations lay mainly around the shoulders and interproximal surfaces. Digital impressions with TRIOS are of good precision and up to the clinical standard. Shoulders and interproximal surfaces scanning are more difficult.

Digital identification of cartographic control points

NASA Technical Reports Server (NTRS)

Gaskell, R. W.

1988-01-01

Techniques have been developed for the sub-pixel location of control points in satellite images returned by the Voyager spacecraft. The procedure uses digital imaging data in the neighborhood of the point to form a multipicture model of a piece of the surface. Comparison of this model with the digital image in each picture determines the control point locations to about a tenth of a pixel. At this level of precision, previously insignificant effects must be considered, including chromatic aberration, high level imaging distortions, and systematic errors due to navigation uncertainties. Use of these methods in the study of Jupiter's satellite Io has proven very fruitful.

Creating an anthropomorphic digital MR phantom—an extensible tool for comparing and evaluating quantitative imaging algorithms

NASA Astrophysics Data System (ADS)

Bosca, Ryan J.; Jackson, Edward F.

2016-01-01

Assessing and mitigating the various sources of bias and variance associated with image quantification algorithms is essential to the use of such algorithms in clinical research and practice. Assessment is usually accomplished with grid-based digital reference objects (DRO) or, more recently, digital anthropomorphic phantoms based on normal human anatomy. Publicly available digital anthropomorphic phantoms can provide a basis for generating realistic model-based DROs that incorporate the heterogeneity commonly found in pathology. Using a publicly available vascular input function (VIF) and digital anthropomorphic phantom of a normal human brain, a methodology was developed to generate a DRO based on the general kinetic model (GKM) that represented realistic and heterogeneously enhancing pathology. GKM parameters were estimated from a deidentified clinical dynamic contrast-enhanced (DCE) MRI exam. This clinical imaging volume was co-registered with a discrete tissue model, and model parameters estimated from clinical images were used to synthesize a DCE-MRI exam that consisted of normal brain tissues and a heterogeneously enhancing brain tumor. An example application of spatial smoothing was used to illustrate potential applications in assessing quantitative imaging algorithms. A voxel-wise Bland-Altman analysis demonstrated negligible differences between the parameters estimated with and without spatial smoothing (using a small radius Gaussian kernel). In this work, we reported an extensible methodology for generating model-based anthropomorphic DROs containing normal and pathological tissue that can be used to assess quantitative imaging algorithms.

Do pre-trained deep learning models improve computer-aided classification of digital mammograms?

NASA Astrophysics Data System (ADS)

Aboutalib, Sarah S.; Mohamed, Aly A.; Zuley, Margarita L.; Berg, Wendie A.; Luo, Yahong; Wu, Shandong

2018-02-01

Digital mammography screening is an important exam for the early detection of breast cancer and reduction in mortality. False positives leading to high recall rates, however, results in unnecessary negative consequences to patients and health care systems. In order to better aid radiologists, computer-aided tools can be utilized to improve distinction between image classifications and thus potentially reduce false recalls. The emergence of deep learning has shown promising results in the area of biomedical imaging data analysis. This study aimed to investigate deep learning and transfer learning methods that can improve digital mammography classification performance. In particular, we evaluated the effect of pre-training deep learning models with other imaging datasets in order to boost classification performance on a digital mammography dataset. Two types of datasets were used for pre-training: (1) a digitized film mammography dataset, and (2) a very large non-medical imaging dataset. By using either of these datasets to pre-train the network initially, and then fine-tuning with the digital mammography dataset, we found an increase in overall classification performance in comparison to a model without pre-training, with the very large non-medical dataset performing the best in improving the classification accuracy.

Teaching technology to technologists.

PubMed

Lehrer, Rich

2008-01-01

The field of radiologic technology is in a transition period between the traditional film-based model and the digital-based model. To determine the extent to which educational programs accredited by the Joint Review Committee on Education in Radiologic Technology (JRCERT) are providing digital imaging-specific education. A survey regarding digital imaging instruction was administered electronically to program directors of 289 JRCERT-accredited educational programs in the United States. One hundred forty-four responses were received, for a response rate of 50%. The survey revealed that the majority of educational programs (73.6%) have added, modified or are already covering digital imaging topics, while other programs (21.5%) were in the planning stages of preparing coursework.

Generation of high-dynamic range image from digital photo

NASA Astrophysics Data System (ADS)

Wang, Ying; Potemin, Igor S.; Zhdanov, Dmitry D.; Wang, Xu-yang; Cheng, Han

2016-10-01

A number of the modern applications such as medical imaging, remote sensing satellites imaging, virtual prototyping etc use the High Dynamic Range Image (HDRI). Generally to obtain HDRI from ordinary digital image the camera is calibrated. The article proposes the camera calibration method based on the clear sky as the standard light source and takes sky luminance from CIE sky model for the corresponding geographical coordinates and time. The article considers base algorithms for getting real luminance values from ordinary digital image and corresponding programmed implementation of the algorithms. Moreover, examples of HDRI reconstructed from ordinary images illustrate the article.

Evaluation of a novel laparoscopic camera for characterization of renal ischemia in a porcine model using digital light processing (DLP) hyperspectral imaging

NASA Astrophysics Data System (ADS)

Olweny, Ephrem O.; Tan, Yung K.; Faddegon, Stephen; Jackson, Neil; Wehner, Eleanor F.; Best, Sara L.; Park, Samuel K.; Thapa, Abhas; Cadeddu, Jeffrey A.; Zuzak, Karel J.

2012-03-01

Digital light processing hyperspectral imaging (DLP® HSI) was adapted for use during laparoscopic surgery by coupling a conventional laparoscopic light guide with a DLP-based Agile Light source (OL 490, Optronic Laboratories, Orlando, FL), incorporating a 0° laparoscope, and a customized digital CCD camera (DVC, Austin, TX). The system was used to characterize renal ischemia in a porcine model.

A model for a PC-based, universal-format, multimedia digitization system: moving beyond the scanner.

PubMed

McEachen, James C; Cusack, Thomas J; McEachen, John C

2003-08-01

Digitizing images for use in case presentations based on hardcopy films, slides, photographs, negatives, books, and videos can present a challenging task. Scanners and digital cameras have become standard tools of the trade. Unfortunately, use of these devices to digitize multiple images in many different media formats can be a time-consuming and in some cases unachievable process. The authors' goal was to create a PC-based solution for digitizing multiple media formats in a timely fashion while maintaining adequate image presentation quality. The authors' PC-based solution makes use of off-the-shelf hardware applications to include a digital document camera (DDC), VHS video player, and video-editing kit. With the assistance of five staff radiologists, the authors examined the quality of multiple image types digitized with this equipment. The authors also quantified the speed of digitization of various types of media using the DDC and video-editing kit. With regard to image quality, the five staff radiologists rated the digitized angiography, CT, and MR images as adequate to excellent for use in teaching files and case presentations. With regard to digitized plain films, the average rating was adequate. As for performance, the authors recognized a 68% improvement in the time required to digitize hardcopy films using the DDC instead of a professional quality scanner. The PC-based solution provides a means for digitizing multiple images from many different types of media in a timely fashion while maintaining adequate image presentation quality.

Point Cloud and Digital Surface Model Generation from High Resolution Multiple View Stereo Satellite Imagery

NASA Astrophysics Data System (ADS)

Gong, K.; Fritsch, D.

2018-05-01

Nowadays, multiple-view stereo satellite imagery has become a valuable data source for digital surface model generation and 3D reconstruction. In 2016, a well-organized multiple view stereo publicly benchmark for commercial satellite imagery has been released by the John Hopkins University Applied Physics Laboratory, USA. This benchmark motivates us to explore the method that can generate accurate digital surface models from a large number of high resolution satellite images. In this paper, we propose a pipeline for processing the benchmark data to digital surface models. As a pre-procedure, we filter all the possible image pairs according to the incidence angle and capture date. With the selected image pairs, the relative bias-compensated model is applied for relative orientation. After the epipolar image pairs' generation, dense image matching and triangulation, the 3D point clouds and DSMs are acquired. The DSMs are aligned to a quasi-ground plane by the relative bias-compensated model. We apply the median filter to generate the fused point cloud and DSM. By comparing with the reference LiDAR DSM, the accuracy, the completeness and the robustness are evaluated. The results show, that the point cloud reconstructs the surface with small structures and the fused DSM generated by our pipeline is accurate and robust.

Accuracy of Bolton analysis measured in laser scanned digital models compared with plaster models (gold standard) and cone-beam computer tomography images

PubMed Central

Kim, Jooseong

2016-01-01

Objective The aim of this study was to compare the accuracy of Bolton analysis obtained from digital models scanned with the Ortho Insight three-dimensional (3D) laser scanner system to those obtained from cone-beam computed tomography (CBCT) images and traditional plaster models. Methods CBCT scans and plaster models were obtained from 50 patients. Plaster models were scanned using the Ortho Insight 3D laser scanner; Bolton ratios were calculated with its software. CBCT scans were imported and analyzed using AVIZO software. Plaster models were measured with a digital caliper. Data were analyzed with descriptive statistics and the intraclass correlation coefficient (ICC). Results Anterior and overall Bolton ratios obtained by the three different modalities exhibited excellent agreement (> 0.970). The mean differences between the scanned digital models and physical models and between the CBCT images and scanned digital models for overall Bolton ratios were 0.41 ± 0.305% and 0.45 ± 0.456%, respectively; for anterior Bolton ratios, 0.59 ± 0.520% and 1.01 ± 0.780%, respectively. ICC results showed that intraexaminer error reliability was generally excellent (> 0.858 for all three diagnostic modalities), with < 1.45% discrepancy in the Bolton analysis. Conclusions Laser scanned digital models are highly accurate compared to physical models and CBCT scans for assessing the spatial relationships of dental arches for orthodontic diagnosis. PMID:26877978

Topographic correction realization based on the CBERS-02B image

NASA Astrophysics Data System (ADS)

Qin, Hui-ping; Yi, Wei-ning; Fang, Yong-hua

2011-08-01

The special topography of mountain terrain will induce the retrieval distortion in same species and surface spectral lines. In order to improve the research accuracy of topographic surface characteristic, many researchers have focused on topographic correction. Topographic correction methods can be statistical-empirical model or physical model, in which the methods based on the digital elevation model data are most popular. Restricted by spatial resolution, previous model mostly corrected topographic effect based on Landsat TM image, whose spatial resolution is 30 meter that can be easily achieved from internet or calculated from digital map. Some researchers have also done topographic correction based on high spatial resolution images, such as Quickbird and Ikonos, but there is little correlative research on the topographic correction of CBERS-02B image. In this study, liao-ning mountain terrain was taken as the objective. The digital elevation model data was interpolated to 2.36 meter by 15 meter original digital elevation model one meter by one meter. The C correction, SCS+C correction, Minnaert correction and Ekstrand-r were executed to correct the topographic effect. Then the corrected results were achieved and compared. The images corrected with C correction, SCS+C correction, Minnaert correction and Ekstrand-r were compared, and the scatter diagrams between image digital number and cosine of solar incidence angel with respect to surface normal were shown. The mean value, standard variance, slope of scatter diagram, and separation factor were statistically calculated. The analysed result shows that the shadow is weakened in corrected images than the original images, and the three-dimensional affect is removed. The absolute slope of fitting lines in scatter diagram is minished. Minnaert correction method has the most effective result. These demonstrate that the former correction methods can be successfully adapted to CBERS-02B images. The DEM data can be interpolated step by step to get the corresponding spatial resolution approximately for the condition that high spatial resolution elevation data is hard to get.

Topology-Preserving Rigid Transformation of 2D Digital Images.

PubMed

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.

Information Seeking Behavior in Digital Image Collections: A Cognitive Approach

ERIC Educational Resources Information Center

Matusiak, Krystyna K.

2006-01-01

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

ACR/NEMA Digital Image Interface Standard (An Illustrated Protocol Overview)

NASA Astrophysics Data System (ADS)

Lawrence, G. Robert

1985-09-01

The American College of Radiologists (ACR) and the National Electrical Manufacturers Association (NEMA) have sponsored a joint standards committee mandated to develop a universal interface standard for the transfer of radiology images among a variety of PACS imaging devicesl. The resulting standard interface conforms to the ISO/OSI standard reference model for network protocol layering. The standard interface specifies the lower layers of the reference model (Physical, Data Link, Transport and Session) and implies a requirement of the Network Layer should a requirement for a network exist. The message content has been considered and a flexible message and image format specified. The following Imaging Equipment modalities are supported by the standard interface... CT Computed Tomograpy DS Digital Subtraction NM Nuclear Medicine US Ultrasound MR Magnetic Resonance DR Digital Radiology The following data types are standardized over the transmission interface media.... IMAGE DATA DIGITIZED VOICE HEADER DATA RAW DATA TEXT REPORTS GRAPHICS OTHERS This paper consists of text supporting the illustrated protocol data flow. Each layer will be individually treated. Particular emphasis will be given to the Data Link layer (Frames) and the Transport layer (Packets). The discussion utilizes a finite state sequential machine model for the protocol layers.

Digital image analysis: improving accuracy and reproducibility of radiographic measurement.

PubMed

Bould, M; Barnard, S; Learmonth, I D; Cunningham, J L; Hardy, J R

1999-07-01

To assess the accuracy and reproducibility of a digital image analyser and the human eye, in measuring radiographic dimensions. We experimentally compared radiographic measurement using either an image analyser system or the human eye with digital caliper. The assessment of total hip arthroplasty wear from radiographs relies on both the accuracy of radiographic images and the accuracy of radiographic measurement. Radiographs were taken of a slip gauge (30+/-0.00036 mm) and slip gauge with a femoral stem. The projected dimensions of the radiographic images were calculated by trigonometry. The radiographic dimensions were then measured by blinded observers using both techniques. For a single radiograph, the human eye was accurate to 0.26 mm and reproducible to +/-0.1 mm. In comparison the digital image analyser system was accurate to 0.01 mm with a reproducibility of +/-0.08 mm. In an arthroplasty model, where the dimensions of an object were corrected for magnification by the known dimensions of a femoral head, the human eye was accurate to 0.19 mm, whereas the image analyser system was accurate to 0.04 mm. The digital image analysis system is up to 20 times more accurate than the human eye, and in an arthroplasty model the accuracy of measurement increases four-fold. We believe such image analysis may allow more accurate and reproducible measurement of wear from standard follow-up radiographs.

Model-based frequency response characterization of a digital-image analysis system for epifluorescence microscopy

NASA Technical Reports Server (NTRS)

Hazra, Rajeeb; Viles, Charles L.; Park, Stephen K.; Reichenbach, Stephen E.; Sieracki, Michael E.

1992-01-01

Consideration is given to a model-based method for estimating the spatial frequency response of a digital-imaging system (e.g., a CCD camera) that is modeled as a linear, shift-invariant image acquisition subsystem that is cascaded with a linear, shift-variant sampling subsystem. The method characterizes the 2D frequency response of the image acquisition subsystem to beyond the Nyquist frequency by accounting explicitly for insufficient sampling and the sample-scene phase. Results for simulated systems and a real CCD-based epifluorescence microscopy system are presented to demonstrate the accuracy of the method.

Derivation of planetary topography using multi-image shape-from-shading

USGS Publications Warehouse

Lohse, V.; Heipke, C.; Kirk, R.L.

2006-01-01

In many cases, the derivation of high-resolution digital terrain models (DTMs) from planetary surfaces using conventional digital image matching is a problem. The matching methods need at least one stereo pair of images with sufficient texture. However, many space missions provide only a few stereo images and planetary surfaces often possess insufficient texture. This paper describes a method for the generation of high-resolution DTMs from planetary surfaces, which has the potential to overcome the described problem. The suggested method, developed by our group, is based on shape-from-shading using an arbitrary number of digital optical images, and is termed "multi-image shape-from-shading" (MI-SFS). The paper contains an explanation of the theory of MI-SFS, followed by a presentation of current results, which were obtained using images from NASA's lunar mission Clementine, and constitute the first practical application with our method using extraterrestrial imagery. The lunar surface is reconstructed under the assumption of different kinds of reflectance models (e.g. Lommel-Seeliger and Lambert). The represented results show that the derivation of a high-resolution DTM of real digital planetary images by means of MI-SFS is feasible. ?? 2006 Elsevier Ltd. All rights reserved.

Generation of topographic terrain models utilizing synthetic aperture radar and surface level data

NASA Technical Reports Server (NTRS)

Imhoff, Marc L. (Inventor)

1991-01-01

Topographical terrain models are generated by digitally delineating the boundary of the region under investigation from the data obtained from an airborne synthetic aperture radar image and surface elevation data concurrently acquired either from an airborne instrument or at ground level. A set of coregistered boundary maps thus generated are then digitally combined in three dimensional space with the acquired surface elevation data by means of image processing software stored in a digital computer. The method is particularly applicable for generating terrain models of flooded regions covered entirely or in part by foliage.

The Process of Digitizing of Old Globe

NASA Astrophysics Data System (ADS)

Ambrožová, K.; Havrlanta, J.; Talich, M.; Böhm, O.

2016-06-01

This paper describes the process of digitalization of old globes that brings with it the possibility to use globes in their digital form. Created digital models are available to the general public through modern technology in the Internet network. This gives an opportunity to study old globes located in various historical collections, and prevent damage of the originals. Another benefit of digitization is also a possibility of comparing different models both among themselves and with current map data by increasing the transparency of individual layers. Digitization is carried out using special device that allows digitizing globes with a diameter ranging from 5 cm to 120 cm. This device can be easily disassembled, and it is fully mobile therefore the globes can be digitized in the place of its storage. Image data of globe surface are acquired by digital camera firmly fastened to the device. Acquired image data are then georeferenced by using a method of complex adjustment. The last step of digitization is publication of the final models that is realized by two ways. The first option is in the form of 3D model through JavaScript library Cesium or Google Earth plug-in in the Web browser. The second option is as a georeferenced map using Tile Map Service.

Geological terrain models

NASA Technical Reports Server (NTRS)

Kaupp, V. H.; Macdonald, H. C.; Waite, W. P.

1981-01-01

The initial phase of a program to determine the best interpretation strategy and sensor configuration for a radar remote sensing system for geologic applications is discussed. In this phase, terrain modeling and radar image simulation were used to perform parametric sensitivity studies. A relatively simple computer-generated terrain model is presented, and the data base, backscatter file, and transfer function for digital image simulation are described. Sets of images are presented that simulate the results obtained with an X-band radar from an altitude of 800 km and at three different terrain-illumination angles. The simulations include power maps, slant-range images, ground-range images, and ground-range images with statistical noise incorporated. It is concluded that digital image simulation and computer modeling provide cost-effective methods for evaluating terrain variations and sensor parameter changes, for predicting results, and for defining optimum sensor parameters.

Utilizing typical color appearance models to represent perceptual brightness and colorfulness for digital images

NASA Astrophysics Data System (ADS)

Gong, Rui; Wang, Qing; Shao, Xiaopeng; Zhou, Conghao

2016-12-01

This study aims to expand the applications of color appearance models to representing the perceptual attributes for digital images, which supplies more accurate methods for predicting image brightness and image colorfulness. Two typical models, i.e., the CIELAB model and the CIECAM02, were involved in developing algorithms to predict brightness and colorfulness for various images, in which three methods were designed to handle pixels of different color contents. Moreover, massive visual data were collected from psychophysical experiments on two mobile displays under three lighting conditions to analyze the characteristics of visual perception on these two attributes and to test the prediction accuracy of each algorithm. Afterward, detailed analyses revealed that image brightness and image colorfulness were predicted well by calculating the CIECAM02 parameters of lightness and chroma; thus, the suitable methods for dealing with different color pixels were determined for image brightness and image colorfulness, respectively. This study supplies an example of enlarging color appearance models to describe image perception.

Determination of Shed Ice Particle Size Using High Speed Digital Imaging

NASA Technical Reports Server (NTRS)

Broughton, Howard; Owens, Jay; Sims, James J.; Bond, Thomas H.

1996-01-01

A full scale model of an aircraft engine inlet was tested at NASA Lewis Research Center's Icing Research Tunnel. Simulated natural ice sheds from the engine inlet lip were studied using high speed digital image acquisition and image analysis. Strategic camera placement integrated at the model design phase allowed the study of ice accretion on the inlet lip and the resulting shed ice particles at the aerodynamic interface plane at the rear of the inlet prior to engine ingestion. The resulting digital images were analyzed using commercial and proprietary software to determine the size of the ice particles that could potentially be ingested by the engine during a natural shedding event. A methodology was developed to calibrate the imaging system and insure consistent and accurate measurements of the ice particles for a wide range of icing conditions.

A comprehensive study on urban true orthorectification

USGS Publications Warehouse

Zhou, G.; Chen, W.; Kelmelis, J.A.; Zhang, Dongxiao

2005-01-01

To provide some advanced technical bases (algorithms and procedures) and experience needed for national large-scale digital orthophoto generation and revision of the Standards for National Large-Scale City Digital Orthophoto in the National Digital Orthophoto Program (NDOP), this paper presents a comprehensive study on theories, algorithms, and methods of large-scale urban orthoimage generation. The procedures of orthorectification for digital terrain model (DTM)-based and digital building model (DBM)-based orthoimage generation and their mergence for true orthoimage generation are discussed in detail. A method of compensating for building occlusions using photogrammetric geometry is developed. The data structure needed to model urban buildings for accurately generating urban orthoimages is presented. Shadow detection and removal, the optimization of seamline for automatic mosaic, and the radiometric balance of neighbor images are discussed. Street visibility analysis, including the relationship between flight height, building height, street width, and relative location of the street to the imaging center, is analyzed for complete true orthoimage generation. The experimental results demonstrated that our method can effectively and correctly orthorectify the displacements caused by terrain and buildings in urban large-scale aerial images. ?? 2005 IEEE.

Textured digital elevation model formation from low-cost UAV LADAR/digital image data

NASA Astrophysics Data System (ADS)

Bybee, Taylor C.; Budge, Scott E.

2015-05-01

Textured digital elevation models (TDEMs) have valuable use in precision agriculture, situational awareness, and disaster response. However, scientific-quality models are expensive to obtain using conventional aircraft-based methods. The cost of creating an accurate textured terrain model can be reduced by using a low-cost (<$20k) UAV system fitted with ladar and electro-optical (EO) sensors. A texel camera fuses calibrated ladar and EO data upon simultaneous capture, creating a texel image. This eliminates the problem of fusing the data in a post-processing step and enables both 2D- and 3D-image registration techniques to be used. This paper describes formation of TDEMs using simulated data from a small UAV gathering swaths of texel images of the terrain below. Being a low-cost UAV, only a coarse knowledge of position and attitude is known, and thus both 2D- and 3D-image registration techniques must be used to register adjacent swaths of texel imagery to create a TDEM. The process of creating an aggregate texel image (a TDEM) from many smaller texel image swaths is described. The algorithm is seeded with the rough estimate of position and attitude of each capture. Details such as the required amount of texel image overlap, registration models, simulated flight patterns (level and turbulent), and texture image formation are presented. In addition, examples of such TDEMs are shown and analyzed for accuracy.

Topography changes monitoring of small islands using camera drone

NASA Astrophysics Data System (ADS)

Bang, E.

2017-12-01

Drone aerial photogrammetry was conducted for monitoring topography changes of small islands in the east sea of Korea. Severe weather and sea wave is eroding the islands and sometimes cause landslide and falling rock. Due to rugged cliffs in all direction and bad accessibility, ground based survey methods are less efficient in monitoring topography changes of the whole area. Camera drones can provide digital images and movie in every corner of the islands, and drone aerial photogrammetry is powerful to get precise digital surface model (DSM) for a limited area. We have got a set of digital images to construct a textured 3D model of the project area every year since 2014. Flight height is in less than 100m from the top of those islands to get enough ground sampling distance (GSD). Most images were vertically captured with automatic flights, but we also flied drones around the islands with about 30°-45° camera angle for constructing 3D model better. Every digital image has geo-reference, but we set several ground control points (GCPs) on the islands and their coordinates were measured with RTK surveying methods to increase the absolute accuracy of the project. We constructed 3D textured model using photogrammetry tool, which generates 3D spatial information from digital images. From the polygonal model, we could get DSM with contour lines. Thematic maps such as hill shade relief map, aspect map and slope map were also processed. Those maps make us understand topography condition of the project area better. The purpose of this project is monitoring topography change of these small islands. Elevation difference map between DSMs of each year is constructed. There are two regions showing big negative difference value. By comparing constructed textured models and captured digital images around these regions, it is checked that a region have experienced real topography change. It is due to huge rock fall near the center of the east island. The size of fallen rock can be measured on the digital model exactly, which is about 13m*6m*2m (height*width*thickness). We believe that drone aerial photogrammetry can be an efficient topography changes detection method for a complicated terrain area.

Computing mammographic density from a multiple regression model constructed with image-acquisition parameters from a full-field digital mammographic unit

PubMed Central

Lu, Lee-Jane W.; Nishino, Thomas K.; Khamapirad, Tuenchit; Grady, James J; Leonard, Morton H.; Brunder, Donald G.

2009-01-01

Breast density (the percentage of fibroglandular tissue in the breast) has been suggested to be a useful surrogate marker for breast cancer risk. It is conventionally measured using screen-film mammographic images by a labor intensive histogram segmentation method (HSM). We have adapted and modified the HSM for measuring breast density from raw digital mammograms acquired by full-field digital mammography. Multiple regression model analyses showed that many of the instrument parameters for acquiring the screening mammograms (e.g. breast compression thickness, radiological thickness, radiation dose, compression force, etc) and image pixel intensity statistics of the imaged breasts were strong predictors of the observed threshold values (model R2=0.93) and %density (R2=0.84). The intra-class correlation coefficient of the %-density for duplicate images was estimated to be 0.80, using the regression model-derived threshold values, and 0.94 if estimated directly from the parameter estimates of the %-density prediction regression model. Therefore, with additional research, these mathematical models could be used to compute breast density objectively, automatically bypassing the HSM step, and could greatly facilitate breast cancer research studies. PMID:17671343

An object-oriented simulator for 3D digital breast tomosynthesis imaging system.

PubMed

Seyyedi, Saeed; Cengiz, Kubra; Kamasak, Mustafa; Yildirim, Isa

2013-01-01

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

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

PubMed Central

Cengiz, Kubra

2013-01-01

Digital breast tomosynthesis (DBT) is an innovative imaging modality that provides 3D reconstructed images of breast to detect the breast cancer. Projections obtained with an X-ray source moving in a limited angle interval are used to reconstruct 3D image of breast. Several reconstruction algorithms are available for DBT imaging. Filtered back projection algorithm has traditionally been used to reconstruct images from projections. Iterative reconstruction algorithms such as algebraic reconstruction technique (ART) were later developed. Recently, compressed sensing based methods have been proposed in tomosynthesis imaging problem. We have developed an object-oriented simulator for 3D digital breast tomosynthesis (DBT) imaging system using C++ programming language. The simulator is capable of implementing different iterative and compressed sensing based reconstruction methods on 3D digital tomosynthesis data sets and phantom models. A user friendly graphical user interface (GUI) helps users to select and run the desired methods on the designed phantom models or real data sets. The simulator has been tested on a phantom study that simulates breast tomosynthesis imaging problem. Results obtained with various methods including algebraic reconstruction technique (ART) and total variation regularized reconstruction techniques (ART+TV) are presented. Reconstruction results of the methods are compared both visually and quantitatively by evaluating performances of the methods using mean structural similarity (MSSIM) values. PMID:24371468

Ground-Level Digital Terrain Model (DTM) Construction from Tandem-X InSAR Data and Worldview Stereo-Photogrammetric Images

NASA Technical Reports Server (NTRS)

Lee, Seung-Kuk; Fatoyinbo, Temilola; Lagomasino, David; Osmanoglu, Batuhan; Feliciano, Emanuelle

2016-01-01

The ground-level digital elevation model (DEM) or digital terrain model (DTM) information are invaluable for environmental modeling, such as water dynamics in forests, canopy height, forest biomass, carbon estimation, etc. We propose to extract the DTM over forested areas from the combination of interferometric complex coherence from single-pass TanDEM-X (TDX) data at HH polarization and Digital Surface Model (DSM) derived from high-resolution WorldView (WV) image pair by means of random volume over ground (RVoG) model. The RVoG model is a widely and successfully used model for polarimetric SAR interferometry (Pol-InSAR) technique for vertical forest structure parameter retrieval [1][2][3][4]. The ground-level DEM have been obtained by complex volume decorrelation in the RVoG model with the DSM using stereo-photogrammetric technique. Finally, the airborne lidar data were used to validate the ground-level DEM and forest canopy height results.

VENI, video, VICI: The merging of computer and video technologies

NASA Technical Reports Server (NTRS)

Horowitz, Jay G.

1993-01-01

The topics covered include the following: High Definition Television (HDTV) milestones; visual information bandwidth; television frequency allocation and bandwidth; horizontal scanning; workstation RGB color domain; NTSC color domain; American HDTV time-table; HDTV image size; digital HDTV hierarchy; task force on digital image architecture; open architecture model; future displays; and the ULTIMATE imaging system.

Simulation of digital mammography images

NASA Astrophysics Data System (ADS)

Workman, Adam

2005-04-01

A number of different technologies are available for digital mammography. However, it is not clear how differences in the physical performance aspects of the different imaging technologies affect clinical performance. Randomised controlled trials provide a means of gaining information on clinical performance however do not provide direct comparison of the different digital imaging technologies. This work describes a method of simulating the performance of different digital mammography systems. The method involves modifying the imaging performance parameters of images from a small field of view (SFDM), high resolution digital imaging system used for spot imaging. Under normal operating conditions this system produces images with higher signal-to-noise ratio (SNR) over a wide spatial frequency range than current full field digital mammography (FFDM) systems. The SFDM images can be 'degraded" by computer processing to simulate the characteristics of a FFDM system. Initial work characterised the physical performance (MTF, NPS) of the SFDM detector and developed a model and method for simulating signal transfer and noise properties of a FFDM system. It was found that the SNR properties of the simulated FFDM images were very similar to those measured from an actual FFDM system verifying the methodology used. The application of this technique to clinical images from the small field system will allow the clinical performance of different FFDM systems to be simulated and directly compared using the same clinical image datasets.

Developing tools for digital radar image data evaluation

NASA Technical Reports Server (NTRS)

Domik, G.; Leberl, F.; Raggam, J.

1986-01-01

The refinement of radar image analysis methods has led to a need for a systems approach to radar image processing software. Developments stimulated through satellite radar are combined with standard image processing techniques to create a user environment to manipulate and analyze airborne and satellite radar images. One aim is to create radar products for the user from the original data to enhance the ease of understanding the contents. The results are called secondary image products and derive from the original digital images. Another aim is to support interactive SAR image analysis. Software methods permit use of a digital height model to create ortho images, synthetic images, stereo-ortho images, radar maps or color combinations of different component products. Efforts are ongoing to integrate individual tools into a combined hardware/software environment for interactive radar image analysis.

CD-ROM publication of the Mars digital cartographic data base

NASA Technical Reports Server (NTRS)

Batson, R. M.; Eliason, E. M.; Soderblom, L. A.; Edwards, Kathleen; Wu, Sherman S. C.

1991-01-01

The recently completed Mars mosaicked digital image model (MDIM) and the soon-to-be-completed Mars digital terrain model (DTM) are being transcribed to optical disks to simplify distribution to planetary investigators. These models, completed in FY 1991, provide a cartographic base to which all existing Mars data can be registered. The digital image map of Mars is a cartographic extension of a set of compact disk read-only memory (CD-ROM) volumes containing individual Viking Orbiter images now being released. The data in these volumes are pristine in the sense that they were processed only to the extent required to view them as images. They contain the artifacts and the radiometric, geometric, and photometric characteristics of the raw data transmitted by the spacecraft. This new set of volumes, on the other hand, contains cartographic compilations made by processing the raw images to reduce radiometric and geometric distortions and to form geodetically controlled MDIM's. It also contains digitized versions of an airbrushed map of Mars as well as a listing of all feature names approved by the International Astronomical Union. In addition, special geodetic and photogrammetric processing has been performed to derive rasters of topographic data, or DTM's. The latter have a format similar to that of MDIM, except that elevation values are used in the array instead of image brightness values. The set consists of seven volumes: (1) Vastitas Borealis Region of Mars; (2) Xanthe Terra of Mars; (3) Amazonis Planitia Region of Mars; (4) Elysium Planitia Region of Mars; (5) Arabia Terra of Mars; (6) Planum Australe Region of Mars; and (7) a digital topographic map of Mars.

Comparison of optometry vs digital photography screening for diabetic retinopathy in a single district.

PubMed

Tu, K L; Palimar, P; Sen, S; Mathew, P; Khaleeli, A

2004-01-01

To compare (a). the clinical effectiveness and (b). cost effectiveness of the two models in screening for diabetic retinopathy. (a). Retrospective analysis of referral diagnoses of each screening model in their first respective years of operation and an audit of screen positive patients and a sample of screen negatives referred to the hospital eye service from both screening programmes. (b). Cost effectiveness study. (1). A total of 1643 patients screened in the community and in digital photography clinics; (2). 109 consecutive patients referred to the Diabetic Eye Clinic through the two existing models of diabetic retinopathy screening; (3). 55 screen negative patients from the optometry model; (4). 68 screen negative patients audited from the digital photography model. The compliance rate was 45% for optometry (O) vs 50% for the digital imaging system (I). Background retinopathy was recorded at screening in 22% (O) vs 17% (I) (P=0.03) and maculopathy in 3.8% (O) vs 1.7% (I) (P=0.02). Hospital referral rates were 3.8% (O) vs 4.2% (I) Sensitivity (75% for optometry, 80% for digital photography) and specificity (98% for optometry and digital photography) were similar in both models. The cost of screening each patient was pound 23.99 (O) vs pound 29.29 (I). The cost effectiveness was pound 832 (O) vs pound 853(I) in the first year. The imaging system was not always able to detect early retinopathy and maculopathy; it was equally specific in identifying sight-threatening disease. Cost effectiveness was poor in both models, in their first operational year largely as a result of poor compliance rates in the newly introduced screening programme. Cost effectiveness of the imaging model should further improve with falling costs of imaging systems. Until then, it is essential to continue any existing well-coordinated optometry model.

Overview of Digital Forensics Algorithms in Dslr Cameras

NASA Astrophysics Data System (ADS)

Aminova, E.; Trapeznikov, I.; Priorov, A.

2017-05-01

The widespread usage of the mobile technologies and the improvement of the digital photo devices getting has led to more frequent cases of falsification of images including in the judicial practice. Consequently, the actual task for up-to-date digital image processing tools is the development of algorithms for determining the source and model of the DSLR (Digital Single Lens Reflex) camera and improve image formation algorithms. Most research in this area based on the mention that the extraction of unique sensor trace of DSLR camera could be possible on the certain stage of the imaging process into the camera. It is considered that the study focuses on the problem of determination of unique feature of DSLR cameras based on optical subsystem artifacts and sensor noises.

Effect of sway on image fidelity in whole-body digitizing

NASA Astrophysics Data System (ADS)

Corner, Brian D.; Hu, Anmin

1998-03-01

For 3D digitizers to be useful data collection tools in scientific and human factors engineering applications, the models created from scan data must match the original object very closely. Factors such as ambient light, characteristics of the object's surface, and object movement, among others can affect the quality of the image produced by any 3D digitizing system. Recently, Cyberware has developed a whole body digitizer for collecting data on human size and shape. With a digitizing time of about 15 seconds, the effect subject movement, or sway, on model fidelity is an important issue to be addressed. The effect of sway is best measured by comparing the dimensions of an object of known geometry to the model of the same object captured by the digitizer. Since it is difficult to know the geometry of a human body accurately, it was decided to compare an object of simple geometry to its digitized counterpart. Preliminary analysis showed that a single cardboard tube would provide the best artifact for detecting sway. A tube was attached to the subjects using supports that allowed the cylinder to stand away from the body. The stand-off was necessary to minimize occluded areas. Multiple scans were taken of 1 subject and the cylinder extracted from the images. Comparison of the actual cylinder dimensions to those extracted from the whole body images found the effect of sway to be minimal. This follows earlier findings that anthropometric dimensions extracted from whole body scans are very close to the same dimensions measured using standard manual methods. Recommendations for subject preparation and stabilization are discussed.

Generation of fluoroscopic 3D images with a respiratory motion model based on an external surrogate signal

NASA Astrophysics Data System (ADS)

Hurwitz, Martina; Williams, Christopher L.; Mishra, Pankaj; Rottmann, Joerg; Dhou, Salam; Wagar, Matthew; Mannarino, Edward G.; Mak, Raymond H.; Lewis, John H.

2015-01-01

Respiratory motion during radiotherapy can cause uncertainties in definition of the target volume and in estimation of the dose delivered to the target and healthy tissue. In this paper, we generate volumetric images of the internal patient anatomy during treatment using only the motion of a surrogate signal. Pre-treatment four-dimensional CT imaging is used to create a patient-specific model correlating internal respiratory motion with the trajectory of an external surrogate placed on the chest. The performance of this model is assessed with digital and physical phantoms reproducing measured irregular patient breathing patterns. Ten patient breathing patterns are incorporated in a digital phantom. For each patient breathing pattern, the model is used to generate images over the course of thirty seconds. The tumor position predicted by the model is compared to ground truth information from the digital phantom. Over the ten patient breathing patterns, the average absolute error in the tumor centroid position predicted by the motion model is 1.4 mm. The corresponding error for one patient breathing pattern implemented in an anthropomorphic physical phantom was 0.6 mm. The global voxel intensity error was used to compare the full image to the ground truth and demonstrates good agreement between predicted and true images. The model also generates accurate predictions for breathing patterns with irregular phases or amplitudes.

A comparison of defect size and film quality obtained from Film digitized image and digital image radiographs

NASA Astrophysics Data System (ADS)

Kamlangkeng, Poramate; Asa, Prateepasen; Mai, Noipitak

2014-06-01

Digital radiographic testing is an acceptable premature nondestructive examination technique. Its performance and limitation comparing to the old technique are still not widely well known. In this paper conducted the study on the comparison of the accuracy of the defect size measurement and film quality obtained from film and digital radiograph techniques by testing in specimens and known size sample defect. Initially, one specimen was built with three types of internal defect; which are longitudinal cracking, lack of fusion, and porosity. For the known size sample defect, it was machined various geometrical size for comparing the accuracy of the measuring defect size to the real size in both film and digital images. To compare the image quality by considering at smallest detectable wire and the three defect images. In this research used Image Quality Indicator (IQI) of wire type 10/16 FE EN BS EN-462-1-1994. The radiographic films were produced by X-ray and gamma ray using Kodak AA400 size 3.5x8 inches, while the digital images were produced by Fuji image plate type ST-VI with 100 micrometers resolution. During the tests, a radiator GE model MF3 was implemented. The applied energy is varied from 120 to 220 kV and the current from 1.2 to 3.0 mA. The intensity of Iridium 192 gamma ray is in the range of 24-25 Curie. Under the mentioned conditions, the results showed that the deviation of the defect size measurement comparing to the real size obtained from the digital image radiographs is below than that of the film digitized, whereas the quality of film digitizer radiographs is higher in comparison.

Digital analysis of wind tunnel imagery to measure fluid thickness

NASA Technical Reports Server (NTRS)

Easton, Roger L., Jr.; Enge, James

1992-01-01

Documented here are the procedure and results obtained from the application of digital image processing techniques to the problem of measuring the thickness of a deicing fluid on a model airfoil during simulated takeoffs. The fluid contained a fluorescent dye and the images were recorded under flash illumination on photographic film. The films were digitized and analyzed on a personal computer to obtain maps of the fluid thickness.

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

NASA Astrophysics Data System (ADS)

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 with the device's digital camera, and an interface is available for annotating (interpreting) the image using lines and polygons. Image-to-geometry registration is then performed using a developed algorithm, initialised using the coarse pose from the on-board orientation and positioning sensors. The annotations made on the captured images are then available in the 3D model coordinate system for overlay and export. This workflow allows geologists to make interpretations and conceptual models in the field, which can then be linked to and refined in office workflows for later MPS property modelling.

An Approach to 3d Digital Modeling of Surfaces with Poor Texture by Range Imaging Techniques. `SHAPE from Stereo' VS. `SHAPE from Silhouette' in Digitizing Jorge Oteiza's Sculptures

NASA Astrophysics Data System (ADS)

García Fernández, J.; Álvaro Tordesillas, A.; Barba, S.

2015-02-01

Despite eminent development of digital range imaging techniques, difficulties persist in the virtualization of objects with poor radiometric information, in other words, objects consisting of homogeneous colours (totally white, black, etc.), repetitive patterns, translucence, or materials with specular reflection. This is the case for much of the Jorge Oteiza's works, particularly in the sculpture collection of the Museo Fundación Jorge Oteiza (Navarra, Spain). The present study intend to analyse and asses the performance of two digital 3D-modeling methods based on imaging techniques, facing cultural heritage in singular cases, determined by radiometric characteristics as mentioned: Shape from Silhouette and Shape from Stereo. On the other hand, the text proposes the definition of a documentation workflow and presents the results of its application in the collection of sculptures created by Oteiza.

Using Digital Earth to create online scientific reality tourist guides to tourist attractions in Taiwan, China

NASA Astrophysics Data System (ADS)

Ding, Yea-Chung

2010-11-01

In recent years national parks worldwide have introduced online virtual tourism, through which potential visitors can search for tourist information. Most virtual tourism websites are a simulation of an existing location, usually composed of panoramic images, a sequence of hyperlinked still or video images, and/or virtual models of the actual location. As opposed to actual tourism, a virtual tour is typically accessed on a personal computer or an interactive kiosk. Using modern Digital Earth techniques such as high resolution satellite images, precise GPS coordinates and powerful 3D WebGIS, however, it's possible to create more realistic scenic models to present natural terrain and man-made constructions in greater detail. This article explains how to create an online scientific reality tourist guide for the Jinguashi Gold Ecological Park at Jinguashi in northern Taiwan, China. This project uses high-resolution Formosat 2 satellite images and digital aerial images in conjunction with DTM to create a highly realistic simulation of terrain, with the addition of 3DMAX to add man-made constructions and vegetation. Using this 3D Geodatabase model in conjunction with INET 3D WebGIS software, we have found Digital Earth concept can greatly improve and expand the presentation of traditional online virtual tours on the websites.

Digital image classification with the help of artificial neural network by simple histogram.

PubMed

Dey, Pranab; Banerjee, Nirmalya; Kaur, Rajwant

2016-01-01

Visual image classification is a great challenge to the cytopathologist in routine day-to-day work. Artificial neural network (ANN) may be helpful in this matter. In this study, we have tried to classify digital images of malignant and benign cells in effusion cytology smear with the help of simple histogram data and ANN. A total of 404 digital images consisting of 168 benign cells and 236 malignant cells were selected for this study. The simple histogram data was extracted from these digital images and an ANN was constructed with the help of Neurointelligence software [Alyuda Neurointelligence 2.2 (577), Cupertino, California, USA]. The network architecture was 6-3-1. The images were classified as training set (281), validation set (63), and test set (60). The on-line backpropagation training algorithm was used for this study. A total of 10,000 iterations were done to train the ANN system with the speed of 609.81/s. After the adequate training of this ANN model, the system was able to identify all 34 malignant cell images and 24 out of 26 benign cells. The ANN model can be used for the identification of the individual malignant cells with the help of simple histogram data. This study will be helpful in the future to identify malignant cells in unknown situations.

XML-based scripting of multimodality image presentations in multidisciplinary clinical conferences

NASA Astrophysics Data System (ADS)

Ratib, Osman M.; Allada, Vivekanand; Dahlbom, Magdalena; Marcus, Phillip; Fine, Ian; Lapstra, Lorelle

2002-05-01

We developed a multi-modality image presentation software for display and analysis of images and related data from different imaging modalities. The software is part of a cardiac image review and presentation platform that supports integration of digital images and data from digital and analog media such as videotapes, analog x-ray films and 35 mm cine films. The software supports standard DICOM image files as well as AVI and PDF data formats. The system is integrated in a digital conferencing room that includes projections of digital and analog sources, remote videoconferencing capabilities, and an electronic whiteboard. The goal of this pilot project is to: 1) develop a new paradigm for image and data management for presentation in a clinically meaningful sequence adapted to case-specific scenarios, 2) design and implement a multi-modality review and conferencing workstation using component technology and customizable 'plug-in' architecture to support complex review and diagnostic tasks applicable to all cardiac imaging modalities and 3) develop an XML-based scripting model of image and data presentation for clinical review and decision making during routine clinical tasks and multidisciplinary clinical conferences.

Visible digital watermarking system using perceptual models

NASA Astrophysics Data System (ADS)

Cheng, Qiang; Huang, Thomas S.

2001-03-01

This paper presents a visible watermarking system using perceptual models. %how and why A watermark image is overlaid translucently onto a primary image, for the purposes of immediate claim of copyright, instantaneous recognition of owner or creator, or deterrence to piracy of digital images or video. %perceptual The watermark is modulated by exploiting combined DCT-domain and DWT-domain perceptual models. % so that the watermark is visually uniform. The resulting watermarked image is visually pleasing and unobtrusive. The location, size and strength of the watermark vary randomly with the underlying image. The randomization makes the automatic removal of the watermark difficult even though the algorithm is known publicly but the key to the random sequence generator. The experiments demonstrate that the watermarked images have pleasant visual effect and strong robustness. The watermarking system can be used in copyright notification and protection.

Optronic System Imaging Simulator (OSIS): imager simulation tool of the ECOMOS project

NASA Astrophysics Data System (ADS)

Wegner, D.; Repasi, E.

2018-04-01

ECOMOS is a multinational effort within the framework of an EDA Project Arrangement. Its aim is to provide a generally accepted and harmonized European computer model for computing nominal Target Acquisition (TA) ranges of optronic imagers operating in the Visible or thermal Infrared (IR). The project involves close co-operation of defense and security industry and public research institutes from France, Germany, Italy, The Netherlands and Sweden. ECOMOS uses two approaches to calculate Target Acquisition (TA) ranges, the analytical TRM4 model and the image-based Triangle Orientation Discrimination model (TOD). In this paper the IR imager simulation tool, Optronic System Imaging Simulator (OSIS), is presented. It produces virtual camera imagery required by the TOD approach. Pristine imagery is degraded by various effects caused by atmospheric attenuation, optics, detector footprint, sampling, fixed pattern noise, temporal noise and digital signal processing. Resulting images might be presented to observers or could be further processed for automatic image quality calculations. For convenience OSIS incorporates camera descriptions and intermediate results provided by TRM4. For input OSIS uses pristine imagery tied with meta information about scene content, its physical dimensions, and gray level interpretation. These images represent planar targets placed at specified distances to the imager. Furthermore, OSIS is extended by a plugin functionality that enables integration of advanced digital signal processing techniques in ECOMOS such as compression, local contrast enhancement, digital turbulence mitiga- tion, to name but a few. By means of this image-based approach image degradations and image enhancements can be investigated, which goes beyond the scope of the analytical TRM4 model.

Perception of facial esthetics by native Chinese participants by using manipulated digital imagery techniques.

PubMed

Maganzini, A L; Tseng, J Y; Epstein, J Z

2000-10-01

This investigation utilized a manipulated digital video imaging model to elicit profile facial esthetics preferences in a lay population of native Chinese participants from Beijing. A series of 4 distinct digitized distortions were constructed from an initial lateral cephalogram. These images represented skeletal or dental changes that differed by 2 standard deviations from the normative values for Chinese adults. Video morphing then created soft-tissue profiles. A series of nonparametric tests validated the digitized distortion model. The native Chinese participants in this sample found that the profile distortions most acceptable were the "flatter", or bimaxillary retrusive distortion, in the male stimulus face and the "anterior divergent", or maxillary deficiency, in the female stimulus face.

Scoping of Flood Hazard Mapping Needs for Belknap County, New Hampshire

DTIC Science & Technology

2006-01-01

DEM Digital Elevation Model DFIRM Digital Flood Insurance Rate Map DOQ Digital Orthophoto Quadrangle DOQQ Digital Ortho Quarter Quadrangle DTM...Agriculture Imag- ery Program (NAIP) color Digital Orthophoto Quadrangles (DOQs)). Remote sensing, base map information, GIS data (for example, contour data...found on USGS topographic maps. More recently developed data were derived from digital orthophotos providing improved base map accuracy. NH GRANIT is

The role of digital sample information within the digital geoscience infrastructure: a pragmatic approach

NASA Astrophysics Data System (ADS)

Howe, Michael

2014-05-01

Much of the digital geological information on the composition, properties and dynamics of the subsurface is based ultimately on physical samples, many of which are archived to provide a basis for the information. Online metadata catalogues of these collections have now been available for many years. Many of these are institutional and tightly focussed, with UK examples including the British Geological Survey's (BGS) palaeontological samples database, PalaeoSaurus (http://www.bgs.ac.uk/palaeosaurus/), and mineralogical and petrological sample database, Britrocks (http://www.bgs.ac.uk/data/britrocks.html) . There are now a growing number of international sample metadata databases, including The Palaeobiology Database (http://paleobiodb.org/) and SESAR, the IGSN (International Geo Sample Number) database (http://www.geosamples.org/catalogsearch/ ). More recently the emphasis has moved beyond metadata (locality, identification, age, citations, etc) to digital imagery, with the intention of providing the user with at least enough information to determine whether viewing the sample would be worthwhile. Recent BGS examples include high resolution (e.g. 7216 x 5412 pixel) hydrocarbon well core images (http://www.bgs.ac.uk/data/offshoreWells/wells.cfc?method=searchWells) , high resolution rock thin section images (e.g. http://www.largeimages.bgs.ac.uk/iip/britrocks.html?id=290000/291739 ) and building stone images (http://geoscenic.bgs.ac.uk/asset-bank/action/browseItems?categoryId=1547&categoryTypeId=1) . This has been developed further with high resolution stereo images. The Jisc funded GB3D type fossils online project delivers these as red-cyan anaglyphs (http://www.3d-fossils.ac.uk/). More innovatively, the GB3D type fossils project has laser scanned several thousand type fossils and the resulting 3d-digital models are now being delivered through the online portal. Importantly, this project also represents collaboration between the BGS, Oxford and Cambridge Universities, the National Museums of Wales, and numerous other national, local and regional museums. The lack of currently accepted international standards and infrastructures for the delivery of high resolution images and 3d-digital models has necessitated the BGS in developing or selecting its own. Most high resolution images have been delivered using the JPEG 2000 format because of its quality and speed. Digital models have been made available in both .PLY and .OBJ format because of their respective efficient file size, and flexibility. Consideration must now be given to European and international standards and infrastructures for the delivery of high resolution images and 3d-digital models.

Multiresolution image registration in digital x-ray angiography with intensity variation modeling.

PubMed

Nejati, Mansour; Pourghassem, Hossein

2014-02-01

Digital subtraction angiography (DSA) is a widely used technique for visualization of vessel anatomy in diagnosis and treatment. However, due to unavoidable patient motions, both externally and internally, the subtracted angiography images often suffer from motion artifacts that adversely affect the quality of the medical diagnosis. To cope with this problem and improve the quality of DSA images, registration algorithms are often employed before subtraction. In this paper, a novel elastic registration algorithm for registration of digital X-ray angiography images, particularly for the coronary location, is proposed. This algorithm includes a multiresolution search strategy in which a global transformation is calculated iteratively based on local search in coarse and fine sub-image blocks. The local searches are accomplished in a differential multiscale framework which allows us to capture both large and small scale transformations. The local registration transformation also explicitly accounts for local variations in the image intensities which incorporated into our model as a change of local contrast and brightness. These local transformations are then smoothly interpolated using thin-plate spline interpolation function to obtain the global model. Experimental results with several clinical datasets demonstrate the effectiveness of our algorithm in motion artifact reduction.

Digital optical imaging of green fluorescent proteins for tracking vascular gene expression: feasibility study in rabbit and human cell models.

PubMed

Yang, X; Liu, H; Li, D; Zhou, X; Jung, W C; Deans, A E; Cui, Y; Cheng, L

2001-04-01

To investigate the feasibility of using a sensitive digital optical imaging technique to detect green fluorescent protein (GFP) expressed in rabbit vasculature and human arterial smooth muscle cells. A GFP plasmid was transfected into human arterial smooth muscle cells to obtain a GFP-smooth muscle cell solution. This solution was imaged in cell phantoms by using a prototype digital optical imaging system. For in vivo validation, a GFP-lentivirus vector was transfected during surgery into the carotid arteries of two rabbits, and GFP-targeted vessels were harvested for digital optical imaging ex vivo. Optical imaging of cell phantoms resulted in a spatial resolution of 25 microm/pixel. Fluorescent signals were detected as diffusely distributed bright spots. At ex vivo optical imaging of arterial tissues, the average fluorescent signal was significantly higher (P <.05) in GFP-targeted tissues (mean +/- SD, 9,357.3 absolute units of density +/- 1,001.3) than in control tissues (5,633.7 absolute units of density +/- 985.2). Both fluorescence microscopic and immunohistochemical findings confirmed these differences between GFP-targeted and control vessels. The digital optical imaging system was sensitive to GFPs and may potentially provide an in vivo imaging tool to monitor and track vascular gene transfer and expression in experimental investigations.

Migration of the digital interactive breast-imaging teaching file

NASA Astrophysics Data System (ADS)

Cao, Fei; Sickles, Edward A.; Huang, H. K.; Zhou, Xiaoqiang

1998-06-01

The digital breast imaging teaching file developed during the last two years in our laboratory has been used successfully at UCSF (University of California, San Francisco) as a routine teaching tool for training radiology residents and fellows in mammography. Building on this success, we have ported the teaching file from an old Pixar imaging/Sun SPARC 470 display system to our newly designed telemammography display workstation (Ultra SPARC 2 platform with two DOME Md5/SBX display boards). The old Pixar/Sun 470 system, although adequate for fast and high-resolution image display, is 4- year-old technology, expensive to maintain and difficult to upgrade. The new display workstation is more cost-effective and is also compatible with the digital image format from a full-field direct digital mammography system. The digital teaching file is built on a sophisticated computer-aided instruction (CAI) model, which simulates the management sequences used in imaging interpretation and work-up. Each user can be prompted to respond by making his/her own observations, assessments, and work-up decisions as well as the marking of image abnormalities. This effectively replaces the traditional 'show-and-tell' teaching file experience with an interactive, response-driven type of instruction.

Localization of Diagnostically Relevant Regions of Interest in Whole Slide Images: a Comparative Study.

PubMed

Mercan, Ezgi; Aksoy, Selim; Shapiro, Linda G; Weaver, Donald L; Brunyé, Tad T; Elmore, Joann G

2016-08-01

Whole slide digital imaging technology enables researchers to study pathologists' interpretive behavior as they view digital slides and gain new understanding of the diagnostic medical decision-making process. In this study, we propose a simple yet important analysis to extract diagnostically relevant regions of interest (ROIs) from tracking records using only pathologists' actions as they viewed biopsy specimens in the whole slide digital imaging format (zooming, panning, and fixating). We use these extracted regions in a visual bag-of-words model based on color and texture features to predict diagnostically relevant ROIs on whole slide images. Using a logistic regression classifier in a cross-validation setting on 240 digital breast biopsy slides and viewport tracking logs of three expert pathologists, we produce probability maps that show 74 % overlap with the actual regions at which pathologists looked. We compare different bag-of-words models by changing dictionary size, visual word definition (patches vs. superpixels), and training data (automatically extracted ROIs vs. manually marked ROIs). This study is a first step in understanding the scanning behaviors of pathologists and the underlying reasons for diagnostic errors.

A Digital View of History: Drawing and Discussing Models of Historical Concepts

ERIC Educational Resources Information Center

Manfra, Meghan McGlinn; Coven, Robert M.

2011-01-01

Digital history refers to "the study of the past using a variety of electronically reproduced primary source texts, images, and artifacts as well as the constructed narratives, accounts, or presentations that result from digital historical inquiry." Access to digitized primary sources can promote active instruction in historical thinking. A…

Bas-Relief Modeling from Normal Images with Intuitive Styles.

PubMed

Ji, Zhongping; Ma, Weiyin; Sun, Xianfang

2014-05-01

Traditional 3D model-based bas-relief modeling methods are often limited to model-dependent and monotonic relief styles. This paper presents a novel method for digital bas-relief modeling with intuitive style control. Given a composite normal image, the problem discussed in this paper involves generating a discontinuity-free depth field with high compression of depth data while preserving or even enhancing fine details. In our framework, several layers of normal images are composed into a single normal image. The original normal image on each layer is usually generated from 3D models or through other techniques as described in this paper. The bas-relief style is controlled by choosing a parameter and setting a targeted height for them. Bas-relief modeling and stylization are achieved simultaneously by solving a sparse linear system. Different from previous work, our method can be used to freely design bas-reliefs in normal image space instead of in object space, which makes it possible to use any popular image editing tools for bas-relief modeling. Experiments with a wide range of 3D models and scenes show that our method can effectively generate digital bas-reliefs.

Digital image processing for the earth resources technology satellite data.

NASA Technical Reports Server (NTRS)

Will, P. M.; Bakis, R.; Wesley, M. A.

1972-01-01

This paper discusses the problems of digital processing of the large volumes of multispectral image data that are expected to be received from the ERTS program. Correction of geometric and radiometric distortions are discussed and a byte oriented implementation is proposed. CPU timing estimates are given for a System/360 Model 67, and show that a processing throughput of 1000 image sets per week is feasible.

A new, open-source, multi-modality digital breast phantom

NASA Astrophysics Data System (ADS)

Graff, Christian G.

2016-03-01

An anthropomorphic digital breast phantom has been developed with the goal of generating random voxelized breast models that capture the anatomic variability observed in vivo. This is a new phantom and is not based on existing digital breast phantoms or segmentation of patient images. It has been designed at the outset to be modality agnostic (i.e., suitable for use in modeling x-ray based imaging systems, magnetic resonance imaging, and potentially other imaging systems) and open source so that users may freely modify the phantom to suit a particular study. In this work we describe the modeling techniques that have been developed, the capabilities and novel features of this phantom, and study simulated images produced from it. Starting from a base quadric, a series of deformations are performed to create a breast with a particular volume and shape. Initial glandular compartments are generated using a Voronoi technique and a ductal tree structure with terminal duct lobular units is grown from the nipple into each compartment. An additional step involving the creation of fat and glandular lobules using a Perlin noise function is performed to create more realistic glandular/fat tissue interfaces and generate a Cooper's ligament network. A vascular tree is grown from the chest muscle into the breast tissue. Breast compression is performed using a neo-Hookean elasticity model. We show simulated mammographic and T1-weighted MRI images and study properties of these images.

A note on digital dental radiography in forensic odontology.

PubMed

Chiam, Sher-Lin

2014-09-01

Digital dental radiography, intraoral and extraoral, is becoming more popular in dental practice. It offers convenience, such as lower exposure to radiation, ease of storing of images, and elimination of chemical processing. However, it also has disadvantages and drawbacks. One of these is the potential for confusion of the orientation of the image. This paper outlines one example of this, namely, the lateral inversion of the image. This source of confusion is partly inherent in the older model of phosphor storage plates (PSPs), as they allow both sides to be exposed without clue to the fact that the image is acquired on the wrong side. The native software allows digital manipulation of the X-ray image, permitting both rotation and inversion. Attempts to orientate the X-ray according to the indicator incorporated on the plate can then sometimes lead to inadvertent lateral inversion of the image. This article discusses the implications of such mistakes in dental digital radiography to forensic odontology and general dental practice.

A Q-Ising model application for linear-time image segmentation

NASA Astrophysics Data System (ADS)

Bentrem, Frank W.

2010-10-01

A computational method is presented which efficiently segments digital grayscale images by directly applying the Q-state Ising (or Potts) model. Since the Potts model was first proposed in 1952, physicists have studied lattice models to gain deep insights into magnetism and other disordered systems. For some time, researchers have realized that digital images may be modeled in much the same way as these physical systems ( i.e., as a square lattice of numerical values). A major drawback in using Potts model methods for image segmentation is that, with conventional methods, it processes in exponential time. Advances have been made via certain approximations to reduce the segmentation process to power-law time. However, in many applications (such as for sonar imagery), real-time processing requires much greater efficiency. This article contains a description of an energy minimization technique that applies four Potts (Q-Ising) models directly to the image and processes in linear time. The result is analogous to partitioning the system into regions of four classes of magnetism. This direct Potts segmentation technique is demonstrated on photographic, medical, and acoustic images.

New Trends of Emerging Technologies in Digital Pathology.

PubMed

Bueno, Gloria; Fernández-Carrobles, M Milagro; Deniz, Oscar; García-Rojo, Marcial

2016-01-01

The future paradigm of pathology will be digital. Instead of conventional microscopy, a pathologist will perform a diagnosis through interacting with images on computer screens and performing quantitative analysis. The fourth generation of virtual slide telepathology systems, so-called virtual microscopy and whole-slide imaging (WSI), has allowed for the storage and fast dissemination of image data in pathology and other biomedical areas. These novel digital imaging modalities encompass high-resolution scanning of tissue slides and derived technologies, including automatic digitization and computational processing of whole microscopic slides. Moreover, automated image analysis with WSI can extract specific diagnostic features of diseases and quantify individual components of these features to support diagnoses and provide informative clinical measures of disease. Therefore, the challenge is to apply information technology and image analysis methods to exploit the new and emerging digital pathology technologies effectively in order to process and model all the data and information contained in WSI. The final objective is to support the complex workflow from specimen receipt to anatomic pathology report transmission, that is, to improve diagnosis both in terms of pathologists' efficiency and with new information. This article reviews the main concerns about and novel methods of digital pathology discussed at the latest workshop in the field carried out within the European project AIDPATH (Academia and Industry Collaboration for Digital Pathology). © 2016 S. Karger AG, Basel.

Fourth-order partial differential equation noise removal on welding images

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halim, Suhaila Abd; Ibrahim, Arsmah; Sulong, Tuan Nurul Norazura Tuan

2015-10-22

Partial differential equation (PDE) has become one of the important topics in mathematics and is widely used in various fields. It can be used for image denoising in the image analysis field. In this paper, a fourth-order PDE is discussed and implemented as a denoising method on digital images. The fourth-order PDE is solved computationally using finite difference approach and then implemented on a set of digital radiographic images with welding defects. The performance of the discretized model is evaluated using Peak Signal to Noise Ratio (PSNR). Simulation is carried out on the discretized model on different level of Gaussianmore » noise in order to get the maximum PSNR value. The convergence criteria chosen to determine the number of iterations required is measured based on the highest PSNR value. Results obtained show that the fourth-order PDE model produced promising results as an image denoising tool compared with median filter.« less

Automated image processing of LANDSAT 2 digital data for watershed runoff prediction

NASA Technical Reports Server (NTRS)

Sasso, R. R.; Jensen, J. R.; Estes, J. E.

1977-01-01

The U.S. Soil Conservation Service (SCS) model for watershed runoff prediction uses soil and land cover information as its major drivers. Kern County Water Agency is implementing the SCS model to predict runoff for 10,400 sq cm of mountainous watershed in Kern County, California. The Remote Sensing Unit, University of California, Santa Barbara, was commissioned by KCWA to conduct a 230 sq cm feasibility study in the Lake Isabella, California region to evaluate remote sensing methodologies which could be ultimately extrapolated to the entire 10,400 sq cm Kern County watershed. Digital results indicate that digital image processing of Landsat 2 data will provide usable land cover required by KCWA for input to the SCS runoff model.

Development of digital phantoms based on a finite element model to simulate low-attenuation areas in CT imaging for pulmonary emphysema quantification.

PubMed

Diciotti, Stefano; Nobis, Alessandro; Ciulli, Stefano; Landini, Nicholas; Mascalchi, Mario; Sverzellati, Nicola; Innocenti, Bernardo

2017-09-01

To develop an innovative finite element (FE) model of lung parenchyma which simulates pulmonary emphysema on CT imaging. The model is aimed to generate a set of digital phantoms of low-attenuation areas (LAA) images with different grades of emphysema severity. Four individual parameter configurations simulating different grades of emphysema severity were utilized to generate 40 FE models using ten randomizations for each setting. We compared two measures of emphysema severity (relative area (RA) and the exponent D of the cumulative distribution function of LAA clusters size) between the simulated LAA images and those computed directly on the models output (considered as reference). The LAA images obtained from our model output can simulate CT-LAA images in subjects with different grades of emphysema severity. Both RA and D computed on simulated LAA images were underestimated as compared to those calculated on the models output, suggesting that measurements in CT imaging may not be accurate in the assessment of real emphysema extent. Our model is able to mimic the cluster size distribution of LAA on CT imaging of subjects with pulmonary emphysema. The model could be useful to generate standard test images and to design physical phantoms of LAA images for the assessment of the accuracy of indexes for the radiologic quantitation of emphysema.

Evaluation of Acoustic Propagation Paths into the Human Head

DTIC Science & Technology

2005-07-25

paths. A 3D finite-element solid mesh was constructed using a digital image database of an adult male head. Finite-element analysis was used to model the...air-borne sound pressure amplitude) via the alternate propagation paths. A 3D finite-element solid mesh was constructed using a digital image database ... database of an adult male head Coupled acoustic-mechanical finite-element analysis (FEA) was used to model the wave propagation through the fluid-solid

Digital image classification with the help of artificial neural network by simple histogram

PubMed Central

Dey, Pranab; Banerjee, Nirmalya; Kaur, Rajwant

2016-01-01

Background: Visual image classification is a great challenge to the cytopathologist in routine day-to-day work. Artificial neural network (ANN) may be helpful in this matter. Aims and Objectives: In this study, we have tried to classify digital images of malignant and benign cells in effusion cytology smear with the help of simple histogram data and ANN. Materials and Methods: A total of 404 digital images consisting of 168 benign cells and 236 malignant cells were selected for this study. The simple histogram data was extracted from these digital images and an ANN was constructed with the help of Neurointelligence software [Alyuda Neurointelligence 2.2 (577), Cupertino, California, USA]. The network architecture was 6-3-1. The images were classified as training set (281), validation set (63), and test set (60). The on-line backpropagation training algorithm was used for this study. Result: A total of 10,000 iterations were done to train the ANN system with the speed of 609.81/s. After the adequate training of this ANN model, the system was able to identify all 34 malignant cell images and 24 out of 26 benign cells. Conclusion: The ANN model can be used for the identification of the individual malignant cells with the help of simple histogram data. This study will be helpful in the future to identify malignant cells in unknown situations. PMID:27279679

Spatial imaging in color and HDR: prometheus unchained

NASA Astrophysics Data System (ADS)

McCann, John J.

2013-03-01

The Human Vision and Electronic Imaging Conferences (HVEI) at the IS and T/SPIE Electronic Imaging meetings have brought together research in the fundamentals of both vision and digital technology. This conference has incorporated many color disciplines that have contributed to the theory and practice of today's imaging: color constancy, models of vision, digital output, high-dynamic-range imaging, and the understanding of perceptual mechanisms. Before digital imaging, silver halide color was a pixel-based mechanism. Color films are closely tied to colorimetry, the science of matching pixels in a black surround. The quanta catch of the sensitized silver salts determines the amount of colored dyes in the final print. The rapid expansion of digital imaging over the past 25 years has eliminated the limitations of using small local regions in forming images. Spatial interactions can now generate images more like vision. Since the 1950's, neurophysiology has shown that post-receptor neural processing is based on spatial interactions. These results reinforced the findings of 19th century experimental psychology. This paper reviews the role of HVEI in color, emphasizing the interaction of research on vision and the new algorithms and processes made possible by electronic imaging.

Air Force Human Resources Laboratory Annual Report - Fiscal Year 1983.

DTIC Science & Technology

1984-08-01

were performed - digital image-generation visual system and three in the Advanced Simulator for Pilot Training at associated wide-angle windows. The...inputs by the trainee. This arrangement, and survivability in high-threat environments are , with its corresponding analog-to- digital interface... digitized models of various military vehicles and aircraft for continual update/expansion. Utilization: An interactive modeling system will be user

An application of the MPP to the interactive manipulation of stereo images of digital terrain models

NASA Technical Reports Server (NTRS)

Pol, Sanjay; Mcallister, David; Davis, Edward

1987-01-01

Massively Parallel Processor algorithms were developed for the interactive manipulation of flat shaded digital terrain models defined over grids. The emphasis is on real time manipulation of stereo images. Standard graphics transformations are applied to a 128 x 128 grid of elevations followed by shading and a perspective projection to produce the right eye image. The surface is then rendered using a simple painter's algorithm for hidden surface removal. The left eye image is produced by rotating the surface 6 degs about the viewer's y axis followed by a perspective projection and rendering of the image as described above. The left and right eye images are then presented on a graphics device using standard stereo technology. Performance evaluations and comparisons are presented.

A position and attitude vision measurement system for wind tunnel slender model

NASA Astrophysics Data System (ADS)

Cheng, Lei; Yang, Yinong; Xue, Bindang; Zhou, Fugen; Bai, Xiangzhi

2014-11-01

A position and attitude vision measurement system for drop test slender model in wind tunnel is designed and developed. The system used two high speed cameras, one is put to the side of the model and another is put to the position where the camera can look up the model. Simple symbols are set on the model. The main idea of the system is based on image matching technique between the 3D-digital model projection image and the image captured by the camera. At first, we evaluate the pitch angles, the roll angles and the position of the centroid of a model through recognizing symbols in the images captured by the side camera. And then, based on the evaluated attitude info, giving a series of yaw angles, a series of projection images of the 3D-digital model are obtained. Finally, these projection images are matched with the image which captured by the looking up camera, and the best match's projection images corresponds to the yaw angle is the very yaw angle of the model. Simulation experiments are conducted and the results show that the maximal error of attitude measurement is less than 0.05°, which can meet the demand of test in wind tunnel.

A method to incorporate the effect of beam quality on image noise in a digitally reconstructed radiograph (DRR) based computer simulation for optimisation of digital radiography

NASA Astrophysics Data System (ADS)

Moore, Craig S.; Wood, Tim J.; Saunderson, John R.; Beavis, Andrew W.

2017-09-01

The use of computer simulated digital x-radiographs for optimisation purposes has become widespread in recent years. To make these optimisation investigations effective, it is vital simulated radiographs contain accurate anatomical and system noise. Computer algorithms that simulate radiographs based solely on the incident detector x-ray intensity (‘dose’) have been reported extensively in the literature. However, while it has been established for digital mammography that x-ray beam quality is an important factor when modelling noise in simulated images there are no such studies for diagnostic imaging of the chest, abdomen and pelvis. This study investigates the influence of beam quality on image noise in a digital radiography (DR) imaging system, and incorporates these effects into a digitally reconstructed radiograph (DRR) computer simulator. Image noise was measured on a real DR imaging system as a function of dose (absorbed energy) over a range of clinically relevant beam qualities. Simulated ‘absorbed energy’ and ‘beam quality’ DRRs were then created for each patient and tube voltage under investigation. Simulated noise images, corrected for dose and beam quality, were subsequently produced from the absorbed energy and beam quality DRRs, using the measured noise, absorbed energy and beam quality relationships. The noise images were superimposed onto the noiseless absorbed energy DRRs to create the final images. Signal-to-noise measurements in simulated chest, abdomen and spine images were within 10% of the corresponding measurements in real images. This compares favourably to our previous algorithm where images corrected for dose only were all within 20%.

Developing digital vegetation for central hardwood forest types: A case study from Leslie County, KY

Treesearch

Bo Song; Wei-lun Tsai; Chiao-ying Chou; Thomas M. Williams; William Conner; Brian J. Williams

2011-01-01

Digital vegetation is the computerized representation, with either virtual images or animations, of vegetation types and conditions based on current measurements or ecological models. Digital vegetation can be useful in evaluating past, present, or future land use; changes in vegetation linked to climate change; or restoration efforts. Digital vegetation can be...

Theoretical Limits of Lunar Vision Aided Navigation with Inertial Navigation System

DTIC Science & Technology

2015-03-26

camera model. Light reflected or projected from objects in the scene of the outside world is taken in by the aperture (or opening) shaped as a double...model’s analog aspects with an analog-to-digital interface converting raw images of the outside world scene into digital information a computer can use to...Figure 2.7. Digital Image Coordinate System. Used with permission [30]. Angular Field of View. The angular field of view is the angle of the world scene

An Automatic Procedure for Combining Digital Images and Laser Scanner Data

NASA Astrophysics Data System (ADS)

Moussa, W.; Abdel-Wahab, M.; Fritsch, D.

2012-07-01

Besides improving both the geometry and the visual quality of the model, the integration of close-range photogrammetry and terrestrial laser scanning techniques directs at filling gaps in laser scanner point clouds to avoid modeling errors, reconstructing more details in higher resolution and recovering simple structures with less geometric details. Thus, within this paper a flexible approach for the automatic combination of digital images and laser scanner data is presented. Our approach comprises two methods for data fusion. The first method starts by a marker-free registration of digital images based on a point-based environment model (PEM) of a scene which stores the 3D laser scanner point clouds associated with intensity and RGB values. The PEM allows the extraction of accurate control information for the direct computation of absolute camera orientations with redundant information by means of accurate space resection methods. In order to use the computed relations between the digital images and the laser scanner data, an extended Helmert (seven-parameter) transformation is introduced and its parameters are estimated. Precedent to that, in the second method, the local relative orientation parameters of the camera images are calculated by means of an optimized Structure and Motion (SaM) reconstruction method. Then, using the determined transformation parameters results in having absolute oriented images in relation to the laser scanner data. With the resulting absolute orientations we have employed robust dense image reconstruction algorithms to create oriented dense image point clouds, which are automatically combined with the laser scanner data to form a complete detailed representation of a scene. Examples of different data sets are shown and experimental results demonstrate the effectiveness of the presented procedures.

Prediction of troponin-T degradation using color image texture features in 10d aged beef longissimus steaks.

PubMed

Sun, X; Chen, K J; Berg, E P; Newman, D J; Schwartz, C A; Keller, W L; Maddock Carlin, K R

2014-02-01

The objective was to use digital color image texture features to predict troponin-T degradation in beef. Image texture features, including 88 gray level co-occurrence texture features, 81 two-dimension fast Fourier transformation texture features, and 48 Gabor wavelet filter texture features, were extracted from color images of beef strip steaks (longissimus dorsi, n = 102) aged for 10d obtained using a digital camera and additional lighting. Steaks were designated degraded or not-degraded based on troponin-T degradation determined on d 3 and d 10 postmortem by immunoblotting. Statistical analysis (STEPWISE regression model) and artificial neural network (support vector machine model, SVM) methods were designed to classify protein degradation. The d 3 and d 10 STEPWISE models were 94% and 86% accurate, respectively, while the d 3 and d 10 SVM models were 63% and 71%, respectively, in predicting protein degradation in aged meat. STEPWISE and SVM models based on image texture features show potential to predict troponin-T degradation in meat. © 2013.

[Analysis of Cost-effectiveness of screening for breast cancer with conventional mammography, digital and magnetic resonance imaging].

PubMed

Peregrino, Antonio Augusto de Freitas; Vianna, Cid Manso de Mello; de Almeida, Carlos Eduardo Veloso; Gonzáles, Gabriela Bittencourt; Machado, Samara Cristina Ferreira; Costa e Silva, Frances Valéria; Rodrigues, Marcus Paulo da Silva

2012-01-01

A cost-effectiveness analysis was conducted in screening for breast cancer. The use of conventional mammography, digital and magnetic resonance imaging were compared with natural disease history as a baseline. A Markov model projected breast cancer in a group of 100,000 women for a 30 year period, with screening every two years. Four distinct scenarios were modeled: (1) the natural history of breast cancer, as a baseline, (2) conventional film mammography, (3) digital mammography and (4) magnetic resonance imaging. The costs of the scenarios modeled ranged from R$ 194.216,68 for natural history, to R$ 48.614.338,31, for screening with magnetic resonance imaging. The difference in effectiveness between the interventions ranged from 300 to 78.000 years of life gained in the cohort. The ratio of incremental cost-effectiveness in terms of cost per life-year gains, conventional mammographic screening has produced an extra year for R$ 13.573,07. The ICER of magnetic resonance imaging was R$ 2.904.328,88, compared to no screening. In conclusion, it is more cost-effective to perform the screening with conventional mammography than other technological interventions.

Classifying Physical Morphology of Cocoa Beans Digital Images using Multiclass Ensemble Least-Squares Support Vector Machine

NASA Astrophysics Data System (ADS)

Lawi, Armin; Adhitya, Yudhi

2018-03-01

The objective of this research is to determine the quality of cocoa beans through morphology of their digital images. Samples of cocoa beans were scattered on a bright white paper under a controlled lighting condition. A compact digital camera was used to capture the images. The images were then processed to extract their morphological parameters. Classification process begins with an analysis of cocoa beans image based on morphological feature extraction. Parameters for extraction of morphological or physical feature parameters, i.e., Area, Perimeter, Major Axis Length, Minor Axis Length, Aspect Ratio, Circularity, Roundness, Ferret Diameter. The cocoa beans are classified into 4 groups, i.e.: Normal Beans, Broken Beans, Fractured Beans, and Skin Damaged Beans. The model of classification used in this paper is the Multiclass Ensemble Least-Squares Support Vector Machine (MELS-SVM), a proposed improvement model of SVM using ensemble method in which the separate hyperplanes are obtained by least square approach and the multiclass procedure uses One-Against- All method. The result of our proposed model showed that the classification with morphological feature input parameters were accurately as 99.705% for the four classes, respectively.

Determination of fat and total protein content in milk using conventional digital imaging.

PubMed

Kucheryavskiy, Sergey; Melenteva, Anastasiia; Bogomolov, Andrey

2014-04-01

The applicability of conventional digital imaging to quantitative determination of fat and total protein in cow's milk, based on the phenomenon of light scatter, has been proved. A new algorithm for extracting features from digital images of milk samples has been developed. The algorithm takes into account spatial distribution of light, diffusely transmitted through a sample. The proposed method has been tested on two sample sets prepared from industrial raw milk standards, with variable fat and protein content. Partial Least-Squares (PLS) regression on the features calculated from images of monochromatically illuminated milk samples resulted in models with high prediction performance when analysed the sets separately (best models with cross-validated R(2)=0.974 for protein and R(2)=0.973 for fat content). However when analysed the sets jointly with the obtained results were significantly worse (best models with cross-validated R(2)=0.890 for fat content and R(2)=0.720 for protein content). The results have been compared with previously published Vis/SW-NIR spectroscopic study of similar samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Standardization efforts of digital pathology in Europe.

PubMed

Rojo, Marcial García; Daniel, Christel; Schrader, Thomas

2012-01-01

EURO-TELEPATH is a European COST Action IC0604. It started in 2007 and will end in November 2011. Its main objectives are evaluating and validating the common technological framework and communication standards required to access, transmit, and manage digital medical records by pathologists and other medical specialties in a networked environment. Working Group 1, "Business Modelling in Pathology," has designed main pathology processes - Frozen Study, Formalin Fixed Specimen Study, Telepathology, Cytology, and Autopsy - using Business Process Modelling Notation (BPMN). Working Group 2 has been dedicated to promoting the application of informatics standards in pathology, collaborating with Integrating Healthcare Enterprise (IHE), Digital Imaging and Communications in Medicine (DICOM), Health Level Seven (HL7), and other standardization bodies. Health terminology standardization research has become a topic of great interest. Future research work should focus on standardizing automatic image analysis and tissue microarrays imaging.

Selecting a digital camera for telemedicine.

PubMed

Patricoski, Chris; Ferguson, A Stewart

2009-06-01

The digital camera is an essential component of store-and-forward telemedicine (electronic consultation). There are numerous makes and models of digital cameras on the market, and selecting a suitable consumer-grade camera can be complicated. Evaluation of digital cameras includes investigating the features and analyzing image quality. Important features include the camera settings, ease of use, macro capabilities, method of image transfer, and power recharging. Consideration needs to be given to image quality, especially as it relates to color (skin tones) and detail. It is important to know the level of the photographer and the intended application. The goal is to match the characteristics of the camera with the telemedicine program requirements. In the end, selecting a digital camera is a combination of qualitative (subjective) and quantitative (objective) analysis. For the telemedicine program in Alaska in 2008, the camera evaluation and decision process resulted in a specific selection based on the criteria developed for our environment.

[Reliability of three dimensional resin model by rapid prototyping manufacturing and digital modeling].

PubMed

Zeng, Fei-huang; Xu, Yuan-zhi; Fang, Li; Tang, Xiao-shan

2012-02-01

To describe a new technique for fabricating an 3D resin model by 3D reconstruction and rapid prototyping, and to analyze the precision of this method. An optical grating scanner was used to acquire the data of silastic cavity block , digital dental cast was reconstructed with the data through Geomagic Studio image processing software. The final 3D reconstruction was saved in the pattern of Stl. The 3D resin model was fabricated by fuse deposition modeling, and was compared with the digital model and gypsum model. The data of three groups were statistically analyzed using SPSS 16.0 software package. No significant difference was found in gypsum model,digital dental cast and 3D resin model (P>0.05). Rapid prototyping manufacturing and digital modeling would be helpful for dental information acquisition, treatment design, appliance manufacturing, and can improve the communications between patients and doctors.

The Digital Slide Archive: A Software Platform for Management, Integration, and Analysis of Histology for Cancer Research.

PubMed

Gutman, David A; Khalilia, Mohammed; Lee, Sanghoon; Nalisnik, Michael; Mullen, Zach; Beezley, Jonathan; Chittajallu, Deepak R; Manthey, David; Cooper, Lee A D

2017-11-01

Tissue-based cancer studies can generate large amounts of histology data in the form of glass slides. These slides contain important diagnostic, prognostic, and biological information and can be digitized into expansive and high-resolution whole-slide images using slide-scanning devices. Effectively utilizing digital pathology data in cancer research requires the ability to manage, visualize, share, and perform quantitative analysis on these large amounts of image data, tasks that are often complex and difficult for investigators with the current state of commercial digital pathology software. In this article, we describe the Digital Slide Archive (DSA), an open-source web-based platform for digital pathology. DSA allows investigators to manage large collections of histologic images and integrate them with clinical and genomic metadata. The open-source model enables DSA to be extended to provide additional capabilities. Cancer Res; 77(21); e75-78. ©2017 AACR . ©2017 American Association for Cancer Research.

Digital photography provides a fast, reliable, and noninvasive method to estimate anthocyanin pigment concentration in reproductive and vegetative plant tissues.

PubMed

Del Valle, José C; Gallardo-López, Antonio; Buide, Mª Luisa; Whittall, Justen B; Narbona, Eduardo

2018-03-01

Anthocyanin pigments have become a model trait for evolutionary ecology as they often provide adaptive benefits for plants. Anthocyanins have been traditionally quantified biochemically or more recently using spectral reflectance. However, both methods require destructive sampling and can be labor intensive and challenging with small samples. Recent advances in digital photography and image processing make it the method of choice for measuring color in the wild. Here, we use digital images as a quick, noninvasive method to estimate relative anthocyanin concentrations in species exhibiting color variation. Using a consumer-level digital camera and a free image processing toolbox, we extracted RGB values from digital images to generate color indices. We tested petals, stems, pedicels, and calyces of six species, which contain different types of anthocyanin pigments and exhibit different pigmentation patterns. Color indices were assessed by their correlation to biochemically determined anthocyanin concentrations. For comparison, we also calculated color indices from spectral reflectance and tested the correlation with anthocyanin concentration. Indices perform differently depending on the nature of the color variation. For both digital images and spectral reflectance, the most accurate estimates of anthocyanin concentration emerge from anthocyanin content-chroma ratio, anthocyanin content-chroma basic, and strength of green indices. Color indices derived from both digital images and spectral reflectance strongly correlate with biochemically determined anthocyanin concentration; however, the estimates from digital images performed better than spectral reflectance in terms of r 2 and normalized root-mean-square error. This was particularly noticeable in a species with striped petals, but in the case of striped calyces, both methods showed a comparable relationship with anthocyanin concentration. Using digital images brings new opportunities to accurately quantify the anthocyanin concentrations in both floral and vegetative tissues. This method is efficient, completely noninvasive, applicable to both uniform and patterned color, and works with samples of any size.

Digital preservation of anatomical variation: 3D-modeling of embalmed and plastinated cadaveric specimens using uCT and MRI.

PubMed

Moore, Colin W; Wilson, Timothy D; Rice, Charles L

2017-01-01

Anatomy educators have an opportunity to teach anatomical variations as a part of medical and allied health curricula using both cadaveric and three-dimensional (3D) digital models of these specimens. Beyond published cadaveric case reports, anatomical variations identified during routine gross anatomy dissection can be powerful teaching tools and a medium to discuss several anatomical sub-disciplines from embryology to medical imaging. The purpose of this study is to document how cadaveric anatomical variation identified during routine dissection can be scanned using medical imaging techniques to create two-dimensional axial images and interactive 3D models for teaching and learning of anatomical variations. Three cadaveric specimens (2 formalin embalmed, 1 plastinated) depicting anatomical variations and an embryological malformation were scanned using magnetic resonance imaging (MRI) and micro-computed tomography (μCT) for visualization in cross-section and for creation of 3D volumetric models. Results provide educational options to enable visualization and facilitate learning of anatomical variations from cross-sectional scans. Furthermore, the variations can be highlighted, digitized, modeled and manipulated using 3D imaging software and viewed in the anatomy laboratory in conjunction with traditional anatomical dissection. This study provides an example for anatomy educators to teach and describe anatomical variations in the undergraduate medical curriculum. Copyright © 2016 Elsevier GmbH. All rights reserved.

Earth Explorer

USGS Publications Warehouse

,

2000-01-01

The U.S. Geological Survey's (USGS) Earth Explorer Web site provides access to millions of land-related products, including the following: Satellite images from Landsat, advanced very high resolution radiometer (AVHRR), and Corona data sets. Aerial photographs from the National Aerial Photography Program, NASA, and USGS data sets.  Digital cartographic data from digital elevation models, digital line graphs, digital raster graphics, and digital orthophoto quadrangles. USGS paper maps Digital, film, and paper products are available, and many products can be previewed before ordering.

Integration of aerial remote sensing imaging data in a 3D-GIS environment

NASA Astrophysics Data System (ADS)

Moeller, Matthias S.

2003-03-01

For some years sensor systems have been available providing digital images of a new quality. Especially aerial stereo scanners acquire digital multispectral images with an extremely high ground resolution of about 0.10 - 0.15m and provide in addition a Digital Surface Models (DSM). These imaging products both can be used for a detailed monitoring at scales up to 1:500. The processed georeferenced multispectral orthoimages can be readily integrated into GIS making them useful for a number of applications. The DSM, derived from forward and backward facing sensors of an aerial imaging system provides a ground resolution of 0.5 m and can be used for 3D visualization purposes. In some cases it is essential, to store the ground elevation as a Digital Terrain Model (DTM) and also the height of 3-dimensional objects in a separated database. Existing automated algorithms do not work precise for the extraction of DTM from aerial scanner DSM. This paper presents a new approach which combines the visible image data and the DSM data for the generation of DTM with a reliable geometric accuracy. Already existing cadastral data can be used as a knowledge base for the extraction of building heights in cities. These elevation data is the essential source for a GIS based urban information system with a 3D visualization component.

Pipeline for effective denoising of digital mammography and digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Borges, Lucas R.; Bakic, Predrag R.; Foi, Alessandro; Maidment, Andrew D. A.; Vieira, Marcelo A. C.

2017-03-01

Denoising can be used as a tool to enhance image quality and enforce low radiation doses in X-ray medical imaging. The effectiveness of denoising techniques relies on the validity of the underlying noise model. In full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT), calibration steps like the detector offset and flat-fielding can affect some assumptions made by most denoising techniques. Furthermore, quantum noise found in X-ray images is signal-dependent and can only be treated by specific filters. In this work we propose a pipeline for FFDM and DBT image denoising that considers the calibration steps and simplifies the modeling of the noise statistics through variance-stabilizing transformations (VST). The performance of a state-of-the-art denoising method was tested with and without the proposed pipeline. To evaluate the method, objective metrics such as the normalized root mean square error (N-RMSE), noise power spectrum, modulation transfer function (MTF) and the frequency signal-to-noise ratio (SNR) were analyzed. Preliminary tests show that the pipeline improves denoising. When the pipeline is not used, bright pixels of the denoised image are under-filtered and dark pixels are over-smoothed due to the assumption of a signal-independent Gaussian model. The pipeline improved denoising up to 20% in terms of spatial N-RMSE and up to 15% in terms of frequency SNR. Besides improving the denoising, the pipeline does not increase signal smoothing significantly, as shown by the MTF. Thus, the proposed pipeline can be used with state-of-the-art denoising techniques to improve the quality of DBT and FFDM images.

Image processing of aerodynamic data

NASA Technical Reports Server (NTRS)

Faulcon, N. D.

1985-01-01

The use of digital image processing techniques in analyzing and evaluating aerodynamic data is discussed. An image processing system that converts images derived from digital data or from transparent film into black and white, full color, or false color pictures is described. Applications to black and white images of a model wing with a NACA 64-210 section in simulated rain and to computed low properties for transonic flow past a NACA 0012 airfoil are presented. Image processing techniques are used to visualize the variations of water film thicknesses on the wing model and to illustrate the contours of computed Mach numbers for the flow past the NACA 0012 airfoil. Since the computed data for the NACA 0012 airfoil are available only at discrete spatial locations, an interpolation method is used to provide values of the Mach number over the entire field.

Determining the Suitability of Different Digital Elevation Models and Satellite Images for Fancy Maps. An Example of Cyprus

NASA Astrophysics Data System (ADS)

Drachal, J.; Kawel, A. K.

2016-06-01

The article describes the possibility of developing an overall map of the selected area on the basis of publicly available data. Such a map would take the form designed by the author with the colors that meets his expectations and a content, which he considers to be appropriate. Among the data available it was considered the use of satellite images of the terrain in real colors and, in the form of shaded relief, digital terrain models with different resolutions of the terrain mesh. Specifically the considered data were: MODIS, Landsat 8, GTOPO-30, SRTM-30, SRTM-1, SRTM-3, ASTER. For the test area the island of Cyprus was chosen because of the importance in tourism, a relatively small area and a clearly defined boundary. In the paper there are shown and discussed various options of the Cyprus terrain image obtained synthetically from variants of Modis, Landsat and digital elevation models of different resolutions.

Modeling human faces with multi-image photogrammetry

NASA Astrophysics Data System (ADS)

D'Apuzzo, Nicola

2002-03-01

Modeling and measurement of the human face have been increasing by importance for various purposes. Laser scanning, coded light range digitizers, image-based approaches and digital stereo photogrammetry are the used methods currently employed in medical applications, computer animation, video surveillance, teleconferencing and virtual reality to produce three dimensional computer models of the human face. Depending on the application, different are the requirements. Ours are primarily high accuracy of the measurement and automation in the process. The method presented in this paper is based on multi-image photogrammetry. The equipment, the method and results achieved with this technique are here depicted. The process is composed of five steps: acquisition of multi-images, calibration of the system, establishment of corresponding points in the images, computation of their 3-D coordinates and generation of a surface model. The images captured by five CCD cameras arranged in front of the subject are digitized by a frame grabber. The complete system is calibrated using a reference object with coded target points, which can be measured fully automatically. To facilitate the establishment of correspondences in the images, texture in the form of random patterns can be projected from two directions onto the face. The multi-image matching process, based on a geometrical constrained least squares matching algorithm, produces a dense set of corresponding points in the five images. Neighborhood filters are then applied on the matching results to remove the errors. After filtering the data, the three-dimensional coordinates of the matched points are computed by forward intersection using the results of the calibration process; the achieved mean accuracy is about 0.2 mm in the sagittal direction and about 0.1 mm in the lateral direction. The last step of data processing is the generation of a surface model from the point cloud and the application of smooth filters. Moreover, a color texture image can be draped over the model to achieve a photorealistic visualization. The advantage of the presented method over laser scanning and coded light range digitizers is the acquisition of the source data in a fraction of a second, allowing the measurement of human faces with higher accuracy and the possibility to measure dynamic events like the speech of a person.

3D digital image correlation methods for full-field vibration measurement

NASA Astrophysics Data System (ADS)

Helfrick, Mark N.; Niezrecki, Christopher; Avitabile, Peter; Schmidt, Timothy

2011-04-01

In the area of modal test/analysis/correlation, significant effort has been expended over the past twenty years in order to make reduced models and to expand test data for correlation and eventual updating of the finite element models. This has been restricted by vibration measurements which are traditionally limited to the location of relatively few applied sensors. Advances in computers and digital imaging technology have allowed 3D digital image correlation (DIC) methods to measure the shape and deformation of a vibrating structure. This technique allows for full-field measurement of structural response, thus providing a wealth of simultaneous test data. This paper presents some preliminary results for the test/analysis/correlation of data measured using the DIC approach along with traditional accelerometers and a scanning laser vibrometer for comparison to a finite element model. The results indicate that all three approaches correlated well with the finite element model and provide validation for the DIC approach for full-field vibration measurement. Some of the advantages and limitations of the technique are presented and discussed.

First Digit Law and Its Application to Digital Forensics

NASA Astrophysics Data System (ADS)

Shi, Yun Q.

Digital data forensics, which gathers evidence of data composition, origin, and history, is crucial in our digital world. Although this new research field is still in its infancy stage, it has started to attract increasing attention from the multimedia-security research community. This lecture addresses the first digit law and its applications to digital forensics. First, the Benford and generalized Benford laws, referred to as first digit law, are introduced. Then, the application of first digit law to detection of JPEG compression history for a given BMP image and detection of double JPEG compressions are presented. Finally, applying first digit law to detection of double MPEG video compressions is discussed. It is expected that the first digit law may play an active role in other task of digital forensics. The lesson learned is that statistical models play an important role in digital forensics and for a specific forensic task different models may provide different performance.

Evaluating RGB photogrammetry and multi-temporal digital surface models for detecting soil erosion

NASA Astrophysics Data System (ADS)

Anders, Niels; Keesstra, Saskia; Seeger, Manuel

2013-04-01

Photogrammetry is a widely used tool for generating high-resolution digital surface models. Unmanned Aerial Vehicles (UAVs), equipped with a Red Green Blue (RGB) camera, have great potential in quickly acquiring multi-temporal high-resolution orthophotos and surface models. Such datasets would ease the monitoring of geomorphological processes, such as local soil erosion and rill formation after heavy rainfall events. In this study we test a photogrammetric setup to determine data requirements for soil erosion studies with UAVs. We used a rainfall simulator (5 m2) and above a rig with attached a Panasonic GX1 16 megapixel digital camera and 20mm lens. The soil material in the simulator consisted of loamy sand at an angle of 5 degrees. Stereo pair images were taken before and after rainfall simulation with 75-85% overlap. Acquired images were automatically mosaicked to create high-resolution orthorectified images and digital surface models (DSM). We resampled the DSM to different spatial resolutions to analyze the effect of cell size to the accuracy of measured rill depth and soil loss estimations, and determined an optimal cell size (thus flight altitude). Furthermore, the high spatial accuracy of the acquired surface models allows further analysis of rill formation and channel initiation related to e.g. surface roughness. We suggest implementing near-infrared and temperature sensors to combine soil moisture and soil physical properties with surface morphology for future investigations.

Statistical colour models: an automated digital image analysis method for quantification of histological biomarkers.

PubMed

Shu, Jie; Dolman, G E; Duan, Jiang; Qiu, Guoping; Ilyas, Mohammad

2016-04-27

Colour is the most important feature used in quantitative immunohistochemistry (IHC) image analysis; IHC is used to provide information relating to aetiology and to confirm malignancy. Statistical modelling is a technique widely used for colour detection in computer vision. We have developed a statistical model of colour detection applicable to detection of stain colour in digital IHC images. Model was first trained by massive colour pixels collected semi-automatically. To speed up the training and detection processes, we removed luminance channel, Y channel of YCbCr colour space and chose 128 histogram bins which is the optimal number. A maximum likelihood classifier is used to classify pixels in digital slides into positively or negatively stained pixels automatically. The model-based tool was developed within ImageJ to quantify targets identified using IHC and histochemistry. The purpose of evaluation was to compare the computer model with human evaluation. Several large datasets were prepared and obtained from human oesophageal cancer, colon cancer and liver cirrhosis with different colour stains. Experimental results have demonstrated the model-based tool achieves more accurate results than colour deconvolution and CMYK model in the detection of brown colour, and is comparable to colour deconvolution in the detection of pink colour. We have also demostrated the proposed model has little inter-dataset variations. A robust and effective statistical model is introduced in this paper. The model-based interactive tool in ImageJ, which can create a visual representation of the statistical model and detect a specified colour automatically, is easy to use and available freely at http://rsb.info.nih.gov/ij/plugins/ihc-toolbox/index.html . Testing to the tool by different users showed only minor inter-observer variations in results.

ImageJ: A Free, Easy, and Reliable Method to Measure Leg Ulcers Using Digital Pictures.

PubMed

Aragón-Sánchez, Javier; Quintana-Marrero, Yurena; Aragón-Hernández, Cristina; Hernández-Herero, María José

2017-12-01

Wound measurement to document the healing course of chronic leg ulcers has an important role in the management of these patients. Digital cameras in smartphones are readily available and easy to use, and taking pictures of wounds is becoming a routine in specialized departments. Analyzing digital pictures with appropriate software provides clinicians a quick, clean, and easy-to-use tool for measuring wound area. A set of 25 digital pictures of plain foot and leg ulcers was the basis of this study. Photographs were taken placing a ruler next to the wound in parallel with the healthy skin with the iPhone 6S (Apple Inc, Cupertino, CA), which has a camera of 12 megapixels using the flash. The digital photographs were visualized with ImageJ 1.45s freeware (National Institutes of Health, Rockville, MD; http://imagej.net/ImageJ ). Wound area measurement was carried out by 4 raters: head of the department, wound care nurse, physician, and medical student. We assessed intra- and interrater reliability using the interclass correlation coefficient. To determine intraobserver reliability, 2 of the raters repeated the measurement of the set 1 week after the first reading. The interrater model displayed an interclass correlation coefficient of 0.99 with 95% confidence interval of 0.999 to 1.000, showing excellent reliability. The intrarater model of both examiners showed excellent reliability. In conclusion, analyzing digital images of leg ulcers with ImageJ estimates wound area with excellent reliability. This method provides a free, rapid, and accurate way to measure wounds and could routinely be used to document wound healing in daily clinical practice.

Measuring noise equivalent irradiance of a digital short-wave infrared imaging system using a broadband source to simulate the night spectrum

NASA Astrophysics Data System (ADS)

Green, John R.; Robinson, Timothy

2015-05-01

There is a growing interest in developing helmet-mounted digital imaging systems (HMDIS) for integration into military aircraft cockpits. This interest stems from the multiple advantages of digital vs. analog imaging such as image fusion from multiple sensors, data processing to enhance the image contrast, superposition of non-imaging data over the image, and sending images to remote location for analysis. There are several properties an HMDIS must have in order to aid the pilot during night operations. In addition to the resolution, image refresh rate, dynamic range, and sensor uniformity over the entire Focal Plane Array (FPA); the imaging system must have the sensitivity to detect the limited night light available filtered through cockpit transparencies. Digital sensor sensitivity is generally measured monochromatically using a laser with a wavelength near the peak detector quantum efficiency, and is generally reported as either the Noise Equivalent Power (NEP) or Noise Equivalent Irradiance (NEI). This paper proposes a test system that measures NEI of Short-Wave Infrared (SWIR) digital imaging systems using a broadband source that simulates the night spectrum. This method has a few advantages over a monochromatic method. Namely, the test conditions provide spectrum closer to what is experienced by the end-user, and the resulting NEI may be compared directly to modeled night glow irradiance calculation. This comparison may be used to assess the Technology Readiness Level of the imaging system for the application. The test system is being developed under a Cooperative Research and Development Agreement (CRADA) with the Air Force Research Laboratory.

Temporal Subtraction of Digital Breast Tomosynthesis Images for Improved Mass Detection

DTIC Science & Technology

2009-11-01

imaging using two distinct methods7-15: mathematically based models defined by geometric primitives and voxelized models derived from real human...trees to complete them. We also plan to add further detail by defining the Cooper’s ligaments using geometrical NURBS surfaces. Realistic...generated model for the coronary arterial tree based on multislice CT and morphometric data," Medical Imaging 2006: Physics of Medical Imaging 6142

Learning optimal features for visual pattern recognition

NASA Astrophysics Data System (ADS)

Labusch, Kai; Siewert, Udo; Martinetz, Thomas; Barth, Erhardt

2007-02-01

The optimal coding hypothesis proposes that the human visual system has adapted to the statistical properties of the environment by the use of relatively simple optimality criteria. We here (i) discuss how the properties of different models of image coding, i.e. sparseness, decorrelation, and statistical independence are related to each other (ii) propose to evaluate the different models by verifiable performance measures (iii) analyse the classification performance on images of handwritten digits (MNIST data base). We first employ the SPARSENET algorithm (Olshausen, 1998) to derive a local filter basis (on 13 × 13 pixels windows). We then filter the images in the database (28 × 28 pixels images of digits) and reduce the dimensionality of the resulting feature space by selecting the locally maximal filter responses. We then train a support vector machine on a training set to classify the digits and report results obtained on a separate test set. Currently, the best state-of-the-art result on the MNIST data base has an error rate of 0,4%. This result, however, has been obtained by using explicit knowledge that is specific to the data (elastic distortion model for digits). We here obtain an error rate of 0,55% which is second best but does not use explicit data specific knowledge. In particular it outperforms by far all methods that do not use data-specific knowledge.

Three-dimensional displays for natural hazards analysis, using classified Landsat Thematic Mapper digital data and large-scale digital elevation models

NASA Technical Reports Server (NTRS)

Butler, David R.; Walsh, Stephen J.; Brown, Daniel G.

1991-01-01

Methods are described for using Landsat Thematic Mapper digital data and digital elevation models for the display of natural hazard sites in a mountainous region of northwestern Montana, USA. Hazard zones can be easily identified on the three-dimensional images. Proximity of facilities such as highways and building locations to hazard sites can also be easily displayed. A temporal sequence of Landsat TM (or similar) satellite data sets could also be used to display landscape changes associated with dynamic natural hazard processes.

A cryptologic based trust center for medical images.

PubMed

Wong, S T

1996-01-01

To investigate practical solutions that can integrate cryptographic techniques and picture archiving and communication systems (PACS) to improve the security of medical images. The PACS at the University of California San Francisco Medical Center consolidate images and associated data from various scanners into a centralized data archive and transmit them to remote display stations for review and consultation purposes. The purpose of this study is to investigate the model of a digital trust center that integrates cryptographic algorithms and protocols seamlessly into such a digital radiology environment to improve the security of medical images. The timing performance of encryption, decryption, and transmission of the cryptographic protocols over 81 volumetric PACS datasets has been measured. Lossless data compression is also applied before the encryption. The transmission performance is measured against three types of networks of different bandwidths: narrow-band Integrated Services Digital Network, Ethernet, and OC-3c Asynchronous Transfer Mode. The proposed digital trust center provides a cryptosystem solution to protect the confidentiality and to determine the authenticity of digital images in hospitals. The results of this study indicate that diagnostic images such as x-rays and magnetic resonance images could be routinely encrypted in PACS. However, applying encryption in teleradiology and PACS is a tradeoff between communications performance and security measures. Many people are uncertain about how to integrate cryptographic algorithms coherently into existing operations of the clinical enterprise. This paper describes a centralized cryptosystem architecture to ensure image data authenticity in a digital radiology department. The system performance has been evaluated in a hospital-integrated PACS environment.

A cryptologic based trust center for medical images.

PubMed Central

Wong, S T

1996-01-01

OBJECTIVE: To investigate practical solutions that can integrate cryptographic techniques and picture archiving and communication systems (PACS) to improve the security of medical images. DESIGN: The PACS at the University of California San Francisco Medical Center consolidate images and associated data from various scanners into a centralized data archive and transmit them to remote display stations for review and consultation purposes. The purpose of this study is to investigate the model of a digital trust center that integrates cryptographic algorithms and protocols seamlessly into such a digital radiology environment to improve the security of medical images. MEASUREMENTS: The timing performance of encryption, decryption, and transmission of the cryptographic protocols over 81 volumetric PACS datasets has been measured. Lossless data compression is also applied before the encryption. The transmission performance is measured against three types of networks of different bandwidths: narrow-band Integrated Services Digital Network, Ethernet, and OC-3c Asynchronous Transfer Mode. RESULTS: The proposed digital trust center provides a cryptosystem solution to protect the confidentiality and to determine the authenticity of digital images in hospitals. The results of this study indicate that diagnostic images such as x-rays and magnetic resonance images could be routinely encrypted in PACS. However, applying encryption in teleradiology and PACS is a tradeoff between communications performance and security measures. CONCLUSION: Many people are uncertain about how to integrate cryptographic algorithms coherently into existing operations of the clinical enterprise. This paper describes a centralized cryptosystem architecture to ensure image data authenticity in a digital radiology department. The system performance has been evaluated in a hospital-integrated PACS environment. PMID:8930857

Scoping of Flood Hazard Mapping Needs for Merrimack County, New Hampshire

DTIC Science & Technology

2006-01-01

DOQ Digital Orthophoto Quadrangle DOQQ Digital Ortho Quarter Quadrangle DTM Digital Terrain Model FBFM Flood Boundary and Floodway Map FEMA Federal...discussed available data and coverages within New Hampshire (for example, 2003 National Agriculture Imag- ery Program (NAIP) color Digital Orthophoto ... orthophotos providing improved base map accuracy. NH GRANIT is presently converting the standard, paper FIRMs and Flood Boundary and Floodway maps (FBFMs

Pharmacology Students' Perceptions of Creating Multimodal Digital Explanations

ERIC Educational Resources Information Center

Nielsen, W.; Hoban G.; Hyland, C. J. T.

2017-01-01

Students can now digitally construct their own representations of scientific concepts using a variety of modes including writing, diagrams, 2-D and 3-D models, images or speech, all of which communicate meaning. In this study, final-year chemistry students studying a pharmacology subject created a ''blended media'' digital product as an assignment…

Imaging model for the scintillator and its application to digital radiography image enhancement.

PubMed

Wang, Qian; Zhu, Yining; Li, Hongwei

2015-12-28

Digital Radiography (DR) images obtained by OCD-based (optical coupling detector) Micro-CT system usually suffer from low contrast. In this paper, a mathematical model is proposed to describe the image formation process in scintillator. By solving the correlative inverse problem, the quality of DR images is improved, i.e. higher contrast and spatial resolution. By analyzing the radiative transfer process of visible light in scintillator, scattering is recognized as the main factor leading to low contrast. Moreover, involved blurring effect is also concerned and described as point spread function (PSF). Based on these physical processes, the scintillator imaging model is then established. When solving the inverse problem, pre-correction to the intensity of x-rays, dark channel prior based haze removing technique, and an effective blind deblurring approach are employed. Experiments on a variety of DR images show that the proposed approach could improve the contrast of DR images dramatically as well as eliminate the blurring vision effectively. Compared with traditional contrast enhancement methods, such as CLAHE, our method could preserve the relative absorption values well.

Increasing Visual Literacy Skills with Digital Imagery: Successful Models for Using a Set of Digital Cameras in a College of Education

ERIC Educational Resources Information Center

Wilhelm, Lance

2005-01-01

The use of images is becoming more pervasive in modern culture, and schools must adapt their curricula and instructional practices accordingly. Visual literacy is becoming more important from a curricular standpoint as society relies to a greater degree on images and visual communication strategies. Thus, in order for students to be marketable in…

Digital hand atlas and computer-aided bone age assessment via the Web

NASA Astrophysics Data System (ADS)

Cao, Fei; Huang, H. K.; Pietka, Ewa; Gilsanz, Vicente

1999-07-01

A frequently used assessment method of bone age is atlas matching by a radiological examination of a hand image against a reference set of atlas patterns of normal standards. We are in a process of developing a digital hand atlas with a large standard set of normal hand and wrist images that reflect the skeletal maturity, race and sex difference, and current child development. The digital hand atlas will be used for a computer-aided bone age assessment via Web. We have designed and partially implemented a computer-aided diagnostic (CAD) system for Web-based bone age assessment. The system consists of a digital hand atlas, a relational image database and a Web-based user interface. The digital atlas is based on a large standard set of normal hand an wrist images with extracted bone objects and quantitative features. The image database uses a content- based indexing to organize the hand images and their attributes and present to users in a structured way. The Web-based user interface allows users to interact with the hand image database from browsers. Users can use a Web browser to push a clinical hand image to the CAD server for a bone age assessment. Quantitative features on the examined image, which reflect the skeletal maturity, will be extracted and compared with patterns from the atlas database to assess the bone age. The relevant reference imags and the final assessment report will be sent back to the user's browser via Web. The digital atlas will remove the disadvantages of the currently out-of-date one and allow the bone age assessment to be computerized and done conveniently via Web. In this paper, we present the system design and Web-based client-server model for computer-assisted bone age assessment and our initial implementation of the digital atlas database.

Digital image management project for dermatological health care environments: a new dedicated software and review of the literature.

PubMed

Rubegni, Pietro; Nami, Niccolò; Poggiali, Sara; Tataranno, Domenico; Fimiani, M

2009-05-01

Because the skin is the only organ completely accessible to visual examination, digital technology has therefore attracted the attention of dermatologists for documenting, monitoring, measuring and classifying morphological manifestations. To describe a digital image management system dedicated to dermatological health care environments and to compare it with other existing softwares for digital image storage. We designed a reliable hardware structure that could ensure future scaling, because storage needs tend to grow exponentially. For the software, we chose a client-web server application based on a relational database and with a 'minimalist' user interface. We developed a software with a ready-made, adaptable index of skin pathologies. It facilitates classification by pathology, patient and visit, with an advanced search option allowing access to all images according to personalized criteria. The software also offers the possibility of comparing two or more digital images (follow-up). The fact that the archives of years of digital photos acquired and saved on PCs can easily be entered in the program distinguishes it from the others in the market. This option is fundamental for accessing all the photos taken in years of practice in the program without entering them one by one. The program is available to any user connected to the local Intranet and the system may directly be available in the future from the Internet. All clinics and surgeries, especially those that rely on digital images, are obliged to keep up with technological advances. It is therefore hoped that our project will become a model for medical structures intending to rationalise digital and other data according to statutory requirements.

Personalized development of human organs using 3D printing technology.

PubMed

Radenkovic, Dina; Solouk, Atefeh; Seifalian, Alexander

2016-02-01

3D printing is a technique of fabricating physical models from a 3D volumetric digital image. The image is sliced and printed using a specific material into thin layers, and successive layering of the material produces a 3D model. It has already been used for printing surgical models for preoperative planning and in constructing personalized prostheses for patients. The ultimate goal is to achieve the development of functional human organs and tissues, to overcome limitations of organ transplantation created by the lack of organ donors and life-long immunosuppression. We hypothesized a precision medicine approach to human organ fabrication using 3D printed technology, in which the digital volumetric data would be collected by imaging of a patient, i.e. CT or MRI images followed by mathematical modeling to create a digital 3D image. Then a suitable biocompatible material, with an optimal resolution for cells seeding and maintenance of cell viability during the printing process, would be printed with a compatible printer type and finally implanted into the patient. Life-saving operations with 3D printed implants were already performed in patients. However, several issues need to be addressed before translational application of 3D printing into clinical medicine. These are vascularization, innervation, and financial cost of 3D printing and safety of biomaterials used for the construct. Copyright © 2015 Elsevier Ltd. All rights reserved.

Application of snakes and dynamic programming optimisation technique in modeling of buildings in informal settlement areas

NASA Astrophysics Data System (ADS)

Rüther, Heinz; Martine, Hagai M.; Mtalo, E. G.

This paper presents a novel approach to semiautomatic building extraction in informal settlement areas from aerial photographs. The proposed approach uses a strategy of delineating buildings by optimising their approximate building contour position. Approximate building contours are derived automatically by locating elevation blobs in digital surface models. Building extraction is then effected by means of the snakes algorithm and the dynamic programming optimisation technique. With dynamic programming, the building contour optimisation problem is realized through a discrete multistage process and solved by the "time-delayed" algorithm, as developed in this work. The proposed building extraction approach is a semiautomatic process, with user-controlled operations linking fully automated subprocesses. Inputs into the proposed building extraction system are ortho-images and digital surface models, the latter being generated through image matching techniques. Buildings are modeled as "lumps" or elevation blobs in digital surface models, which are derived by altimetric thresholding of digital surface models. Initial windows for building extraction are provided by projecting the elevation blobs centre points onto an ortho-image. In the next step, approximate building contours are extracted from the ortho-image by region growing constrained by edges. Approximate building contours thus derived are inputs into the dynamic programming optimisation process in which final building contours are established. The proposed system is tested on two study areas: Marconi Beam in Cape Town, South Africa, and Manzese in Dar es Salaam, Tanzania. Sixty percent of buildings in the study areas have been extracted and verified and it is concluded that the proposed approach contributes meaningfully to the extraction of buildings in moderately complex and crowded informal settlement areas.

Digital photogrammetric analysis of the IMP camera images: Mapping the Mars Pathfinder landing site in three dimensions

USGS Publications Warehouse

Kirk, R.L.; Howington-Kraus, E.; Hare, T.; Dorrer, E.; Cook, D.; Becker, K.; Thompson, K.; Redding, B.; Blue, J.; Galuszka, D.; Lee, E.M.; Gaddis, L.R.; Johnson, J. R.; Soderblom, L.A.; Ward, A.W.; Smith, P.H.; Britt, D.T.

1999-01-01

This paper describes our photogrammetric analysis of the Imager for Mars Pathfinder data, part of a broader program of mapping the Mars Pathfinder landing site in support of geoscience investigations. This analysis, carried out primarily with a commercial digital photogrammetric system, supported by our in-house Integrated Software for Imagers and Spectrometers (ISIS), consists of three steps: (1) geometric control: simultaneous solution for refined estimates of camera positions and pointing plus three-dimensional (3-D) coordinates of ???103 features sitewide, based on the measured image coordinates of those features; (2) topographic modeling: identification of ???3 ?? 105 closely spaced points in the images and calculation (based on camera parameters from step 1) of their 3-D coordinates, yielding digital terrain models (DTMs); and (3) geometric manipulation of the data: combination of the DTMs from different stereo pairs into a sitewide model, and reprojection of image data to remove parallax between the different spectral filters in the two cameras and to provide an undistorted planimetric view of the site. These processes are described in detail and example products are shown. Plans for combining the photogrammetrically derived topographic data with spectrophotometry are also described. These include photometric modeling using surface orientations from the DTM to study surface microtextures and improve the accuracy of spectral measurements, and photoclinometry to refine the DTM to single-pixel resolution where photometric properties are sufficiently uniform. Finally, the inclusion of rover images in a joint photogrammetric analysis with IMP images is described. This challenging task will provide coverage of areas hidden to the IMP, but accurate ranging of distant features can be achieved only if the lander is also visible in the rover image used. Copyright 1999 by the American Geophysical Union.

Comparing Dimensional Accuracy Between a Polyvinyl Chloride Skull and Its Virtually Constructed Counterpart

DTIC Science & Technology

2015-06-01

exposure settings…………………...26 Table 4. Kodak 9500 Cone Beam 3D System exposure settings…………..….27 Table 5. Average and statistical analysis results...42 Figure 6 Image of Mounted PVC Skull Model on the Kodak 9500……….…......43 Figure 7 Screen image of Reconstructed CBCT Digital...replica was taken with the Kodak 9500 Cone Beam 3D System. To create the digital dental models fifteen type IV maxillary dental casts were made on the

Deep-turbulence wavefront sensing using digital holography in the on-axis phase shifting recording geometry

NASA Astrophysics Data System (ADS)

Thornton, Douglas E.; Spencer, Mark F.; Perram, Glen P.

2017-09-01

The effects of deep turbulence in long-range imaging applications presents unique challenges to properly measure and correct for aberrations incurred along the atmospheric path. In practice, digital holography can detect the path-integrated wavefront distortions caused by deep turbulence, and di erent recording geometries offer different benefits depending on the application of interest. Previous studies have evaluated the performance of the off-axis image and pupil plane recording geometries for deep-turbulence sensing. This study models digital holography in the on-axis phase shifting recording geometry using wave optics simulations. In particular, the analysis models spherical-wave propagation through varying deep-turbulence conditions to estimate the complex optical field, and performance is evaluated by calculating the field-estimated Strehl ratio and RMS wavefront error. Altogether, the results show that digital holography in the on-axis phase shifting recording geometry is an effective wavefront-sensing method in the presence of deep turbulence.

A method for mandibular dental arch superimposition using 3D cone beam CT and orthodontic 3D digital model

PubMed Central

Park, Tae-Joon; Lee, Sang-Hyun

2012-01-01

Objective The purpose of this study was to develop superimposition method on the lower arch using 3-dimensional (3D) cone beam computed tomography (CBCT) images and orthodontic 3D digital modeling. Methods Integrated 3D CBCT images were acquired by substituting the dental portion of 3D CBCT images with precise dental images of an orthodontic 3D digital model. Images were acquired before and after treatment. For the superimposition, 2 superimposition methods were designed. Surface superimposition was based on the basal bone structure of the mandible by surface-to-surface matching (best-fit method). Plane superimposition was based on anatomical structures (mental and lingual foramen). For the evaluation, 10 landmarks including teeth and anatomic structures were assigned, and 30 times of superimpositions and measurements were performed to determine the more reproducible and reliable method. Results All landmarks demonstrated that the surface superimposition method produced relatively more consistent coordinate values. The mean distances of measured landmarks values from the means were statistically significantly lower with the surface superimpositions method. Conclusions Between the 2 superimposition methods designed for the evaluation of 3D changes in the lower arch, surface superimposition was the simpler, more reproducible, reliable method. PMID:23112948

Three-Dimensional Pathology Specimen Modeling Using "Structure-From-Motion" Photogrammetry: A Powerful New Tool for Surgical Pathology.

PubMed

Turchini, John; Buckland, Michael E; Gill, Anthony J; Battye, Shane

2018-05-30

- Three-dimensional (3D) photogrammetry is a method of image-based modeling in which data points in digital images, taken from offset viewpoints, are analyzed to generate a 3D model. This modeling technique has been widely used in the context of geomorphology and artificial imagery, but has yet to be used within the realm of anatomic pathology. - To describe the application of a 3D photogrammetry system capable of producing high-quality 3D digital models and its uses in routine surgical pathology practice as well as medical education. - We modeled specimens received in the 2 participating laboratories. The capture and photogrammetry process was automated using user control software, a digital single-lens reflex camera, and digital turntable, to generate a 3D model with the output in a PDF file. - The entity demonstrated in each specimen was well demarcated and easily identified. Adjacent normal tissue could also be easily distinguished. Colors were preserved. The concave shapes of any cystic structures or normal convex rounded structures were discernable. Surgically important regions were identifiable. - Macroscopic 3D modeling of specimens can be achieved through Structure-From-Motion photogrammetry technology and can be applied quickly and easily in routine laboratory practice. There are numerous advantages to the use of 3D photogrammetry in pathology, including improved clinicopathologic correlation for the surgeon and enhanced medical education, revolutionizing the digital pathology museum with virtual reality environments and 3D-printing specimen models.

Quantitative comparison of the application accuracy between NDI and IGT tracking systems

NASA Astrophysics Data System (ADS)

Li, Qinghang; Zamorano, Lucia J.; Jiang, Charlie Z. W.; Gong, JianXing; Diaz, Fernando

1999-07-01

The application accuracy is a crucial factor for the stereotactic surgical localization system in which space digitization system is one of the most important part of equipment. In this study we compared the application accuracy of using the OPTOTRAK space digitization system (OPTOTRAK 3020, Northern Digital, Waterloo, CAN) and FlashPoint Model 3000 and 5000 3-D digitizer systems (FlashPoint Model 3000 and 5000, Image Guided Surgery Technology Inc., Boulder, CO 80301, USA) for interactive localization of intracranial lesions. A phantom was mounted with the implantable frameless marker system (Fischer- Leibinger, Freiburg, Germany) which randomly distributed markers on the surface of the phantom. The target point was digitized and the coordinates were recorded and compared with reference points. The differences from the reference points were used as the deviation from the `true point'. The mean square root was calculated to show the sum of vectors. A paired t-test was used to analyze results. The results of the phantom showed that the mean square roots were 0.76 +/- 0.54 mm for the OPTOTRAK system and 1.23 +/- 0.53 mm for FlashPoint Model 3000 3-D digitizer system and 1.00 +/- 0.42 mm for FlashPoint Model 3000 3-D digitizer system in the 1 mm sections of CT scan. This preliminary results showed that there is no significant difference between two tracking systems. Both of them can be used for image guided surgery procedure.

Comparison of manually produced and automated cross country movement maps using digital image processing techniques

NASA Technical Reports Server (NTRS)

Wynn, L. K.

1985-01-01

The Image-Based Information System (IBIS) was used to automate the cross country movement (CCM) mapping model developed by the Defense Mapping Agency (DMA). Existing terrain factor overlays and a CCM map, produced by DMA for the Fort Lewis, Washington area, were digitized and reformatted into geometrically registered images. Terrain factor data from Slope, Soils, and Vegetation overlays were entered into IBIS, and were then combined utilizing IBIS-programmed equations to implement the DMA CCM model. The resulting IBIS-generated CCM map was then compared with the digitized manually produced map to test similarity. The numbers of pixels comprising each CCM region were compared between the two map images, and percent agreement between each two regional counts was computed. The mean percent agreement equalled 86.21%, with an areally weighted standard deviation of 11.11%. Calculation of Pearson's correlation coefficient yielded +9.997. In some cases, the IBIS-calculated map code differed from the DMA codes: analysis revealed that IBIS had calculated the codes correctly. These highly positive results demonstrate the power and accuracy of IBIS in automating models which synthesize a variety of thematic geographic data.

Study of fish response using particle image velocimetry and high-speed, high-resolution imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Z.; Richmond, M. C.; Mueller, R. P.

2004-10-01

Fish swimming has fascinated both engineers and fish biologists for decades. Digital particle image velocimetry (DPIV) and high-speed, high-resolution digital imaging are recently developed analysis tools that can help engineers and biologists better understand how fish respond to turbulent environments. This report details studies to evaluate DPIV. The studies included a review of existing literature on DPIV, preliminary studies to test the feasibility of using DPIV conducted at our Flow Biology Laboratory in Richland, Washington September through December 2003, and applications of high-speed, high-resolution digital imaging with advanced motion analysis to investigations of fish injury mechanisms in turbulent shear flowsmore » and bead trajectories in laboratory physical models. Several conclusions were drawn based on these studies, which are summarized as recommendations for proposed research at the end of this report.« less

Accuracy Validation of Large-scale Block Adjustment without Control of ZY3 Images over China

NASA Astrophysics Data System (ADS)

Yang, Bo

2016-06-01

Mapping from optical satellite images without ground control is one of the goals of photogrammetry. Using 8802 three linear array stereo images (a total of 26406 images) of ZY3 over China, we propose a large-scale and non-control block adjustment method of optical satellite images based on the RPC model, in which a single image is regarded as an adjustment unit to be organized. To overcome the block distortion caused by unstable adjustment without ground control and the excessive accumulation of errors, we use virtual control points created by the initial RPC model of the images as the weighted observations and add them into the adjustment model to refine the adjustment. We use 8000 uniformly distributed high precision check points to evaluate the geometric accuracy of the DOM (Digital Ortho Model) and DSM (Digital Surface Model) production, for which the standard deviations of plane and elevation are 3.6 m and 4.2 m respectively. The geometric accuracy is consistent across the whole block and the mosaic accuracy of neighboring DOM is within a pixel, thus, the seamless mosaic could take place. This method achieves the goal of an accuracy of mapping without ground control better than 5 m for the whole China from ZY3 satellite images.

Cartographic services contract...for everything geographic

USGS Publications Warehouse

,

2003-01-01

The U.S. Geological Survey's (USGS) Cartographic Services Contract (CSC) is used to award work for photogrammetric and mapping services under the umbrella of Architect-Engineer (A&E) contracting. The A&E contract is broad in scope and can accommodate any activity related to standard, nonstandard, graphic, and digital cartographic products. Services provided may include, but are not limited to, photogrammetric mapping and aerotriangulation; orthophotography; thematic mapping (for example, land characterization); analog and digital imagery applications; geographic information systems development; surveying and control acquisition, including ground-based and airborne Global Positioning System; analog and digital image manipulation, analysis, and interpretation; raster and vector map digitizing; data manipulations (for example, transformations, conversions, generalization, integration, and conflation); primary and ancillary data acquisition (for example, aerial photography, satellite imagery, multispectral, multitemporal, and hyperspectral data); image scanning and processing; metadata production, revision, and creation; and production or revision of standard USGS products defined by formal and informal specification and standards, such as those for digital line graphs, digital elevation models, digital orthophoto quadrangles, and digital raster graphics.

Digital image transformation and rectification of spacecraft and radar images

NASA Technical Reports Server (NTRS)

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.

Digital camera with apparatus for authentication of images produced from an image file

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1993-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely based upon the private key that digital data encrypted with the private key by the processor may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating at any time the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match, since even one bit change in the image hash will cause the image hash to be totally different from the secure hash.

A search for Ganymede stereo images and 3D mapping opportunities

NASA Astrophysics Data System (ADS)

Zubarev, A.; Nadezhdina, I.; Brusnikin, E.; Giese, B.; Oberst, J.

2017-10-01

We used 126 Voyager-1 and -2 as well as 87 Galileo images of Ganymede and searched for stereo images suitable for digital 3D stereo analysis. Specifically, we consider image resolutions, stereo angles, as well as matching illumination conditions of respective stereo pairs. Lists of regions and local areas with stereo coverage are compiled. We present anaglyphs and we selected areas, not previously discussed, for which we constructed Digital Elevation Models and associated visualizations. The terrain characteristics in the models are in agreement with our previous notion of Ganymede morphology, represented by families of lineaments and craters of various sizes and degradation stages. The identified areas of stereo coverage may serve as important reference targets for the Ganymede Laser Altimeter (GALA) experiment on the future JUICE (Jupiter Icy Moons Explorer) mission.

Validation of a digital mammographic unit model for an objective and highly automated clinical image quality assessment.

PubMed

Perez-Ponce, Hector; Daul, Christian; Wolf, Didier; Noel, Alain

2013-08-01

In mammography, image quality assessment has to be directly related to breast cancer indicator (e.g. microcalcifications) detectability. Recently, we proposed an X-ray source/digital detector (XRS/DD) model leading to such an assessment. This model simulates very realistic contrast-detail phantom (CDMAM) images leading to gold disc (representing microcalcifications) detectability thresholds that are very close to those of real images taken under the simulated acquisition conditions. The detection step was performed with a mathematical observer. The aim of this contribution is to include human observers into the disc detection process in real and virtual images to validate the simulation framework based on the XRS/DD model. Mathematical criteria (contrast-detail curves, image quality factor, etc.) are used to assess and to compare, from the statistical point of view, the cancer indicator detectability in real and virtual images. The quantitative results given in this paper show that the images simulated by the XRS/DD model are useful for image quality assessment in the case of all studied exposure conditions using either human or automated scoring. Also, this paper confirms that with the XRS/DD model the image quality assessment can be automated and the whole time of the procedure can be drastically reduced. Compared to standard quality assessment methods, the number of images to be acquired is divided by a factor of eight. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Ultramap: the all in One Photogrammetric Solution

NASA Astrophysics Data System (ADS)

Wiechert, A.; Gruber, M.; Karner, K.

2012-07-01

This paper describes in detail the dense matcher developed since years by Vexcel Imaging in Graz for Microsoft's Bing Maps project. This dense matcher was exclusively developed for and used by Microsoft for the production of the 3D city models of Virtual Earth. It will now be made available to the public with the UltraMap software release mid-2012. That represents a revolutionary step in digital photogrammetry. The dense matcher generates digital surface models (DSM) and digital terrain models (DTM) automatically out of a set of overlapping UltraCam images. The models have an outstanding point density of several hundred points per square meter and sub-pixel accuracy and are generated automatically. The dense matcher consists of two steps. The first step rectifies overlapping image areas to speed up the dense image matching process. This rectification step ensures a very efficient processing and detects occluded areas by applying a back-matching step. In this dense image matching process a cost function consisting of a matching score as well as a smoothness term is minimized. In the second step the resulting range image patches are fused into a DSM by optimizing a global cost function. The whole process is optimized for multi-core CPUs and optionally uses GPUs if available. UltraMap 3.0 features also an additional step which is presented in this paper, a complete automated true-ortho and ortho workflow. For this, the UltraCam images are combined with the DSM or DTM in an automated rectification step and that results in high quality true-ortho or ortho images as a result of a highly automated workflow. The paper presents the new workflow and first results.

Comparison of 7.5-minute and 1-degree digital elevation models

NASA Technical Reports Server (NTRS)

Isaacson, Dennis L.; Ripple, William J.

1995-01-01

We compared two digital elevation models (DEM's) for the Echo Mountain SE quadrangle in the Cascade Mountains of Oregon. Comparisons were made between 7.5-minute (1:24,000-scale) and 1-degree (1:250,000-scale) images using the variables of elevation, slope aspect, and slope gradient. Both visual and statistical differences are presented.

Comparison of 7.5-minute and 1-degree digital elevation models

NASA Technical Reports Server (NTRS)

Isaacson, Dennis L.; Ripple, William J.

1990-01-01

Two digital elevation models are compared for the Echo Mountain SE quadrangle in the Cascade Mountains of Oregon. Comparisons were made between 7.5-minute (1:24,000-scale) and 1-degree (1:250,000-scale) images using the variables of elevation, slope aspect, and slope gradient. Both visual and statistical differences are presented.

Remote Sensing Soil Moisture Analysis by Unmanned Aerial Vehicles Digital Imaging

NASA Astrophysics Data System (ADS)

Yeh, C. Y.; Lin, H. R.; Chen, Y. L.; Huang, S. Y.; Wen, J. C.

2017-12-01

In recent years, remote sensing analysis has been able to apply to the research of climate change, environment monitoring, geology, hydro-meteorological, and so on. However, the traditional methods for analyzing wide ranges of surface soil moisture of spatial distribution surveys may require plenty resources besides the high cost. In the past, remote sensing analysis performed soil moisture estimates through shortwave, thermal infrared ray, or infrared satellite, which requires lots of resources, labor, and money. Therefore, the digital image color was used to establish the multiple linear regression model. Finally, we can find out the relationship between surface soil color and soil moisture. In this study, we use the Unmanned Aerial Vehicle (UAV) to take an aerial photo of the fallow farmland. Simultaneously, we take the surface soil sample from 0-5 cm of the surface. The soil will be baking by 110° C and 24 hr. And the software ImageJ 1.48 is applied for the analysis of the digital images and the hue analysis into Red, Green, and Blue (R, G, B) hue values. The correlation analysis is the result from the data obtained from the image hue and the surface soil moisture at each sampling point. After image and soil moisture analysis, we use the R, G, B and soil moisture to establish the multiple regression to estimate the spatial distributions of surface soil moisture. In the result, we compare the real soil moisture and the estimated soil moisture. The coefficient of determination (R2) can achieve 0.5-0.7. The uncertainties in the field test, such as the sun illumination, the sun exposure angle, even the shadow, will affect the result; therefore, R2 can achieve 0.5-0.7 reflects good effect for the in-suit test by using the digital image to estimate the soil moisture. Based on the outcomes of the research, using digital images from UAV to estimate the surface soil moisture is acceptable. However, further investigations need to be collected more than ten days (four times a day) data to verify the relation between the image hue and the soil moisture for reliable moisture estimated model. And it is better to use the digital single lens reflex camera to prevent the deformation of the image and to have a better auto exposure. Keywords: soil, moisture, remote sensing

Development of alternative data analysis techniques for improving the accuracy and specificity of natural resource inventories made with digital remote sensing data

NASA Technical Reports Server (NTRS)

Lillesand, T. M.; Meisner, D. E. (Principal Investigator)

1980-01-01

An investigation was conducted into ways to improve the involvement of state and local user personnel in the digital image analysis process by isolating those elements of the analysis process which require extensive involvement by field personnel and providing means for performing those activities apart from a computer facility. In this way, the analysis procedure can be converted from a centralized activity focused on a computer facility to a distributed activity in which users can interact with the data at the field office level or in the field itself. A general image processing software was developed on the University of Minnesota computer system (Control Data Cyber models 172 and 74). The use of color hardcopy image data as a primary medium in supervised training procedures was investigated and digital display equipment and a coordinate digitizer were procured.

Modeling light

NASA Astrophysics Data System (ADS)

Dawson, P.; Gage, J.; Takatsuka, M.; Goyette, S.

2009-02-01

To compete with other digital images, holograms must go beyond the current range of source-image types, such as sequences of photographs, laser scans, and 3D computer graphics (CG) scenes made with software designed for other applications. This project develops a set of innovative techniques for creating 3D digital content specifically for digital holograms, with virtual tools which enable the direct hand-crafting of subjects, mark by mark, analogous to Michelangelo's practice in drawing, painting and sculpture. The haptic device, the Phantom Premium 1.5 is used to draw against three-dimensional laser- scan templates of Michelangelo's sculpture placed within the holographic viewing volume.

Recognition of degraded handwritten digits using dynamic Bayesian networks

NASA Astrophysics Data System (ADS)

Likforman-Sulem, Laurence; Sigelle, Marc

2007-01-01

We investigate in this paper the application of dynamic Bayesian networks (DBNs) to the recognition of handwritten digits. The main idea is to couple two separate HMMs into various architectures. First, a vertical HMM and a horizontal HMM are built observing the evolving streams of image columns and image rows respectively. Then, two coupled architectures are proposed to model interactions between these two streams and to capture the 2D nature of character images. Experiments performed on the MNIST handwritten digit database show that coupled architectures yield better recognition performances than non-coupled ones. Additional experiments conducted on artificially degraded (broken) characters demonstrate that coupled architectures better cope with such degradation than non coupled ones and than discriminative methods such as SVMs.

Full-color digitized holography for large-scale holographic 3D imaging of physical and nonphysical objects.

PubMed

Matsushima, Kyoji; Sonobe, Noriaki

2018-01-01

Digitized holography techniques are used to reconstruct three-dimensional (3D) images of physical objects using large-scale computer-generated holograms (CGHs). The object field is captured at three wavelengths over a wide area at high densities. Synthetic aperture techniques using single sensors are used for image capture in phase-shifting digital holography. The captured object field is incorporated into a virtual 3D scene that includes nonphysical objects, e.g., polygon-meshed CG models. The synthetic object field is optically reconstructed as a large-scale full-color CGH using red-green-blue color filters. The CGH has a wide full-parallax viewing zone and reconstructs a deep 3D scene with natural motion parallax.

Increasing the UAV data value by an OBIA methodology

NASA Astrophysics Data System (ADS)

García-Pedrero, Angel; Lillo-Saavedra, Mario; Rodriguez-Esparragon, Dionisio; Rodriguez-Gonzalez, Alejandro; Gonzalo-Martin, Consuelo

2017-10-01

Recently, there has been a noteworthy increment of using images registered by unmanned aerial vehicles (UAV) in different remote sensing applications. Sensors boarded on UAVs has lower operational costs and complexity than other remote sensing platforms, quicker turnaround times as well as higher spatial resolution. Concerning this last aspect, particular attention has to be paid on the limitations of classical algorithms based on pixels when they are applied to high resolution images. The objective of this study is to investigate the capability of an OBIA methodology developed for the automatic generation of a digital terrain model of an agricultural area from Digital Elevation Model (DEM) and multispectral images registered by a Parrot Sequoia multispectral sensor board on a eBee SQ agricultural drone. The proposed methodology uses a superpixel approach for obtaining context and elevation information used for merging superpixels and at the same time eliminating objects such as trees in order to generate a Digital Terrain Model (DTM) of the analyzed area. Obtained results show the potential of the approach, in terms of accuracy, when it is compared with a DTM generated by manually eliminating objects.

Fusion of range camera and photogrammetry: a systematic procedure for improving 3-D models metric accuracy.

PubMed

Guidi, G; Beraldin, J A; Ciofi, S; Atzeni, C

2003-01-01

The generation of three-dimensional (3-D) digital models produced by optical technologies in some cases involves metric errors. This happens when small high-resolution 3-D images are assembled together in order to model a large object. In some applications, as for example 3-D modeling of Cultural Heritage, the problem of metric accuracy is a major issue and no methods are currently available for enhancing it. The authors present a procedure by which the metric reliability of the 3-D model, obtained through iterative alignments of many range maps, can be guaranteed to a known acceptable level. The goal is the integration of the 3-D range camera system with a close range digital photogrammetry technique. The basic idea is to generate a global coordinate system determined by the digital photogrammetric procedure, measuring the spatial coordinates of optical targets placed around the object to be modeled. Such coordinates, set as reference points, allow the proper rigid motion of few key range maps, including a portion of the targets, in the global reference system defined by photogrammetry. The other 3-D images are normally aligned around these locked images with usual iterative algorithms. Experimental results on an anthropomorphic test object, comparing the conventional and the proposed alignment method, are finally reported.

Digital processing of radiographic images from PACS to publishing.

PubMed

Christian, M E; Davidson, H C; Wiggins, R H; Berges, G; Cannon, G; Jackson, G; Chapman, B; Harnsberger, H R

2001-03-01

Several studies have addressed the implications of filmless radiologic imaging on telemedicine, diagnostic ability, and electronic teaching files. However, many publishers still require authors to submit hard-copy images for publication of articles and textbooks. This study compares the quality digital images directly exported from picture archive and communications systems (PACS) to images digitized from radiographic film. The authors evaluated the quality of publication-grade glossy photographs produced from digital radiographic images using 3 different methods: (1) film images digitized using a desktop scanner and then printed, (2) digital images obtained directly from PACS then printed, and (3) digital images obtained from PACS and processed to improve sharpness prior to printing. Twenty images were printed using each of the 3 different methods and rated for quality by 7 radiologists. The results were analyzed for statistically significant differences among the image sets. Subjective evaluations of the filmless images found them to be of equal or better quality than the digitized images. Direct electronic transfer of PACS images reduces the number of steps involved in creating publication-quality images as well as providing the means to produce high-quality radiographic images in a digital environment.

Digital Camera with Apparatus for Authentication of Images Produced from an Image File

NASA Technical Reports Server (NTRS)

Friedman, Gary L. (Inventor)

1996-01-01

A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely related to the private key that digital data encrypted with the private key may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature. The authenticating apparatus calculates from the image file an image hash using the same algorithm as before. By comparing this last image hash with the secure image hash, authenticity of the image file is determined if they match. Other techniques to address time-honored methods of deception, such as attaching false captions or inducing forced perspectives, are included.

Nonlinear research of an image motion stabilization system embedded in a space land-survey telescope

NASA Astrophysics Data System (ADS)

Somov, Yevgeny; Butyrin, Sergey; Siguerdidjane, Houria

2017-01-01

We consider an image motion stabilization system embedded into a space telescope for a scanning optoelectronic observation of terrestrial targets. Developed model of this system is presented taking into account physical hysteresis of piezo-ceramic driver and a time delay at a forming of digital control. We have presented elaborated algorithms for discrete filtering and digital control, obtained results on analysis of the image motion velocity oscillations in the telescope focal plane, and also methods for terrestrial and in-flight verification of the system.

21 CFR 892.2030 - Medical image digitizer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical image digitizer. 892.2030 Section 892.2030...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2030 Medical image digitizer. (a) Identification. A medical image digitizer is a device intended to convert an analog medical image into a digital...

21 CFR 892.2030 - Medical image digitizer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Medical image digitizer. 892.2030 Section 892.2030...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2030 Medical image digitizer. (a) Identification. A medical image digitizer is a device intended to convert an analog medical image into a digital...

21 CFR 892.2030 - Medical image digitizer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Medical image digitizer. 892.2030 Section 892.2030...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2030 Medical image digitizer. (a) Identification. A medical image digitizer is a device intended to convert an analog medical image into a digital...

21 CFR 892.2030 - Medical image digitizer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Medical image digitizer. 892.2030 Section 892.2030...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.2030 Medical image digitizer. (a) Identification. A medical image digitizer is a device intended to convert an analog medical image into a digital...

Airborne digital-image data for monitoring the Colorado River corridor below Glen Canyon Dam, Arizona, 2009 - Image-mosaic production and comparison with 2002 and 2005 image mosaics

USGS Publications Warehouse

Davis, Philip A.

2012-01-01

Airborne digital-image data were collected for the Arizona part of the Colorado River ecosystem below Glen Canyon Dam in 2009. These four-band image data are similar in wavelength band (blue, green, red, and near infrared) and spatial resolution (20 centimeters) to image collections of the river corridor in 2002 and 2005. These periodic image collections are used by the Grand Canyon Monitoring and Research Center (GCMRC) of the U.S. Geological Survey to monitor the effects of Glen Canyon Dam operations on the downstream ecosystem. The 2009 collection used the latest model of the Leica ADS40 airborne digital sensor (the SH52), which uses a single optic for all four bands and collects and stores band radiance in 12-bits, unlike the image sensors that GCMRC used in 2002 and 2005. This study examined the performance of the SH52 sensor, on the basis of the collected image data, and determined that the SH52 sensor provided superior data relative to the previously employed sensors (that is, an early ADS40 model and Zeiss Imaging's Digital Mapping Camera) in terms of band-image registration, dynamic range, saturation, linearity to ground reflectance, and noise level. The 2009 image data were provided as orthorectified segments of each flightline to constrain the size of the image files; each river segment was covered by 5 to 6 overlapping, linear flightlines. Most flightline images for each river segment had some surface-smear defects and some river segments had cloud shadows, but these two conditions did not generally coincide in the majority of the overlapping flightlines for a particular river segment. Therefore, the final image mosaic for the 450-kilometer (km)-long river corridor required careful selection and editing of numerous flightline segments (a total of 513 segments, each 3.2 km long) to minimize surface defects and cloud shadows. The final image mosaic has a total of only 3 km of surface defects. The final image mosaic for the western end of the corridor has areas of cloud shadow because of persistent inclement weather during data collection. This report presents visual comparisons of the 2002, 2005, and 2009 digital-image mosaics for various physical, biological, and cultural resources within the Colorado River ecosystem. All of the comparisons show the superior quality of the 2009 image data. In fact, the 2009 four-band image mosaic is perhaps the best image dataset that exists for the entire Arizona part of the Colorado River.

Model-based error diffusion for high fidelity lenticular screening.

PubMed

Lau, Daniel; Smith, Trebor

2006-04-17

Digital halftoning is the process of converting a continuous-tone image into an arrangement of black and white dots for binary display devices such as digital ink-jet and electrophotographic printers. As printers are achieving print resolutions exceeding 1,200 dots per inch, it is becoming increasingly important for halftoning algorithms to consider the variations and interactions in the size and shape of printed dots between neighboring pixels. In the case of lenticular screening where statistically independent images are spatially multiplexed together, ignoring these variations and interactions, such as dot overlap, will result in poor lenticular image quality. To this end, we describe our use of model-based error-diffusion for the lenticular screening problem where statistical independence between component images is achieved by restricting the diffusion of error to only those pixels of the same component image where, in order to avoid instabilities, the proposed approach involves a novel error-clipping procedure.

Barriers and facilitators to adoption of soft copy interpretation from the user perspective: Lessons learned from filmless radiology for slideless pathology

PubMed Central

Patterson, Emily S.; Rayo, Mike; Gill, Carolina; Gurcan, Metin N.

2011-01-01

Background: Adoption of digital images for pathological specimens has been slower than adoption of digital images in radiology, despite a number of anticipated advantages for digital images in pathology. In this paper, we explore the factors that might explain this slower rate of adoption. Materials and Method: Semi-structured interviews on barriers and facilitators to the adoption of digital images were conducted with two radiologists, three pathologists, and one pathologist's assistant. Results: Barriers and facilitators to adoption of digital images were reported in the areas of performance, workflow-efficiency, infrastructure, integration with other software, and exposure to digital images. The primary difference between the settings was that performance with the use of digital images as compared to the traditional method was perceived to be higher in radiology and lower in pathology. Additionally, exposure to digital images was higher in radiology than pathology, with some radiologists exclusively having been trained and/or practicing with digital images. The integration of digital images both improved and reduced efficiency in routine and non-routine workflow patterns in both settings, and was variable across the different organizations. A comparison of these findings with prior research on adoption of other health information technologies suggests that the barriers to adoption of digital images in pathology are relatively tractable. Conclusions: Improving performance using digital images in pathology would likely accelerate adoption of innovative technologies that are facilitated by the use of digital images, such as electronic imaging databases, electronic health records, double reading for challenging cases, and computer-aided diagnostic systems. PMID:21383925

Image manipulation: Fraudulence in digital dental records: Study and review

PubMed Central

Chowdhry, Aman; Sircar, Keya; Popli, Deepika Bablani; Tandon, Ankita

2014-01-01

Introduction: In present-day times, freely available software allows dentists to tweak their digital records as never before. But, there is a fine line between acceptable enhancements and scientific delinquency. Aims and Objective: To manipulate digital images (used in forensic dentistry) of casts, lip prints, and bite marks in order to highlight tampering techniques and methods of detecting and preventing manipulation of digital images. Materials and Methods: Digital image records of forensic data (casts, lip prints, and bite marks photographed using Samsung Techwin L77 digital camera) were manipulated using freely available software. Results: Fake digital images can be created either by merging two or more digital images, or by altering an existing image. Discussion and Conclusion: Retouched digital images can be used for fraudulent purposes in forensic investigations. However, tools are available to detect such digital frauds, which are extremely difficult to assess visually. Thus, all digital content should mandatorily have attached metadata and preferably watermarking in order to avert their malicious re-use. Also, computer alertness, especially about imaging software's, should be promoted among forensic odontologists/dental professionals. PMID:24696587

Flame colour characterization in the visible and infrared spectrum using a digital camera and image processing

NASA Astrophysics Data System (ADS)

Huang, Hua-Wei; Zhang, Yang

2008-08-01

An attempt has been made to characterize the colour spectrum of methane flame under various burning conditions using RGB and HSV colour models instead of resolving the real physical spectrum. The results demonstrate that each type of flame has its own characteristic distribution in both the RGB and HSV space. It has also been observed that the averaged B and G values in the RGB model represent well the CH* and C*2 emission of methane premixed flame. Theses features may be utilized for flame measurement and monitoring. The great advantage of using a conventional camera for monitoring flame properties based on the colour spectrum is that it is readily available, easy to interface with a computer, cost effective and has certain spatial resolution. Furthermore, it has been demonstrated that a conventional digital camera is able to image flame not only in the visible spectrum but also in the infrared. This feature is useful in avoiding the problem of image saturation typically encountered in capturing the very bright sooty flames. As a result, further digital imaging processing and quantitative information extraction is possible. It has been identified that an infrared image also has its own distribution in both the RGB and HSV colour space in comparison with a flame image in the visible spectrum.

Toward uniform implementation of parametric map Digital Imaging and Communication in Medicine standard in multisite quantitative diffusion imaging studies.

PubMed

Malyarenko, Dariya; Fedorov, Andriy; Bell, Laura; Prah, Melissa; Hectors, Stefanie; Arlinghaus, Lori; Muzi, Mark; Solaiyappan, Meiyappan; Jacobs, Michael; Fung, Maggie; Shukla-Dave, Amita; McManus, Kevin; Boss, Michael; Taouli, Bachir; Yankeelov, Thomas E; Quarles, Christopher Chad; Schmainda, Kathleen; Chenevert, Thomas L; Newitt, David C

2018-01-01

This paper reports on results of a multisite collaborative project launched by the MRI subgroup of Quantitative Imaging Network to assess current capability and provide future guidelines for generating a standard parametric diffusion map Digital Imaging and Communication in Medicine (DICOM) in clinical trials that utilize quantitative diffusion-weighted imaging (DWI). Participating sites used a multivendor DWI DICOM dataset of a single phantom to generate parametric maps (PMs) of the apparent diffusion coefficient (ADC) based on two models. The results were evaluated for numerical consistency among models and true phantom ADC values, as well as for consistency of metadata with attributes required by the DICOM standards. This analysis identified missing metadata descriptive of the sources for detected numerical discrepancies among ADC models. Instead of the DICOM PM object, all sites stored ADC maps as DICOM MR objects, generally lacking designated attributes and coded terms for quantitative DWI modeling. Source-image reference, model parameters, ADC units and scale, deemed important for numerical consistency, were either missing or stored using nonstandard conventions. Guided by the identified limitations, the DICOM PM standard has been amended to include coded terms for the relevant diffusion models. Open-source software has been developed to support conversion of site-specific formats into the standard representation.

Digital image transformation and rectification of spacecraft and radar images

USGS Publications Warehouse

Wu, S.S.C.

1985-01-01

Digital image transformation and rectification can be described in three categories: (1) digital rectification of spacecraft pictures on workable stereoplotters; (2) digital correction of radar image geometry; and (3) digital reconstruction of shaded relief maps and perspective views including stereograms. Digital rectification can make high-oblique pictures workable on stereoplotters that would otherwise not accommodate such extreme tilt angles. It also enables panoramic line-scan geometry to be used to compile contour maps with photogrammetric plotters. Rectifications were digitally processed on both Viking Orbiter and Lander pictures of Mars as well as radar images taken by various radar systems. By merging digital terrain data with image data, perspective and three-dimensional views of Olympus Mons and Tithonium Chasma, also of Mars, are reconstructed through digital image processing. ?? 1985.

Digital radiographic imaging: is the dental practice ready?

PubMed

Parks, Edwin T

2008-04-01

Digital radiographic imaging is slowly, but surely, replacing film-based imaging. It has many advantages over traditional imaging, but the technology also has some drawbacks. The author presents an overview of the types of digital image receptors available, image enhancement software and the range of costs for the new technology. PRACTICE IMPLICATIONS. The expenses associated with converting to digital radiographic imaging are considerable. The purpose of this article is to provide the clinician with an overview of digital radiographic imaging technology so that he or she can be an informed consumer when evaluating the numerous digital systems in the marketplace.

Image understanding and the man-machine interface II; Proceedings of the Meeting, Los Angeles, CA, Jan. 17, 18, 1989

NASA Technical Reports Server (NTRS)

Barrett, Eamon B. (Editor); Pearson, James J. (Editor)

1989-01-01

Image understanding concepts and models, image understanding systems and applications, advanced digital processors and software tools, and advanced man-machine interfaces are among the topics discussed. Particular papers are presented on such topics as neural networks for computer vision, object-based segmentation and color recognition in multispectral images, the application of image algebra to image measurement and feature extraction, and the integration of modeling and graphics to create an infrared signal processing test bed.

A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds

PubMed Central

Sawicki, Piotr

2018-01-01

The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011. PMID:29509679

A New Approach for Inspection of Selected Geometric Parameters of a Railway Track Using Image-Based Point Clouds.

PubMed

Gabara, Grzegorz; Sawicki, Piotr

2018-03-06

The paper presents the results of testing a proposed image-based point clouds measuring method for geometric parameters determination of a railway track. The study was performed based on a configuration of digital images and reference control network. A DSLR (digital Single-Lens-Reflex) Nikon D5100 camera was used to acquire six digital images of the tested section of railway tracks. The dense point clouds and the 3D mesh model were generated with the use of two software systems, RealityCapture and PhotoScan, which have implemented different matching and 3D object reconstruction techniques: Multi-View Stereo and Semi-Global Matching, respectively. The study found that both applications could generate appropriate 3D models. Final meshes of 3D models were filtered with the MeshLab software. The CloudCompare application was used to determine the track gauge and cant for defined cross-sections, and the results obtained from point clouds by dense image matching techniques were compared with results of direct geodetic measurements. The obtained RMS difference in the horizontal (gauge) and vertical (cant) plane was RMS∆ < 0.45 mm. The achieved accuracy meets the accuracy condition of measurements and inspection of the rail tracks (error m < 1 mm), specified in the Polish branch railway instruction Id-14 (D-75) and the European technical norm EN 13848-4:2011.

Development of a digital impression procedure using photogrammetry for complete denture fabrication.

PubMed

Matsuda, Takashi; Goto, Takaharu; Kurahashi, Kosuke; Kashiwabara, Toshiya; Ichikawa, Tetsuo

We developed an innovative procedure for digitizing maxillary edentulous residual ridges with a photogrammetric system capable of estimating three-dimensional (3D) digital forms from multiple two-dimensional (2D) digital images. The aim of this study was to validate the effectiveness of the photogrammetric system. Impressions of the maxillary residual ridges of five edentulous patients were taken with four kinds of procedures: three conventional impression procedures and the photogrammetric system. Plaster models were fabricated from conventional impressions and digitized with a 3D scanner. Two 3D forms out of four forms were superimposed with 3D inspection software, and differences were evaluated using a least squares best fit algorithm. The in vitro experiment suggested that better imaging conditions were in the horizontal range of ± 15 degrees and at a vertical angle of 45 degrees. The mean difference between the photogrammetric image (Form A) and the image taken from conventional preliminarily impression (Form C) was 0.52 ± 0.22 mm. The mean difference between the image taken of final impression through a special tray (Form B) and Form C was 0.26 ± 0.06 mm. The mean difference between the image taken from conventional final impression (Form D) and Form C was 0.25 ± 0.07 mm. The difference between Forms A and C was significantly larger than the differences between Forms B and C and between Forms D and C. The results of this study suggest that obtaining digital impressions of edentulous residual ridges using a photogrammetric system is feasible and available for clinical use.

Symmetrical group theory for mathematical complexity reduction of digital holograms

NASA Astrophysics Data System (ADS)

Perez-Ramirez, A.; Guerrero-Juk, J.; Sanchez-Lara, R.; Perez-Ramirez, M.; Rodriguez-Blanco, M. A.; May-Alarcon, M.

2017-10-01

This work presents the use of mathematical group theory through an algorithm to reduce the multiplicative computational complexity in the process of creating digital holograms. An object is considered as a set of point sources using mathematical symmetry properties of both the core in the Fresnel integral and the image, where the image is modeled using group theory. This algorithm has multiplicative complexity equal to zero and an additive complexity ( k - 1) × N for the case of sparse matrices and binary images, where k is the number of pixels other than zero and N is the total points in the image.

Accuracy of Digital Impressions and Fitness of Single Crowns Based on Digital Impressions

PubMed Central

Yang, Xin; Lv, Pin; Liu, Yihong; Si, Wenjie; Feng, Hailan

2015-01-01

In this study, the accuracy (precision and trueness) of digital impressions and the fitness of single crowns manufactured based on digital impressions were evaluated. #14-17 epoxy resin dentitions were made, while full-crown preparations of extracted natural teeth were embedded at #16. (1) To assess precision, deviations among repeated scan models made by intraoral scanner TRIOS and MHT and model scanner D700 and inEos were calculated through best-fit algorithm and three-dimensional (3D) comparison. Root mean square (RMS) and color-coded difference images were offered. (2) To assess trueness, micro computed tomography (micro-CT) was used to get the reference model (REF). Deviations between REF and repeated scan models (from (1)) were calculated. (3) To assess fitness, single crowns were manufactured based on TRIOS, MHT, D700 and inEos scan models. The adhesive gaps were evaluated under stereomicroscope after cross-sectioned. Digital impressions showed lower precision and better trueness. Except for MHT, the means of RMS for precision were lower than 10 μm. Digital impressions showed better internal fitness. Fitness of single crowns based on digital impressions was up to clinical standard. Digital impressions could be an alternative method for single crowns manufacturing. PMID:28793417

The COST Action IC0604 "Telepathology Network in Europe" (EURO-TELEPATH).

PubMed

García-Rojo, Marcial; Gonçalves, Luís; Blobel, Bernd

2012-01-01

The COST Action IC0604 "Telepathology Network in Europe" (EURO-TELEPATH) is a European COST Action that has been running from 2007 to 2011. COST Actions are funded by the COST (European Cooperation in the field of Scientific and Technical Research) Agency, supported by the Seventh Framework Programme for Research and Technological Development (FP7), of the European Union. EURO-TELEPATH's main objectives were evaluating and validating the common technological framework and communication standards required to access, transmit and manage digital medical records by pathologists and other medical professionals in a networked environment. The project was organized in four working groups. orking Group 1 "Business modeling in pathology" has designed main pathology processes - Frozen Study, Formalin Fixed Specimen Study, Telepathology, Cytology, and Autopsy -using Business Process Modeling Notation (BPMN). orking Group 2 "Informatics standards in pathology" has been dedicated to promoting the development and application of informatics standards in pathology, collaborating with Integrating the Healthcare Enterprise (IHE), Digital Imaging and Communications in Medicine (DICOM), Health Level Seven (HL7), and other standardization bodies. Working Group 3 "Images: Analysis, Processing, Retrieval and Management" worked on the use of virtual or digital slides that are fostering the use of image processing and analysis in pathology not only for research purposes, but also in daily practice. Working Group 4 "Technology and Automation in Pathology" was focused on studying the adequacy of current existing technical solutions, including, e.g., the quality of images obtained by slide scanners, or the efficiency of image analysis applications. Major outcome of this action are the collaboration with international health informatics standardization bodies to foster the development of standards for digital pathology, offering a new approach for workflow analysis, based in business process modeling. Health terminology standardization research has become a topic of high interest. Future research work should focus on standardization of automatic image analysis and tissue microarrays imaging.

Dual-energy contrast-enhanced digital mammography (DE-CEDM): optimization on digital subtraction with practical x-ray low/high-energy spectra

NASA Astrophysics Data System (ADS)

Chen, Biao; Jing, Zhenxue; Smith, Andrew P.; Parikh, Samir; Parisky, Yuri

2006-03-01

Dual-energy contrast enhanced digital mammography (DE-CEDM), which is based upon the digital subtraction of low/high-energy image pairs acquired before/after the administration of contrast agents, may provide physicians physiologic and morphologic information of breast lesions and help characterize their probability of malignancy. This paper proposes to use only one pair of post-contrast low / high-energy images to obtain digitally subtracted dual-energy contrast-enhanced images with an optimal weighting factor deduced from simulated characteristics of the imaging chain. Based upon our previous CEDM framework, quantitative characteristics of the materials and imaging components in the x-ray imaging chain, including x-ray tube (tungsten) spectrum, filters, breast tissues / lesions, contrast agents (non-ionized iodine solution), and selenium detector, were systemically modeled. Using the base-material (polyethylene-PMMA) decomposition method based on entrance low / high-energy x-ray spectra and breast thickness, the optimal weighting factor was calculated to cancel the contrast between fatty and glandular tissues while enhancing the contrast of iodized lesions. By contrast, previous work determined the optimal weighting factor through either a calibration step or through acquisition of a pre-contrast low/high-energy image pair. Computer simulations were conducted to determine weighting factors, lesions' contrast signal values, and dose levels as functions of x-ray techniques and breast thicknesses. Phantom and clinical feasibility studies were performed on a modified Selenia full field digital mammography system to verify the proposed method and computer-simulated results. The resultant conclusions from the computer simulations and phantom/clinical feasibility studies will be used in the upcoming clinical study.

49 CFR 384.227 - Record of digital image or photograph.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 5 2014-10-01 2014-10-01 false Record of digital image or photograph. 384.227... § 384.227 Record of digital image or photograph. The State must: (a) Record the digital color image or.... The digital color image or photograph or black and white laser engraved photograph must either be made...

49 CFR 384.227 - Record of digital image or photograph.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 5 2013-10-01 2013-10-01 false Record of digital image or photograph. 384.227... § 384.227 Record of digital image or photograph. The State must: (a) Record the digital color image or.... The digital color image or photograph or black and white laser engraved photograph must either be made...

49 CFR 384.227 - Record of digital image or photograph.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 5 2011-10-01 2011-10-01 false Record of digital image or photograph. 384.227... § 384.227 Record of digital image or photograph. The State must: (a) Record the digital color image or.... The digital color image or photograph or black and white laser engraved photograph must either be made...

49 CFR 384.227 - Record of digital image or photograph.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 5 2012-10-01 2012-10-01 false Record of digital image or photograph. 384.227... § 384.227 Record of digital image or photograph. The State must: (a) Record the digital color image or.... The digital color image or photograph or black and white laser engraved photograph must either be made...

Validation of model-based deformation correction in image-guided liver surgery via tracked intraoperative ultrasound: preliminary method and results

NASA Astrophysics Data System (ADS)

Clements, Logan W.; Collins, Jarrod A.; Wu, Yifei; Simpson, Amber L.; Jarnagin, William R.; Miga, Michael I.

2015-03-01

Soft tissue deformation represents a significant error source in current surgical navigation systems used for open hepatic procedures. While numerous algorithms have been proposed to rectify the tissue deformation that is encountered during open liver surgery, clinical validation of the proposed methods has been limited to surface based metrics and sub-surface validation has largely been performed via phantom experiments. Tracked intraoperative ultrasound (iUS) provides a means to digitize sub-surface anatomical landmarks during clinical procedures. The proposed method involves the validation of a deformation correction algorithm for open hepatic image-guided surgery systems via sub-surface targets digitized with tracked iUS. Intraoperative surface digitizations were acquired via a laser range scanner and an optically tracked stylus for the purposes of computing the physical-to-image space registration within the guidance system and for use in retrospective deformation correction. Upon completion of surface digitization, the organ was interrogated with a tracked iUS transducer where the iUS images and corresponding tracked locations were recorded. After the procedure, the clinician reviewed the iUS images to delineate contours of anatomical target features for use in the validation procedure. Mean closest point distances between the feature contours delineated in the iUS images and corresponding 3-D anatomical model generated from the preoperative tomograms were computed to quantify the extent to which the deformation correction algorithm improved registration accuracy. The preliminary results for two patients indicate that the deformation correction method resulted in a reduction in target error of approximately 50%.

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

PubMed

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.

Steepness of Slopes at the Luna-Glob Landing Sites: Estimating by the Shaded Area Percentage in the LROC NAC Images

NASA Astrophysics Data System (ADS)

Krasilnikov, S. S.; Basilevsky, A. T.; Ivanov, M. A.; Abdrakhimov, A. M.; Kokhanov, A. A.

2018-03-01

The paper presents estimates of the occurrence probability of slopes, whose steep surfaces could be dangerous for the landing of the Luna-Glob descent probe ( Luna-25) given the baseline of the span between the landing pads ( 3.5 m), for five potential landing ellipses. As a rule, digital terrain models built from stereo pairs of high-resolution images (here, the images taken by the Narrow Angle Camera onboard the Lunar Reconnaissance Orbiter (LROC NAC)) are used in such cases. However, the planned landing sites are at high latitudes (67°-74° S), which makes it impossible to build digital terrain models, since the difference in the observation angle of the overlapping images is insufficient at these latitudes. Because of this, to estimate the steepness of slopes, we considered the interrelation between the shaded area percentage in the image and the Sun angle over horizon at the moment of imaging. For five proposed landing ellipses, the LROC NAC images (175 images in total) with a resolution from 0.4 to 1.2 m/pixel were analyzed. From the results of the measurements in each of the ellipses, the dependence of the shaded area percentage on the solar angle were built, which was converted to the occurrence probability of slopes. For this, the data on the Apollo 16 landing region ware used, which is covered by both the LROC NAC images and the digital terrain model with high resolution. As a result, the occurrence probability of slopes with different steepness has been estimated on the baseline of 3.5 m for five landing ellipses according to the steepness categories of <7°, 7°-10°, 10°-15°, 15°-20°, and >20°.

Large scale digital atlases in neuroscience

NASA Astrophysics Data System (ADS)

Hawrylycz, M.; Feng, D.; Lau, C.; Kuan, C.; Miller, J.; Dang, C.; Ng, L.

2014-03-01

Imaging in neuroscience has revolutionized our current understanding of brain structure, architecture and increasingly its function. Many characteristics of morphology, cell type, and neuronal circuitry have been elucidated through methods of neuroimaging. Combining this data in a meaningful, standardized, and accessible manner is the scope and goal of the digital brain atlas. Digital brain atlases are used today in neuroscience to characterize the spatial organization of neuronal structures, for planning and guidance during neurosurgery, and as a reference for interpreting other data modalities such as gene expression and connectivity data. The field of digital atlases is extensive and in addition to atlases of the human includes high quality brain atlases of the mouse, rat, rhesus macaque, and other model organisms. Using techniques based on histology, structural and functional magnetic resonance imaging as well as gene expression data, modern digital atlases use probabilistic and multimodal techniques, as well as sophisticated visualization software to form an integrated product. Toward this goal, brain atlases form a common coordinate framework for summarizing, accessing, and organizing this knowledge and will undoubtedly remain a key technology in neuroscience in the future. Since the development of its flagship project of a genome wide image-based atlas of the mouse brain, the Allen Institute for Brain Science has used imaging as a primary data modality for many of its large scale atlas projects. We present an overview of Allen Institute digital atlases in neuroscience, with a focus on the challenges and opportunities for image processing and computation.

Dynamic Chest Image Analysis: Evaluation of Model-Based Pulmonary Perfusion Analysis With Pyramid Images

DTIC Science & Technology

2001-10-25

Image Analysis aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the Dynamic Pulmonary Imaging technique 18,5,17,6. We have proposed and evaluated a multiresolutional method with an explicit ventilation model based on pyramid images for ventilation analysis. We have further extended the method for ventilation analysis to pulmonary perfusion. This paper focuses on the clinical evaluation of our method for

The AAPM/RSNA physics tutorial for residents: digital fluoroscopy.

PubMed

Pooley, R A; McKinney, J M; Miller, D A

2001-01-01

A digital fluoroscopy system is most commonly configured as a conventional fluoroscopy system (tube, table, image intensifier, video system) in which the analog video signal is converted to and stored as digital data. Other methods of acquiring the digital data (eg, digital or charge-coupled device video and flat-panel detectors) will become more prevalent in the future. Fundamental concepts related to digital imaging in general include binary numbers, pixels, and gray levels. Digital image data allow the convenient use of several image processing techniques including last image hold, gray-scale processing, temporal frame averaging, and edge enhancement. Real-time subtraction of digital fluoroscopic images after injection of contrast material has led to widespread use of digital subtraction angiography (DSA). Additional image processing techniques used with DSA include road mapping, image fade, mask pixel shift, frame summation, and vessel size measurement. Peripheral angiography performed with an automatic moving table allows imaging of the peripheral vasculature with a single contrast material injection.

A software to digital image processing to be used in the voxel phantom development.

PubMed

Vieira, J W; Lima, F R A

2009-11-15

Anthropomorphic models used in computational dosimetry, also denominated phantoms, are based on digital images recorded from scanning of real people by Computed Tomography (CT) or Magnetic Resonance Imaging (MRI). The voxel phantom construction requests computational processing for transformations of image formats, to compact two-dimensional (2-D) images forming of three-dimensional (3-D) matrices, image sampling and quantization, image enhancement, restoration and segmentation, among others. Hardly the researcher of computational dosimetry will find all these available abilities in single software, and almost always this difficulty presents as a result the decrease of the rhythm of his researches or the use, sometimes inadequate, of alternative tools. The need to integrate the several tasks mentioned above to obtain an image that can be used in an exposure computational model motivated the development of the Digital Image Processing (DIP) software, mainly to solve particular problems in Dissertations and Thesis developed by members of the Grupo de Pesquisa em Dosimetria Numérica (GDN/CNPq). Because of this particular objective, the software uses the Portuguese idiom in their implementations and interfaces. This paper presents the second version of the DIP, whose main changes are the more formal organization on menus and menu items, and menu for digital image segmentation. Currently, the DIP contains the menus Fundamentos, Visualizações, Domínio Espacial, Domínio de Frequências, Segmentações and Estudos. Each menu contains items and sub-items with functionalities that, usually, request an image as input and produce an image or an attribute in the output. The DIP reads edits and writes binary files containing the 3-D matrix corresponding to a stack of axial images from a given geometry that can be a human body or other volume of interest. It also can read any type of computational image and to make conversions. When the task involves only an output image, this is saved as a JPEG file in the Windows default; when it involves an image stack, the output binary file is denominated SGI (Simulações Gráficas Interativas (Interactive Graphic Simulations), an acronym already used in other publications of the GDN/CNPq.

Reconstruction of measurable three-dimensional point cloud model based on large-scene archaeological excavation sites

NASA Astrophysics Data System (ADS)

Zhang, Chun-Sen; Zhang, Meng-Meng; Zhang, Wei-Xing

2017-01-01

This paper outlines a low-cost, user-friendly photogrammetric technique with nonmetric cameras to obtain excavation site digital sequence images, based on photogrammetry and computer vision. Digital camera calibration, automatic aerial triangulation, image feature extraction, image sequence matching, and dense digital differential rectification are used, combined with a certain number of global control points of the excavation site, to reconstruct the high precision of measured three-dimensional (3-D) models. Using the acrobatic figurines in the Qin Shi Huang mausoleum excavation as an example, our method solves the problems of little base-to-height ratio, high inclination, unstable altitudes, and significant ground elevation changes affecting image matching. Compared to 3-D laser scanning, the 3-D color point cloud obtained by this method can maintain the same visual result and has advantages of low project cost, simple data processing, and high accuracy. Structure-from-motion (SfM) is often used to reconstruct 3-D models of large scenes and has lower accuracy if it is a reconstructed 3-D model of a small scene at close range. Results indicate that this method quickly achieves 3-D reconstruction of large archaeological sites and produces heritage site distribution of orthophotos providing a scientific basis for accurate location of cultural relics, archaeological excavations, investigation, and site protection planning. This proposed method has a comprehensive application value.

Color model comparative analysis for breast cancer diagnosis using H and E stained images

NASA Astrophysics Data System (ADS)

Li, Xingyu; Plataniotis, Konstantinos N.

2015-03-01

Digital cancer diagnosis is a research realm where signal processing techniques are used to analyze and to classify color histopathology images. Different from grayscale image analysis of magnetic resonance imaging or X-ray, colors in histopathology images convey large amount of histological information and thus play significant role in cancer diagnosis. Though color information is widely used in histopathology works, as today, there is few study on color model selections for feature extraction in cancer diagnosis schemes. This paper addresses the problem of color space selection for digital cancer classification using H and E stained images, and investigates the effectiveness of various color models (RGB, HSV, CIE L*a*b*, and stain-dependent H and E decomposition model) in breast cancer diagnosis. Particularly, we build a diagnosis framework as a comparison benchmark and take specific concerns of medical decision systems into account in evaluation. The evaluation methodologies include feature discriminate power evaluation and final diagnosis performance comparison. Experimentation on a publicly accessible histopathology image set suggests that the H and E decomposition model outperforms other assessed color spaces. For reasons behind various performance of color spaces, our analysis via mutual information estimation demonstrates that color components in the H and E model are less dependent, and thus most feature discriminate power is collected in one channel instead of spreading out among channels in other color spaces.

Detecting Copy Move Forgery In Digital Images

NASA Astrophysics Data System (ADS)

Gupta, Ashima; Saxena, Nisheeth; Vasistha, S. K.

2012-03-01

In today's world several image manipulation software's are available. Manipulation of digital images has become a serious problem nowadays. There are many areas like medical imaging, digital forensics, journalism, scientific publications, etc, where image forgery can be done very easily. To determine whether a digital image is original or doctored is a big challenge. To find the marks of tampering in a digital image is a challenging task. The detection methods can be very useful in image forensics which can be used as a proof for the authenticity of a digital image. In this paper we propose the method to detect region duplication forgery by dividing the image into overlapping block and then perform searching to find out the duplicated region in the image.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features.

PubMed

McDonald, Linda S; Panozzo, Joseph F; Salisbury, Phillip A; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features

PubMed Central

McDonald, Linda S.; Panozzo, Joseph F.; Salisbury, Phillip A.; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective. PMID:27176469

Multiscale image processing and antiscatter grids in digital radiography.

PubMed

Lo, Winnie Y; Hornof, William J; Zwingenberger, Allison L; Robertson, Ian D

2009-01-01

Scatter radiation is a source of noise and results in decreased signal-to-noise ratio and thus decreased image quality in digital radiography. We determined subjectively whether a digitally processed image made without a grid would be of similar quality to an image made with a grid but without image processing. Additionally the effects of exposure dose and of a using a grid with digital radiography on overall image quality were studied. Thoracic and abdominal radiographs of five dogs of various sizes were made. Four acquisition techniques were included (1) with a grid, standard exposure dose, digital image processing; (2) without a grid, standard exposure dose, digital image processing; (3) without a grid, half the exposure dose, digital image processing; and (4) with a grid, standard exposure dose, no digital image processing (to mimic a film-screen radiograph). Full-size radiographs as well as magnified images of specific anatomic regions were generated. Nine reviewers rated the overall image quality subjectively using a five-point scale. All digitally processed radiographs had higher overall scores than nondigitally processed radiographs regardless of patient size, exposure dose, or use of a grid. The images made at half the exposure dose had a slightly lower quality than those made at full dose, but this was only statistically significant in magnified images. Using a grid with digital image processing led to a slight but statistically significant increase in overall quality when compared with digitally processed images made without a grid but whether this increase in quality is clinically significant is unknown.

Documenting Bronze Age Akrotiri on Thera Using Laser Scanning, Image-Based Modelling and Geophysical Prospection

NASA Astrophysics Data System (ADS)

Trinks, I.; Wallner, M.; Kucera, M.; Verhoeven, G.; Torrejón Valdelomar, J.; Löcker, K.; Nau, E.; Sevara, C.; Aldrian, L.; Neubauer, E.; Klein, M.

2017-02-01

The excavated architecture of the exceptional prehistoric site of Akrotiri on the Greek island of Thera/Santorini is endangered by gradual decay, damage due to accidents, and seismic shocks, being located on an active volcano in an earthquake-prone area. Therefore, in 2013 and 2014 a digital documentation project has been conducted with support of the National Geographic Society in order to generate a detailed digital model of Akrotiri's architecture using terrestrial laser scanning and image-based modeling. Additionally, non-invasive geophysical prospection has been tested in order to investigate its potential to explore and map yet buried archaeological remains. This article describes the project and the generated results.

The National Institutes of Health Clinical Center Digital Imaging Network, Picture Archival and Communication System, and Radiology Information System.

PubMed

Goldszal, A F; Brown, G K; McDonald, H J; Vucich, J J; Staab, E V

2001-06-01

In this work, we describe the digital imaging network (DIN), picture archival and communication system (PACS), and radiology information system (RIS) currently being implemented at the Clinical Center, National Institutes of Health (NIH). These systems are presently in clinical operation. The DIN is a redundant meshed network designed to address gigabit density and expected high bandwidth requirements for image transfer and server aggregation. The PACS projected workload is 5.0 TB of new imaging data per year. Its architecture consists of a central, high-throughput Digital Imaging and Communications in Medicine (DICOM) data repository and distributed redundant array of inexpensive disks (RAID) servers employing fiber-channel technology for immediate delivery of imaging data. On demand distribution of images and reports to clinicians and researchers is accomplished via a clustered web server. The RIS follows a client-server model and provides tools to order exams, schedule resources, retrieve and review results, and generate management reports. The RIS-hospital information system (HIS) interfaces include admissions, discharges, and transfers (ATDs)/demographics, orders, appointment notifications, doctors update, and results.

Unified Digital Image Display And Processing System

NASA Astrophysics Data System (ADS)

Horii, Steven C.; Maguire, Gerald Q.; Noz, Marilyn E.; Schimpf, James H.

1981-11-01

Our institution like many others, is faced with a proliferation of medical imaging techniques. Many of these methods give rise to digital images (e.g. digital radiography, computerized tomography (CT) , nuclear medicine and ultrasound). We feel that a unified, digital system approach to image management (storage, transmission and retrieval), image processing and image display will help in integrating these new modalities into the present diagnostic radiology operations. Future techniques are likely to employ digital images, so such a system could readily be expanded to include other image sources. We presently have the core of such a system. We can both view and process digital nuclear medicine (conventional gamma camera) images, positron emission tomography (PET) and CT images on a single system. Images from our recently installed digital radiographic unit can be added. Our paper describes our present system, explains the rationale for its configuration, and describes the directions in which it will expand.

Positive dental identification using tooth anatomy and digital superimposition.

PubMed

Johansen, Raymond J; Michael Bowers, C

2013-03-01

Dental identification of unknown human remains continues to be a relevant and reliable adjunct to forensic investigations. The advent of genomic and mitochondrial DNA procedures has not displaced the practical use of dental and related osseous structures remaining after destructive incidents that can render human remains unrecognizable, severely burned, and fragmented. The ability to conclusively identify victims of accident and homicide is based on the availability of antemortem records containing substantial and unambiguous proof of dental and related osseous characteristics. This case report documents the use of digital comparative analysis of antemortem dental models and postmortem dentition, to determine a dental identification. Images of dental models were digitally analyzed using Adobe Photoshop(TM) software. Individual tooth anatomy was compared between the antemortem and postmortem images. Digital superimposition techniques were also used for the comparison. With the absence of antemortem radiographs, this method proved useful to reach a positive identification in this case. © 2012 American Academy of Forensic Sciences.

The role of digital imaging and communications in medicine in an evolving healthcare computing environment: the model is the message.

PubMed

Bidgood, W D; alSafadi, Y; Tucker, M; Prior, F; Hagan, G; Mattison, J E

1998-02-01

The decision to use Digital Imaging and Communications in Medicine (DICOM), Health Level 7 (HL7), a common object broker such as the Common Object Request Brokering Architecture (CORBA) or ActiveX (Microsoft Corp, Redmond, WA) or any other protocol for the transfer of DICOM data depends on the requirements of a particular implementation. The selection of protocol is independent of the information model. Our goal as message standards developers is to design a data interchange infrastructure that will faithfully convey the computer-based patient record and make it available to authorized health care providers when and where it is needed for patient care. DICOM accurately and expressively represents the clinically significant properties of images and the semantics of image-related information. The DICOM data model is small and well-defined. The model can be expressed in Standard Generalized Markup Language (SGML) or Object Management Group Interface Definition Language or other common syntax-and can be implemented using any reliable communications protocol. Therefore our opinion is that the DICOM semantic data model should serve as the basis for a logically equivalent set of specifications in HL7, CORBA, ActiveX, and SGML for the interchange of biomedical images and image-related information.

A digital rat atlas of sectional anatomy

NASA Astrophysics Data System (ADS)

Yu, Li; Liu, Qian; Bai, Xueling; Liao, Yinping; Luo, Qingming; Gong, Hui

2006-09-01

This paper describes a digital rat alias of sectional anatomy made by milling. Two healthy Sprague-Dawley (SD) rat weighing 160-180 g were used for the generation of this atlas. The rats were depilated completely, then euthanized by Co II. One was via vascular perfusion, the other was directly frozen at -85 °C over 24 hour. After that, the frozen specimens were transferred into iron molds for embedding. A 3% gelatin solution colored blue was used to fill the molds and then frozen at -85 °C for one or two days. The frozen specimen-blocks were subsequently sectioned on the cryosection-milling machine in a plane oriented approximately transverse to the long axis of the body. The surface of specimen-blocks were imaged by a scanner and digitalized into 4,600 x2,580 x 24 bit array through a computer. Finally 9,475 sectional images (arterial vessel were not perfused) and 1,646 sectional images (arterial vessel were perfused) were captured, which made the volume of the digital atlas up to 369.35 Gbyte. This digital rat atlas is aimed at the whole rat and the rat arterial vessels are also presented. We have reconstructed this atlas. The information from the two-dimensional (2-D) images of serial sections and three-dimensional (3-D) surface model all shows that the digital rat atlas we constructed is high quality. This work lays the foundation for a deeper study of digital rat.

Demonstration of three gorges archaeological relics based on 3D-visualization technology

NASA Astrophysics Data System (ADS)

Xu, Wenli

2015-12-01

This paper mainly focuses on the digital demonstration of three gorges archeological relics to exhibit the achievements of the protective measures. A novel and effective method based on 3D-visualization technology, which includes large-scaled landscape reconstruction, virtual studio, and virtual panoramic roaming, etc, is proposed to create a digitized interactive demonstration system. The method contains three stages: pre-processing, 3D modeling and integration. Firstly, abundant archaeological information is classified according to its history and geographical information. Secondly, build up a 3D-model library with the technology of digital images processing and 3D modeling. Thirdly, use virtual reality technology to display the archaeological scenes and cultural relics vividly and realistically. The present work promotes the application of virtual reality to digital projects and enriches the content of digital archaeology.

Images of Women in Sport and Physical Education: Creating and Integrating a Digital Collection into the Classroom

ERIC Educational Resources Information Center

Gustafson, Julia Chance; Meese, Brenda L.

2016-01-01

This article will highlight key points in the process of collaboration, creation, and assessment of a digital collection intended to be used initially as a classroom tool, in addition to being a model of digital scholarship that can be used for research from anywhere in the world. This project originated from a class assignment for a course in…

s48-e-007

NASA Image and Video Library

2013-01-15

S48-E-007 (12 Sept 1991) --- Astronaut James F. Buchli, mission specialist, catches snack crackers as they float in the weightless environment of the earth-orbiting Discovery. This image was transmitted by the Electronic Still Camera, Development Test Objective (DTO) 648. The ESC is making its initial appearance on a Space Shuttle flight. Electronic still photography is a new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital image is stored on removable hard disks or small optical disks, and can be converted to a format suitable for downlink transmission or enhanced using image processing software. The Electronic Still Camera (ESC) was developed by the Man- Systems Division at the Johnson Space Center and is the first model in a planned evolutionary development leading to a family of high-resolution digital imaging devices. H. Don Yeates, JSC's Man-Systems Division, is program manager for the ESC. THIS IS A SECOND GENERATION PRINT MADE FROM AN ELECTRONICALLY PRODUCED NEGATIVE

Coastal Bathymetry Using Satellite Observation in Support of Intelligence Preparation of the Environment

DTIC Science & Technology

2011-09-01

Sensor ..........................................................................25 2. The Environment for Visualizing Images 4.7 (ENVI......DEM Digital Elevation Model ENVI Environment for Visualizing Images HADR Humanitarian and Disaster Relief IfSAR Interferometric Synthetic Aperture

Topography of Vesta Surface

NASA Image and Video Library

2011-08-26

This view of the topography of asteroid Vesta surface is composed of several images obtained with the framing camera on NASA Dawn spacecraft on August 6, 2011. The image mosaic is shown superimposed on a digital terrain model.

The impact of digital imaging in the field of cytopathology.

PubMed

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.

Incorporating digital imaging into dental hygiene practice.

PubMed

Saxe, M J; West, D J

1997-01-01

The objective of this paper is to describe digital imaging technology: available modalities, scientific imaging process, advantages and limitations, and applications to dental hygiene practice. Advances in technology have created innovative imaging modalities for intraoral radiography that eliminate film as the traditional image receptor. Digital imaging generates instantaneous radiographic images on a display monitor following exposure. Advantages include lower patient exposure per image and elimination of film processing. Digital imaging enhances diagnostic capabilities and, therefore, treatment decisions by the oral healthcare provider. Utilization of digital imaging technology for intraoral radiography will advance the practice of dental hygiene. Although spatial resolution is inferior to conventional film, digital imaging provides adequate resolution to diagnose oral diseases. Dental hygienists must evaluate new technologies in radiography to continue providing quality care while reducing patient exposure to ionizing radiation.

Radiometry simulation within the end-to-end simulation tool SENSOR

NASA Astrophysics Data System (ADS)

Wiest, Lorenz; Boerner, Anko

2001-02-01

12 An end-to-end simulation is a valuable tool for sensor system design, development, optimization, testing, and calibration. This contribution describes the radiometry module of the end-to-end simulation tool SENSOR. It features MODTRAN 4.0-based look up tables in conjunction with a cache-based multilinear interpolation algorithm to speed up radiometry calculations. It employs a linear reflectance parameterization to reduce look up table size, considers effects due to the topology of a digital elevation model (surface slope, sky view factor) and uses a reflectance class feature map to assign Lambertian and BRDF reflectance properties to the digital elevation model. The overall consistency of the radiometry part is demonstrated by good agreement between ATCOR 4-retrieved reflectance spectra of a simulated digital image cube and the original reflectance spectra used to simulate this image data cube.

[Constructing 3-dimensional colorized digital dental model assisted by digital photography].

PubMed

Ye, Hong-qiang; Liu, Yu-shu; Liu, Yun-song; Ning, Jing; Zhao, Yi-jiao; Zhou, Yong-sheng

2016-02-18

To explore a method of constructing universal 3-dimensional (3D) colorized digital dental model which can be displayed and edited in common 3D software (such as Geomagic series), in order to improve the visual effect of digital dental model in 3D software. The morphological data of teeth and gingivae were obtained by intra-oral scanning system (3Shape TRIOS), constructing 3D digital dental models. The 3D digital dental models were exported as STL files. Meanwhile, referring to the accredited photography guide of American Academy of Cosmetic Dentistry (AACD), five selected digital photographs of patients'teeth and gingivae were taken by digital single lens reflex camera (DSLR) with the same exposure parameters (except occlusal views) to capture the color data. In Geomagic Studio 2013, after STL file of 3D digital dental model being imported, digital photographs were projected on 3D digital dental model with corresponding position and angle. The junctions of different photos were carefully trimmed to get continuous and natural color transitions. Then the 3D colorized digital dental model was constructed, which was exported as OBJ file or WRP file which was a special file for software of Geomagic series. For the purpose of evaluating the visual effect of the 3D colorized digital model, a rating scale on color simulation effect in views of patients'evaluation was used. Sixteen patients were recruited and their scores on colored and non-colored digital dental models were recorded. The data were analyzed using McNemar-Bowker test in SPSS 20. Universal 3D colorized digital dental model with better color simulation was constructed based on intra-oral scanning and digital photography. For clinical application, the 3D colorized digital dental models, combined with 3D face images, were introduced into 3D smile design of aesthetic rehabilitation, which could improve the patients' cognition for the esthetic digital design and virtual prosthetic effect. Universal 3D colorized digital dental model with better color simulation can be constructed assisted by 3D dental scanning system and digital photography. In clinical practice, the communication between dentist and patients could be improved assisted by the better visual perception since the colorized 3D digital dental models with better color simulation effect.

[COMPARISON OF FEMORAL CONDYLAR TWIST ANGLE IN THREE DIMENSIONAL RECONSTRUCTION DIGITAL MODELS OF KNEE JOINT BASED ON TWO DIMENSIONAL IMAGES OF MRI AND CT].

PubMed

Huang, Zan; Li, Yanlin; Hu, Meng; Li, Jian; You, Zhimin; Wang, Guoliang; He, Chuan

2015-02-01

To study the difference of femoral condylar twist angle (CTA) measurement in three dimensional (3-D) reconstruction digital models of human knee joint based on the two dimensional (2-D) images of MRI and CT so as to provide a reference for selecting the best method of CTA measurement in preoperative design for the femoral prosthesis rotational position. The CTA of 10 human cadaveric knee joint was measured in 3-D digital models based on MRI (group A), in 3-D digital models based on CT (group B), in the cadaveric knee joint with cartilage (group C), and in the cadaveric knee joint without cartilage (group D), respectively. The statistical analysis of the differences was made among the measurements of the CTA. The CTA values measured in 3-D digital models were (6.43 ± 0.53) degrees in group A and (3.31 ± 1.07) degrees in group B, showing significant difference (t = 10.235, P = 0.000). The CTA values measured in the cadaveric knee joint were (5.21 ± 1.28) degrees in group C and (3.33 ± 1.12) degrees in group D, showing significant difference (t = 5.770, P = 0.000). There was significant difference in the CTA values between group B and group C (t = 5.779, P = 0.000), but no significant difference was found between group A and group C (t = 3.219, P = 0.110). The CTA values measured in the 3-D digital models based on MRI are closer to the actual values measured in the knee joint with cartilage, and benefit for preoperative plan.

Refraction error correction for deformation measurement by digital image correlation at elevated temperature

NASA Astrophysics Data System (ADS)

Su, Yunquan; Yao, Xuefeng; Wang, Shen; Ma, Yinji

2017-03-01

An effective correction model is proposed to eliminate the refraction error effect caused by an optical window of a furnace in digital image correlation (DIC) deformation measurement under high-temperature environment. First, a theoretical correction model with the corresponding error correction factor is established to eliminate the refraction error induced by double-deck optical glass in DIC deformation measurement. Second, a high-temperature DIC experiment using a chromium-nickel austenite stainless steel specimen is performed to verify the effectiveness of the correction model by the correlation calculation results under two different conditions (with and without the optical glass). Finally, both the full-field and the divisional displacement results with refraction influence are corrected by the theoretical model and then compared to the displacement results extracted from the images without refraction influence. The experimental results demonstrate that the proposed theoretical correction model can effectively improve the measurement accuracy of DIC method by decreasing the refraction errors from measured full-field displacements under high-temperature environment.

Image compression system and method having optimized quantization tables

NASA Technical Reports Server (NTRS)

Ratnakar, Viresh (Inventor); Livny, Miron (Inventor)

1998-01-01

A digital image compression preprocessor for use in a discrete cosine transform-based digital image compression device is provided. The preprocessor includes a gathering mechanism for determining discrete cosine transform statistics from input digital image data. A computing mechanism is operatively coupled to the gathering mechanism to calculate a image distortion array and a rate of image compression array based upon the discrete cosine transform statistics for each possible quantization value. A dynamic programming mechanism is operatively coupled to the computing mechanism to optimize the rate of image compression array against the image distortion array such that a rate-distortion-optimal quantization table is derived. In addition, a discrete cosine transform-based digital image compression device and a discrete cosine transform-based digital image compression and decompression system are provided. Also, a method for generating a rate-distortion-optimal quantization table, using discrete cosine transform-based digital image compression, and operating a discrete cosine transform-based digital image compression and decompression system are provided.

Advanced digital image archival system using MPEG technologies

NASA Astrophysics Data System (ADS)

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.

Validity and reliability of intraoral scanners compared to conventional gypsum models measurements: a systematic review.

PubMed

Aragón, Mônica L C; Pontes, Luana F; Bichara, Lívia M; Flores-Mir, Carlos; Normando, David

2016-08-01

The development of 3D technology and the trend of increasing the use of intraoral scanners in dental office routine lead to the need for comparisons with conventional techniques. To determine if intra- and inter-arch measurements from digital dental models acquired by an intraoral scanner are as reliable and valid as the similar measurements achieved from dental models obtained through conventional intraoral impressions. An unrestricted electronic search of seven databases until February 2015. Studies that focused on the accuracy and reliability of images obtained from intraoral scanners compared to images obtained from conventional impressions. After study selection the QUADAS risk of bias assessment tool for diagnostic studies was used to assess the risk of bias (RoB) among the included studies. Four articles were included in the qualitative synthesis. The scanners evaluated were OrthoProof, Lava, iOC intraoral, Lava COS, iTero and D250. These studies evaluated the reliability of tooth widths, Bolton ratio measurements, and image superimposition. Two studies were classified as having low RoB; one had moderate RoB and the remaining one had high RoB. Only one study evaluated the time required to complete clinical procedures and patient's opinion about the procedure. Patients reported feeling more comfortable with the conventional dental impression method. Associated costs were not considered in any of the included study. Inter- and intra-arch measurements from digital models produced from intraoral scans appeared to be reliable and accurate in comparison to those from conventional impressions. This assessment only applies to the intraoral scanners models considered in the finally included studies. Digital models produced by intraoral scan eliminate the need of impressions materials; however, currently, longer time is needed to take the digital images. PROSPERO (CRD42014009702). None. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

A novel interpolation approach for the generation of 3D-geometric digital bone models from image stacks

PubMed Central

Mittag, U.; Kriechbaumer, A.; Rittweger, J.

2017-01-01

The authors propose a new 3D interpolation algorithm for the generation of digital geometric 3D-models of bones from existing image stacks obtained by peripheral Quantitative Computed Tomography (pQCT) or Magnetic Resonance Imaging (MRI). The technique is based on the interpolation of radial gray value profiles of the pQCT cross sections. The method has been validated by using an ex-vivo human tibia and by comparing interpolated pQCT images with images from scans taken at the same position. A diversity index of <0.4 (1 meaning maximal diversity) even for the structurally complex region of the epiphysis, along with the good agreement of mineral-density-weighted cross-sectional moment of inertia (CSMI), demonstrate the high quality of our interpolation approach. Thus the authors demonstrate that this interpolation scheme can substantially improve the generation of 3D models from sparse scan sets, not only with respect to the outer shape but also with respect to the internal gray-value derived material property distribution. PMID:28574415

WE-A-17A-06: Evaluation of An Automatic Interstitial Catheter Digitization Algorithm That Reduces Treatment Planning Time and Provide Means for Adaptive Re-Planning in HDR Brachytherapy of Gynecologic Cancers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dise, J; Liang, X; Lin, L

Purpose: To evaluate an automatic interstitial catheter digitization algorithm that reduces treatment planning time and provide means for adaptive re-planning in HDR Brachytherapy of Gynecologic Cancers. Methods: The semi-automatic catheter digitization tool utilizes a region growing algorithm in conjunction with a spline model of the catheters. The CT images were first pre-processed to enhance the contrast between the catheters and soft tissue. Several seed locations were selected in each catheter for the region growing algorithm. The spline model of the catheters assisted in the region growing by preventing inter-catheter cross-over caused by air or metal artifacts. Source dwell positions frommore » day one CT scans were applied to subsequent CTs and forward calculated using the automatically digitized catheter positions. This method was applied to 10 patients who had received HDR interstitial brachytherapy on an IRB approved image-guided radiation therapy protocol. The prescribed dose was 18.75 or 20 Gy delivered in 5 fractions, twice daily, over 3 consecutive days. Dosimetric comparisons were made between automatic and manual digitization on day two CTs. Results: The region growing algorithm, assisted by the spline model of the catheters, was able to digitize all catheters. The difference between automatic and manually digitized positions was 0.8±0.3 mm. The digitization time ranged from 34 minutes to 43 minutes with a mean digitization time of 37 minutes. The bulk of the time was spent on manual selection of initial seed positions and spline parameter adjustments. There was no significance difference in dosimetric parameters between the automatic and manually digitized plans. D90% to the CTV was 91.5±4.4% for the manual digitization versus 91.4±4.4% for the automatic digitization (p=0.56). Conclusion: A region growing algorithm was developed to semi-automatically digitize interstitial catheters in HDR brachytherapy using the Syed-Neblett template. This automatic digitization tool was shown to be accurate compared to manual digitization.« less

Omniview motionless camera orientation system

NASA Technical Reports Server (NTRS)

Martin, H. Lee (Inventor); Kuban, Daniel P. (Inventor); Zimmermann, Steven D. (Inventor); Busko, Nicholas (Inventor)

2010-01-01

An apparatus and method is provided for converting digital images for use in an imaging system. The apparatus includes a data memory which stores digital data representing an image having a circular or spherical field of view such as an image captured by a fish-eye lens, a control input for receiving a signal for selecting a portion of the image, and a converter responsive to the control input for converting digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. Various methods include the steps of storing digital data representing an image having a circular or spherical field of view, selecting a portion of the image, and converting the stored digital data corresponding to the selected portion into digital data representing a planar image for subsequent display. In various embodiments, the data converter and data conversion step may use an orthogonal set of transformation algorithms.

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

PubMed

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 and optical shape representation and pattern recognition; Proceedings of the Meeting, Orlando, FL, Apr. 4-6, 1988

NASA Technical Reports Server (NTRS)

Juday, Richard D. (Editor)

1988-01-01

The present conference discusses topics in pattern-recognition correlator architectures, digital stereo systems, geometric image transformations and their applications, topics in pattern recognition, filter algorithms, object detection and classification, shape representation techniques, and model-based object recognition methods. Attention is given to edge-enhancement preprocessing using liquid crystal TVs, massively-parallel optical data base management, three-dimensional sensing with polar exponential sensor arrays, the optical processing of imaging spectrometer data, hybrid associative memories and metric data models, the representation of shape primitives in neural networks, and the Monte Carlo estimation of moment invariants for pattern recognition.

Optimizing digital elevation models (DEMs) accuracy for planning and design of mobile communication networks

NASA Astrophysics Data System (ADS)

Hassan, Mahmoud A.

2004-02-01

Digital elevation models (DEMs) are important tools in the planning, design and maintenance of mobile communication networks. This research paper proposes a method for generating high accuracy DEMs based on SPOT satellite 1A stereo pair images, ground control points (GCP) and Erdas OrthoBASE Pro image processing software. DEMs with 0.2911 m mean error were achieved for the hilly and heavily populated city of Amman. The generated DEM was used to design a mobile communication network resulted in a minimum number of radio base transceiver stations, maximum number of covered regions and less than 2% of dead zones.

Quantitative Image Restoration in Bright Field Optical Microscopy.

PubMed

Gutiérrez-Medina, Braulio; Sánchez Miranda, Manuel de Jesús

2017-11-07

Bright field (BF) optical microscopy is regarded as a poor method to observe unstained biological samples due to intrinsic low image contrast. We introduce quantitative image restoration in bright field (QRBF), a digital image processing method that restores out-of-focus BF images of unstained cells. Our procedure is based on deconvolution, using a point spread function modeled from theory. By comparing with reference images of bacteria observed in fluorescence, we show that QRBF faithfully recovers shape and enables quantify size of individual cells, even from a single input image. We applied QRBF in a high-throughput image cytometer to assess shape changes in Escherichia coli during hyperosmotic shock, finding size heterogeneity. We demonstrate that QRBF is also applicable to eukaryotic cells (yeast). Altogether, digital restoration emerges as a straightforward alternative to methods designed to generate contrast in BF imaging for quantitative analysis. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Towards objective hand hygiene technique assessment: validation of the ultraviolet-dye-based hand-rubbing quality assessment procedure.

PubMed

Lehotsky, Á; Szilágyi, L; Bánsághi, S; Szerémy, P; Wéber, G; Haidegger, T

2017-09-01

Ultraviolet spectrum markers are widely used for hand hygiene quality assessment, although their microbiological validation has not been established. A microbiology-based assessment of the procedure was conducted. Twenty-five artificial hand models underwent initial full contamination, then disinfection with UV-dyed hand-rub solution, digital imaging under UV-light, microbiological sampling and cultivation, and digital imaging of the cultivated flora were performed. Paired images of each hand model were registered by a software tool, then the UV-marked regions were compared with the pathogen-free sites pixel by pixel. Statistical evaluation revealed that the method indicates correctly disinfected areas with 95.05% sensitivity and 98.01% specificity. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

A framework for comparing different image segmentation methods and its use in studying equivalences between level set and fuzzy connectedness frameworks

PubMed Central

Ciesielski, Krzysztof Chris; Udupa, Jayaram K.

2011-01-01

In the current vast image segmentation literature, there seems to be considerable redundancy among algorithms, while there is a serious lack of methods that would allow their theoretical comparison to establish their similarity, equivalence, or distinctness. In this paper, we make an attempt to fill this gap. To accomplish this goal, we argue that: (1) every digital segmentation algorithm A should have a well defined continuous counterpart MA, referred to as its model, which constitutes an asymptotic of A when image resolution goes to infinity; (2) the equality of two such models MA and MA′ establishes a theoretical (asymptotic) equivalence of their digital counterparts A and A′. Such a comparison is of full theoretical value only when, for each involved algorithm A, its model MA is proved to be an asymptotic of A. So far, such proofs do not appear anywhere in the literature, even in the case of algorithms introduced as digitizations of continuous models, like level set segmentation algorithms. The main goal of this article is to explore a line of investigation for formally pairing the digital segmentation algorithms with their asymptotic models, justifying such relations with mathematical proofs, and using the results to compare the segmentation algorithms in this general theoretical framework. As a first step towards this general goal, we prove here that the gradient based thresholding model M∇ is the asymptotic for the fuzzy connectedness Udupa and Samarasekera segmentation algorithm used with gradient based affinity A∇. We also argue that, in a sense, M∇ is the asymptotic for the original front propagation level set algorithm of Malladi, Sethian, and Vemuri, thus establishing a theoretical equivalence between these two specific algorithms. Experimental evidence of this last equivalence is also provided. PMID:21442014

3D Reconstruction of Static Human Body with a Digital Camera

NASA Astrophysics Data System (ADS)

Remondino, Fabio

2003-01-01

Nowadays the interest in 3D reconstruction and modeling of real humans is one of the most challenging problems and a topic of great interest. The human models are used for movies, video games or ergonomics applications and they are usually created with 3D scanner devices. In this paper a new method to reconstruct the shape of a static human is presented. Our approach is based on photogrammetric techniques and uses a sequence of images acquired around a standing person with a digital still video camera or with a camcorder. First the images are calibrated and orientated using a bundle adjustment. After the establishment of a stable adjusted image block, an image matching process is performed between consecutive triplets of images. Finally the 3D coordinates of the matched points are computed with a mean accuracy of ca 2 mm by forward ray intersection. The obtained point cloud can then be triangulated to generate a surface model of the body or a virtual human model can be fitted to the recovered 3D data. Results of the 3D human point cloud with pixel color information are presented.

High-Resolution Topography of Mercury from Messenger Orbital Stereo Imaging - the Southern Hemisphere Quadrangles

NASA Astrophysics Data System (ADS)

Preusker, F.; Oberst, J.; Stark, A.; Burmeister, S.

2018-04-01

We produce high-resolution (222 m/grid element) Digital Terrain Models (DTMs) for Mercury using stereo images from the MESSENGER orbital mission. We have developed a scheme to process large numbers, typically more than 6000, images by photogrammetric techniques, which include, multiple image matching, pyramid strategy, and bundle block adjustments. In this paper, we present models for map quadrangles of the southern hemisphere H11, H12, H13, and H14.

The Characterization of a DIRSIG Simulation Environment to Support the Inter-Calibration of Spaceborne Sensors

NASA Technical Reports Server (NTRS)

Ambeau, Brittany L.; Gerace, Aaron D.; Montanaro, Matthew; McCorkel, Joel

2016-01-01

Climate change studies require long-term, continuous records that extend beyond the lifetime, and the temporal resolution, of a single remote sensing satellite sensor. The inter-calibration of spaceborne sensors is therefore desired to provide spatially, spectrally, and temporally homogeneous datasets. The Digital Imaging and Remote Sensing Image Generation (DIRSIG) tool is a first principle-based synthetic image generation model that has the potential to characterize the parameters that impact the accuracy of the inter-calibration of spaceborne sensors. To demonstrate the potential utility of the model, we compare the radiance observed in real image data to the radiance observed in simulated image from DIRSIG. In the present work, a synthetic landscape of the Algodones Sand Dunes System is created. The terrain is facetized using a 2-meter digital elevation model generated from NASA Goddard's LiDAR, Hyperspectral, and Thermal (G-LiHT) imager. The material spectra are assigned using hyperspectral measurements of sand collected from the Algodones Sand Dunes System. Lastly, the bidirectional reflectance distribution function (BRDF) properties are assigned to the modeled terrain using the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF product in conjunction with DIRSIG's Ross-Li capability. The results of this work indicate that DIRSIG is in good agreement with real image data. The potential sources of residual error are identified and the possibilities for future work are discussed..

The characterization of a DIRSIG simulation environment to support the inter-calibration of spaceborne sensors

NASA Astrophysics Data System (ADS)

Ambeau, Brittany L.; Gerace, Aaron D.; Montanaro, Matthew; McCorkel, Joel

2016-09-01

Climate change studies require long-term, continuous records that extend beyond the lifetime, and the temporal resolution, of a single remote sensing satellite sensor. The inter-calibration of spaceborne sensors is therefore desired to provide spatially, spectrally, and temporally homogeneous datasets. The Digital Imaging and Remote Sensing Image Generation (DIRSIG) tool is a first principle-based synthetic image generation model that has the potential to characterize the parameters that impact the accuracy of the inter-calibration of spaceborne sensors. To demonstrate the potential utility of the model, we compare the radiance observed in real image data to the radiance observed in simulated image from DIRSIG. In the present work, a synthetic landscape of the Algodones Sand Dunes System is created. The terrain is facetized using a 2-meter digital elevation model generated from NASA Goddard's LiDAR, Hyperspectral, and Thermal (G-LiHT) imager. The material spectra are assigned using hyperspectral measurements of sand collected from the Algodones Sand Dunes System. Lastly, the bidirectional reflectance distribution function (BRDF) properties are assigned to the modeled terrain using the Moderate Resolution Imaging Spectroradiometer (MODIS) BRDF product in conjunction with DIRSIG's Ross-Li capability. The results of this work indicate that DIRSIG is in good agreement with real image data. The potential sources of residual error are identified and the possibilities for future work are discussed.

Compressed Sensing (CS) Imaging with Wide FOV and Dynamic Magnification

DTIC Science & Technology

2011-03-14

Digital Micromirror Device (DMD) to implement the CS measurement patterns. The core component of the DMD is a 768(V)?1024(H) aluminum micromirror array...image has different curves and textures, thus has different statistical model parameters. The sampling 19 Table 2: Reconstruction of images in

Digital Imaging

NASA Technical Reports Server (NTRS)

1986-01-01

Digital Imaging is the computer processed numerical representation of physical images. Enhancement of images results in easier interpretation. Quantitative digital image analysis by Perceptive Scientific Instruments, locates objects within an image and measures them to extract quantitative information. Applications are CAT scanners, radiography, microscopy in medicine as well as various industrial and manufacturing uses. The PSICOM 327 performs all digital image analysis functions. It is based on Jet Propulsion Laboratory technology, is accurate and cost efficient.

Utility of Digital Stereo Images for Optic Disc Evaluation

PubMed Central

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 < 0.001), including improved stereo (P < 0.001), but the primary 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 < 0.0001); both the nerve fiber layer (P < 0.0001) and the paths of blood vessels on the optic disc (P < 0.0001) were best seen in grayscale. The preference for 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

An Imaging And Graphics Workstation For Image Sequence Analysis

NASA Astrophysics Data System (ADS)

Mostafavi, Hassan

1990-01-01

This paper describes an application-specific engineering workstation designed and developed to analyze imagery sequences from a variety of sources. The system combines the software and hardware environment of the modern graphic-oriented workstations with the digital image acquisition, processing and display techniques. The objective is to achieve automation and high throughput for many data reduction tasks involving metric studies of image sequences. The applications of such an automated data reduction tool include analysis of the trajectory and attitude of aircraft, missile, stores and other flying objects in various flight regimes including launch and separation as well as regular flight maneuvers. The workstation can also be used in an on-line or off-line mode to study three-dimensional motion of aircraft models in simulated flight conditions such as wind tunnels. The system's key features are: 1) Acquisition and storage of image sequences by digitizing real-time video or frames from a film strip; 2) computer-controlled movie loop playback, slow motion and freeze frame display combined with digital image sharpening, noise reduction, contrast enhancement and interactive image magnification; 3) multiple leading edge tracking in addition to object centroids at up to 60 fields per second from both live input video or a stored image sequence; 4) automatic and manual field-of-view and spatial calibration; 5) image sequence data base generation and management, including the measurement data products; 6) off-line analysis software for trajectory plotting and statistical analysis; 7) model-based estimation and tracking of object attitude angles; and 8) interface to a variety of video players and film transport sub-systems.

Automation in photogrammetry: Recent developments and applications (1972-1976)

USGS Publications Warehouse

Thompson, M.M.; Mikhail, E.M.

1976-01-01

An overview of recent developments in the automation of photogrammetry in various countries is presented. Conclusions regarding automated photogrammetry reached at the 1972 Congress in Ottawa are reviewed first as a background for examining the developments of 1972-1976. Applications are described for each country reporting significant developments. Among fifteen conclusions listed are statements concerning: the widespread practice of equipping existing stereoplotters with simple digitizers; the growing tendency to use minicomputers on-line with stereoplotters; the optimization of production of digital terrain models by progressive sampling in stereomodels; the potential of digitization of a photogrammetric model by density correlation on epipolar lines; the capabilities and economic aspects of advanced systems which permit simultaneous production of orthophotos, contours, and digital terrain models; the economy of off-line orthophoto systems; applications of digital image processing; automation by optical techniques; applications of sensors other than photographic imagery, and the role of photogrammetric phases in a completely automated cartographic system. ?? 1976.

Anatomical education and surgical simulation based on the Chinese Visible Human: a three-dimensional virtual model of the larynx region.

PubMed

Liu, Kaijun; Fang, Binji; Wu, Yi; Li, Ying; Jin, Jun; Tan, Liwen; Zhang, Shaoxiang

2013-09-01

Anatomical knowledge of the larynx region is critical for understanding laryngeal disease and performing required interventions. Virtual reality is a useful method for surgical education and simulation. Here, we assembled segmented cross-section slices of the larynx region from the Chinese Visible Human dataset. The laryngeal structures were precisely segmented manually as 2D images, then reconstructed and displayed as 3D images in the virtual reality Dextrobeam system. Using visualization and interaction with the virtual reality modeling language model, a digital laryngeal anatomy instruction was constructed using HTML and JavaScript languages. The volume larynx models can thus display an arbitrary section of the model and provide a virtual dissection function. This networked teaching system of the digital laryngeal anatomy can be read remotely, displayed locally, and manipulated interactively.

Trueness and precision of digital impressions obtained using an intraoral scanner with different head size in the partially edentulous mandible.

PubMed

Hayama, Hironari; Fueki, Kenji; Wadachi, Juro; Wakabayashi, Noriyuki

2018-03-01

It remains unclear whether digital impressions obtained using an intraoral scanner are sufficiently accurate for use in fabrication of removable partial dentures. We therefore compared the trueness and precision between conventional and digital impressions in the partially edentulous mandible. Mandibular Kennedy Class I and III models with soft silicone simulated-mucosa placed on the residual edentulous ridge were used. The reference models were converted to standard triangulated language (STL) file format using an extraoral scanner. Digital impressions were obtained using an intraoral scanner with a large or small scanning head, and converted to STL files. For conventional impressions, pressure impressions of the reference models were made and working casts fabricated using modified dental stone; these were converted to STL file format using an extraoral scanner. Conversion to STL file format was performed 5 times for each method. Trueness and precision were evaluated by deviation analysis using three-dimensional image processing software. Digital impressions had superior trueness (54-108μm), but inferior precision (100-121μm) compared to conventional impressions (trueness 122-157μm, precision 52-119μm). The larger intraoral scanning head showed better trueness and precision than the smaller head, and on average required fewer scanned images of digital impressions than the smaller head (p<0.05). On the color map, the deviation distribution tended to differ between the conventional and digital impressions. Digital impressions are partially comparable to conventional impressions in terms of accuracy; the use of a larger scanning head may improve the accuracy for removable partial denture fabrication. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

HIPAA, dermatology images, and the law.

PubMed

Scheinfeld, Noah; Rothstein, Brooke

2013-12-01

From smart phones to iPads, the world has grown increasingly reliant on new technology. In this ever-expanding digital age, medicine is at the forefront of these new technologies. In the field of dermatology and general medicine, digital images have become an important tool used in patient management. Today, one can even find physicians who use their cellular phone cameras to take patient images and transmit them to other physicians. However, as digital imaging technology has become more prevalent so too have concerns about the impact of this technology on the electronic medical record, quality of patient care, and medicolegal issues. This article will discuss the advent of digital imaging technology in dermatology and the legal ramifications digital images have on medical care, abiding by HIPAA, the use of digital images as evidence, and the possible abuses digital images can pose in a health care setting.

3D fluoroscopic image estimation using patient-specific 4DCBCT-based motion models

PubMed Central

Dhou, Salam; Hurwitz, Martina; Mishra, Pankaj; Cai, Weixing; Rottmann, Joerg; Li, Ruijiang; Williams, Christopher; Wagar, Matthew; Berbeco, Ross; Ionascu, Dan; Lewis, John H.

2015-01-01

3D fluoroscopic images represent volumetric patient anatomy during treatment with high spatial and temporal resolution. 3D fluoroscopic images estimated using motion models built using 4DCT images, taken days or weeks prior to treatment, do not reliably represent patient anatomy during treatment. In this study we develop and perform initial evaluation of techniques to develop patient-specific motion models from 4D cone-beam CT (4DCBCT) images, taken immediately before treatment, and use these models to estimate 3D fluoroscopic images based on 2D kV projections captured during treatment. We evaluate the accuracy of 3D fluoroscopic images by comparing to ground truth digital and physical phantom images. The performance of 4DCBCT- and 4DCT- based motion models are compared in simulated clinical situations representing tumor baseline shift or initial patient positioning errors. The results of this study demonstrate the ability for 4DCBCT imaging to generate motion models that can account for changes that cannot be accounted for with 4DCT-based motion models. When simulating tumor baseline shift and patient positioning errors of up to 5 mm, the average tumor localization error and the 95th percentile error in six datasets were 1.20 and 2.2 mm, respectively, for 4DCBCT-based motion models. 4DCT-based motion models applied to the same six datasets resulted in average tumor localization error and the 95th percentile error of 4.18 and 5.4 mm, respectively. Analysis of voxel-wise intensity differences was also conducted for all experiments. In summary, this study demonstrates the feasibility of 4DCBCT-based 3D fluoroscopic image generation in digital and physical phantoms, and shows the potential advantage of 4DCBCT-based 3D fluoroscopic image estimation when there are changes in anatomy between the time of 4DCT imaging and the time of treatment delivery. PMID:25905722

Image processing techniques for digital orthophotoquad production

USGS Publications Warehouse

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.

Foveated model observers to predict human performance in 3D images

NASA Astrophysics Data System (ADS)

Lago, Miguel A.; Abbey, Craig K.; Eckstein, Miguel P.

2017-03-01

We evaluate 3D search requires model observers that take into account the peripheral human visual processing (foveated models) to predict human observer performance. We show that two different 3D tasks, free search and location-known detection, influence the relative human visual detectability of two signals of different sizes in synthetic backgrounds mimicking the noise found in 3D digital breast tomosynthesis. One of the signals resembled a microcalcification (a small and bright sphere), while the other one was designed to look like a mass (a larger Gaussian blob). We evaluated current standard models observers (Hotelling; Channelized Hotelling; non-prewhitening matched filter with eye filter, NPWE; and non-prewhitening matched filter model, NPW) and showed that they incorrectly predict the relative detectability of the two signals in 3D search. We propose a new model observer (3D Foveated Channelized Hotelling Observer) that incorporates the properties of the visual system over a large visual field (fovea and periphery). We show that the foveated model observer can accurately predict the rank order of detectability of the signals in 3D images for each task. Together, these results motivate the use of a new generation of foveated model observers for predicting image quality for search tasks in 3D imaging modalities such as digital breast tomosynthesis or computed tomography.

Validation of the international labour office digitized standard images for recognition and classification of radiographs of pneumoconiosis.

PubMed

Halldin, Cara N; Petsonk, Edward L; Laney, A Scott

2014-03-01

Chest radiographs are recommended for prevention and detection of pneumoconiosis. In 2011, the International Labour Office (ILO) released a revision of the International Classification of Radiographs of Pneumoconioses that included a digitized standard images set. The present study compared results of classifications of digital chest images performed using the new ILO 2011 digitized standard images to classification approaches used in the past. Underground coal miners (N = 172) were examined using both digital and film-screen radiography (FSR) on the same day. Seven National Institute for Occupational Safety and Health-certified B Readers independently classified all 172 digital radiographs, once using the ILO 2011 digitized standard images (DRILO2011-D) and once using digitized standard images used in the previous research (DRRES). The same seven B Readers classified all the miners' chest films using the ILO film-based standards. Agreement between classifications of FSR and digital radiography was identical, using a standard image set (either DRILO2011-D or DRRES). The overall weighted κ value was 0.58. Some specific differences in the results were seen and noted. However, intrareader variability in this study was similar to the published values and did not appear to be affected by the use of the new ILO 2011 digitized standard images. These findings validate the use of the ILO digitized standard images for classification of small pneumoconiotic opacities. When digital chest radiographs are obtained and displayed appropriately, results of pneumoconiosis classifications using the 2011 ILO digitized standards are comparable to film-based ILO classifications and to classifications using earlier research standards. Published by Elsevier Inc.

Application of High Speed Digital Image Correlation in Rocket Engine Hot Fire Testing

NASA Technical Reports Server (NTRS)

Gradl, Paul R.; Schmidt, Tim

2016-01-01

Hot fire testing of rocket engine components and rocket engine systems is a critical aspect of the development process to understand performance, reliability and system interactions. Ground testing provides the opportunity for highly instrumented development testing to validate analytical model predictions and determine necessary design changes and process improvements. To properly obtain discrete measurements for model validation, instrumentation must survive in the highly dynamic and extreme temperature application of hot fire testing. Digital Image Correlation has been investigated and being evaluated as a technique to augment traditional instrumentation during component and engine testing providing further data for additional performance improvements and cost savings. The feasibility of digital image correlation techniques were demonstrated in subscale and full scale hotfire testing. This incorporated a pair of high speed cameras to measure three-dimensional, real-time displacements and strains installed and operated under the extreme environments present on the test stand. The development process, setup and calibrations, data collection, hotfire test data collection and post-test analysis and results are presented in this paper.

42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... image acquisition, digitization, processing, compression, transmission, display, archiving, and... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable quality...

42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... image acquisition, digitization, processing, compression, transmission, display, archiving, and... quality digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object... digital radiographic image files from six or more sample chest radiographs that are of acceptable quality...

Study of optical techniques for the Ames unitary wind tunnel: Digital image processing, part 6

NASA Technical Reports Server (NTRS)

Lee, George

1993-01-01

A survey of digital image processing techniques and processing systems for aerodynamic images has been conducted. These images covered many types of flows and were generated by many types of flow diagnostics. These include laser vapor screens, infrared cameras, laser holographic interferometry, Schlieren, and luminescent paints. Some general digital image processing systems, imaging networks, optical sensors, and image computing chips were briefly reviewed. Possible digital imaging network systems for the Ames Unitary Wind Tunnel were explored.

42 CFR 37.51 - Interpreting and classifying chest radiographs-digital radiography systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... standard digital chest radiographic images provided for use with the Guidelines for the Use of the ILO... NIOSH-approved standard digital images may be used for classifying digital chest images for pneumoconiosis. Modification of the appearance of the standard images using software tools is not permitted. (d...

[Application and prospect of digital technology in the field of orthodontics].

PubMed

Zhou, Y H

2016-06-01

The three-dimensional(3D)digital technology has brought a revolutionary change in diagnostic planning and treatment strategy of orthodontics. Acquisition of 3D image data of the hard and soft tissues of the patients, diagnostic analysis and treatment prediction, and ultimately the individualized orthodontic appliance, will become the development trend and workflow of the 3D orthodontics. With the development of 3D digital technology, the traditional plaster model has been gradually replacing by 3D digital models. Meanwhile, 3D facial soft tissue scan and cone-beam CT scan have been gradually applied to clinical orthodontics, making it possible to get 3D virtual anatomical structure for patients. With the help of digital technology, the diagnostic process is much easier for orthodontist. However how to command the whole digital workflow and put it into practice in the daily work is still a long way to go. The purpose of this article is to enlighten the orthodontists interested in digital technology and discuss the future of digital orthodontics in China.

Integration of orthophotographic and sidescan sonar imagery: an example from Lake Garda, Italy

USGS Publications Warehouse

Gentili, Giuseppe; Twichell, David C.; Schwab, Bill

1996-01-01

Digital orthophotos of Lake Garda basin area are available at the scale of up to 1:10,000 from a 1994 high altitude (average scale of 1:75,000) air photo coverage of Italy collected with an RC30 camera and Panatomic film. In October 1994 the lake bed was surveyed by USGS and CISIG personnel using a SIS 1000 Sea-Floor Mapping System. Subsystems of the SIS-1000 include high resolution sidescan sonar and sub-bottom profiler. The sidescan imagery was collected in ranges up to 1500m, while preserving a 50cm pixel resolution. The system was navigated using differential GPS. The extended operational range of the sidescan sonar permitted surveying the 370km lake area in 11 days. Data were compiled into a digital image with a pixel resolution of about 2m and stored as 12 gigabytes in exabyte 8mm tape and converted from WGS84 coordinate system to the European Datum (ED50) and integrated with bathymetric data digitized from maps.The digital bathymetric model was generated by interpolation using commercial software and was merged with the land elevation model to obtain a digital elevation model of the Lake Garda basin.The sidescan image data was also projected in the same coordinate system and seamed with the digital orthophoto of the land to produce a continuous image of the basin as if the water were removed. Some perspective scenes were generated by combining elevation and bathymetric data with basin and lake floor images. In deep water the lake's thermal structure created problems with the imagery indicating that winter or spring is best survey period. In shallow waters, ≤ 10 m, where data are missing, the bottom data gap can be filled with available images from the first few channels of the Daedalus built MIVIS, a 102 channel hyperspectral scanner with 20 channel bands of 0.020 μm width, operating in the visible part of the spectrum. By integrating orthophotos with sidescan imagery we can see how the basin morphology extends across the lake, the paths taken by the lake inlet along the lake bed and the areal distribution of sediments. An extensive exposure of debris aprons were noted on the western side of the lake. Various anthropogenic objects were recognized: pipelines, sites of waste disposal on the lake's bed, and relicts of Venitian and Austrian(?) boats.

Modeling digital breast tomosynthesis imaging systems for optimization studies

NASA Astrophysics Data System (ADS)

Lau, Beverly Amy

Digital breast tomosynthesis (DBT) is a new imaging modality for breast imaging. In tomosynthesis, multiple images of the compressed breast are acquired at different angles, and the projection view images are reconstructed to yield images of slices through the breast. One of the main problems to be addressed in the development of DBT is the optimal parameter settings to obtain images ideal for detection of cancer. Since it would be unethical to irradiate women multiple times to explore potentially optimum geometries for tomosynthesis, it is ideal to use a computer simulation to generate projection images. Existing tomosynthesis models have modeled scatter and detector without accounting for oblique angles of incidence that tomosynthesis introduces. Moreover, these models frequently use geometry-specific physical factors measured from real systems, which severely limits the robustness of their algorithms for optimization. The goal of this dissertation was to design the framework for a computer simulation of tomosynthesis that would produce images that are sensitive to changes in acquisition parameters, so an optimization study would be feasible. A computer physics simulation of the tomosynthesis system was developed. The x-ray source was modeled as a polychromatic spectrum based on published spectral data, and inverse-square law was applied. Scatter was applied using a convolution method with angle-dependent scatter point spread functions (sPSFs), followed by scaling using an angle-dependent scatter-to-primary ratio (SPR). Monte Carlo simulations were used to generate sPSFs for a 5-cm breast with a 1-cm air gap. Detector effects were included through geometric propagation of the image onto layers of the detector, which were blurred using depth-dependent detector point-spread functions (PRFs). Depth-dependent PRFs were calculated every 5-microns through a 200-micron thick CsI detector using Monte Carlo simulations. Electronic noise was added as Gaussian noise as a last step of the model. The sPSFs and detector PRFs were verified to match published data, and noise power spectrum (NPS) from simulated flat field images were shown to match empirically measured data from a digital mammography unit. A novel anthropomorphic software breast phantom was developed for 3D imaging simulation. Projection view images of the phantom were shown to have similar structure as real breasts in the spatial frequency domain, using the power-law exponent beta to quantify tissue complexity. The physics simulation and computer breast phantom were used together, following methods from a published study with real tomosynthesis images of real breasts. The simulation model and 3D numerical breast phantoms were able to reproduce the trends in the experimental data. This result demonstrates the ability of the tomosynthesis physics model to generate images sensitive to changes in acquisition parameters.

Quantitative evaluation of the accuracy and variance of individual pixels in a scientific CMOS (sCMOS) camera for computational imaging

NASA Astrophysics Data System (ADS)

Watanabe, Shigeo; Takahashi, Teruo; Bennett, Keith

2017-02-01

The"scientific" CMOS (sCMOS) camera architecture fundamentally differs from CCD and EMCCD cameras. In digital CCD and EMCCD cameras, conversion from charge to the digital output is generally through a single electronic chain, and the read noise and the conversion factor from photoelectrons to digital outputs are highly uniform for all pixels, although quantum efficiency may spatially vary. In CMOS cameras, the charge to voltage conversion is separate for each pixel and each column has independent amplifiers and analog-to-digital converters, in addition to possible pixel-to-pixel variation in quantum efficiency. The "raw" output from the CMOS image sensor includes pixel-to-pixel variability in the read noise, electronic gain, offset and dark current. Scientific camera manufacturers digitally compensate the raw signal from the CMOS image sensors to provide usable images. Statistical noise in images, unless properly modeled, can introduce errors in methods such as fluctuation correlation spectroscopy or computational imaging, for example, localization microscopy using maximum likelihood estimation. We measured the distributions and spatial maps of individual pixel offset, dark current, read noise, linearity, photoresponse non-uniformity and variance distributions of individual pixels for standard, off-the-shelf Hamamatsu ORCA-Flash4.0 V3 sCMOS cameras using highly uniform and controlled illumination conditions, from dark conditions to multiple low light levels between 20 to 1,000 photons / pixel per frame to higher light conditions. We further show that using pixel variance for flat field correction leads to errors in cameras with good factory calibration.

Positional Quality Assessment of Orthophotos Obtained from Sensors Onboard Multi-Rotor UAV Platforms

PubMed Central

Mesas-Carrascosa, Francisco Javier; Rumbao, Inmaculada Clavero; Berrocal, Juan Alberto Barrera; Porras, Alfonso García-Ferrer

2014-01-01

In this study we explored the positional quality of orthophotos obtained by an unmanned aerial vehicle (UAV). A multi-rotor UAV was used to obtain images using a vertically mounted digital camera. The flight was processed taking into account the photogrammetry workflow: perform the aerial triangulation, generate a digital surface model, orthorectify individual images and finally obtain a mosaic image or final orthophoto. The UAV orthophotos were assessed with various spatial quality tests used by national mapping agencies (NMAs). Results showed that the orthophotos satisfactorily passed the spatial quality tests and are therefore a useful tool for NMAs in their production flowchart. PMID:25587877

Positional quality assessment of orthophotos obtained from sensors onboard multi-rotor UAV platforms.

PubMed

Mesas-Carrascosa, Francisco Javier; Rumbao, Inmaculada Clavero; Berrocal, Juan Alberto Barrera; Porras, Alfonso García-Ferrer

2014-11-26

In this study we explored the positional quality of orthophotos obtained by an unmanned aerial vehicle (UAV). A multi-rotor UAV was used to obtain images using a vertically mounted digital camera. The flight was processed taking into account the photogrammetry workflow: perform the aerial triangulation, generate a digital surface model, orthorectify individual images and finally obtain a mosaic image or final orthophoto. The UAV orthophotos were assessed with various spatial quality tests used by national mapping agencies (NMAs). Results showed that the orthophotos satisfactorily passed the spatial quality tests and are therefore a useful tool for NMAs in their production flowchart.

[Comparative evaluation of six different body regions of the dog using analog and digital radiography].

PubMed

Meyer-Lindenberg, Andrea; Ebermaier, Christine; Wolvekamp, Pim; Tellhelm, Bernd; Meutstege, Freek J; Lang, Johann; Hartung, Klaus; Fehr, Michael; Nolte, Ingo

2008-01-01

In this study the quality of digital and analog radiography in dogs was compared. For this purpose, three conventional radiographs (varying in exposure) and three digital radiographs (varying in MUSI-contrast [MUSI = MUlti Scale Image Contrast], the main post-processing parameter) of six different body regions of the dog were evaluated (thorax, abdomen, skull, femur, hip joints, elbow). The quality of the radiographs was evaluated by eight veterinary specialists familiar with radiographic images using a questionnaire based on details of each body region significant in obtaining a radiographic diagnosis. In the first part of the study the overall quality of the radiographs was evaluated. Within one region, 89.5% (43/48) chose a digital radiograph as the best image. Divided into analog and digital groups, the digital image with the highest MUSI-contrast was most often considered the best, while the analog image considered the best varied between the one with the medium and the one with the longest exposure time. In the second part of the study, each image was rated for the visibility of specific, diagnostically important details. After summarisation of the scores for each criterion, divided into analog and digital imaging, the digital images were rated considerably superior to conventional images. The results of image comparison revealed that digital radiographs showed better image detail than radiographs taken with the analog technique in all six areas of the body.

Character recognition using a neural network model with fuzzy representation

NASA Technical Reports Server (NTRS)

Tavakoli, Nassrin; Seniw, David

1992-01-01

The degree to which digital images are recognized correctly by computerized algorithms is highly dependent upon the representation and the classification processes. Fuzzy techniques play an important role in both processes. In this paper, the role of fuzzy representation and classification on the recognition of digital characters is investigated. An experimental Neural Network model with application to character recognition was developed. Through a set of experiments, the effect of fuzzy representation on the recognition accuracy of this model is presented.

Geometrical modeling of complete dental shapes by using panoramic X-ray, digital mouth data and anatomical templates.

PubMed

Barone, Sandro; Paoli, Alessandro; Razionale, Armando Viviano

2015-07-01

In the field of orthodontic planning, the creation of a complete digital dental model to simulate and predict treatments is of utmost importance. Nowadays, orthodontists use panoramic radiographs (PAN) and dental crown representations obtained by optical scanning. However, these data do not contain any 3D information regarding tooth root geometries. A reliable orthodontic treatment should instead take into account entire geometrical models of dental shapes in order to better predict tooth movements. This paper presents a methodology to create complete 3D patient dental anatomies by combining digital mouth models and panoramic radiographs. The modeling process is based on using crown surfaces, reconstructed by optical scanning, and root geometries, obtained by adapting anatomical CAD templates over patient specific information extracted from radiographic data. The radiographic process is virtually replicated on crown digital geometries through the Discrete Radon Transform (DRT). The resulting virtual PAN image is used to integrate the actual radiographic data and the digital mouth model. This procedure provides the root references on the 3D digital crown models, which guide a shape adjustment of the dental CAD templates. The entire geometrical models are finally created by merging dental crowns, captured by optical scanning, and root geometries, obtained from the CAD templates. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of 3d Reconstruction Services and Terrestrial Laser Scanning for Cultural Heritage Documentation

NASA Astrophysics Data System (ADS)

Rasztovits, S.; Dorninger, P.

2013-07-01

Terrestrial Laser Scanning (TLS) is an established method to reconstruct the geometrical surface of given objects. Current systems allow for fast and efficient determination of 3D models with high accuracy and richness in detail. Alternatively, 3D reconstruction services are using images to reconstruct the surface of an object. While the instrumental expenses for laser scanning systems are high, upcoming free software services as well as open source software packages enable the generation of 3D models using digital consumer cameras. In addition, processing TLS data still requires an experienced user while recent web-services operate completely automatically. An indisputable advantage of image based 3D modeling is its implicit capability for model texturing. However, the achievable accuracy and resolution of the 3D models is lower than those of laser scanning data. Within this contribution, we investigate the results of automated web-services for image based 3D model generation with respect to a TLS reference model. For this, a copper sculpture was acquired using a laser scanner and using image series of different digital cameras. Two different webservices, namely Arc3D and AutoDesk 123D Catch were used to process the image data. The geometric accuracy was compared for the entire model and for some highly structured details. The results are presented and interpreted based on difference models. Finally, an economical comparison of the generation of the models is given considering the interactive and processing time costs.

Digital mammography, cancer screening: Factors important for image compression

NASA Technical Reports Server (NTRS)

Clarke, Laurence P.; Blaine, G. James; Doi, Kunio; Yaffe, Martin J.; Shtern, Faina; Brown, G. Stephen; Winfield, Daniel L.; Kallergi, Maria

1993-01-01

The use of digital mammography for breast cancer screening poses several novel problems such as development of digital sensors, computer assisted diagnosis (CAD) methods for image noise suppression, enhancement, and pattern recognition, compression algorithms for image storage, transmission, and remote diagnosis. X-ray digital mammography using novel direct digital detection schemes or film digitizers results in large data sets and, therefore, image compression methods will play a significant role in the image processing and analysis by CAD techniques. In view of the extensive compression required, the relative merit of 'virtually lossless' versus lossy methods should be determined. A brief overview is presented here of the developments of digital sensors, CAD, and compression methods currently proposed and tested for mammography. The objective of the NCI/NASA Working Group on Digital Mammography is to stimulate the interest of the image processing and compression scientific community for this medical application and identify possible dual use technologies within the NASA centers.

Digital PET compliance to EARL accreditation specifications.

PubMed

Koopman, Daniëlle; Groot Koerkamp, Maureen; Jager, Pieter L; Arkies, Hester; Knollema, Siert; Slump, Cornelis H; Sanches, Pedro G; van Dalen, Jorn A

2017-12-01

Our aim was to evaluate if a recently introduced TOF PET system with digital photon counting technology (Philips Healthcare), potentially providing an improved image quality over analogue systems, can fulfil EANM research Ltd (EARL) accreditation specifications for tumour imaging with FDG-PET/CT. We have performed a phantom study on a digital TOF PET system using a NEMA NU2-2001 image quality phantom with six fillable spheres. Phantom preparation and PET/CT acquisition were performed according to the European Association of Nuclear Medicine (EANM) guidelines. We made list-mode ordered-subsets expectation maximization (OSEM) TOF PET reconstructions, with default settings, three voxel sizes (4 × 4 × 4 mm 3 , 2 × 2 × 2 mm 3 and 1 × 1 × 1 mm 3 ) and with/without point spread function (PSF) modelling. On each PET dataset, mean and maximum activity concentration recovery coefficients (RC mean and RC max ) were calculated for all phantom spheres and compared to EARL accreditation specifications. The RCs of the 4 × 4 × 4 mm 3 voxel dataset without PSF modelling proved closest to EARL specifications. Next, we added a Gaussian post-smoothing filter with varying kernel widths of 1-7 mm. EARL specifications were fulfilled when using kernel widths of 2 to 4 mm. TOF PET using digital photon counting technology fulfils EARL accreditation specifications for FDG-PET/CT tumour imaging when using an OSEM reconstruction with 4 × 4 × 4 mm 3 voxels, no PSF modelling and including a Gaussian post-smoothing filter of 2 to 4 mm.

Denoised ordered subset statistically penalized algebraic reconstruction technique (DOS-SPART) in digital breast tomosynthesis

NASA Astrophysics Data System (ADS)

Garrett, John; Li, Yinsheng; Li, Ke; Chen, Guang-Hong

2017-03-01

Digital breast tomosynthesis (DBT) is a three dimensional (3D) breast imaging modality in which projections are acquired over a limited angular span around the compressed breast and reconstructed into image slices parallel to the detector. DBT has been shown to help alleviate the breast tissue overlapping issues of two dimensional (2D) mammography. Since the overlapping tissues may simulate cancer masses or obscure true cancers, this improvement is critically important for improved breast cancer screening and diagnosis. In this work, a model-based image reconstruction method is presented to show that spatial resolution in DBT volumes can be maintained while dose is reduced using the presented method when compared to that of a state-of-the-art commercial reconstruction technique. Spatial resolution was measured in phantom images and subjectively in a clinical dataset. Noise characteristics were explored in a cadaver study. In both the quantitative and subjective results the image sharpness was maintained and overall image quality was maintained at reduced doses when the model-based iterative reconstruction was used to reconstruct the volumes.

Lumbar spine radiography — poor collimation practices after implementation of digital technology

PubMed Central

Zetterberg, L G; Espeland, A

2011-01-01

Objectives The transition from analogue to digital radiography may have reduced the motivation to perform proper collimation, as digital techniques have made it possible to mask areas irradiated outside the area of diagnostic interest (ADI). We examined the hypothesis that collimation practices have deteriorated since digitalisation. Methods After defining the ADI, we compared the proportion of the irradiated field outside the ADI in 86 digital and 86 analogue frontal lumbar spine radiographs using the Mann–Whitney test. 50 digital images and 50 analogue images were from a Norwegian hospital and the remainder from a Danish hospital. Consecutive digital images were compared with analogue images (from the hospitals' archives) produced in the 4 years prior to digitalisation. Both hospitals' standard radiographic procedures remained unchanged during the study. For digital images, the irradiated field was assessed using non-masked raw-data images. Results The proportion of the irradiated field outside the ADI was larger in digital than in analogue images (mean 61.7% vs 42.4%, p<0.001), and also in a subsample of 39 image pairs that could be matched for patient age (p<0.001). The mean total field size was 46% larger in digital than in analogue images (791 cm2 vs 541 cm2). Conclusion Following the implementation of digital radiography, considerably larger areas were irradiated. This causes unnecessarily high radiation doses to patients. PMID:21606070

Children's accuracy of portion size estimation using digital food images: effects of interface design and size of image on computer screen.

PubMed

Baranowski, Tom; Baranowski, Janice C; Watson, Kathleen B; Martin, Shelby; Beltran, Alicia; Islam, Noemi; Dadabhoy, Hafza; Adame, Su-heyla; Cullen, Karen; Thompson, Debbe; Buday, Richard; Subar, Amy

2011-03-01

To test the effect of image size and presence of size cues on the accuracy of portion size estimation by children. Children were randomly assigned to seeing images with or without food size cues (utensils and checked tablecloth) and were presented with sixteen food models (foods commonly eaten by children) in varying portion sizes, one at a time. They estimated each food model's portion size by selecting a digital food image. The same food images were presented in two ways: (i) as small, graduated portion size images all on one screen or (ii) by scrolling across large, graduated portion size images, one per sequential screen. Laboratory-based with computer and food models. Volunteer multi-ethnic sample of 120 children, equally distributed by gender and ages (8 to 13 years) in 2008-2009. Average percentage of correctly classified foods was 60·3 %. There were no differences in accuracy by any design factor or demographic characteristic. Multiple small pictures on the screen at once took half the time to estimate portion size compared with scrolling through large pictures. Larger pictures had more overestimation of size. Multiple images of successively larger portion sizes of a food on one computer screen facilitated quicker portion size responses with no decrease in accuracy. This is the method of choice for portion size estimation on a computer.

Digital Image Analysis System for Monitoring Crack Growth at Elevated Temperature

DTIC Science & Technology

1988-05-01

The objective of the research work reported here was to develop a new concept, based on Digital Image Analysis , for monitoring the crack-tip position...a 512 x 512 pixel frame. c) Digital Image Analysis software developed to locate and digitize the position of the crack-tip, on the observed image

[Improvement of Digital Capsule Endoscopy System and Image Interpolation].

PubMed

Zhao, Shaopeng; Yan, Guozheng; Liu, Gang; Kuang, Shuai

2016-01-01

Traditional capsule image collects and transmits analog image, with weak anti-interference ability, low frame rate, low resolution. This paper presents a new digital image capsule, which collects and transmits digital image, with frame rate up to 30 frames/sec and pixels resolution of 400 x 400. The image is compressed in the capsule, and is transmitted to the outside of the capsule for decompression and interpolation. A new type of interpolation algorithm is proposed, which is based on the relationship between the image planes, to obtain higher quality colour images. capsule endoscopy, digital image, SCCB protocol, image interpolation

Assessment of HRSC Digital Terrain Models Produced for the South Polar Residual Cap

NASA Astrophysics Data System (ADS)

Putri, Alfiah Rizky Diana; Sidiropoulos, Panagiotis; Muller, Jan-Peter

2017-04-01

The current Digital Terrain Models available for Mars consist of NASA MOLA (Mars Orbital Laser Altimeter) Digital Terrain Models with an average resolution of 112 m/ pixel (512 pixels/degree) for the polar region. The ESA/DLR High Resolution Stereo Camera is currently orbiting Mars and mapping its surface, 98% with resolution of ≤100 m/pixel and better and 100% at lower resolution [1]. It is possible to produce Digital Terrain Models from HRSC images using various methods. In this study, the method developed on Kim and Muller [2] which uses the VICAR open source program together with photogrammetry sofrware from DLR (Deutschen Zentrums für Luft- und Raumfahrt) with image matching based on the GOTCHA (Gruen-Otto-Chau) algorithm [3]. Digital Terrain Models have been processed over the South Pole with emphasis on areas around South Polar Residual Cap from High Resolution Stereo Camera images [4]. Digital Terrain Models have been produced for 31 orbits out of 149 polar orbits available. This study analyses the quality of the DTMs including an assessment of accuracy of elevations using the MOLA MEGDR (Mission Experiment Gridded Data Records) which has roughly 42 million MOLA PEDR (Precision Experiment Data Records) points between latitudes of 78 o -90 o S. The issues encountered in the production of Digital Terrain Models will be described and the statistical results and assessment method will be presented. The resultant DTMs will be accessible via http://i-Mars.eu/web-GIS References: [1] Neukum, G. et. al, 2004. Mars Express: The Scientific Payload pp. 17-35. [2] Kim, J.-R. and J.-P. Muller. 2009. PSS vol. 57, pp. 2095-2112. [3] Shin, D. and J.-P. Muller. 2012. Pattern Recognition, 45(10), 3795 -3809. [4] Putri, A.R. D., et al., Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci., XLI-B4, 463-469 Acknowledgements: The research leading to these results has received partial funding from the STFC "MSSL Consolidated Grant" ST/K000977/1 and partial support from the European Union's Seventh Framework Programme (FP7/2007-2013) under iMars grant agreement n ˚ 607379. The first author would like to acknowledge support for her studies from Indonesia Endowment Fund for Education (LPDP), Ministry of Finance, Republic of Indonesia. The authors would also like to thank Alexander Dumke (Freie Universitaet Berlin) for providing the EXTORI exterior orientation elements which were critical in the production of accuracy geolocations.

Remote Sensing of Landscapes with Spectral Images

NASA Astrophysics Data System (ADS)

Adams, John B.; Gillespie, Alan R.

2006-05-01

Remote Sensing of Landscapes with Spectral Images describes how to process and interpret spectral images using physical models to bridge the gap between the engineering and theoretical sides of remote-sensing and the world that we encounter when we venture outdoors. The emphasis is on the practical use of images rather than on theory and mathematical derivations. Examples are drawn from a variety of landscapes and interpretations are tested against the reality seen on the ground. The reader is led through analysis of real images (using figures and explanations); the examples are chosen to illustrate important aspects of the analytic framework. This textbook will form a valuable reference for graduate students and professionals in a variety of disciplines including ecology, forestry, geology, geography, urban planning, archeology and civil engineering. It is supplemented by a web-site hosting digital color versions of figures in the book as well as ancillary images (www.cambridge.org/9780521662214). Presents a coherent view of practical remote sensing, leading from imaging and field work to the generation of useful thematic maps Explains how to apply physical models to help interpret spectral images Supplemented by a website hosting digital colour versions of figures in the book, as well as additional colour figures

Use of Standardized, Quantitative Digital Photography in a Multicenter Web-based Study

PubMed Central

Molnar, Joseph A.; Lew, Wesley K.; Rapp, Derek A.; Gordon, E. Stanley; Voignier, Denise; Rushing, Scott; Willner, William

2009-01-01

Objective: We developed a Web-based, blinded, prospective, randomized, multicenter trial, using standardized digital photography to clinically evaluate hand burn depth and accurately determine wound area with digital planimetry. Methods: Photos in each center were taken with identical digital cameras with standardized settings on a custom backdrop developed at Wake Forest University containing a gray, white, black, and centimeter scale. The images were downloaded, transferred via the Web, and stored on servers at the principal investigator's home institution. Color adjustments to each photo were made using Adobe Photoshop 6.0 (Adobe, San Jose, Calif). In an initial pilot study, model hands marked with circles of known areas were used to determine the accuracy of the planimetry technique. Two-dimensional digital planimetry using SigmaScan Pro 5.0 (SPSS Science, Chicago, Ill) was used to calculate wound area from the digital images. Results: Digital photography is a simple and cost-effective method for quantifying wound size when used in conjunction with digital planimetry (SigmaScan) and photo enhancement (Adobe Photoshop) programs. The accuracy of the SigmaScan program in calculating predetermined areas was within 4.7% (95% CI, 3.4%–5.9%). Dorsal hand burns of the initial 20 patients in a national study involving several centers were evaluated with this technique. Images obtained by individuals denying experience in photography proved reliable and useful for clinical evaluation and quantification of wound area. Conclusion: Standardized digital photography may be used quantitatively in a Web-based, multicenter trial of burn care. This technique could be modified for other medical studies with visual endpoints. PMID:19212431

Use of standardized, quantitative digital photography in a multicenter Web-based study.

PubMed

Molnar, Joseph A; Lew, Wesley K; Rapp, Derek A; Gordon, E Stanley; Voignier, Denise; Rushing, Scott; Willner, William

2009-01-01

We developed a Web-based, blinded, prospective, randomized, multicenter trial, using standardized digital photography to clinically evaluate hand burn depth and accurately determine wound area with digital planimetry. Photos in each center were taken with identical digital cameras with standardized settings on a custom backdrop developed at Wake Forest University containing a gray, white, black, and centimeter scale. The images were downloaded, transferred via the Web, and stored on servers at the principal investigator's home institution. Color adjustments to each photo were made using Adobe Photoshop 6.0 (Adobe, San Jose, Calif). In an initial pilot study, model hands marked with circles of known areas were used to determine the accuracy of the planimetry technique. Two-dimensional digital planimetry using SigmaScan Pro 5.0 (SPSS Science, Chicago, Ill) was used to calculate wound area from the digital images. Digital photography is a simple and cost-effective method for quantifying wound size when used in conjunction with digital planimetry (SigmaScan) and photo enhancement (Adobe Photoshop) programs. The accuracy of the SigmaScan program in calculating predetermined areas was within 4.7% (95% CI, 3.4%-5.9%). Dorsal hand burns of the initial 20 patients in a national study involving several centers were evaluated with this technique. Images obtained by individuals denying experience in photography proved reliable and useful for clinical evaluation and quantification of wound area. Standardized digital photography may be used quantitatively in a Web-based, multicenter trial of burn care. This technique could be modified for other medical studies with visual endpoints.

s48-e-013

NASA Image and Video Library

2012-11-08

S48-E-013 (15 Sept 1991) --- The Upper Atmosphere Research Satellite (UARS) in the payload bay of the earth- orbiting Discovery. UARS is scheduled for deploy on flight day three of the STS-48 mission. Data from UARS will enable scientists to study ozone depletion in the stratosphere, or upper atmosphere. This image was transmitted by the Electronic Still Camera (ESC), Development Test Objective (DTO) 648. The ESC is making its initial appearance on a Space Shuttle flight. Electronic still photography is a new technology that enables a camera to electronically capture and digitize an image with resolution approaching film quality. The digital image is stored on removable hard disks or small optical disks, and can be converted to a format suitable for downlink transmission or enhanced using image processing software. The Electronic Still Camera (ESC) was developed by the Man- Systems Division at the Johnson Space Center and is the first model in a planned evolutionary development leading to a family of high-resolution digital imaging devices. H. Don Yeates, JSC's Man-Systems Division, is program manager for the ESC. THIS IS A SECOND GENERATION PRINT MADE FROM AN ELECTRONICALLY PRODUCED NEGATIVE.

SU-E-T-366: Clinical Implementation of MR-Guided Vaginal Cylinder Brachytherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owrangi, A; Jolly, S; Balter, J

2014-06-01

Purpose: To evaluate the accuracy of MR-based vaginal brachytherapy source localization using an in-house MR-visible marker versus the alignment of an applicator model to MR images. Methods: Three consecutive patients undergoing vaginal HDR brachytherapy with a plastic cylinder were scanned with both CT and MRI (including T1- and T2- weighted images). An MR-visible source localization marker, consisting of a sealed thin catheter filled with either water (for T2 contrast) or Gd-doped water (for T1 contrast), was assembled shortly before scanning. Clinically, the applicator channel was digitized on CT with an x-ray marker. To evaluate the efficacy of MR-based applicator reconstruction,more » each MR image volume was aligned locally to the CT images based on the region containing the cylinder. Applicator digitization was performed on the MR images using (1) the MR visible marker and (2) alignment of an applicator surface model from Varian's Brachytherapy Planning software to the MRI images. Resulting source positions were compared with the original CT digitization. Results: Although the source path was visualized by the MR marker, the applicator tip proved difficult to identify due to challenges in achieving a watertight seal. This resulted in observed displacements of the catheter tip, at times >1cm. Deviations between the central source positions identified via aligning the applicator surface model to MR and using the xray marker on CT ranged from 0.07 – 0.19 cm and 0.07 – 0.20 cm on T1- weighted and T2-weighted images, respectively. Conclusion: Based on the current study, aligning the applicator model to MRI provides a practical, current approach to perform MR-based brachytherapy planning. Further study is needed to produce catheters with reliably and reproducibly identifiable tips. Attempts are being made to improve catheter seals, as well as to increase the viscosity of the contrast material to decrease fluid mobility inside the catheter.« less

Patient-generated Digital Images after Pediatric Ambulatory Surgery.

PubMed

Miller, Matthew W; Ross, Rachael K; Voight, Christina; Brouwer, Heather; Karavite, Dean J; Gerber, Jeffrey S; Grundmeier, Robert W; Coffin, Susan E

2016-07-06

To describe the use of digital images captured by parents or guardians and sent to clinicians for assessment of wounds after pediatric ambulatory surgery. Subjects with digital images of post-operative wounds were identified as part of an on-going cohort study of infections after ambulatory surgery within a large pediatric healthcare system. We performed a structured review of the electronic health record (EHR) to determine how digital images were documented in the EHR and used in clinical care. We identified 166 patients whose parent or guardian reported sending a digital image of the wound to the clinician after surgery. A corresponding digital image was located in the EHR in only 121 of these encounters. A change in clinical management was documented in 20% of these encounters, including referral for in-person evaluation of the wound and antibiotic prescription. Clinical teams have developed ad hoc workflows to use digital images to evaluate post-operative pediatric surgical patients. Because the use of digital images to support follow-up care after ambulatory surgery is likely to increase, it is important that high-quality images are captured and documented appropriately in the EHR to ensure privacy, security, and a high-level of care.

Patient-Generated Digital Images after Pediatric Ambulatory Surgery

PubMed Central

Ross, Rachael K.; Voight, Christina; Brouwer, Heather; Karavite, Dean J.; Gerber, Jeffrey S.; Grundmeier, Robert W.; Coffin, Susan E.

2016-01-01

Summary Objective To describe the use of digital images captured by parents or guardians and sent to clinicians for assessment of wounds after pediatric ambulatory surgery. Methods Subjects with digital images of post-operative wounds were identified as part of an ongoing cohort study of infections after ambulatory surgery within a large pediatric healthcare system. We performed a structured review of the electronic health record (EHR) to determine how digital images were documented in the EHR and used in clinical care. Results We identified 166 patients whose parent or guardian reported sending a digital image of the wound to the clinician after surgery. A corresponding digital image was located in the EHR in only 121 of these encounters. A change in clinical management was documented in 20% of these encounters, including referral for in-person evaluation of the wound and antibiotic prescription. Conclusion Clinical teams have developed ad hoc workflows to use digital images to evaluate post-operative pediatric surgical patients. Because the use of digital images to support follow-up care after ambulatory surgery is likely to increase, it is important that high-quality images are captured and documented appropriately in the EHR to ensure privacy, security, and a high-level of care. PMID:27452477

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

PubMed

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

2005-05-01

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

Single-shot full resolution region-of-interest (ROI) reconstruction in image plane digital holographic microscopy

NASA Astrophysics Data System (ADS)

Singh, Mandeep; Khare, Kedar

2018-05-01

We describe a numerical processing technique that allows single-shot region-of-interest (ROI) reconstruction in image plane digital holographic microscopy with full pixel resolution. The ROI reconstruction is modelled as an optimization problem where the cost function to be minimized consists of an L2-norm squared data fitting term and a modified Huber penalty term that are minimized alternately in an adaptive fashion. The technique can provide full pixel resolution complex-valued images of the selected ROI which is not possible to achieve with the commonly used Fourier transform method. The technique can facilitate holographic reconstruction of individual cells of interest from a large field-of-view digital holographic microscopy data. The complementary phase information in addition to the usual absorption information already available in the form of bright field microscopy can make the methodology attractive to the biomedical user community.

Photogrammetry of a 5m Inflatable Space Antenna With Consumer Digital Cameras

NASA Technical Reports Server (NTRS)

Pappa, Richard S.; Giersch, Louis R.; Quagliaroli, Jessica M.

2000-01-01

This paper discusses photogrammetric measurements of a 5m-diameter inflatable space antenna using four Kodak DC290 (2.1 megapixel) digital cameras. The study had two objectives: 1) Determine the photogrammetric measurement precision obtained using multiple consumer-grade digital cameras and 2) Gain experience with new commercial photogrammetry software packages, specifically PhotoModeler Pro from Eos Systems, Inc. The paper covers the eight steps required using this hardware/software combination. The baseline data set contained four images of the structure taken from various viewing directions. Each image came from a separate camera. This approach simulated the situation of using multiple time-synchronized cameras, which will be required in future tests of vibrating or deploying ultra-lightweight space structures. With four images, the average measurement precision for more than 500 points on the antenna surface was less than 0.020 inches in-plane and approximately 0.050 inches out-of-plane.

Contrast-enhanced digital mammography (CEDM): imaging modeling, computer simulations, and phantom study

NASA Astrophysics Data System (ADS)

Chen, Biao; Jing, Zhenxue; Smith, Andrew

2005-04-01

Contrast enhanced digital mammography (CEDM), which is based upon the analysis of a series of x-ray projection images acquired before/after the administration of contrast agents, may provide physicians critical physiologic and morphologic information of breast lesions to determine the malignancy of lesions. This paper proposes to combine the kinetic analysis (KA) of contrast agent uptake/washout process and the dual-energy (DE) contrast enhancement together to formulate a hybrid contrast enhanced breast-imaging framework. The quantitative characteristics of materials and imaging components in the x-ray imaging chain, including x-ray tube (tungsten) spectrum, filter, breast tissues/lesions, contrast agents (non-ionized iodine solution), and selenium detector, were systematically modeled. The contrast-noise-ration (CNR) of iodinated lesions and mean absorbed glandular dose were estimated mathematically. The x-ray techniques optimization was conducted through a series of computer simulations to find the optimal tube voltage, filter thickness, and exposure levels for various breast thicknesses, breast density, and detectable contrast agent concentration levels in terms of detection efficiency (CNR2/dose). A phantom study was performed on a modified Selenia full field digital mammography system to verify the simulated results. The dose level was comparable to the dose in diagnostic mode (less than 4 mGy for an average 4.2 cm compressed breast). The results from the computer simulations and phantom study are being used to optimize an ongoing clinical study.

Non-destructive evaluation of chlorophyll content in quinoa and amaranth leaves by simple and multiple regression analysis of RGB image components.

PubMed

Riccardi, M; Mele, G; Pulvento, C; Lavini, A; d'Andria, R; Jacobsen, S-E

2014-06-01

Leaf chlorophyll content provides valuable information about physiological status of plants; it is directly linked to photosynthetic potential and primary production. In vitro assessment by wet chemical extraction is the standard method for leaf chlorophyll determination. This measurement is expensive, laborious, and time consuming. Over the years alternative methods, rapid and non-destructive, have been explored. The aim of this work was to evaluate the applicability of a fast and non-invasive field method for estimation of chlorophyll content in quinoa and amaranth leaves based on RGB components analysis of digital images acquired with a standard SLR camera. Digital images of leaves from different genotypes of quinoa and amaranth were acquired directly in the field. Mean values of each RGB component were evaluated via image analysis software and correlated to leaf chlorophyll provided by standard laboratory procedure. Single and multiple regression models using RGB color components as independent variables have been tested and validated. The performance of the proposed method was compared to that of the widely used non-destructive SPAD method. Sensitivity of the best regression models for different genotypes of quinoa and amaranth was also checked. Color data acquisition of the leaves in the field with a digital camera was quick, more effective, and lower cost than SPAD. The proposed RGB models provided better correlation (highest R (2)) and prediction (lowest RMSEP) of the true value of foliar chlorophyll content and had a lower amount of noise in the whole range of chlorophyll studied compared with SPAD and other leaf image processing based models when applied to quinoa and amaranth.

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

21 CFR 892.1715 - Full-field digital mammography system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... planar digital x-ray images of the entire breast. This generic type of device may include digital mammography acquisition software, full-field digital image receptor, acquisition workstation, automatic exposure control, image processing and reconstruction programs, patient and equipment supports, component...

D Modeling with Photogrammetry by Uavs and Model Quality Verification

NASA Astrophysics Data System (ADS)

Barrile, V.; Bilotta, G.; Nunnari, A.

2017-11-01

This paper deals with a test lead by Geomatics laboratory (DICEAM, Mediterranea University of Reggio Calabria), concerning the application of UAV photogrammetry for survey, monitoring and checking. The study case relies with the surroundings of the Department of Agriculture Sciences. In the last years, such area was interested by landslides and survey activities carried out to take the phenomenon under control. For this purpose, a set of digital images were acquired through a UAV equipped with a digital camera and GPS. Successively, the processing for the production of a 3D georeferenced model was performed by using the commercial software Agisoft PhotoScan. Similarly, the use of a terrestrial laser scanning technique allowed to product dense cloud and 3D models of the same area. To assess the accuracy of the UAV-derived 3D models, a comparison between image and range-based methods was performed.

Feasibility study for automatic reduction of phase change imagery

NASA Technical Reports Server (NTRS)

Nossaman, G. O.

1971-01-01

The feasibility of automatically reducing a form of pictorial aerodynamic heating data is discussed. The imagery, depicting the melting history of a thin coat of fusible temperature indicator painted on an aerodynamically heated model, was previously reduced by manual methods. Careful examination of various lighting theories and approaches led to an experimentally verified illumination concept capable of yielding high-quality imagery. Both digital and video image processing techniques were applied to reduction of the data, and it was demonstrated that either method can be used to develop superimposed contours. Mathematical techniques were developed to find the model-to-image and the inverse image-to-model transformation using six conjugate points, and methods were developed using these transformations to determine heating rates on the model surface. A video system was designed which is able to reduce the imagery rapidly, economically and accurately. Costs for this system were estimated. A study plan was outlined whereby the mathematical transformation techniques developed to produce model coordinate heating data could be applied to operational software, and methods were discussed and costs estimated for obtaining the digital information necessary for this software.

A generalized Benford's law for JPEG coefficients and its applications in image forensics

NASA Astrophysics Data System (ADS)

Fu, Dongdong; Shi, Yun Q.; Su, Wei

2007-02-01

In this paper, a novel statistical model based on Benford's law for the probability distributions of the first digits of the block-DCT and quantized JPEG coefficients is presented. A parametric logarithmic law, i.e., the generalized Benford's law, is formulated. Furthermore, some potential applications of this model in image forensics are discussed in this paper, which include the detection of JPEG compression for images in bitmap format, the estimation of JPEG compression Qfactor for JPEG compressed bitmap image, and the detection of double compressed JPEG image. The results of our extensive experiments demonstrate the effectiveness of the proposed statistical model.

Skeletonization and Partitioning of Digital Images Using Discrete Morse Theory.

PubMed

Delgado-Friedrichs, Olaf; Robins, Vanessa; Sheppard, Adrian

2015-03-01

We show how discrete Morse theory provides a rigorous and unifying foundation for defining skeletons and partitions of grayscale digital images. We model a grayscale image as a cubical complex with a real-valued function defined on its vertices (the voxel values). This function is extended to a discrete gradient vector field using the algorithm presented in Robins, Wood, Sheppard TPAMI 33:1646 (2011). In the current paper we define basins (the building blocks of a partition) and segments of the skeleton using the stable and unstable sets associated with critical cells. The natural connection between Morse theory and homology allows us to prove the topological validity of these constructions; for example, that the skeleton is homotopic to the initial object. We simplify the basins and skeletons via Morse-theoretic cancellation of critical cells in the discrete gradient vector field using a strategy informed by persistent homology. Simple working Python code for our algorithms for efficient vector field traversal is included. Example data are taken from micro-CT images of porous materials, an application area where accurate topological models of pore connectivity are vital for fluid-flow modelling.

Digital Image Compression Using Artificial Neural Networks

NASA Technical Reports Server (NTRS)

Serra-Ricart, M.; Garrido, L.; Gaitan, V.; Aloy, A.

1993-01-01

The problem of storing, transmitting, and manipulating digital images is considered. Because of the file sizes involved, large amounts of digitized image information are becoming common in modern projects. Our goal is to described an image compression transform coder based on artificial neural networks techniques (NNCTC). A comparison of the compression results obtained from digital astronomical images by the NNCTC and the method used in the compression of the digitized sky survey from the Space Telescope Science Institute based on the H-transform is performed in order to assess the reliability of the NNCTC.

Skin colour assessment of replanted fingers in digital images and its reliability for the incorporation of images in nursing progress notes.

PubMed

Terashima, Taiko; Yoshimura, Sadako

2018-03-01

To determine whether nurses can accurately assess the skin colour of replanted fingers displayed as digital images on a computer screen. Colour measurement and clinical diagnostic methods for medical digital images have been studied, but reproducing skin colour on a computer screen remains difficult. The inter-rater reliability of skin colour assessment scores was evaluated. In May 2014, 21 nurses who worked on a trauma ward in Japan participated in testing. Six digital images with different skin colours were used. Colours were scored from both digital images and direct patient's observation. The score from a digital image was defined as the test score, and its difference from the direct assessment score as the difference score. Intraclass correlation coefficients were calculated. Nurses' opinions were classified and summarised. The intraclass correlation coefficients for the test scores were fair. Although the intraclass correlation coefficients for the difference scores were poor, they improved to good when three images that might have contributed to poor reliability were excluded. Most nurses stated that it is difficult to assess skin colour in digital images; they did not think it could be a substitute for direct visual assessment. However, most nurses were in favour of including images in nursing progress notes. Although the inter-rater reliability was fairly high, the reliability of colour reproduction in digital images as indicated by the difference scores was poor. Nevertheless, nurses expect the incorporation of digital images in nursing progress notes to be useful. This gap between the reliability of digital colour reproduction and nurses' expectations towards it must be addressed. High inter-rater reliability for digital images in nursing progress notes was not observed. Assessments of future improvements in colour reproduction technologies are required. Further digitisation and visualisation of nursing records might pose challenges. © 2017 John Wiley & Sons Ltd.

3D digital image processing for biofilm quantification from confocal laser scanning microscopy: Multidimensional statistical analysis of biofilm modeling

NASA Astrophysics Data System (ADS)

Zielinski, Jerzy S.

The dramatic increase in number and volume of digital images produced in medical diagnostics, and the escalating demand for rapid access to these relevant medical data, along with the need for interpretation and retrieval has become of paramount importance to a modern healthcare system. Therefore, there is an ever growing need for processed, interpreted and saved images of various types. Due to the high cost and unreliability of human-dependent image analysis, it is necessary to develop an automated method for feature extraction, using sophisticated mathematical algorithms and reasoning. This work is focused on digital image signal processing of biological and biomedical data in one- two- and three-dimensional space. Methods and algorithms presented in this work were used to acquire data from genomic sequences, breast cancer, and biofilm images. One-dimensional analysis was applied to DNA sequences which were presented as a non-stationary sequence and modeled by a time-dependent autoregressive moving average (TD-ARMA) model. Two-dimensional analyses used 2D-ARMA model and applied it to detect breast cancer from x-ray mammograms or ultrasound images. Three-dimensional detection and classification techniques were applied to biofilm images acquired using confocal laser scanning microscopy. Modern medical images are geometrically arranged arrays of data. The broadening scope of imaging as a way to organize our observations of the biophysical world has led to a dramatic increase in our ability to apply new processing techniques and to combine multiple channels of data into sophisticated and complex mathematical models of physiological function and dysfunction. With explosion of the amount of data produced in a field of biomedicine, it is crucial to be able to construct accurate mathematical models of the data at hand. Two main purposes of signal modeling are: data size conservation and parameter extraction. Specifically, in biomedical imaging we have four key problems that were addressed in this work: (i) registration, i.e. automated methods of data acquisition and the ability to align multiple data sets with each other; (ii) visualization and reconstruction, i.e. the environment in which registered data sets can be displayed on a plane or in multidimensional space; (iii) segmentation, i.e. automated and semi-automated methods to create models of relevant anatomy from images; (iv) simulation and prediction, i.e. techniques that can be used to simulate growth end evolution of researched phenomenon. Mathematical models can not only be used to verify experimental findings, but also to make qualitative and quantitative predictions, that might serve as guidelines for the future development of technology and/or treatment.

Geodesy and cartography of the Martian satellites

NASA Technical Reports Server (NTRS)

Batson, R. M.; Edwards, Kathleen; Duxbury, T. C.

1992-01-01

The difficulties connected with conventional maps of Phobos and Deimos are largely overcome by producing maps in digital forms, i.e., by projecting Viking Orbiter images onto a global topographic model made from collections of radii derived by photogrammetry. The resulting digital mosaics are then formatted as arrays of body-centered latitudes, longitudes, radii, and brightness values of Viking Orbiter images. The Phobos mapping described was done with Viking Orbiter data. Significant new coverage was obtained by the Soviet Phobos mission. The mapping of Deimos is in progress, using the techniques developed for Phobos.

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

NASA Astrophysics Data System (ADS)

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.

Modeling of digital mammograms using bicubic spline functions and additive noise

NASA Astrophysics Data System (ADS)

Graffigne, Christine; Maintournam, Aboubakar; Strauss, Anne

1998-09-01

The purpose of our work is the microcalcifications detection on digital mammograms. In order to do so, we model the grey levels of digital mammograms by the sum of a surface trend (bicubic spline function) and an additive noise or texture. We also introduce a robust estimation method in order to overcome the bias introduced by the microcalcifications. After the estimation we consider the subtraction image values as noise. If the noise is not correlated, we adjust its distribution probability by the Pearson's system of densities. It allows us to threshold accurately the images of subtraction and therefore to detect the microcalcifications. If the noise is correlated, a unilateral autoregressive process is used and its coefficients are again estimated by the least squares method. We then consider non overlapping windows on the residues image. In each window the texture residue is computed and compared with an a priori threshold. This provides correct localization of the microcalcifications clusters. However this technique is definitely more time consuming that then automatic threshold assuming uncorrelated noise and does not lead to significantly better results. As a conclusion, even if the assumption of uncorrelated noise is not correct, the automatic thresholding based on the Pearson's system performs quite well on most of our images.

Statistical modeling, detection, and segmentation of stains in digitized fabric images

NASA Astrophysics Data System (ADS)

Gururajan, Arunkumar; Sari-Sarraf, Hamed; Hequet, Eric F.

2007-02-01

This paper will describe a novel and automated system based on a computer vision approach, for objective evaluation of stain release on cotton fabrics. Digitized color images of the stained fabrics are obtained, and the pixel values in the color and intensity planes of these images are probabilistically modeled as a Gaussian Mixture Model (GMM). Stain detection is posed as a decision theoretic problem, where the null hypothesis corresponds to absence of a stain. The null hypothesis and the alternate hypothesis mathematically translate into a first order GMM and a second order GMM respectively. The parameters of the GMM are estimated using a modified Expectation-Maximization (EM) algorithm. Minimum Description Length (MDL) is then used as the test statistic to decide the verity of the null hypothesis. The stain is then segmented by a decision rule based on the probability map generated by the EM algorithm. The proposed approach was tested on a dataset of 48 fabric images soiled with stains of ketchup, corn oil, mustard, ragu sauce, revlon makeup and grape juice. The decision theoretic part of the algorithm produced a correct detection rate (true positive) of 93% and a false alarm rate of 5% on these set of images.

Exploring s-CIELAB as a scanner metric for print uniformity

NASA Astrophysics Data System (ADS)

Hertel, Dirk W.

2005-01-01

The s-CIELAB color difference metric combines the standard CIELAB metric for perceived color difference with spatial contrast sensitivity filtering. When studying the performance of digital image processing algorithms, maps of spatial color difference between 'before' and 'after' images are a measure of perceived image difference. A general image quality metric can be obtained by modeling the perceived difference from an ideal image. This paper explores the s-CIELAB concept for evaluating the quality of digital prints. Prints present the challenge that the 'ideal print' which should serve as the reference when calculating the delta E* error map is unknown, and thus be estimated from the scanned print. A reasonable estimate of what the ideal print 'should have been' is possible at least for images of known content such as flat fields or continuous wedges, where the error map can be calculated against a global or local mean. While such maps showing the perceived error at each pixel are extremely useful when analyzing print defects, it is desirable to statistically reduce them to a more manageable dataset. Examples of digital print uniformity are given, and the effect of specific print defects on the s-CIELAB delta E* metric are discussed.

Combining remote sensing image with DEM to identify ancient Minqin Oasis, northwest of China

NASA Astrophysics Data System (ADS)

Xie, Yaowen

2008-10-01

The developing and desertification process of Minqin oasis is representative in the whole arid area of northwest China. Combining Remote Sensing image with Digital Elevation Model (DEM) can produce the three-dimensional image of the research area which can give prominence to the spatial background of historical geography phenomenon's distribution, providing the conditions for extracting and analyzing historical geographical information thoroughly. This research rebuilds the ancient artificial Oasis based on the three-dimensional images produced by the TM digital Remote Sensing image and DEM created using 1:100000 topographic maps. The result indicates that the whole area of the ancient artificial oasis in Minqin Basin over the whole historical period reaches 321km2, in the form of discontinuous sheet, separated on the two banks of ancient Shiyang River and its branches, namely, Xishawo area, west to modern Minqin Basin and Zhongshawo area, in the center of the oasis. Except for a little of the ancient oasis unceasingly used by later people, most of it became desert. The combination of digital Remote Sensing image and DEM can integrate the advantages of both in identifying ancient oasis and improve the interpreting accuracy greatly.

Computation of dynamic seismic responses to viscous fluid of digitized three-dimensional Berea sandstones with a coupled finite-difference method.

PubMed

Zhang, Yang; Toksöz, M Nafi

2012-08-01

The seismic response of saturated porous rocks is studied numerically using microtomographic images of three-dimensional digitized Berea sandstones. A stress-strain calculation is employed to compute the velocities and attenuations of rock samples whose sizes are much smaller than the seismic wavelength of interest. To compensate for the contributions of small cracks lost in the imaging process to the total velocity and attenuation, a hybrid method is developed to recover the crack distribution, in which the differential effective medium theory, the Kuster-Toksöz model, and a modified squirt-flow model are utilized in a two-step Monte Carlo inversion. In the inversion, the velocities of P- and S-waves measured for the dry and water-saturated cases, and the measured attenuation of P-waves for different fluids are used. By using such a hybrid method, both the velocities of saturated porous rocks and the attenuations are predicted accurately when compared to laboratory data. The hybrid method is a practical way to model numerically the seismic properties of saturated porous rocks until very high resolution digital data are available. Cracks lost in the imaging process are critical for accurately predicting velocities and attenuations of saturated porous rocks.

SFM Technique and Focus Stacking for Digital Documentation of Archaeological Artifacts

NASA Astrophysics Data System (ADS)

Clini, P.; Frapiccini, N.; Mengoni, M.; Nespeca, R.; Ruggeri, L.

2016-06-01

Digital documentation and high-quality 3D representation are always more requested in many disciplines and areas due to the large amount of technologies and data available for fast, detailed and quick documentation. This work aims to investigate the area of medium and small sized artefacts and presents a fast and low cost acquisition system that guarantees the creation of 3D models with an high level of detail, making the digitalization of cultural heritage a simply and fast procedure. The 3D models of the artefacts are created with the photogrammetric technique Structure From Motion that makes it possible to obtain, in addition to three-dimensional models, high-definition images for a deepened study and understanding of the artefacts. For the survey of small objects (only few centimetres) it is used a macro lens and the focus stacking, a photographic technique that consists in capturing a stack of images at different focus planes for each camera pose so that is possible to obtain a final image with a higher depth of field. The acquisition with focus stacking technique has been finally validated with an acquisition with laser triangulation scanner Minolta that demonstrates the validity compatible with the allowable error in relation to the expected precision.

The variability of software scoring of the CDMAM phantom associated with a limited number of images

NASA Astrophysics Data System (ADS)

Yang, Chang-Ying J.; Van Metter, Richard

2007-03-01

Software scoring approaches provide an attractive alternative to human evaluation of CDMAM images from digital mammography systems, particularly for annual quality control testing as recommended by the European Protocol for the Quality Control of the Physical and Technical Aspects of Mammography Screening (EPQCM). Methods for correlating CDCOM-based results with human observer performance have been proposed. A common feature of all methods is the use of a small number (at most eight) of CDMAM images to evaluate the system. This study focuses on the potential variability in the estimated system performance that is associated with these methods. Sets of 36 CDMAM images were acquired under carefully controlled conditions from three different digital mammography systems. The threshold visibility thickness (TVT) for each disk diameter was determined using previously reported post-analysis methods from the CDCOM scorings for a randomly selected group of eight images for one measurement trial. This random selection process was repeated 3000 times to estimate the variability in the resulting TVT values for each disk diameter. The results from using different post-analysis methods, different random selection strategies and different digital systems were compared. Additional variability of the 0.1 mm disk diameter was explored by comparing the results from two different image data sets acquired under the same conditions from the same system. The magnitude and the type of error estimated for experimental data was explained through modeling. The modeled results also suggest a limitation in the current phantom design for the 0.1 mm diameter disks. Through modeling, it was also found that, because of the binomial statistic nature of the CDMAM test, the true variability of the test could be underestimated by the commonly used method of random re-sampling.

Performance of dense digital surface models based on image matching in the estimation of plot-level forest variables

NASA Astrophysics Data System (ADS)

Nurminen, Kimmo; Karjalainen, Mika; Yu, Xiaowei; Hyyppä, Juha; Honkavaara, Eija

2013-09-01

Recent research results have shown that the performance of digital surface model extraction using novel high-quality photogrammetric images and image matching is a highly competitive alternative to laser scanning. In this article, we proceed to compare the performance of these two methods in the estimation of plot-level forest variables. Dense point clouds extracted from aerial frame images were used to estimate the plot-level forest variables needed in a forest inventory covering 89 plots. We analyzed images with 60% and 80% forward overlaps and used test plots with off-nadir angles of between 0° and 20°. When compared to reference ground measurements, the airborne laser scanning (ALS) data proved to be the most accurate: it yielded root mean square error (RMSE) values of 6.55% for mean height, 11.42% for mean diameter, and 20.72% for volume. When we applied a forward overlap of 80%, the corresponding results from aerial images were 6.77% for mean height, 12.00% for mean diameter, and 22.62% for volume. A forward overlap of 60% resulted in slightly deteriorated RMSE values of 7.55% for mean height, 12.20% for mean diameter, and 22.77% for volume. According to our results, the use of higher forward overlap produced only slightly better results in the estimation of these forest variables. Additionally, we found that the estimation accuracy was not significantly impacted by the increase in the off-nadir angle. Our results confirmed that digital aerial photographs were about as accurate as ALS in forest resources estimation as long as a terrain model was available.

Digital Longitudinal Tomosynthesis

NASA Astrophysics Data System (ADS)

Rimkus, Daniel Steven

1985-12-01

The purpose of this dissertation was to investigate the clinical utility of digital longitudinal tomosynthesis in radiology. By acquiring a finite group of digital images during a longitudinal tomographic exposure, and processing these images, tomographic planes, other than the fulcrum plane, can be reconstructed. This process is now termed "tomosynthesis". A prototype system utilizing this technique was developed. Both phantom and patient studies were done with this system. The phantom studies were evaluated by subjective, visual criterion and by quantitative analysis of edge sharpness and noise in the reconstructions. Two groups of patients and one volunteer were studied. The first patient group consisted of 8 patients undergoing intravenous urography (IVU). These patients had digital tomography and film tomography of the abdomen. The second patient group consisted of 4 patients with lung cancer admitted to the hospital for laser resection of endobronchial tumor. These patients had mediastinal digital tomograms to evaluate the trachea and mainstem bronchi. The knee of one volunteer was imaged by film tomography and digital tomography. The results of the phantom studies showed that the digital reconstructions accurately produced images of the desired planes. The edge sharpness of the reconstructions approached that of the acquired images. Adequate reconstructions were achieved with as few as 5 images acquired during the exposure, with the quality of the reconstructions improving as the number of images acquired increased. The IVU patients' digital studies had less contrast and spatial resolution than the film tomograms. The single renal lesion visible on the film tomograms was also visible in the digital images. The digital mediastinal studies were felt by several radiologists to be superior to a standard chest xray in evaluating the airways. The digital images of the volunteer's knee showed many of the same anatomic features as the film tomogram, but the digital images had less spatial and contrast resolution. With the equipment improvements discussed in the thesis, digital tomography may have an important role in radiology.

Rapid, low-cost photogrammetry to monitor volcanic eruptions: an example from Mount St. Helens, Washington, USA

USGS Publications Warehouse

Diefenbach, Angela K.; Crider, Juliet G.; Schilling, Steve P.; Dzurisin, Daniel

2012-01-01

We describe a low-cost application of digital photogrammetry using commercially available photogrammetric software and oblique photographs taken with an off-the-shelf digital camera to create sequential digital elevation models (DEMs) of a lava dome that grew during the 2004–2008 eruption of Mount St. Helens (MSH) volcano. Renewed activity at MSH provided an opportunity to devise and test this method, because it could be validated against other observations of this well-monitored volcano. The datasets consist of oblique aerial photographs (snapshots) taken from a helicopter using a digital single-lens reflex camera. Twelve sets of overlapping digital images of the dome taken during 2004–2007 were used to produce DEMs and to calculate lava dome volumes and extrusion rates. Analyses of the digital images were carried out using photogrammetric software to produce three-dimensional coordinates of points identified in multiple photos. The evolving morphology of the dome was modeled by comparing successive DEMs. Results were validated by comparison to volume measurements derived from traditional vertical photogrammetric surveys by the US Geological Survey Cascades Volcano Observatory. Our technique was significantly less expensive and required less time than traditional vertical photogrammetric techniques; yet, it consistently yielded volume estimates within 5% of the traditional method. This technique provides an inexpensive, rapid assessment tool for tracking lava dome growth or other topographic changes at restless volcanoes.

Automatic Large-Scalae 3d Building Shape Refinement Using Conditional Generative Adversarial Networks

NASA Astrophysics Data System (ADS)

Bittner, K.; d'Angelo, P.; Körner, M.; Reinartz, P.

2018-05-01

Three-dimensional building reconstruction from remote sensing imagery is one of the most difficult and important 3D modeling problems for complex urban environments. The main data sources provided the digital representation of the Earths surface and related natural, cultural, and man-made objects of the urban areas in remote sensing are the digital surface models (DSMs). The DSMs can be obtained either by light detection and ranging (LIDAR), SAR interferometry or from stereo images. Our approach relies on automatic global 3D building shape refinement from stereo DSMs using deep learning techniques. This refinement is necessary as the DSMs, which are extracted from image matching point clouds, suffer from occlusions, outliers, and noise. Though most previous works have shown promising results for building modeling, this topic remains an open research area. We present a new methodology which not only generates images with continuous values representing the elevation models but, at the same time, enhances the 3D object shapes, buildings in our case. Mainly, we train a conditional generative adversarial network (cGAN) to generate accurate LIDAR-like DSM height images from the noisy stereo DSM input. The obtained results demonstrate the strong potential of creating large areas remote sensing depth images where the buildings exhibit better-quality shapes and roof forms.

Rigorous Photogrammetric Processing of CHANG'E-1 and CHANG'E-2 Stereo Imagery for Lunar Topographic Mapping

NASA Astrophysics Data System (ADS)

Di, K.; Liu, Y.; Liu, B.; Peng, M.

2012-07-01

Chang'E-1(CE-1) and Chang'E-2(CE-2) are the two lunar orbiters of China's lunar exploration program. Topographic mapping using CE-1 and CE-2 images is of great importance for scientific research as well as for preparation of landing and surface operation of Chang'E-3 lunar rover. In this research, we developed rigorous sensor models of CE-1 and CE-2 CCD cameras based on push-broom imaging principle with interior and exterior orientation parameters. Based on the rigorous sensor model, the 3D coordinate of a ground point in lunar body-fixed (LBF) coordinate system can be calculated by space intersection from the image coordinates of con-jugate points in stereo images, and the image coordinates can be calculated from 3D coordinates by back-projection. Due to uncer-tainties of the orbit and the camera, the back-projected image points are different from the measured points. In order to reduce these inconsistencies and improve precision, we proposed two methods to refine the rigorous sensor model: 1) refining EOPs by correcting the attitude angle bias, 2) refining the interior orientation model by calibration of the relative position of the two linear CCD arrays. Experimental results show that the mean back-projection residuals of CE-1 images are reduced to better than 1/100 pixel by method 1 and the mean back-projection residuals of CE-2 images are reduced from over 20 pixels to 0.02 pixel by method 2. Consequently, high precision DEM (Digital Elevation Model) and DOM (Digital Ortho Map) are automatically generated.

Cost-effective handling of digital medical images in the telemedicine environment.

PubMed

Choong, Miew Keen; Logeswaran, Rajasvaran; Bister, Michel

2007-09-01

This paper concentrates on strategies for less costly handling of medical images. Aspects of digitization using conventional digital cameras, lossy compression with good diagnostic quality, and visualization through less costly monitors are discussed. For digitization of film-based media, subjective evaluation of the suitability of digital cameras as an alternative to the digitizer was undertaken. To save on storage, bandwidth and transmission time, the acceptable degree of compression with diagnostically no loss of important data was studied through randomized double-blind tests of the subjective image quality when compression noise was kept lower than the inherent noise. A diagnostic experiment was undertaken to evaluate normal low cost computer monitors as viable viewing displays for clinicians. The results show that conventional digital camera images of X-ray images were diagnostically similar to the expensive digitizer. Lossy compression, when used moderately with the imaging noise to compression noise ratio (ICR) greater than four, can bring about image improvement with better diagnostic quality than the original image. Statistical analysis shows that there is no diagnostic difference between expensive high quality monitors and conventional computer monitors. The results presented show good potential in implementing the proposed strategies to promote widespread cost-effective telemedicine and digital medical environments. 2006 Elsevier Ireland Ltd

Processing, mosaicking and management of the Monterey Bay digital sidescan-sonar images

USGS Publications Warehouse

Chavez, P.S.; Isbrecht, J.; Galanis, P.; Gabel, G.L.; Sides, S.C.; Soltesz, D.L.; Ross, Stephanie L.; Velasco, M.G.

2002-01-01

Sidescan-sonar imaging systems with digital capabilities have now been available for approximately 20 years. In this paper we present several of the various digital image processing techniques developed by the U.S. Geological Survey (USGS) and used to apply intensity/radiometric and geometric corrections, as well as enhance and digitally mosaic, sidescan-sonar images of the Monterey Bay region. New software run by a WWW server was designed and implemented to allow very large image data sets, such as the digital mosaic, to be easily viewed interactively, including the ability to roam throughout the digital mosaic at the web site in either compressed or full 1-m resolution. The processing is separated into the two different stages: preprocessing and information extraction. In the preprocessing stage, sensor-specific algorithms are applied to correct for both geometric and intensity/radiometric distortions introduced by the sensor. This is followed by digital mosaicking of the track-line strips into quadrangle format which can be used as input to either visual or digital image analysis and interpretation. An automatic seam removal procedure was used in combination with an interactive digital feathering/stenciling procedure to help minimize tone or seam matching problems between image strips from adjacent track-lines. The sidescan-sonar image processing package is part of the USGS Mini Image Processing System (MIPS) and has been designed to process data collected by any 'generic' digital sidescan-sonar imaging system. The USGS MIPS software, developed over the last 20 years as a public domain package, is available on the WWW at: http://terraweb.wr.usgs.gov/trs/software.html.

City of Flagstaff Project: Ground Water Resource Evaluation, Remote Sensing Component

USGS Publications Warehouse

Chavez, Pat S.; Velasco, Miguel G.; Bowell, Jo-Ann; Sides, Stuart C.; Gonzalez, Rosendo R.; Soltesz, Deborah L.

1996-01-01

Many regions, cities, and towns in the Western United States need new or expanded water resources because of both population growth and increased development. Any tools or data that can help in the evaluation of an area's potential water resources must be considered for this increasingly critical need. Remotely sensed satellite images and subsequent digital image processing have been under-utilized in ground water resource evaluation and exploration. Satellite images can be helpful in detecting and mapping an area's regional structural patterns, including major fracture and fault systems, two important geologic settings for an area's surface to ground water relations. Within the United States Geological Survey's (USGS) Flagstaff Field Center, expertise and capabilities in remote sensing and digital image processing have been developed over the past 25 years through various programs. For the City of Flagstaff project, this expertise and these capabilities were combined with traditional geologic field mapping to help evaluate ground water resources in the Flagstaff area. Various enhancement and manipulation procedures were applied to the digital satellite images; the results, in both digital and hardcopy format, were used for field mapping and analyzing the regional structure. Relative to surface sampling, remotely sensed satellite and airborne images have improved spatial coverage that can help study, map, and monitor the earth surface at local and/or regional scales. Advantages offered by remotely sensed satellite image data include: 1. a synoptic/regional view compared to both aerial photographs and ground sampling, 2. cost effectiveness, 3. high spatial resolution and coverage compared to ground sampling, and 4. relatively high temporal coverage on a long term basis. Remotely sensed images contain both spectral and spatial information. The spectral information provides various properties and characteristics about the surface cover at a given location or pixel (that is, vegetation and/or soil type). The spatial information gives the distribution, variation, and topographic relief of the cover types from pixel to pixel. Therefore, the main characteristics that determine a pixel's brightness/reflectance and, consequently, the digital number (DN) assigned to the pixel, are the physical properties of the surface and near surface, the cover type, and the topographic slope. In this application, the ability to detect and map lineaments, especially those related to fractures and faults, is critical. Therefore, the extraction of spatial information from the digital images was of prime interest in this project. The spatial information varies among the different spectral bands available; in particular, a near infrared spectral band is better than a visible band when extracting spatial information in highly vegetated areas. In this study, both visible and near infrared bands were analyzed and used to extract the desired spatial information from the images. The wide swath coverage of remotely sensed satellite digital images makes them ideal for regional analysis and mapping. Since locating and mapping highly fractured and faulted areas is a major requirement for ground water resource evaluation and exploration this aspect of satellite images was considered critical; it allowed us to stand back (actually up about 440 miles), look at, and map the regional structural setting of the area. The main focus of the remote sensing and digital image processing component of this project was to use both remotely sensed digital satellite images and a Digital Elevation Model (DEM) to extract spatial information related to the structural and topographic patterns in the area. The data types used were digital satellite images collected by the United States' Landsat Thematic Mapper (TM) and French Systeme Probatoire d'Observation de laTerre (SPOT) imaging systems, along with a DEM of the Flagstaff region. The USGS Mini Image Processing Sy

A New Method for Non-destructive Measurement of Biomass, Growth Rates, Vertical Biomass Distribution and Dry Matter Content Based on Digital Image Analysis

PubMed Central

Tackenberg, Oliver

2007-01-01

Background and Aims Biomass is an important trait in functional ecology and growth analysis. The typical methods for measuring biomass are destructive. Thus, they do not allow the development of individual plants to be followed and they require many individuals to be cultivated for repeated measurements. Non-destructive methods do not have these limitations. Here, a non-destructive method based on digital image analysis is presented, addressing not only above-ground fresh biomass (FBM) and oven-dried biomass (DBM), but also vertical biomass distribution as well as dry matter content (DMC) and growth rates. Methods Scaled digital images of the plants silhouettes were taken for 582 individuals of 27 grass species (Poaceae). Above-ground biomass and DMC were measured using destructive methods. With image analysis software Zeiss KS 300, the projected area and the proportion of greenish pixels were calculated, and generalized linear models (GLMs) were developed with destructively measured parameters as dependent variables and parameters derived from image analysis as independent variables. A bootstrap analysis was performed to assess the number of individuals required for re-calibration of the models. Key Results The results of the developed models showed no systematic errors compared with traditionally measured values and explained most of their variance (R2 ≥ 0·85 for all models). The presented models can be directly applied to herbaceous grasses without further calibration. Applying the models to other growth forms might require a re-calibration which can be based on only 10–20 individuals for FBM or DMC and on 40–50 individuals for DBM. Conclusions The methods presented are time and cost effective compared with traditional methods, especially if development or growth rates are to be measured repeatedly. Hence, they offer an alternative way of determining biomass, especially as they are non-destructive and address not only FBM and DBM, but also vertical biomass distribution and DMC. PMID:17353204

Low-cost conversion of the Polaroid MD-4 land camera to a digital gel documentation system.

PubMed

Porch, Timothy G; Erpelding, John E

2006-04-30

A simple, inexpensive design is presented for the rapid conversion of the popular MD-4 Polaroid land camera to a high quality digital gel documentation system. Images of ethidium bromide stained DNA gels captured using the digital system were compared to images captured on Polaroid instant film. Resolution and sensitivity were enhanced using the digital system. In addition to the low cost and superior image quality of the digital system, there is also the added convenience of real-time image viewing through the swivel LCD of the digital camera, wide flexibility of gel sizes, accurate automatic focusing, variable image resolution, and consistent ease of use and quality. Images can be directly imported to a computer by using the USB port on the digital camera, further enhancing the potential of the digital system for documentation, analysis, and archiving. The system is appropriate for use as a start-up gel documentation system and for routine gel analysis.

Digital imaging and remote sensing image generator (DIRSIG) as applied to NVESD sensor performance modeling

NASA Astrophysics Data System (ADS)

Kolb, Kimberly E.; Choi, Hee-sue S.; Kaur, Balvinder; Olson, Jeffrey T.; Hill, Clayton F.; Hutchinson, James A.

2016-05-01

The US Army's Communications Electronics Research, Development and Engineering Center (CERDEC) Night Vision and Electronic Sensors Directorate (referred to as NVESD) is developing a virtual detection, recognition, and identification (DRI) testing methodology using simulated imagery as a means of augmenting the field testing component of sensor performance evaluation, which is expensive, resource intensive, time consuming, and limited to the available target(s) and existing atmospheric visibility and environmental conditions at the time of testing. Existing simulation capabilities such as the Digital Imaging Remote Sensing Image Generator (DIRSIG) and NVESD's Integrated Performance Model Image Generator (NVIPM-IG) can be combined with existing detection algorithms to reduce cost/time, minimize testing risk, and allow virtual/simulated testing using full spectral and thermal object signatures, as well as those collected in the field. NVESD has developed an end-to-end capability to demonstrate the feasibility of this approach. Simple detection algorithms have been used on the degraded images generated by NVIPM-IG to determine the relative performance of the algorithms on both DIRSIG-simulated and collected images. Evaluating the degree to which the algorithm performance agrees between simulated versus field collected imagery is the first step in validating the simulated imagery procedure.

Programmable Remapper with Single Flow Architecture

NASA Technical Reports Server (NTRS)

Fisher, Timothy E. (Inventor)

1993-01-01

An apparatus for image processing comprising a camera for receiving an original visual image and transforming the original visual image into an analog image, a first converter for transforming the analog image of the camera to a digital image, a processor having a single flow architecture for receiving the digital image and producing, with a single algorithm, an output image, a second converter for transforming the digital image of the processor to an analog image, and a viewer for receiving the analog image, transforming the analog image into a transformed visual image for observing the transformations applied to the original visual image. The processor comprises one or more subprocessors for the parallel reception of a digital image for producing an output matrix of the transformed visual image. More particularly, the processor comprises a plurality of subprocessors for receiving in parallel and transforming the digital image for producing a matrix of the transformed visual image, and an output interface means for receiving the respective portions of the transformed visual image from the respective subprocessor for producing an output matrix of the transformed visual image.

Digital Imaging and the Cognitive Revolution: A Media Challenge.

ERIC Educational Resources Information Center

Sartorius, Ute

This paper discusses the role of digital technology within the cognitive revolution of the perception of images. It analyzes the traditional values placed on images as a source of cognition. These values are discussed in terms of the ethical and social issues raised by the use of digital image manipulation in so far as the digital era is falsely…

Data Visualization and Animation Lab (DVAL) overview

NASA Technical Reports Server (NTRS)

Stacy, Kathy; Vonofenheim, Bill

1994-01-01

The general capabilities of the Langley Research Center Data Visualization and Animation Laboratory is described. These capabilities include digital image processing, 3-D interactive computer graphics, data visualization and analysis, video-rate acquisition and processing of video images, photo-realistic modeling and animation, video report generation, and color hardcopies. A specialized video image processing system is also discussed.

A deep learning method for classifying mammographic breast density categories.

PubMed

Mohamed, Aly A; Berg, Wendie A; Peng, Hong; Luo, Yahong; Jankowitz, Rachel C; Wu, Shandong

2018-01-01

Mammographic breast density is an established risk marker for breast cancer and is visually assessed by radiologists in routine mammogram image reading, using four qualitative Breast Imaging and Reporting Data System (BI-RADS) breast density categories. It is particularly difficult for radiologists to consistently distinguish the two most common and most variably assigned BI-RADS categories, i.e., "scattered density" and "heterogeneously dense". The aim of this work was to investigate a deep learning-based breast density classifier to consistently distinguish these two categories, aiming at providing a potential computerized tool to assist radiologists in assigning a BI-RADS category in current clinical workflow. In this study, we constructed a convolutional neural network (CNN)-based model coupled with a large (i.e., 22,000 images) digital mammogram imaging dataset to evaluate the classification performance between the two aforementioned breast density categories. All images were collected from a cohort of 1,427 women who underwent standard digital mammography screening from 2005 to 2016 at our institution. The truths of the density categories were based on standard clinical assessment made by board-certified breast imaging radiologists. Effects of direct training from scratch solely using digital mammogram images and transfer learning of a pretrained model on a large nonmedical imaging dataset were evaluated for the specific task of breast density classification. In order to measure the classification performance, the CNN classifier was also tested on a refined version of the mammogram image dataset by removing some potentially inaccurately labeled images. Receiver operating characteristic (ROC) curves and the area under the curve (AUC) were used to measure the accuracy of the classifier. The AUC was 0.9421 when the CNN-model was trained from scratch on our own mammogram images, and the accuracy increased gradually along with an increased size of training samples. Using the pretrained model followed by a fine-tuning process with as few as 500 mammogram images led to an AUC of 0.9265. After removing the potentially inaccurately labeled images, AUC was increased to 0.9882 and 0.9857 for without and with the pretrained model, respectively, both significantly higher (P < 0.001) than when using the full imaging dataset. Our study demonstrated high classification accuracies between two difficult to distinguish breast density categories that are routinely assessed by radiologists. We anticipate that our approach will help enhance current clinical assessment of breast density and better support consistent density notification to patients in breast cancer screening. © 2017 American Association of Physicists in Medicine.

Digital photography for the light microscope: results with a gated, video-rate CCD camera and NIH-image software.

PubMed

Shaw, S L; Salmon, E D; Quatrano, R S

1995-12-01

In this report, we describe a relatively inexpensive method for acquiring, storing and processing light microscope images that combines the advantages of video technology with the powerful medium now termed digital photography. Digital photography refers to the recording of images as digital files that are stored, manipulated and displayed using a computer. This report details the use of a gated video-rate charge-coupled device (CCD) camera and a frame grabber board for capturing 256 gray-level digital images from the light microscope. This camera gives high-resolution bright-field, phase contrast and differential interference contrast (DIC) images but, also, with gated on-chip integration, has the capability to record low-light level fluorescent images. The basic components of the digital photography system are described, and examples are presented of fluorescence and bright-field micrographs. Digital processing of images to remove noise, to enhance contrast and to prepare figures for printing is discussed.

Using Multi-Angle WorldView-2 Imagery to Determine Ocean Depth Near Oahu, Hawaii

DTIC Science & Technology

2012-09-01

Reflection geometry used in the definition of BRDF (From McConnon [2010...Visible/InfraRed Imaging Spectrometer BRDF : Bidirectional Reflectance Distribution Function DHMs: Digital Height Maps DNs: Digital Numbers EM...navigation and fisheries management, and are also helpful for improving models of ocean circulation, air-sea interaction, weather forecasting, and

Digital focusing of OCT images based on scalar diffraction theory and information entropy.

PubMed

Liu, Guozhong; Zhi, Zhongwei; Wang, Ruikang K

2012-11-01

This paper describes a digital method that is capable of automatically focusing optical coherence tomography (OCT) en face images without prior knowledge of the point spread function of the imaging system. The method utilizes a scalar diffraction model to simulate wave propagation from out-of-focus scatter to the focal plane, from which the propagation distance between the out-of-focus plane and the focal plane is determined automatically via an image-definition-evaluation criterion based on information entropy theory. By use of the proposed approach, we demonstrate that the lateral resolution close to that at the focal plane can be recovered from the imaging planes outside the depth of field region with minimal loss of resolution. Fresh onion tissues and mouse fat tissues are used in the experiments to show the performance of the proposed method.

NASA's Earth Science Use of Commercially Availiable Remote Sensing Datasets: Cover Image

NASA Technical Reports Server (NTRS)

Underwood, Lauren W.; Goward, Samuel N.; Fearon, Matthew G.; Fletcher, Rose; Garvin, Jim; Hurtt, George

2008-01-01

The cover image incorporates high resolution stereo pairs acquired from the DigitalGlobe(R) QuickBird sensor. It shows a digital elevation model of Meteor Crater, Arizona at approximately 1.3 meter point-spacing. Image analysts used the Leica Photogrammetry Suite to produce the DEM. The outside portion was computed from two QuickBird panchromatic scenes acquired October 2006, while an Optech laser scan dataset was used for the crater s interior elevations. The crater s terrain model and image drape were created in a NASA Constellation Program project focused on simulating lunar surface environments for prototyping and testing lunar surface mission analysis and planning tools. This work exemplifies NASA s Scientific Data Purchase legacy and commercial high resolution imagery applications, as scientists use commercial high resolution data to examine lunar analog Earth landscapes for advanced planning and trade studies for future lunar surface activities. Other applications include landscape dynamics related to volcanism, hydrologic events, climate change, and ice movement.

Global detection of large lunar craters based on the CE-1 digital elevation model

NASA Astrophysics Data System (ADS)

Luo, Lei; Mu, Lingli; Wang, Xinyuan; Li, Chao; Ji, Wei; Zhao, Jinjin; Cai, Heng

2013-12-01

Craters, one of the most significant features of the lunar surface, have been widely researched because they offer us the relative age of the surface unit as well as crucial geological information. Research on crater detection algorithms (CDAs) of the Moon and other planetary bodies has concentrated on detecting them from imagery data, but the computational cost of detecting large craters using images makes these CDAs impractical. This paper presents a new approach to crater detection that utilizes a digital elevation model instead of images; this enables fully automatic global detection of large craters. Craters were delineated by terrain attributes, and then thresholding maps of terrain attributes were used to transform topographic data into a binary image, finally craters were detected by using the Hough Transform from the binary image. By using the proposed algorithm, we produced a catalog of all craters ⩾10 km in diameter on the lunar surface and analyzed their distribution and population characteristics.

A Validation Approach for Quasistatic Numerical/Experimental Indentation Analysis in Soft Materials Using 3D Digital Image Correlation.

PubMed

Felipe-Sesé, Luis; López-Alba, Elías; Hannemann, Benedikt; Schmeer, Sebastian; Diaz, Francisco A

2017-06-28

A quasistatic indentation numerical analysis in a round section specimen made of soft material has been performed and validated with a full field experimental technique, i.e., Digital Image Correlation 3D. The contact experiment specifically consisted of loading a 25 mm diameter rubber cylinder of up to a 5 mm indentation and then unloading. Experimental strains fields measured at the surface of the specimen during the experiment were compared with those obtained by performing two numerical analyses employing two different hyperplastic material models. The comparison was performed using an Image Decomposition new methodology that makes a direct comparison of full-field data independently of their scale or orientation possible. Numerical results show a good level of agreement with those measured during the experiments. However, since image decomposition allows for the differences to be quantified, it was observed that one of the adopted material models reproduces lower differences compared to experimental results.

A Validation Approach for Quasistatic Numerical/Experimental Indentation Analysis in Soft Materials Using 3D Digital Image Correlation

PubMed Central

Felipe-Sesé, Luis; López-Alba, Elías; Hannemann, Benedikt; Schmeer, Sebastian; Diaz, Francisco A.

2017-01-01

A quasistatic indentation numerical analysis in a round section specimen made of soft material has been performed and validated with a full field experimental technique, i.e., Digital Image Correlation 3D. The contact experiment specifically consisted of loading a 25 mm diameter rubber cylinder of up to a 5 mm indentation and then unloading. Experimental strains fields measured at the surface of the specimen during the experiment were compared with those obtained by performing two numerical analyses employing two different hyperplastic material models. The comparison was performed using an Image Decomposition new methodology that makes a direct comparison of full-field data independently of their scale or orientation possible. Numerical results show a good level of agreement with those measured during the experiments. However, since image decomposition allows for the differences to be quantified, it was observed that one of the adopted material models reproduces lower differences compared to experimental results. PMID:28773081

Shape priors for segmentation of the cervix region within uterine cervix images

NASA Astrophysics Data System (ADS)

Lotenberg, Shelly; Gordon, Shiri; Greenspan, Hayit

2008-03-01

The work focuses on a unique medical repository of digital Uterine Cervix images ("Cervigrams") collected by the National Cancer Institute (NCI), National Institute of Health, in longitudinal multi-year studies. NCI together with the National Library of Medicine is developing a unique web-based database of the digitized cervix images to study the evolution of lesions related to cervical cancer. Tools are needed for the automated analysis of the cervigram content to support the cancer research. In recent works, a multi-stage automated system for segmenting and labeling regions of medical and anatomical interest within the cervigrams was developed. The current paper concentrates on incorporating prior-shape information in the cervix region segmentation task. In accordance with the fact that human experts mark the cervix region as circular or elliptical, two shape models (and corresponding methods) are suggested. The shape models are embedded within an active contour framework that relies on image features. Experiments indicate that incorporation of the prior shape information augments previous results.

Remote Sensing Image Quality Assessment Experiment with Post-Processing

NASA Astrophysics Data System (ADS)

Jiang, W.; Chen, S.; Wang, X.; Huang, Q.; Shi, H.; Man, Y.

2018-04-01

This paper briefly describes the post-processing influence assessment experiment, the experiment includes three steps: the physical simulation, image processing, and image quality assessment. The physical simulation models sampled imaging system in laboratory, the imaging system parameters are tested, the digital image serving as image processing input are produced by this imaging system with the same imaging system parameters. The gathered optical sampled images with the tested imaging parameters are processed by 3 digital image processes, including calibration pre-processing, lossy compression with different compression ratio and image post-processing with different core. Image quality assessment method used is just noticeable difference (JND) subject assessment based on ISO20462, through subject assessment of the gathered and processing images, the influence of different imaging parameters and post-processing to image quality can be found. The six JND subject assessment experimental data can be validated each other. Main conclusions include: image post-processing can improve image quality; image post-processing can improve image quality even with lossy compression, image quality with higher compression ratio improves less than lower ratio; with our image post-processing method, image quality is better, when camera MTF being within a small range.

Digital management and regulatory submission of medical images from clinical trials: role and benefits of the core laboratory

NASA Astrophysics Data System (ADS)

Robbins, William L.; Conklin, James J.

1995-10-01

Medical images (angiography, CT, MRI, nuclear medicine, ultrasound, x ray) play an increasingly important role in the clinical development and regulatory review process for pharmaceuticals and medical devices. Since medical images are increasingly acquired and archived digitally, or are readily digitized from film, they can be visualized, processed and analyzed in a variety of ways using digital image processing and display technology. Moreover, with image-based data management and data visualization tools, medical images can be electronically organized and submitted to the U.S. Food and Drug Administration (FDA) for review. The collection, processing, analysis, archival, and submission of medical images in a digital format versus an analog (film-based) format presents both challenges and opportunities for the clinical and regulatory information management specialist. The medical imaging 'core laboratory' is an important resource for clinical trials and regulatory submissions involving medical imaging data. Use of digital imaging technology within a core laboratory can increase efficiency and decrease overall costs in the image data management and regulatory review process.

Pre-Flight Radiometric Model of Linear Imager on LAPAN-IPB Satellite

NASA Astrophysics Data System (ADS)

Hadi Syafrudin, A.; Salaswati, Sartika; Hasbi, Wahyudi

2018-05-01

LAPAN-IPB Satellite is Microsatellite class with mission of remote sensing experiment. This satellite carrying Multispectral Line Imager for captured of radiometric reflectance value from earth to space. Radiometric quality of image is important factor to classification object on remote sensing process. Before satellite launch in orbit or pre-flight, Line Imager have been tested by Monochromator and integrating sphere to get spectral and every pixel radiometric response characteristic. Pre-flight test data with variety setting of line imager instrument used to see correlation radiance input and digital number of images output. Output input correlation is described by the radiance conversion model with imager setting and radiometric characteristics. Modelling process from hardware level until normalize radiance formula are presented and discussed in this paper.

3D documentation and visualization of external injury findings by integration of simple photography in CT/MRI data sets (IprojeCT).

PubMed

Campana, Lorenzo; Breitbeck, Robert; Bauer-Kreuz, Regula; Buck, Ursula

2016-05-01

This study evaluated the feasibility of documenting patterned injury using three dimensions and true colour photography without complex 3D surface documentation methods. This method is based on a generated 3D surface model using radiologic slice images (CT) while the colour information is derived from photographs taken with commercially available cameras. The external patterned injuries were documented in 16 cases using digital photography as well as highly precise photogrammetry-supported 3D structured light scanning. The internal findings of these deceased were recorded using CT and MRI. For registration of the internal with the external data, two different types of radiographic markers were used and compared. The 3D surface model generated from CT slice images was linked with the photographs, and thereby digital true-colour 3D models of the patterned injuries could be created (Image projection onto CT/IprojeCT). In addition, these external models were merged with the models of the somatic interior. We demonstrated that 3D documentation and visualization of external injury findings by integration of digital photography in CT/MRI data sets is suitable for the 3D documentation of individual patterned injuries to a body. Nevertheless, this documentation method is not a substitution for photogrammetry and surface scanning, especially when the entire bodily surface is to be recorded in three dimensions including all external findings, and when precise data is required for comparing highly detailed injury features with the injury-inflicting tool.

The future of structural fieldwork - UAV assisted aerial photogrammetry

NASA Astrophysics Data System (ADS)

Vollgger, Stefan; Cruden, Alexander

2015-04-01

Unmanned aerial vehicles (UAVs), commonly referred to as drones, are opening new and low cost possibilities to acquire high-resolution aerial images and digital surface models (DSM) for applications in structural geology. UAVs can be programmed to fly autonomously along a user defined grid to systematically capture high-resolution photographs, even in difficult to access areas. The photographs are subsequently processed using software that employ SIFT (scale invariant feature transform) and SFM (structure from motion) algorithms. These photogrammetric routines allow the extraction of spatial information (3D point clouds, digital elevation models, 3D meshes, orthophotos) from 2D images. Depending on flight altitude and camera setup, sub-centimeter spatial resolutions can be achieved. By "digitally mapping" georeferenced 3D models and images, orientation data can be extracted directly and used to analyse the structural framework of the mapped object or area. We present UAV assisted aerial mapping results from a coastal platform near Cape Liptrap (Victoria, Australia), where deformed metasediments of the Palaeozoic Lachlan Fold Belt are exposed. We also show how orientation and spatial information of brittle and ductile structures extracted from the photogrammetric model can be linked to the progressive development of folds and faults in the region. Even though there are both technical and legislative limitations, which might prohibit the use of UAVs without prior commercial licensing and training, the benefits that arise from the resulting high-resolution, photorealistic models can substantially contribute to the collection of new data and insights for applications in structural geology.

Spatial resolution properties of digital autoradiography systems for pre-clinical alpha particle imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Tanguay, Jesse; Benard, Francois; Celler, Anna; Ruth, Thomas; Schaffer, Paul

2017-03-01

Attaching alpha-emitting radionuclides to cancer-targeting agents increases the anti-tumor effects of targeted cancer therapies. The success of alpha therapy for treating bone metastases has increased interest in using targeted alpha therapy (TAT) to treat a broad spectrum of metastatic cancers. Estimating radiation doses to targeted tumors, including small (<250 μm) clusters of cancer cells, and to non-targeted tissues is critical in the pre-clinical development of TATs. However, accurate quantification of heterogeneous distributions of alpha-emitters in small metastases is not possible with existing pre-clinical in-vivo imaging systems. Ex-vivo digital autoradiography using a scintillator in combination with an image intensifier and a charged coupled device (CCD) has gained interest for pre-clinical ex-vivo alpha particle imaging. We present a simulation-based analysis of the fundamental spatial resolution limits of digital autoradiography systems. Spatial resolution was quantified in terms of the modulation transfer function (MTF) and Wagner's equivalent aperture. We modeled systems operating in either particle-counting (PC) or energy-integrating (EI) mode using a cascaded systems approach that accounts for: 1) the stopping power of alpha particles; 2) the distance alpha particles travel within the scintillator; 3) optical blur, and; 4) binning in detector elements. We applied our analysis to imaging of astatine-211 using an LYSO scintillator with thickness ranging from 10 μm to 20 μm. Our analysis demonstrates that when these systems are operated in particle-counting mode with a centroid-calculation algorithm, the effective apertures of 35 μm can be achieved, which suggests that digital autoradiography may enable quantifying the uptake of alpha emitters in tumors consisting of a few cancer cells. Future work will investigate the image noise and energy-resolution properties of digital autoradiography systems.

The x-ray light valve: a potentially low-cost, digital radiographic imaging system--a liquid crystal cell design for chest radiography.

PubMed

Szeto, Timothy C; Webster, Christie Ann; Koprinarov, Ivaylo; Rowlands, J A

2008-03-01

Digital x-ray radiographic systems are desirable as they offer high quality images which can be processed, transferred, and stored without secondary steps. However, current clinical systems are extraordinarily expensive in comparison to film-based systems. Thus, there is a need for an economical digital imaging system for general radiology. The x-ray light valve (XLV) is a novel digital x-ray detector concept with the potential for high image quality and low cost. The XLV is comprised of a photoconductive detector layer and liquid crystal (LC) cell physically coupled in a sandwich structure. Upon exposure to x rays, charge is collected at the surface of the photoconductor, causing a change in the reflective properties of the LC cell. The visible image so formed can subsequently be digitized with an optical scanner. By choosing the properties of the LC cell in combination with the appropriate photoconductor thickness and bias potentials, the XLV can be optimized for various diagnostic imaging tasks. Specifically for chest radiography, we identified three potentially practical reflective cell designs by selecting from those commonly used in LC display technology. The relationship between reflectance and x-ray exposure (i.e., the characteristic curve) was determined for all three cells using a theoretical model. The results indicate that the reflective electrically controlled birefringence (r-ECB) cell is the preferred choice for chest radiography, provided that the characteristic curve can be shifted towards lower exposures. The feasibility of the shift of the characteristic curve is shown experimentally. The experimental results thus demonstrate that an XLV based on the r-ECB cell design exhibits a characteristic curve suitable for chest radiography.

Introducing DeBRa: a detailed breast model for radiological studies

NASA Astrophysics Data System (ADS)

Ma, Andy K. W.; Gunn, Spencer; Darambara, Dimitra G.

2009-07-01

Currently, x-ray mammography is the method of choice in breast cancer screening programmes. As the mammography technology moves from 2D imaging modalities to 3D, conventional computational phantoms do not have sufficient detail to support the studies of these advanced imaging systems. Studies of these 3D imaging systems call for a realistic and sophisticated computational model of the breast. DeBRa (Detailed Breast model for Radiological studies) is the most advanced, detailed, 3D computational model of the breast developed recently for breast imaging studies. A DeBRa phantom can be constructed to model a compressed breast, as in film/screen, digital mammography and digital breast tomosynthesis studies, or a non-compressed breast as in positron emission mammography and breast CT studies. Both the cranial-caudal and mediolateral oblique views can be modelled. The anatomical details inside the phantom include the lactiferous duct system, the Cooper ligaments and the pectoral muscle. The fibroglandular tissues are also modelled realistically. In addition, abnormalities such as microcalcifications, irregular tumours and spiculated tumours are inserted into the phantom. Existing sophisticated breast models require specialized simulation codes. Unlike its predecessors, DeBRa has elemental compositions and densities incorporated into its voxels including those of the explicitly modelled anatomical structures and the noise-like fibroglandular tissues. The voxel dimensions are specified as needed by any study and the microcalcifications are embedded into the voxels so that the microcalcification sizes are not limited by the voxel dimensions. Therefore, DeBRa works with general-purpose Monte Carlo codes. Furthermore, general-purpose Monte Carlo codes allow different types of imaging modalities and detector characteristics to be simulated with ease. DeBRa is a versatile and multipurpose model specifically designed for both x-ray and γ-ray imaging studies.

A Semi-Automatic Image-Based Close Range 3D Modeling Pipeline Using a Multi-Camera Configuration

PubMed Central

Rau, Jiann-Yeou; Yeh, Po-Chia

2012-01-01

The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum. PMID:23112656

A semi-automatic image-based close range 3D modeling pipeline using a multi-camera configuration.

PubMed

Rau, Jiann-Yeou; Yeh, Po-Chia

2012-01-01

The generation of photo-realistic 3D models is an important task for digital recording of cultural heritage objects. This study proposes an image-based 3D modeling pipeline which takes advantage of a multi-camera configuration and multi-image matching technique that does not require any markers on or around the object. Multiple digital single lens reflex (DSLR) cameras are adopted and fixed with invariant relative orientations. Instead of photo-triangulation after image acquisition, calibration is performed to estimate the exterior orientation parameters of the multi-camera configuration which can be processed fully automatically using coded targets. The calibrated orientation parameters of all cameras are applied to images taken using the same camera configuration. This means that when performing multi-image matching for surface point cloud generation, the orientation parameters will remain the same as the calibrated results, even when the target has changed. Base on this invariant character, the whole 3D modeling pipeline can be performed completely automatically, once the whole system has been calibrated and the software was seamlessly integrated. Several experiments were conducted to prove the feasibility of the proposed system. Images observed include that of a human being, eight Buddhist statues, and a stone sculpture. The results for the stone sculpture, obtained with several multi-camera configurations were compared with a reference model acquired by an ATOS-I 2M active scanner. The best result has an absolute accuracy of 0.26 mm and a relative accuracy of 1:17,333. It demonstrates the feasibility of the proposed low-cost image-based 3D modeling pipeline and its applicability to a large quantity of antiques stored in a museum.

Magnetic resonance imaging of the normal bovine digit.

PubMed

Raji, A R; Sardari, K; Mirmahmoob, P

2009-08-01

The purpose of this study was defining the normal structures of the digits and hoof in Holstein dairy cattle using Magnetic Resonance Image (MRI). Transverse, Sagital and Dorsoplantar MRI images of three isolated cattle cadaver digits were obtained using Gyroscan T5-NT a magnet of 0.5 Tesla and T1 Weighted sequence. The MRI images were compared to corresponding frozen cross-sections and dissect specimens of the cadaver digits. Relevant anatomical structures were identified and labeled at each level. The MRI images provided anatomical detail of the digits and hoof in Holstein dairy cattle. Transversal images provided excellent depiction of anatomical structures when compared to corresponding frozen cross-sections. The information presented in this paper would serve as an initial reference to the evaluation of MRI images of the digits and hoof in Holstein dairy cattle, that can be used by radiologist, clinicians, surgeon or for research propose in bovine lameness.

Digital atlas of fetal brain MRI.

PubMed

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.

Synchronous-digitization for Video Rate Polarization Modulated Beam Scanning Second Harmonic Generation Microscopy.

PubMed

Sullivan, Shane Z; DeWalt, Emma L; Schmitt, Paul D; Muir, Ryan M; Simpson, Garth J

2015-03-09

Fast beam-scanning non-linear optical microscopy, coupled with fast (8 MHz) polarization modulation and analytical modeling have enabled simultaneous nonlinear optical Stokes ellipsometry (NOSE) and linear Stokes ellipsometry imaging at video rate (15 Hz). NOSE enables recovery of the complex-valued Jones tensor that describes the polarization-dependent observables, in contrast to polarimetry, in which the polarization stated of the exciting beam is recorded. Each data acquisition consists of 30 images (10 for each detector, with three detectors operating in parallel), each of which corresponds to polarization-dependent results. Processing of this image set by linear fitting contracts down each set of 10 images to a set of 5 parameters for each detector in second harmonic generation (SHG) and three parameters for the transmittance of the fundamental laser beam. Using these parameters, it is possible to recover the Jones tensor elements of the sample at video rate. Video rate imaging is enabled by performing synchronous digitization (SD), in which a PCIe digital oscilloscope card is synchronized to the laser (the laser is the master clock.) Fast polarization modulation was achieved by modulating an electro-optic modulator synchronously with the laser and digitizer, with a simple sine-wave at 1/10th the period of the laser, producing a repeating pattern of 10 polarization states. This approach was validated using Z-cut quartz, and NOSE microscopy was performed for micro-crystals of naproxen.

Synchronous-digitization for video rate polarization modulated beam scanning second harmonic generation microscopy

NASA Astrophysics Data System (ADS)

Sullivan, Shane Z.; DeWalt, Emma L.; Schmitt, Paul D.; Muir, Ryan D.; Simpson, Garth J.

2015-03-01

Fast beam-scanning non-linear optical microscopy, coupled with fast (8 MHz) polarization modulation and analytical modeling have enabled simultaneous nonlinear optical Stokes ellipsometry (NOSE) and linear Stokes ellipsometry imaging at video rate (15 Hz). NOSE enables recovery of the complex-valued Jones tensor that describes the polarization-dependent observables, in contrast to polarimetry, in which the polarization stated of the exciting beam is recorded. Each data acquisition consists of 30 images (10 for each detector, with three detectors operating in parallel), each of which corresponds to polarization-dependent results. Processing of this image set by linear fitting contracts down each set of 10 images to a set of 5 parameters for each detector in second harmonic generation (SHG) and three parameters for the transmittance of the fundamental laser beam. Using these parameters, it is possible to recover the Jones tensor elements of the sample at video rate. Video rate imaging is enabled by performing synchronous digitization (SD), in which a PCIe digital oscilloscope card is synchronized to the laser (the laser is the master clock.) Fast polarization modulation was achieved by modulating an electro-optic modulator synchronously with the laser and digitizer, with a simple sine-wave at 1/10th the period of the laser, producing a repeating pattern of 10 polarization states. This approach was validated using Z-cut quartz, and NOSE microscopy was performed for micro-crystals of naproxen.

[Development of a digital chest phantom for studies on energy subtraction techniques].

PubMed

Hayashi, Norio; Taniguchi, Anna; Noto, Kimiya; Shimosegawa, Masayuki; Ogura, Toshihiro; Doi, Kunio

2014-03-01

Digital chest phantoms continue to play a significant role in optimizing imaging parameters for chest X-ray examinations. The purpose of this study was to develop a digital chest phantom for studies on energy subtraction techniques under ideal conditions without image noise. Computed tomography (CT) images from the LIDC (Lung Image Database Consortium) were employed to develop a digital chest phantom. The method consisted of the following four steps: 1) segmentation of the lung and bone regions on CT images; 2) creation of simulated nodules; 3) transformation to attenuation coefficient maps from the segmented images; and 4) projection from attenuation coefficient maps. To evaluate the usefulness of digital chest phantoms, we determined the contrast of the simulated nodules in projection images of the digital chest phantom using high and low X-ray energies, soft tissue images obtained by energy subtraction, and "gold standard" images of the soft tissues. Using our method, the lung and bone regions were segmented on the original CT images. The contrast of simulated nodules in soft tissue images obtained by energy subtraction closely matched that obtained using the gold standard images. We thus conclude that it is possible to carry out simulation studies based on energy subtraction techniques using the created digital chest phantoms. Our method is potentially useful for performing simulation studies for optimizing the imaging parameters in chest X-ray examinations.

Three-dimensional information extraction from GaoFen-1 satellite images for landslide monitoring

NASA Astrophysics Data System (ADS)

Wang, Shixin; Yang, Baolin; Zhou, Yi; Wang, Futao; Zhang, Rui; Zhao, Qing

2018-05-01

To more efficiently use GaoFen-1 (GF-1) satellite images for landslide emergency monitoring, a Digital Surface Model (DSM) can be generated from GF-1 across-track stereo image pairs to build a terrain dataset. This study proposes a landslide 3D information extraction method based on the terrain changes of slope objects. The slope objects are mergences of segmented image objects which have similar aspects; and the terrain changes are calculated from the post-disaster Digital Elevation Model (DEM) from GF-1 and the pre-disaster DEM from GDEM V2. A high mountain landslide that occurred in Wenchuan County, Sichuan Province is used to conduct a 3D information extraction test. The extracted total area of the landslide is 22.58 ha; the displaced earth volume is 652,100 m3; and the average sliding direction is 263.83°. The accuracies of them are 0.89, 0.87 and 0.95, respectively. Thus, the proposed method expands the application of GF-1 satellite images to the field of landslide emergency monitoring.

Accuracy evaluation of optical distortion calibration by digital image correlation

NASA Astrophysics Data System (ADS)

Gao, Zeren; Zhang, Qingchuan; Su, Yong; Wu, Shangquan

2017-11-01

Due to its convenience of operation, the camera calibration algorithm, which is based on the plane template, is widely used in image measurement, computer vision and other fields. How to select a suitable distortion model is always a problem to be solved. Therefore, there is an urgent need for an experimental evaluation of the accuracy of camera distortion calibrations. This paper presents an experimental method for evaluating camera distortion calibration accuracy, which is easy to implement, has high precision, and is suitable for a variety of commonly used lens. First, we use the digital image correlation method to calculate the in-plane rigid body displacement field of an image displayed on a liquid crystal display before and after translation, as captured with a camera. Next, we use a calibration board to calibrate the camera to obtain calibration parameters which are used to correct calculation points of the image before and after deformation. The displacement field before and after correction is compared to analyze the distortion calibration results. Experiments were carried out to evaluate the performance of two commonly used industrial camera lenses for four commonly used distortion models.

Digital Rock Physics Aplications: Visualisation Complex Pore and Porosity-Permeability Estimations of the Porous Sandstone Reservoir

NASA Astrophysics Data System (ADS)

Handoyo; Fatkhan; Del, Fourier

2018-03-01

Reservoir rock containing oil and gas generally has high porosity and permeability. High porosity is expected to accommodate hydrocarbon fluid in large quantities and high permeability is associated with the rock’s ability to let hydrocarbon fluid flow optimally. Porosity and permeability measurement of a rock sample is usually performed in the laboratory. We estimate the porosity and permeability of sandstones digitally by using digital images from μCT-Scan. Advantages of the method are non-destructive and can be applied for small rock pieces also easily to construct the model. The porosity values are calculated by comparing the digital image of the pore volume to the total volume of the sandstones; while the permeability values are calculated using the Lattice Boltzmann calculations utilizing the nature of the law of conservation of mass and conservation of momentum of a particle. To determine variations of the porosity and permeability, the main sandstone samples with a dimension of 300 × 300 × 300 pixels are made into eight sub-cubes with a size of 150 × 150 × 150 pixels. Results of digital image modeling fluid flow velocity are visualized as normal velocity (streamline). Variations in value sandstone porosity vary between 0.30 to 0.38 and permeability variations in the range of 4000 mD to 6200 mD. The results of calculations show that the sandstone sample in this research is highly porous and permeable. The method combined with rock physics can be powerful tools for determining rock properties from small rock fragments.

Reliability and validity of tongue color analysis in the prediction of symptom patterns in terms of East Asian Medicine.

PubMed

Park, Young-Jae; Lee, Jin-Moo; Yoo, Seung-Yeon; Park, Young-Bae

2016-04-01

To examine whether color parameters of tongue inspection (TI) using a digital camera was reliable and valid, and to examine which color parameters serve as predictors of symptom patterns in terms of East Asian medicine (EAM). Two hundred female subjects' tongue substances were photographed by a mega-pixel digital camera. Together with the photographs, the subjects were asked to complete Yin deficiency, Phlegm pattern, and Cold-Heat pattern questionnaires. Using three sets of digital imaging software, each digital image was exposure- and white balance-corrected, and finally L* (luminance), a* (red-green balance), and b* (yellow-blue balance) values of the tongues were calculated. To examine intra- and inter-rater reliabilities and criterion validity of the color analysis method, three raters were asked to calculate color parameters for 20 digital image samples. Finally, four hierarchical regression models were formed. Color parameters showed good or excellent reliability (0.627-0.887 for intra-class correlation coefficients) and significant criterion validity (0.523-0.718 for Spearman's correlation). In the hierarchical regression models, age was a significant predictor of Yin deficiency (β = 0.192), and b* value of the tip of the tongue was a determinant predictor of Yin deficiency, Phlegm, and Heat patterns (β = - 0.212, - 0.172, and - 0.163). Luminance (L*) was predictive of Yin deficiency (β = -0.172) and Cold (β = 0.173) pattern. Our results suggest that color analysis of the tongue using the L*a*b* system is reliable and valid, and that color parameters partially serve as symptom pattern predictors in EAM practice.

Digital Forensics Using Local Signal Statistics

ERIC Educational Resources Information Center

Pan, Xunyu

2011-01-01

With the rapid growth of the Internet and the popularity of digital imaging devices, digital imagery has become our major information source. Meanwhile, the development of digital manipulation techniques employed by most image editing software brings new challenges to the credibility of photographic images as the definite records of events. We…

Digital watermarking opportunities enabled by mobile media proliferation

NASA Astrophysics Data System (ADS)

Modro, Sierra; Sharma, Ravi K.

2009-02-01

Consumer usages of mobile devices and electronic media are changing. Mobile devices now include increased computational capabilities, mobile broadband access, better integrated sensors, and higher resolution screens. These enhanced features are driving increased consumption of media such as images, maps, e-books, audio, video, and games. As users become more accustomed to using mobile devices for media, opportunities arise for new digital watermarking usage models. For example, transient media, like images being displayed on screens, could be watermarked to provide a link between mobile devices. Applications based on these emerging usage models utilizing watermarking can provide richer user experiences and drive increased media consumption. We describe the enabling factors and highlight a few of the usage models and new opportunities. We also outline how the new opportunities are driving further innovation in watermarking technologies. We discuss challenges in market adoption of applications based on these usage models.

3D Documentation and BIM Modeling of Cultural Heritage Structures Using UAVs: The Case of the Foinikaria Church

NASA Astrophysics Data System (ADS)

Themistocleous, K.; Agapiou, A.; Hadjimitsis, D.

2016-10-01

The documentation of architectural cultural heritage sites has traditionally been expensive and labor-intensive. New innovative technologies, such as Unmanned Aerial Vehicles (UAVs), provide an affordable, reliable and straightforward method of capturing cultural heritage sites, thereby providing a more efficient and sustainable approach to documentation of cultural heritage structures. In this study, hundreds of images of the Panagia Chryseleousa church in Foinikaria, Cyprus were taken using a UAV with an attached high resolution camera. The images were processed to generate an accurate digital 3D model by using Structure in Motion techniques. Building Information Model (BIM) was then used to generate drawings of the church. The methodology described in the paper provides an accurate, simple and cost-effective method of documenting cultural heritage sites and generating digital 3D models using novel techniques and innovative methods.

Suitability of low cost commercial off-the-shelf aerial platforms and consumer grade digital cameras for small format aerial photography

NASA Astrophysics Data System (ADS)

Turley, Anthony Allen

Many research projects require the use of aerial images. Wetlands evaluation, crop monitoring, wildfire management, environmental change detection, and forest inventory are but a few of the applications of aerial imagery. Low altitude Small Format Aerial Photography (SFAP) is a bridge between satellite and man-carrying aircraft image acquisition and ground-based photography. The author's project evaluates digital images acquired using low cost commercial digital cameras and standard model airplanes to determine their suitability for remote sensing applications. Images from two different sites were obtained. Several photo missions were flown over each site, acquiring images in the visible and near infrared electromagnetic bands. Images were sorted and analyzed to select those with the least distortion, and blended together with Microsoft Image Composite Editor. By selecting images taken within minutes apart, radiometric qualities of the images were virtually identical, yielding no blend lines in the composites. A commercial image stitching program, Autopano Pro, was purchased during the later stages of this study. Autopano Pro was often able to mosaic photos that the free Image Composite Editor was unable to combine. Using telemetry data from an onboard data logger, images were evaluated to calculate scale and spatial resolution. ERDAS ER Mapper and ESRI ArcGIS were used to rectify composite images. Despite the limitations inherent in consumer grade equipment, images of high spatial resolution were obtained. Mosaics of as many as 38 images were created, and the author was able to record detailed aerial images of forest and wetland areas where foot travel was impractical or impossible.

Training system for digital mammographic diagnoses of breast cancer

NASA Astrophysics Data System (ADS)

Thomaz, R. L.; Nirschl Crozara, M. G.; Patrocinio, A. C.

2013-03-01

As the technology evolves, the analog mammography systems are being replaced by digital systems. The digital system uses video monitors as the display of mammographic images instead of the previously used screen-film and negatoscope for analog images. The change in the way of visualizing mammographic images may require a different approach for training the health care professionals in diagnosing the breast cancer with digital mammography. Thus, this paper presents a computational approach to train the health care professionals providing a smooth transition between analog and digital technology also training to use the advantages of digital image processing tools to diagnose the breast cancer. This computational approach consists of a software where is possible to open, process and diagnose a full mammogram case from a database, which has the digital images of each of the mammographic views. The software communicates with a gold standard digital mammogram cases database. This database contains the digital images in Tagged Image File Format (TIFF) and the respective diagnoses according to BI-RADSTM, these files are read by software and shown to the user as needed. There are also some digital image processing tools that can be used to provide better visualization of each single image. The software was built based on a minimalist and a user-friendly interface concept that might help in the smooth transition. It also has an interface for inputting diagnoses from the professional being trained, providing a result feedback. This system has been already completed, but hasn't been applied to any professional training yet.

Image Acquisition and Quality in Digital Radiography.

PubMed

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.

Securing Digital Images Integrity using Artificial Neural Networks

NASA Astrophysics Data System (ADS)

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.

Digital image processing: a primer for JVIR authors and readers: Part 3: Digital image editing.

PubMed

LaBerge, Jeanne M; Andriole, Katherine P

2003-12-01

This is the final installment of a three-part series on digital image processing intended to prepare authors for online submission of manuscripts. In the first two articles of the series, the fundamentals of digital image architecture were reviewed and methods of importing images to the computer desktop were described. In this article, techniques are presented for editing images in preparation for online submission. A step-by-step guide to basic editing with use of Adobe Photoshop is provided and the ethical implications of this activity are explored.

A digital system for surface reconstruction

USGS Publications Warehouse

Zhou, Weiyang; Brock, Robert H.; Hopkins, Paul F.

1996-01-01

A digital photogrammetric system, STEREO, was developed to determine three dimensional coordinates of points of interest (POIs) defined with a grid on a textureless and smooth-surfaced specimen. Two CCD cameras were set up with unknown orientation and recorded digital images of a reference model and a specimen. Points on the model were selected as control or check points for calibrating or assessing the system. A new algorithm for edge-detection called local maximum convolution (LMC) helped extract the POIs from the stereo image pairs. The system then matched the extracted POIs and used a least squares “bundle” adjustment procedure to solve for the camera orientation parameters and the coordinates of the POIs. An experiment with STEREO found that the standard deviation of the residuals at the check points was approximately 24%, 49% and 56% of the pixel size in the X, Y and Z directions, respectively. The average of the absolute values of the residuals at the check points was approximately 19%, 36% and 49% of the pixel size in the X, Y and Z directions, respectively. With the graphical user interface, STEREO demonstrated a high degree of automation and its operation does not require special knowledge of photogrammetry, computers or image processing.

Dyes removal using activated carbon from palm oil waste with digital image colorimetry quantification

NASA Astrophysics Data System (ADS)

Firdaus, M. Lutfi; Puspita, Melfi; Alwi, Wiwit; Ghufira, Nurhamidah, Elvia, Rina

2017-11-01

In the present study, activated carbon prepared from palm oil husk was used as adsorbent to remove synthetic dyes of Reactive Red 120 (RR) and Direct Green 26 (DG) from aqueous solution. The effects of solution pH, contact time, adsorbent weight, dyes concentration, and temperature on adsorption were evaluated based on batch experiments along with determination of the adsorption isotherms, kinetics, and thermodynamics parameters. Visible spectrophotometry was used for the quantification of dyes concentration, in conjunction with digital image colorimetry as a novel quantification method. Compared to visible spectrophotometry, the results of digital image colorimetry were accurate. In addition, improved sensitivity was achieved using this new colorimetry method. At equilibrium, dyes adsorption onto activated carbon followed Freundlich model, with adsorption capacities for RR and DG were 32 and 27 mg/g, respectively. The adsorption kinetics study showed a pseudo-second-order model with thermodynamic parameters of ΔG°, ΔH°, and ΔS° were -1.8 to -3.8 kJ/mol, -13.5 to -24.38 kJ/mol, and 0.001 J/mol, respectively. Therefore, the process of adsorption was exothermic and spontaneous with an increase in the disorder or entropy of the system.

3D Surface Reconstruction for Lower Limb Prosthetic Model using Radon Transform

NASA Astrophysics Data System (ADS)

Sobani, S. S. Mohd; Mahmood, N. H.; Zakaria, N. A.; Razak, M. A. Abdul

2018-03-01

This paper describes the idea to realize three-dimensional surfaces of objects with cylinder-based shapes where the techniques adopted and the strategy developed for a non-rigid three-dimensional surface reconstruction of an object from uncalibrated two-dimensional image sequences using multiple-view digital camera and turntable setup. The surface of an object is reconstructed based on the concept of tomography with the aid of performing several digital image processing algorithms on the two-dimensional images captured by a digital camera in thirty-six different projections and the three-dimensional structure of the surface is analysed. Four different objects are used as experimental models in the reconstructions and each object is placed on a manually rotated turntable. The results shown that the proposed method has successfully reconstruct the three-dimensional surface of the objects and practicable. The shape and size of the reconstructed three-dimensional objects are recognizable and distinguishable. The reconstructions of objects involved in the test are strengthened with the analysis where the maximum percent error obtained from the computation is approximately 1.4 % for the height whilst 4.0%, 4.79% and 4.7% for the diameters at three specific heights of the objects.

Comparison of Image Generation And Processing Techniques For 3D Reconstruction of The Human Skull

DTIC Science & Technology

2001-10-25

inexpensive Microscribe (3D digitizer) with a standard widely used and expensive CT-Scan and/or MRI for 3D reconstruction of a human skull, which will be... Microscribe 3D digitizing unit and another one using the CT-Scans (2D cross-sections) obtained from a GE scanner. Both models were then subjected to stress...these methods are still elaborate, expensive and not readily accessible. Using the hand-held digitizer, the Microscribe , X, Y and Z coordinates

Using High-Dimensional Image Models to Perform Highly Undetectable Steganography

NASA Astrophysics Data System (ADS)

Pevný, Tomáš; Filler, Tomáš; Bas, Patrick

This paper presents a complete methodology for designing practical and highly-undetectable stegosystems for real digital media. The main design principle is to minimize a suitably-defined distortion by means of efficient coding algorithm. The distortion is defined as a weighted difference of extended state-of-the-art feature vectors already used in steganalysis. This allows us to "preserve" the model used by steganalyst and thus be undetectable even for large payloads. This framework can be efficiently implemented even when the dimensionality of the feature set used by the embedder is larger than 107. The high dimensional model is necessary to avoid known security weaknesses. Although high-dimensional models might be problem in steganalysis, we explain, why they are acceptable in steganography. As an example, we introduce HUGO, a new embedding algorithm for spatial-domain digital images and we contrast its performance with LSB matching. On the BOWS2 image database and in contrast with LSB matching, HUGO allows the embedder to hide 7× longer message with the same level of security level.

A Search for Nontoroidal Topological Lensing in the Sloan Digital Sky Survey Quasar Catalog

NASA Astrophysics Data System (ADS)

Fujii, Hirokazu; Yoshii, Yuzuru

2013-08-01

Flat space models with multiply connected topology, which have compact dimensions, are tested against the distribution of high-redshift (z >= 4) quasars of the Sloan Digital Sky Survey (SDSS). When the compact dimensions are smaller in size than the observed universe, topological lensing occurs, in which multiple images of single objects (ghost images) are observed. We improve on the recently introduced method to identify ghost images by means of four-point statistics. Our method is valid for any of the 17 multiply connected flat models, including nontoroidal ones that are compacted by screw motions or glide reflection. Applying the method to the data revealed one possible case of topological lensing caused by sixth-turn screw motion, however, it is consistent with the simply connected model by this test alone. Moreover, simulations suggest that we cannot exclude the other space models despite the absence of their signatures. This uncertainty mainly originates from the patchy coverage of SDSS in the south Galactic cap, and this situation will be improved by future wide-field spectroscopic surveys.

Evaluation of the validity of the Bolton Index using cone-beam computed tomography (CBCT)

PubMed Central

Llamas, José M.; Cibrián, Rosa; Gandía, José L.; Paredes, Vanessa

2012-01-01

Aims: To evaluate the reliability and reproducibility of calculating the Bolton Index using cone-beam computed tomography (CBCT), and to compare this with measurements obtained using the 2D Digital Method. Material and Methods: Traditional study models were obtained from 50 patients, which were then digitized in order to be able to measure them using the Digital Method. Likewise, CBCTs of those same patients were undertaken using the Dental Picasso Master 3D® and the images obtained were then analysed using the InVivoDental programme. Results: By determining the regression lines for both measurement methods, as well as the difference between both of their values, the two methods are shown to be comparable, despite the fact that the measurements analysed presented statistically significant differences. Conclusions: The three-dimensional models obtained from the CBCT are as accurate and reproducible as the digital models obtained from the plaster study casts for calculating the Bolton Index. The differences existing between both methods were clinically acceptable. Key words:Tooth-size, digital models, bolton index, CBCT. PMID:22549690

Losing images in digital radiology: more than you think.

PubMed

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.

Method for the visualization of landform by mapping using low altitude UAV application

NASA Astrophysics Data System (ADS)

Sharan Kumar, N.; Ashraf Mohamad Ismail, Mohd; Sukor, Nur Sabahiah Abdul; Cheang, William

2018-05-01

Unmanned Aerial Vehicle (UAV) and Digital Photogrammetry are evolving drastically in mapping technology. The significance and necessity for digital landform mapping are developing with years. In this study, a mapping workflow is applied to obtain two different input data sets which are the orthophoto and DSM. A fine flying technology is used to capture Low Altitude Aerial Photography (LAAP). Low altitude UAV (Drone) with the fixed advanced camera was utilized for imagery while computerized photogrammetry handling using Photo Scan was applied for cartographic information accumulation. The data processing through photogrammetry and orthomosaic processes is the main applications. High imagery quality is essential for the effectiveness and nature of normal mapping output such as 3D model, Digital Elevation Model (DEM), Digital Surface Model (DSM) and Ortho Images. The exactitude of Ground Control Points (GCP), flight altitude and the resolution of the camera are essential for good quality DEM and Orthophoto.

Digital processing of radiographic images for print publication.

PubMed

Cockerill, James W

2002-01-01

Digital imaging of X-rays yields high quality, evenly exposed negatives and prints. This article outlines the method used, materials and methods of this technique and discusses the advantages of digital radiographic images.

High-resolution Episcopic Microscopy (HREM) - Simple and Robust Protocols for Processing and Visualizing Organic Materials

PubMed Central

Geyer, Stefan H.; Maurer-Gesek, Barbara; Reissig, Lukas F.; Weninger, Wolfgang J.

2017-01-01

We provide simple protocols for generating digital volume data with the high-resolution episcopic microscopy (HREM) method. HREM is capable of imaging organic materials with volumes up to 5 x 5 x 7 mm3 in typical numeric resolutions between 1 x 1 x 1 and 5 x 5 x 5 µm3. Specimens are embedded in methacrylate resin and sectioned on a microtome. After each section an image of the block surface is captured with a digital video camera that sits on the phototube connected to the compound microscope head. The optical axis passes through a green fluorescent protein (GFP) filter cube and is aligned with a position, at which the bock holder arm comes to rest after each section. In this way, a series of inherently aligned digital images, displaying subsequent block surfaces are produced. Loading such an image series in three-dimensional (3D) visualization software facilitates the immediate conversion to digital volume data, which permit virtual sectioning in various orthogonal and oblique planes and the creation of volume and surface rendered computer models. We present three simple, tissue specific protocols for processing various groups of organic specimens, including mouse, chick, quail, frog and zebra fish embryos, human biopsy material, uncoated paper and skin replacement material. PMID:28715372

High-resolution Episcopic Microscopy (HREM) - Simple and Robust Protocols for Processing and Visualizing Organic Materials.

PubMed

Geyer, Stefan H; Maurer-Gesek, Barbara; Reissig, Lukas F; Weninger, Wolfgang J

2017-07-07

We provide simple protocols for generating digital volume data with the high-resolution episcopic microscopy (HREM) method. HREM is capable of imaging organic materials with volumes up to 5 x 5 x 7 mm 3 in typical numeric resolutions between 1 x 1 x 1 and 5 x 5 x 5 µm 3 . Specimens are embedded in methacrylate resin and sectioned on a microtome. After each section an image of the block surface is captured with a digital video camera that sits on the phototube connected to the compound microscope head. The optical axis passes through a green fluorescent protein (GFP) filter cube and is aligned with a position, at which the bock holder arm comes to rest after each section. In this way, a series of inherently aligned digital images, displaying subsequent block surfaces are produced. Loading such an image series in three-dimensional (3D) visualization software facilitates the immediate conversion to digital volume data, which permit virtual sectioning in various orthogonal and oblique planes and the creation of volume and surface rendered computer models. We present three simple, tissue specific protocols for processing various groups of organic specimens, including mouse, chick, quail, frog and zebra fish embryos, human biopsy material, uncoated paper and skin replacement material.

D Building Reconstruction by Multiview Images and the Integrated Application with Augmented Reality

NASA Astrophysics Data System (ADS)

Hwang, Jin-Tsong; Chu, Ting-Chen

2016-10-01

This study presents an approach wherein photographs with a high degree of overlap are clicked using a digital camera and used to generate three-dimensional (3D) point clouds via feature point extraction and matching. To reconstruct a building model, an unmanned aerial vehicle (UAV) is used to click photographs from vertical shooting angles above the building. Multiview images are taken from the ground to eliminate the shielding effect on UAV images caused by trees. Point clouds from the UAV and multiview images are generated via Pix4Dmapper. By merging two sets of point clouds via tie points, the complete building model is reconstructed. The 3D models are reconstructed using AutoCAD 2016 to generate vectors from the point clouds; SketchUp Make 2016 is used to rebuild a complete building model with textures. To apply 3D building models in urban planning and design, a modern approach is to rebuild the digital models; however, replacing the landscape design and building distribution in real time is difficult as the frequency of building replacement increases. One potential solution to these problems is augmented reality (AR). Using Unity3D and Vuforia to design and implement the smartphone application service, a markerless AR of the building model can be built. This study is aimed at providing technical and design skills related to urban planning, urban designing, and building information retrieval using AR.

The wavelet/scalar quantization compression standard for digital fingerprint images

DOE Office of Scientific and Technical Information (OSTI.GOV)

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.

Image-based modeling of tumor shrinkage in head and neck radiation therapy1

PubMed Central

Chao, Ming; Xie, Yaoqin; Moros, Eduardo G.; Le, Quynh-Thu; Xing, Lei

2010-01-01

Purpose: Understanding the kinetics of tumor growth∕shrinkage represents a critical step in quantitative assessment of therapeutics and realization of adaptive radiation therapy. This article presents a novel framework for image-based modeling of tumor change and demonstrates its performance with synthetic images and clinical cases. Methods: Due to significant tumor tissue content changes, similarity-based models are not suitable for describing the process of tumor volume changes. Under the hypothesis that tissue features in a tumor volume or at the boundary region are partially preserved, the kinetic change was modeled in two steps: (1) Autodetection of homologous tissue features shared by two input images using the scale invariance feature transformation (SIFT) method; and (2) establishment of a voxel-to-voxel correspondence between the images for the remaining spatial points by interpolation. The correctness of the tissue feature correspondence was assured by a bidirectional association procedure, where SIFT features were mapped from template to target images and reversely. A series of digital phantom experiments and five head and neck clinical cases were used to assess the performance of the proposed technique. Results: The proposed technique can faithfully identify the known changes introduced when constructing the digital phantoms. The subsequent feature-guided thin plate spline calculation reproduced the “ground truth” with accuracy better than 1.5 mm. For the clinical cases, the new algorithm worked reliably for a volume change as large as 30%. Conclusions: An image-based tumor kinetic algorithm was developed to model the tumor response to radiation therapy. The technique provides a practical framework for future application in adaptive radiation therapy. PMID:20527569

Method for indexing and retrieving manufacturing-specific digital imagery based on image content

DOEpatents

Ferrell, Regina K.; Karnowski, Thomas P.; Tobin, Jr., Kenneth W.

2004-06-15

A method for indexing and retrieving manufacturing-specific digital images based on image content comprises three steps. First, at least one feature vector can be extracted from a manufacturing-specific digital image stored in an image database. In particular, each extracted feature vector corresponds to a particular characteristic of the manufacturing-specific digital image, for instance, a digital image modality and overall characteristic, a substrate/background characteristic, and an anomaly/defect characteristic. Notably, the extracting step includes generating a defect mask using a detection process. Second, using an unsupervised clustering method, each extracted feature vector can be indexed in a hierarchical search tree. Third, a manufacturing-specific digital image associated with a feature vector stored in the hierarchicial search tree can be retrieved, wherein the manufacturing-specific digital image has image content comparably related to the image content of the query image. More particularly, can include two data reductions, the first performed based upon a query vector extracted from a query image. Subsequently, a user can select relevant images resulting from the first data reduction. From the selection, a prototype vector can be calculated, from which a second-level data reduction can be performed. The second-level data reduction can result in a subset of feature vectors comparable to the prototype vector, and further comparable to the query vector. An additional fourth step can include managing the hierarchical search tree by substituting a vector average for several redundant feature vectors encapsulated by nodes in the hierarchical search tree.

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

NASA Astrophysics Data System (ADS)

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.

Radiogenomics analysis identifies correlations of digital mammography with clinical molecular signatures in breast cancer.

PubMed

Tamez-Peña, Jose-Gerardo; Rodriguez-Rojas, Juan-Andrés; Gomez-Rueda, Hugo; Celaya-Padilla, Jose-Maria; Rivera-Prieto, Roxana-Alicia; Palacios-Corona, Rebeca; Garza-Montemayor, Margarita; Cardona-Huerta, Servando; Treviño, Victor

2018-01-01

In breast cancer, well-known gene expression subtypes have been related to a specific clinical outcome. However, their impact on the breast tissue phenotype has been poorly studied. Here, we investigate the association of imaging data of tumors to gene expression signatures from 71 patients with breast cancer that underwent pre-treatment digital mammograms and tumor biopsies. From digital mammograms, a semi-automated radiogenomics analysis generated 1,078 features describing the shape, signal distribution, and texture of tumors along their contralateral image used as control. From tumor biopsy, we estimated the OncotypeDX and PAM50 recurrence scores using gene expression microarrays. Then, we used multivariate analysis under stringent cross-validation to train models predicting recurrence scores. Few univariate features reached Spearman correlation coefficients above 0.4. Nevertheless, multivariate analysis yielded significantly correlated models for both signatures (correlation of OncotypeDX = 0.49 ± 0.07 and PAM50 = 0.32 ± 0.10 in stringent cross-validation and OncotypeDX = 0.83 and PAM50 = 0.78 for a unique model). Equivalent models trained from the unaffected contralateral breast were not correlated suggesting that the image signatures were tumor-specific and that overfitting was not a considerable issue. We also noted that models were improved by combining clinical information (triple negative status and progesterone receptor). The models used mostly wavelets and fractal features suggesting their importance to capture tumor information. Our results suggest that molecular-based recurrence risk and breast cancer subtypes have observable radiographic phenotypes. To our knowledge, this is the first study associating mammographic information to gene expression recurrence signatures.

Radiogenomics analysis identifies correlations of digital mammography with clinical molecular signatures in breast cancer

PubMed Central

Tamez-Peña, Jose-Gerardo; Rodriguez-Rojas, Juan-Andrés; Gomez-Rueda, Hugo; Celaya-Padilla, Jose-Maria; Rivera-Prieto, Roxana-Alicia; Palacios-Corona, Rebeca; Garza-Montemayor, Margarita; Cardona-Huerta, Servando

2018-01-01

In breast cancer, well-known gene expression subtypes have been related to a specific clinical outcome. However, their impact on the breast tissue phenotype has been poorly studied. Here, we investigate the association of imaging data of tumors to gene expression signatures from 71 patients with breast cancer that underwent pre-treatment digital mammograms and tumor biopsies. From digital mammograms, a semi-automated radiogenomics analysis generated 1,078 features describing the shape, signal distribution, and texture of tumors along their contralateral image used as control. From tumor biopsy, we estimated the OncotypeDX and PAM50 recurrence scores using gene expression microarrays. Then, we used multivariate analysis under stringent cross-validation to train models predicting recurrence scores. Few univariate features reached Spearman correlation coefficients above 0.4. Nevertheless, multivariate analysis yielded significantly correlated models for both signatures (correlation of OncotypeDX = 0.49 ± 0.07 and PAM50 = 0.32 ± 0.10 in stringent cross-validation and OncotypeDX = 0.83 and PAM50 = 0.78 for a unique model). Equivalent models trained from the unaffected contralateral breast were not correlated suggesting that the image signatures were tumor-specific and that overfitting was not a considerable issue. We also noted that models were improved by combining clinical information (triple negative status and progesterone receptor). The models used mostly wavelets and fractal features suggesting their importance to capture tumor information. Our results suggest that molecular-based recurrence risk and breast cancer subtypes have observable radiographic phenotypes. To our knowledge, this is the first study associating mammographic information to gene expression recurrence signatures. PMID:29596496

Clinical performance of a prototype flat-panel digital detector for general radiography

NASA Astrophysics Data System (ADS)

Huda, Walter; Scalzetti, Ernest M.; Roskopf, Marsha L.; Geiger, Robert

2001-08-01

Digital radiographs obtained using a prototype Digital Radiography System (Stingray) were compared with those obtained using conventional screen-film. Forty adult volunteers each had two identical radiographs taken at the same level of radiation exposure, one using screen-film and the other the digital detector. Each digital image was processed by hand to ensure that the printed quality was optimal. Ten radiologists compared the diagnostic image quality of the digital images with the corresponding film radiographs using a seven point ranking scheme.

42 CFR 37.44 - Approval of radiographic facilities that use digital radiography systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... effective management, safety, and proper performance of chest image acquisition, digitization, processing... digital chest radiographs by submitting to NIOSH digital radiographic image files of a test object (e.g... radiographic image files from six or more sample chest radiographs that are of acceptable quality to one or...

The Engineer Topographic Laboratories /ETL/ hybrid optical/digital image processor

NASA Astrophysics Data System (ADS)

Benton, J. R.; Corbett, F.; Tuft, R.

1980-01-01

An optical-digital processor for generalized image enhancement and filtering is described. The optical subsystem is a two-PROM Fourier filter processor. Input imagery is isolated, scaled, and imaged onto the first PROM; this input plane acts like a liquid gate and serves as an incoherent-to-coherent converter. The image is transformed onto a second PROM which also serves as a filter medium; filters are written onto the second PROM with a laser scanner in real time. A solid state CCTV camera records the filtered image, which is then digitized and stored in a digital image processor. The operator can then manipulate the filtered image using the gray scale and color remapping capabilities of the video processor as well as the digital processing capabilities of the minicomputer.

15 CFR 786.2 - Recordkeeping.

Code of Federal Regulations, 2012 CFR

2012-01-01

... recognized as complete words or numbers. (iv) The system must preserve the initial image (including both... the system. (3) Requirements applicable to a system based on digital images. For systems based on the storage of digital images, the system must provide accessibility to any digital image in the system. The...

15 CFR 786.2 - Recordkeeping.

Code of Federal Regulations, 2011 CFR

2011-01-01

... recognized as complete words or numbers. (iv) The system must preserve the initial image (including both... the system. (3) Requirements applicable to a system based on digital images. For systems based on the storage of digital images, the system must provide accessibility to any digital image in the system. The...

15 CFR 786.2 - Recordkeeping.

Code of Federal Regulations, 2010 CFR

2010-01-01

... recognized as complete words or numbers. (iv) The system must preserve the initial image (including both... the system. (3) Requirements applicable to a system based on digital images. For systems based on the storage of digital images, the system must provide accessibility to any digital image in the system. The...

15 CFR 786.2 - Recordkeeping.

Code of Federal Regulations, 2014 CFR

2014-01-01

... recognized as complete words or numbers. (iv) The system must preserve the initial image (including both... the system. (3) Requirements applicable to a system based on digital images. For systems based on the storage of digital images, the system must provide accessibility to any digital image in the system. The...

15 CFR 786.2 - Recordkeeping.

Code of Federal Regulations, 2013 CFR

2013-01-01

... recognized as complete words or numbers. (iv) The system must preserve the initial image (including both... the system. (3) Requirements applicable to a system based on digital images. For systems based on the storage of digital images, the system must provide accessibility to any digital image in the system. The...

28 CFR 75.6 - Statement describing location of books and records.

Code of Federal Regulations, 2011 CFR

2011-07-01

...- or computer-manipulated image, digital image, or picture, or other matter (including but not limited... the book, magazine, periodical, film, videotape, digitally- or computer-manipulated image, digital image, picture, or other matter to affix the statement. In this paragraph, the term “copy” includes...

Solid images for geostructural mapping and key block modeling of rock discontinuities

NASA Astrophysics Data System (ADS)

Assali, Pierre; Grussenmeyer, Pierre; Villemin, Thierry; Pollet, Nicolas; Viguier, Flavien

2016-04-01

Rock mass characterization is obviously a key element in rock fall hazard analysis. Managing risk and determining the most adapted reinforcement method require a proper understanding of the considered rock mass. Description of discontinuity sets is therefore a crucial first step in the reinforcement work design process. The on-field survey is then followed by a structural modeling in order to extrapolate the data collected at the rock surface to the inner part of the massif. Traditional compass survey and manual observations can be undoubtedly surpassed by dense 3D data such as LiDAR or photogrammetric point clouds. However, although the acquisition phase is quite fast and highly automated, managing, handling and exploiting such great amount of collected data is an arduous task and especially for non specialist users. In this study, we propose a combined approached using both 3D point clouds (from LiDAR or image matching) and 2D digital images, gathered into the concept of ''solid image''. This product is the connection between the advantages of classical true colors 2D digital images, accessibility and interpretability, and the particular strengths of dense 3D point clouds, i.e. geometrical completeness and accuracy. The solid image can be considered as the information support for carrying-out a digital survey at the surface of the outcrop without being affected by traditional deficiencies (lack of data and sampling difficulties due to inaccessible areas, safety risk in steep sectors, etc.). Computational tools presented in this paper have been implemented into one standalone software through a graphical user interface helping operators with the completion of a digital geostructural survey and analysis. 3D coordinates extraction, 3D distances and area measurement, planar best-fit for discontinuity orientation, directional roughness profiles, block size estimation, and other tools have been experimented on a calcareous quarry in the French Alps.

Deformation-Aware Log-Linear Models

NASA Astrophysics Data System (ADS)

Gass, Tobias; Deselaers, Thomas; Ney, Hermann

In this paper, we present a novel deformation-aware discriminative model for handwritten digit recognition. Unlike previous approaches our model directly considers image deformations and allows discriminative training of all parameters, including those accounting for non-linear transformations of the image. This is achieved by extending a log-linear framework to incorporate a latent deformation variable. The resulting model has an order of magnitude less parameters than competing approaches to handling image deformations. We tune and evaluate our approach on the USPS task and show its generalization capabilities by applying the tuned model to the MNIST task. We gain interesting insights and achieve highly competitive results on both tasks.

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

PubMed Central

Prasad, H; Wanjari, Sangeeta; Parwani, Rajkumar

2011-01-01

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 κ 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. PMID:21572507

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

PubMed

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 holographic image fusion for a larger size object using compressive sensing

NASA Astrophysics Data System (ADS)

Tian, Qiuhong; Yan, Liping; Chen, Benyong; Yao, Jiabao; Zhang, Shihua

2017-05-01

Digital holographic imaging fusion for a larger size object using compressive sensing is proposed. In this method, the high frequency component of the digital hologram under discrete wavelet transform is represented sparsely by using compressive sensing so that the data redundancy of digital holographic recording can be resolved validly, the low frequency component is retained totally to ensure the image quality, and multiple reconstructed images with different clear parts corresponding to a laser spot size are fused to realize the high quality reconstructed image of a larger size object. In addition, a filter combing high-pass and low-pass filters is designed to remove the zero-order term from a digital hologram effectively. The digital holographic experimental setup based on off-axis Fresnel digital holography was constructed. The feasible and comparative experiments were carried out. The fused image was evaluated by using the Tamura texture features. The experimental results demonstrated that the proposed method can improve the processing efficiency and visual characteristics of the fused image and enlarge the size of the measured object effectively.

A Hierarchical Building Segmentation in Digital Surface Models for 3D Reconstruction.

PubMed

Yan, Yiming; Gao, Fengjiao; Deng, Shupei; Su, Nan

2017-01-24

In this study, a hierarchical method for segmenting buildings in a digital surface model (DSM), which is used in a novel framework for 3D reconstruction, is proposed. Most 3D reconstructions of buildings are model-based. However, the limitations of these methods are overreliance on completeness of the offline-constructed models of buildings, and the completeness is not easily guaranteed since in modern cities buildings can be of a variety of types. Therefore, a model-free framework using high precision DSM and texture-images buildings was introduced. There are two key problems with this framework. The first one is how to accurately extract the buildings from the DSM. Most segmentation methods are limited by either the terrain factors or the difficult choice of parameter-settings. A level-set method are employed to roughly find the building regions in the DSM, and then a recently proposed 'occlusions of random textures model' are used to enhance the local segmentation of the buildings. The second problem is how to generate the facades of buildings. Synergizing with the corresponding texture-images, we propose a roof-contour guided interpolation of building facades. The 3D reconstruction results achieved by airborne-like images and satellites are compared. Experiments show that the segmentation method has good performance, and 3D reconstruction is easily performed by our framework, and better visualization results can be obtained by airborne-like images, which can be further replaced by UAV images.

Semantic Integrative Digital Pathology: Insights into Microsemiological Semantics and Image Analysis Scalability.

PubMed

Racoceanu, Daniel; Capron, Frédérique

2016-01-01

Being able to provide a traceable and dynamic second opinion has become an ethical priority for patients and health care professionals in modern computer-aided medicine. In this perspective, a semantic cognitive virtual microscopy approach has been recently initiated, the MICO project, by focusing on cognitive digital pathology. This approach supports the elaboration of pathology-compliant daily protocols dedicated to breast cancer grading, in particular mitotic counts and nuclear atypia. A proof of concept has thus been elaborated, and an extension of these approaches is now underway in a collaborative digital pathology framework, the FlexMIm project. As important milestones on the way to routine digital pathology, a series of pioneer international benchmarking initiatives have been launched for mitosis detection (MITOS), nuclear atypia grading (MITOS-ATYPIA) and glandular structure detection (GlaS), some of the fundamental grading components in diagnosis and prognosis. These initiatives allow envisaging a consolidated validation referential database for digital pathology in the very near future. This reference database will need coordinated efforts from all major teams working in this area worldwide, and it will certainly represent a critical bottleneck for the acceptance of all future imaging modules in clinical practice. In line with recent advances in molecular imaging and genetics, keeping the microscopic modality at the core of future digital systems in pathology is fundamental to insure the acceptance of these new technologies, as well as for a deeper systemic, structured comprehension of the pathologies. After all, at the scale of routine whole-slide imaging (WSI; ∼0.22 µm/pixel), the microscopic image represents a structured 'genomic cluster', enabling a naturally structured support for integrative digital pathology approaches. In order to accelerate and structure the integration of this heterogeneous information, a major effort is and will continue to be devoted to morphological microsemiology (microscopic morphology semantics). Besides insuring the traceability of the results (second opinion) and supporting the orchestration of high-content image analysis modules, the role of semantics will be crucial for the correlation between digital pathology and noninvasive medical imaging modalities. In addition, semantics has an important role in modelling the links between traditional microscopy and recent label-free technologies. The massive amount of visual data is challenging and represents a characteristic intrinsic to digital pathology. The design of an operational integrative microscopy framework needs to focus on scalable multiscale imaging formalism. In this sense, we prospectively consider some of the most recent scalable methodologies adapted to digital pathology as marked point processes for nuclear atypia and point-set mathematical morphology for architecture grading. To orchestrate this scalable framework, semantics-based WSI management (analysis, exploration, indexing, retrieval and report generation support) represents an important means towards approaches to integrating big data into biomedicine. This insight reflects our vision through an instantiation of essential bricks of this type of architecture. The generic approach introduced here is applicable to a number of challenges related to molecular imaging, high-content image management and, more generally, bioinformatics. © 2016 S. Karger AG, Basel.

Instrumentation, digital image correlation, and modeling to monitor bridge behavior and condition assessment.

DOT National Transportation Integrated Search

2015-06-01

Bridge managers have historically relied on visual inspection reports and field observation, including : photographs, to assess bridge health. The inclusion of instrumentation, including strain gauges, along : with a structural model can enhance brid...

Application of Digital Diagnosis and Treatment Technique in Benign Mandibular Diseases.

PubMed

Ju, Rui; Zeng, Wei; Lian, Xiaotian; Chen, Gang; Yin, Huaqiang; Tang, Wei

2018-05-01

To explore the feasibility of preoperative planning for treatment of benign mandibular lesions (BML) using digital technologies such as three-dimensional (3D) reconstruction, measurement, visualization as well as image contrast and design of neural positioning protection template (NPPT) in combination with 3D printing technology in the BML diagnosis and treatment. The 3D models of BML and inferior alveolar nerves (IAN) of 10 BML patients were reconstructed based on their digital imaging and communications in medicine (DICOM) data using MIMICS16.0 software. The models were used to visualize lesions and nerve contrast measurement and guide design of personalized NPPT and osteotomy after operation modality was determined in order to achieve accurate, minimally invasive operation with shortened intraoperative time. Intraoperative NPPT application could accurately locate lesions and their scope and assist osteotomy. The measurement results were consistent with those of preoperative reconstruction and measurement. The BML were curetted completely without damage IAN. The 10 BML patients had no numbness and other discomforts in the lower lip and mandibular teeth after operation. The digital diagnosis and treatment technology is an effective method for functional treatment of BML patients and its application could achieve personalized, minimally invasive and precise treatment and save intraoperation time.

Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging

DOE PAGES

Newman, Justin A.; Zhang, Shijie; Sullivan, Shane Z.; ...

2016-05-16

Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence and bright field by laser transmittance were all acquired simultaneously with perfect image registry at up to video-rate (15 frames s –1). A simple change in the incident wavelength enabled simultaneous imaging by two-photon-excited ultraviolet fluorescence, one-photon-excited visible fluorescence and laser transmittance. Development of an analytical model for the signal-to-noise enhancement afforded by synchronous digitization suggests a 15.6-foldmore » improvement over previous photon-counting techniques. This improvement in turn allowed acquisition on nearly an order of magnitude more pixels than the preceding generation of instrumentation and reductions of well over an order of magnitude in image acquisition times. These improvements have allowed detection of protein crystals on the order of 1 µm in thickness under cryogenic conditions in the beamline. Lastly, these capabilities are well suited to support serial crystallography of crystals approaching 1 µm or less in dimension.« less

Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newman, Justin A.; Zhang, Shijie; Sullivan, Shane Z.

Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence and bright field by laser transmittance were all acquired simultaneously with perfect image registry at up to video-rate (15 frames s –1). A simple change in the incident wavelength enabled simultaneous imaging by two-photon-excited ultraviolet fluorescence, one-photon-excited visible fluorescence and laser transmittance. Development of an analytical model for the signal-to-noise enhancement afforded by synchronous digitization suggests a 15.6-foldmore » improvement over previous photon-counting techniques. This improvement in turn allowed acquisition on nearly an order of magnitude more pixels than the preceding generation of instrumentation and reductions of well over an order of magnitude in image acquisition times. These improvements have allowed detection of protein crystals on the order of 1 µm in thickness under cryogenic conditions in the beamline. Lastly, these capabilities are well suited to support serial crystallography of crystals approaching 1 µm or less in dimension.« less

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

NASA Astrophysics Data System (ADS)

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

2017-03-01

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

Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging

PubMed Central

Newman, Justin A.; Zhang, Shijie; Sullivan, Shane Z.; Dow, Ximeng Y.; Becker, Michael; Sheedlo, Michael J.; Stepanov, Sergey; Carlsen, Mark S.; Everly, R. Michael; Das, Chittaranjan; Fischetti, Robert F.; Simpson, Garth J.

2016-01-01

Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence and bright field by laser transmittance were all acquired simultaneously with perfect image registry at up to video-rate (15 frames s−1). A simple change in the incident wavelength enabled simultaneous imaging by two-photon-excited ultraviolet fluorescence, one-photon-excited visible fluorescence and laser transmittance. Development of an analytical model for the signal-to-noise enhancement afforded by synchronous digitization suggests a 15.6-fold improvement over previous photon-counting techniques. This improvement in turn allowed acquisition on nearly an order of magnitude more pixels than the preceding generation of instrumentation and reductions of well over an order of magnitude in image acquisition times. These improvements have allowed detection of protein crystals on the order of 1 µm in thickness under cryogenic conditions in the beamline. These capabilities are well suited to support serial crystallography of crystals approaching 1 µm or less in dimension. PMID:27359145

The generation and use of numerical shape models for irregular Solar System objects

NASA Technical Reports Server (NTRS)

Simonelli, Damon P.; Thomas, Peter C.; Carcich, Brian T.; Veverka, Joseph

1993-01-01

We describe a procedure that allows the efficient generation of numerical shape models for irregular Solar System objects, where a numerical model is simply a table of evenly spaced body-centered latitudes and longitudes and their associated radii. This modeling technique uses a combination of data from limbs, terminators, and control points, and produces shape models that have some important advantages over analytical shape models. Accurate numerical shape models make it feasible to study irregular objects with a wide range of standard scientific analysis techniques. These applications include the determination of moments of inertia and surface gravity, the mapping of surface locations and structural orientations, photometric measurement and analysis, the reprojection and mosaicking of digital images, and the generation of albedo maps. The capabilities of our modeling procedure are illustrated through the development of an accurate numerical shape model for Phobos and the production of a global, high-resolution, high-pass-filtered digital image mosaic of this Martian moon. Other irregular objects that have been modeled, or are being modeled, include the asteroid Gaspra and the satellites Deimos, Amalthea, Epimetheus, Janus, Hyperion, and Proteus.

AMULET: A MUlti-cLuE Approach to Image Forensics

DTIC Science & Technology

2014-12-31

celebrities have been substituted in the other two pictures. 3.2.5 Choice of reliability properties Let us now apply the BBA mapping approach proposed in...Jiang, and L. Ma, “Ds evidence theory based digital image trustworthiness evaluation model,” in MINES 2009, International Conference on Multimedia

System for objective assessment of image differences in digital cinema

NASA Astrophysics Data System (ADS)

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.

Digital Radiographic Image Processing and Analysis.

PubMed

Yoon, Douglas C; Mol, André; Benn, Douglas K; Benavides, Erika

2018-07-01

This article describes digital radiographic imaging and analysis from the basics of image capture to examples of some of the most advanced digital technologies currently available. The principles underlying the imaging technologies are described to provide a better understanding of their strengths and limitations. Copyright © 2018 Elsevier Inc. All rights reserved.

42 CFR 37.51 - Interpreting and classifying chest radiographs-digital radiography systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... chest radiographic images provided for use with the Guidelines for the Use of the ILO International... standard digital images may be used for classifying digital chest images for pneumoconiosis. Modification of the appearance of the standard images using software tools is not permitted. (d) Viewing systems...

Integrating Digital Images into the Art and Art History Curriculum.

ERIC Educational Resources Information Center

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…

Digital focusing of OCT images based on scalar diffraction theory and information entropy

PubMed Central

Liu, Guozhong; Zhi, Zhongwei; Wang, Ruikang K.

2012-01-01

This paper describes a digital method that is capable of automatically focusing optical coherence tomography (OCT) en face images without prior knowledge of the point spread function of the imaging system. The method utilizes a scalar diffraction model to simulate wave propagation from out-of-focus scatter to the focal plane, from which the propagation distance between the out-of-focus plane and the focal plane is determined automatically via an image-definition-evaluation criterion based on information entropy theory. By use of the proposed approach, we demonstrate that the lateral resolution close to that at the focal plane can be recovered from the imaging planes outside the depth of field region with minimal loss of resolution. Fresh onion tissues and mouse fat tissues are used in the experiments to show the performance of the proposed method. PMID:23162717

Image analysis of ocular fundus for retinopathy characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ushizima, Daniela; Cuadros, Jorge

2010-02-05

Automated analysis of ocular fundus images is a common procedure in countries as England, including both nonemergency examination and retinal screening of patients with diabetes mellitus. This involves digital image capture and transmission of the images to a digital reading center for evaluation and treatment referral. In collaboration with the Optometry Department, University of California, Berkeley, we have tested computer vision algorithms to segment vessels and lesions in ground-truth data (DRIVE database) and hundreds of images of non-macular centric and nonuniform illumination views of the eye fundus from EyePACS program. Methods under investigation involve mathematical morphology (Figure 1) for imagemore » enhancement and pattern matching. Recently, we have focused in more efficient techniques to model the ocular fundus vasculature (Figure 2), using deformable contours. Preliminary results show accurate segmentation of vessels and high level of true-positive microaneurysms.« less

The use of digital images in pathology.

PubMed

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.

Data mining and visualization of average images in a digital hand atlas

NASA Astrophysics Data System (ADS)

Zhang, Aifeng; Gertych, Arkadiusz; Liu, Brent J.; Huang, H. K.

2005-04-01

We have collected a digital hand atlas containing digitized left hand radiographs of normally developed children grouped accordingly by age, sex, and race. A set of features stored in a database reflecting patient's stage of skeletal development has been calculated by automatic image processing procedures. This paper addresses a new concept, "average" image in the digital hand atlas. The "average" reference image in the digital atlas is selected for each of the groups of normal developed children with the best representative skeletal maturity based on bony features. A data mining procedure was designed and applied to find the average image through average feature vector matching. It also provides a temporary solution for the missing feature problem through polynomial regression. As more cases are added to the digital hand atlas, it can grow to provide clinicians accurate reference images to aid the bone age assessment process.

Evaluation of the effect scan pattern has on the trueness and precision of six intraoral digital impression systems.

PubMed

Mennito, Anthony S; Evans, Zachary P; Lauer, Abigail W; Patel, Ravi B; Ludlow, Mark E; Renne, Walter G

2018-03-01

Clinicians have been slow to adopt digital impression technologies due possibly to perceived technique sensitivities involved in data acquisition. This research has two aims: determine whether scan pattern and sequence affects the accuracy of the three-dimensional (3D) model created from this digital impression and to compare the 5 imaging systems with regards to their scanning accuracy for sextant impressions. Six digital intraoral impression systems were used to scan a typodont sextant with optical properties similar to natural teeth. The impressions were taken using five different scan patterns and the resulting digital models were overlayed on a master digital model to determine the accuracy of each scanner performing each scan pattern. Furthermore, regardless of scan pattern, each digital impression system was evaluated for accuracy to the other systems in this same manner. No differences of significance were noted in the accuracy of 3D models created using six distinct scan patterns with one exception involving the CEREC Omnicam. Planmeca Planscan was determined to be the truest scanner while 3Shape Trios was determined to be the most precise for sextant impression making. Scan pattern does not significantly affect the accuracy of the resulting digital model for sextant scanning. Companies who make digital impression systems often recommend a scan pattern specific for their system. However, every clinical scanning scenario is different and may require a different approach. Knowing how important scan pattern is with regards to accuracy would be helpful for guiding a growing number of practitioners who are utilizing this technology. © 2018 Wiley Periodicals, Inc.

Synthesis method from low-coherence digital holograms for improvement of image quality in holographic display.

PubMed

Mori, Yutaka; Nomura, Takanori

2013-06-01

In holographic displays, it is undesirable to observe the speckle noises with the reconstructed images. A method for improvement of reconstructed image quality by synthesizing low-coherence digital holograms is proposed. It is possible to obtain speckleless reconstruction of holograms due to low-coherence digital holography. An image sensor records low-coherence digital holograms, and the holograms are synthesized by computational calculation. Two approaches, the threshold-processing and the picking-a-peak methods, are proposed in order to reduce random noise of low-coherence digital holograms. The reconstructed image quality by the proposed methods is compared with the case of high-coherence digital holography. Quantitative evaluation is given to confirm the proposed methods. In addition, the visual evaluation by 15 people is also shown.

Digital pathology: DICOM-conform draft, testbed, and first results.

PubMed

Zwönitzer, Ralf; Kalinski, Thomas; Hofmann, Harald; Roessner, Albert; Bernarding, Johannes

2007-09-01

Hospital information systems are state of the art nowadays. Therefore, Digital Pathology, also labelled as Virtual Microscopy, has gained increased attention. Triggered by radiology, standardized information models and workflows were world-wide defined based on DICOM. However, DICOM-conform integration of Digital Pathology into existing clinical information systems imposes new problems requiring specific solutions concerning the huge amount of data as well as the special structure of the data to be managed, transferred, and stored. We implemented a testbed to realize and evaluate the workflow of digitized slides from acquisition to archiving. The experiences led to the draft of a DICOM-conform information model that accounted for extensions, definitions, and technical requirements necessary to integrate digital pathology in a hospital-wide DICOM environment. Slides were digitized, compressed, and could be viewed remotely. Real-time transfer of the huge amount of data was optimized using streaming techniques. Compared to a recent discussion in the DICOM Working Group for Digital Pathology (WG26) our experiences led to a preference of a JPEG2000/JPIP-based streaming of the whole slide image. The results showed that digital pathology is feasible but strong efforts by users and vendors are still necessary to integrate Digital Pathology into existing information systems.

The 2011 collapse of Puu Oo pit crater, Hawaii: insights from digital image correlation and Discrete Element Method models

NASA Astrophysics Data System (ADS)

Holohan, E. P.; Walter, T. R.; Schöpfer, M. P. J.; Walsh, J. J.; Orr, T.; Poland, M.

2012-04-01

In March 2011, a spectacular fissure eruption on Kilauea was associated with a major collapse event in the highly-active Puu Oo crater. Time-lapse cameras maintained by the Hawaii Volcano Observatory captured views of the crater in the moments before, during, and after the collapse. The 2011 event hence represents a unique opportunity to characterize the surface deformation related to the onset of a pit crater collapse and to understand what factors influence it. To do so, we used two approaches. First, we analyzed the available series of camera images by means of digital image correlation techniques. This enabled us to gain a semi-quantitative (pixel-unit) description of the surface displacements and the structural development of the collapsing crater floor. Secondly, we ran a series of 'true-scale' numerical pit-crater collapse simulations based on the two-dimensional Distinct Element Method (2D-DEM). This enabled us to gain insights into what geometric and mechanical factors could have controlled the observed surface displacement pattern and structural development. Our analysis of the time-lapse images reveals that the crater floor initially gently sagged, and then rapidly collapsed in association with the appearance of a large ring-like fault scarp. The observed structural development and surface displacement patterns of the March 2011 Puu Oo collapse are best reproduced in DEM models with a relatively shallow magma reservoir that is vertically elongated, and with a crater floor rock mass that is reasonably strong. In combining digital image correlation with DEM modeling, our study highlights the future potential of these relatively new techniques for understanding physical processes at active volcanoes.

Radiology's value chain.

PubMed

Enzmann, Dieter R

2012-04-01

A diagnostic radiology value chain is constructed to define its main components, all of which are vulnerable to change, because digitization has caused disaggregation of the chain. Some components afford opportunities to improve productivity, some add value, while some face outsourcing to lower labor cost and to information technology substitutes, raising commoditization risks. Digital image information, because it can be competitive at smaller economies of scale, allows faster, differential rates of technological innovation of components, initiating a centralization-to-decentralization technology trend. Digitization, having triggered disaggregation of radiology's professional service model, may soon usher in an information business model. This means moving from a mind-set of "reading images" to an orientation of creating and organizing information for greater accuracy, faster speed, and lower cost in medical decision making. Information businesses view value chain investments differently than do small professional services. In the former model, producing a better business product will extend image interpretation beyond a radiologist's personal fund of knowledge to encompass expanding external imaging databases. A follow-on expansion with integration of image and molecular information into a report will offer new value in medical decision making. Improved interpretation plus new integration will enrich and diversify radiology's key service products, the report and consultation. A more robust, information-rich report derived from a "systems" and "computational" radiology approach will be facilitated by a transition from a professional service to an information business. Under health care reform, radiology will transition its emphasis from volume to greater value. Radiology's future brightens with the adoption of a philosophy of offering information rather than "reads" for decision making. Staunchly defending the status quo via turf wars is unlikely to constitute a forward-looking, competitive strategy. © RSNA, 2012.

Image barcodes

NASA Astrophysics Data System (ADS)

Damera-Venkata, Niranjan; Yen, Jonathan

2003-01-01

A Visually significant two-dimensional barcode (VSB) developed by Shaked et. al. is a method used to design an information carrying two-dimensional barcode, which has the appearance of a given graphical entity such as a company logo. The encoding and decoding of information using the VSB, uses a base image with very few graylevels (typically only two). This typically requires the image histogram to be bi-modal. For continuous-tone images such as digital photographs of individuals, the representation of tone or "shades of gray" is not only important to obtain a pleasing rendition of the face, but in most cases, the VSB renders these images unrecognizable due to its inability to represent true gray-tone variations. This paper extends the concept of a VSB to an image bar code (IBC). We enable the encoding and subsequent decoding of information embedded in the hardcopy version of continuous-tone base-images such as those acquired with a digital camera. The encoding-decoding process is modeled by robust data transmission through a noisy print-scan channel that is explicitly modeled. The IBC supports a high information capacity that differentiates it from common hardcopy watermarks. The reason for the improved image quality over the VSB is a joint encoding/halftoning strategy based on a modified version of block error diffusion. Encoder stability, image quality vs. information capacity tradeoffs and decoding issues with and without explicit knowledge of the base-image are discussed.

From Horse-Drawn Wagon to Hot Rod: The University of California's Digital Image Service Experience

ERIC Educational Resources Information Center

Burns, Maureen A.

2006-01-01

This article proposes that a viable approach archivists might consider to meet increasing demands for access to digital images with functional presentation tools is to develop a reciprocal partnership with a digital library. The University of California's experience with the federation of licensed and UC-owned digital image collections is…

Information measures for terrain visualization

NASA Astrophysics Data System (ADS)

Bonaventura, Xavier; Sima, Aleksandra A.; Feixas, Miquel; Buckley, Simon J.; Sbert, Mateu; Howell, John A.

2017-02-01

Many quantitative and qualitative studies in geoscience research are based on digital elevation models (DEMs) and 3D surfaces to aid understanding of natural and anthropogenically-influenced topography. As well as their quantitative uses, the visual representation of DEMs can add valuable information for identifying and interpreting topographic features. However, choice of viewpoints and rendering styles may not always be intuitive, especially when terrain data are augmented with digital image texture. In this paper, an information-theoretic framework for object understanding is applied to terrain visualization and terrain view selection. From a visibility channel between a set of viewpoints and the component polygons of a 3D terrain model, we obtain three polygonal information measures. These measures are used to visualize the information associated with each polygon of the terrain model. In order to enhance the perception of the terrain's shape, we explore the effect of combining the calculated information measures with the supplementary digital image texture. From polygonal information, we also introduce a method to select a set of representative views of the terrain model. Finally, we evaluate the behaviour of the proposed techniques using example datasets. A publicly available framework for both the visualization and the view selection of a terrain has been created in order to provide the possibility to analyse any terrain model.

Open Pit Mine 3d Mapping by Tls and Digital Photogrammetry: 3d Model Update Thanks to a Slam Based Approach

NASA Astrophysics Data System (ADS)

Vassena, G.; Clerici, A.

2018-05-01

The state of the art of 3D surveying technologies, if correctly applied, allows to obtain 3D coloured models of large open pit mines using different technologies as terrestrial laser scanner (TLS), with images, combined with UAV based digital photogrammetry. GNSS and/or total station are also currently used to geo reference the model. The University of Brescia has been realised a project to map in 3D an open pit mine located in Botticino, a famous location of marble extraction close to Brescia in North Italy. Terrestrial Laser Scanner 3D point clouds combined with RGB images and digital photogrammetry from UAV have been used to map a large part of the cave. By rigorous and well know procedures a 3D point cloud and mesh model have been obtained using an easy and rigorous approach. After the description of the combined mapping process, the paper describes the innovative process proposed for the daily/weekly update of the model itself. To realize this task a SLAM technology approach is described, using an innovative approach based on an innovative instrument capable to run an automatic localization process and real time on the field change detection analysis.

Geometric processing of digital images of the planets

NASA Technical Reports Server (NTRS)

Edwards, Kathleen

1987-01-01

New procedures and software have been developed for geometric transformation of images to support digital cartography of the planets. The procedures involve the correction of spacecraft camera orientation of each image with the use of ground control and the transformation of each image to a Sinusoidal Equal-Area map projection with an algorithm which allows the number of transformation calculations to vary as the distortion varies within the image. When the distortion is low in an area of an image, few transformation computations are required, and most pixels can be interpolated. When distortion is extreme, the location of each pixel is computed. Mosaics are made of these images and stored as digital databases. Completed Sinusoidal databases may be used for digital analysis and registration with other spatial data. They may also be reproduced as published image maps by digitally transforming them to appropriate map projections.

Ultramap v3 - a Revolution in Aerial Photogrammetry

NASA Astrophysics Data System (ADS)

Reitinger, B.; Sormann, M.; Zebedin, L.; Schachinger, B.; Hoefler, M.; Tomasi, R.; Lamperter, M.; Gruber, B.; Schiester, G.; Kobald, M.; Unger, M.; Klaus, A.; Bernoegger, S.; Karner, K.; Wiechert, A.; Ponticelli, M.; Gruber, M.

2012-07-01

In the last years, Microsoft has driven innovation in the aerial photogrammetry community. Besides the market leading camera technology, UltraMap has grown to an outstanding photogrammetric workflow system which enables users to effectively work with large digital aerial image blocks in a highly automated way. Best example is the project-based color balancing approach which automatically balances images to a homogeneous block. UltraMap V3 continues innovation, and offers a revolution in terms of ortho processing. A fully automated dense matching module strives for high precision digital surface models (DSMs) which are calculated either on CPUs or on GPUs using a distributed processing framework. By applying constrained filtering algorithms, a digital terrain model can be derived which in turn can be used for fully automated traditional ortho texturing. By having the knowledge about the underlying geometry, seamlines can be generated automatically by applying cost functions in order to minimize visual disturbing artifacts. By exploiting the generated DSM information, a DSMOrtho is created using the balanced input images. Again, seamlines are detected automatically resulting in an automatically balanced ortho mosaic. Interactive block-based radiometric adjustments lead to a high quality ortho product based on UltraCam imagery. UltraMap v3 is the first fully integrated and interactive solution for supporting UltraCam images at best in order to deliver DSM and ortho imagery.

Context indexing of digital cardiac ultrasound records in PACS

NASA Astrophysics Data System (ADS)

Lobodzinski, S. Suave; Meszaros, Georg N.

1998-07-01

Recent wide adoption of the DICOM 3.0 standard by ultrasound equipment vendors created a need for practical clinical implementations of cardiac imaging study visualization, management and archiving, DICOM 3.0 defines only a logical and physical format for exchanging image data (still images, video, patient and study demographics). All DICOM compliant imaging studies must presently be archived on a 650 Mb recordable compact disk. This is a severe limitation for ultrasound applications where studies of 3 to 10 minutes long are a common practice. In addition, DICOM digital echocardiography objects require physiological signal indexing, content segmentation and characterization. Since DICOM 3.0 is an interchange standard only, it does not define how to database composite video objects. The goal of this research was therefore to address the issues of efficient storage, retrieval and management of DICOM compliant cardiac video studies in a distributed PACS environment. Our Web based implementation has the advantage of accommodating both DICOM defined entity-relation modules (equipment data, patient data, video format, etc.) in standard relational database tables and digital indexed video with its attributes in an object relational database. Object relational data model facilitates content indexing of full motion cardiac imaging studies through bi-directional hyperlink generation that tie searchable video attributes and related objects to individual video frames in the temporal domain. Benefits realized from use of bi-directionally hyperlinked data models in an object relational database include: (1) real time video indexing during image acquisition, (2) random access and frame accurate instant playback of previously recorded full motion imaging data, and (3) time savings from faster and more accurate access to data through multiple navigation mechanisms such as multidimensional queries on an index, queries on a hyperlink attribute, free search and browsing.

50 μm pixel pitch wafer-scale CMOS active pixel sensor x-ray detector for digital breast tomosynthesis.

PubMed

Zhao, C; Konstantinidis, A C; Zheng, Y; Anaxagoras, T; Speller, R D; Kanicki, J

2015-12-07

Wafer-scale CMOS active pixel sensors (APSs) have been developed recently for x-ray imaging applications. The small pixel pitch and low noise are very promising properties for medical imaging applications such as digital breast tomosynthesis (DBT). In this work, we evaluated experimentally and through modeling the imaging properties of a 50 μm pixel pitch CMOS APS x-ray detector named DynAMITe (Dynamic Range Adjustable for Medical Imaging Technology). A modified cascaded system model was developed for CMOS APS x-ray detectors by taking into account the device nonlinear signal and noise properties. The imaging properties such as modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE) were extracted from both measurements and the nonlinear cascaded system analysis. The results show that the DynAMITe x-ray detector achieves a high spatial resolution of 10 mm(-1) and a DQE of around 0.5 at spatial frequencies  <1 mm(-1). In addition, the modeling results were used to calculate the image signal-to-noise ratio (SNRi) of microcalcifications at various mean glandular dose (MGD). For an average breast (5 cm thickness, 50% glandular fraction), 165 μm microcalcifications can be distinguished at a MGD of 27% lower than the clinical value (~1.3 mGy). To detect 100 μm microcalcifications, further optimizations of the CMOS APS x-ray detector, image aquisition geometry and image reconstruction techniques should be considered.

A multitemporal (1979-2009) land-use/land-cover dataset of the binational Santa Cruz Watershed

USGS Publications Warehouse

2011-01-01

Trends derived from multitemporal land-cover data can be used to make informed land management decisions and to help managers model future change scenarios. We developed a multitemporal land-use/land-cover dataset for the binational Santa Cruz watershed of southern Arizona, United States, and northern Sonora, Mexico by creating a series of land-cover maps at decadal intervals (1979, 1989, 1999, and 2009) using Landsat Multispectral Scanner and Thematic Mapper data and a classification and regression tree classifier. The classification model exploited phenological changes of different land-cover spectral signatures through the use of biseasonal imagery collected during the (dry) early summer and (wet) late summer following rains from the North American monsoon. Landsat images were corrected to remove atmospheric influences, and the data were converted from raw digital numbers to surface reflectance values. The 14-class land-cover classification scheme is based on the 2001 National Land Cover Database with a focus on "Developed" land-use classes and riverine "Forest" and "Wetlands" cover classes required for specific watershed models. The classification procedure included the creation of several image-derived and topographic variables, including digital elevation model derivatives, image variance, and multitemporal Kauth-Thomas transformations. The accuracy of the land-cover maps was assessed using a random-stratified sampling design, reference aerial photography, and digital imagery. This showed high accuracy results, with kappa values (the statistical measure of agreement between map and reference data) ranging from 0.80 to 0.85.

Investigation of two methods to quantify noise in digital images based on the perception of the human eye

NASA Astrophysics Data System (ADS)

Kleinmann, Johanna; Wueller, Dietmar

2007-01-01

Since the signal to noise measuring method as standardized in the normative part of ISO 15739:2002(E)1 does not quantify noise in a way that matches the perception of the human eye, two alternative methods have been investigated which may be appropriate to quantify the noise perception in a physiological manner: - the model of visual noise measurement proposed by Hung et al2 (as described in the informative annex of ISO 15739:20021) which tries to simulate the process of human vision by using the opponent space and contrast sensitivity functions and uses the CIEL*u*v*1976 colour space for the determination of a so called visual noise value. - The S-CIELab model and CIEDE2000 colour difference proposed by Fairchild et al 3 which simulates human vision approximately the same way as Hung et al2 but uses an image comparison afterwards based on CIEDE2000. With a psychophysical experiment based on just noticeable difference (JND), threshold images could be defined, with which the two approaches mentioned above were tested. The assumption is that if the method is valid, the different threshold images should get the same 'noise value'. The visual noise measurement model results in similar visual noise values for all the threshold images. The method is reliable to quantify at least the JND for noise in uniform areas of digital images. While the visual noise measurement model can only evaluate uniform colour patches in images, the S-CIELab model can be used on images with spatial content as well. The S-CIELab model also results in similar colour difference values for the set of threshold images, but with some limitations: for images which contain spatial structures besides the noise, the colour difference varies depending on the contrast of the spatial content.

Methods in Astronomical Image Processing

NASA Astrophysics Data System (ADS)

Jörsäter, S.

A Brief Introductory Note History of Astronomical Imaging Astronomical Image Data Images in Various Formats Digitized Image Data Digital Image Data Philosophy of Astronomical Image Processing Properties of Digital Astronomical Images Human Image Processing Astronomical vs. Computer Science Image Processing Basic Tools of Astronomical Image Processing Display Applications Calibration of Intensity Scales Calibration of Length Scales Image Re-shaping Feature Enhancement Noise Suppression Noise and Error Analysis Image Processing Packages: Design of AIPS and MIDAS AIPS MIDAS Reduction of CCD Data Bias Subtraction Clipping Preflash Subtraction Dark Subtraction Flat Fielding Sky Subtraction Extinction Correction Deconvolution Methods Rebinning/Combining Summary and Prospects for the Future

On-Ground Processing of Yaogan-24 Remote Sensing Satellite Attitude Data and Verification Using Geometric Field Calibration

PubMed Central

Wang, Mi; Fan, Chengcheng; Yang, Bo; Jin, Shuying; Pan, Jun

2016-01-01

Satellite attitude accuracy is an important factor affecting the geometric processing accuracy of high-resolution optical satellite imagery. To address the problem whereby the accuracy of the Yaogan-24 remote sensing satellite’s on-board attitude data processing is not high enough and thus cannot meet its image geometry processing requirements, we developed an approach involving on-ground attitude data processing and digital orthophoto (DOM) and the digital elevation model (DEM) verification of a geometric calibration field. The approach focuses on three modules: on-ground processing based on bidirectional filter, overall weighted smoothing and fitting, and evaluation in the geometric calibration field. Our experimental results demonstrate that the proposed on-ground processing method is both robust and feasible, which ensures the reliability of the observation data quality, convergence and stability of the parameter estimation model. In addition, both the Euler angle and quaternion could be used to build a mathematical fitting model, while the orthogonal polynomial fitting model is more suitable for modeling the attitude parameter. Furthermore, compared to the image geometric processing results based on on-board attitude data, the image uncontrolled and relative geometric positioning result accuracy can be increased by about 50%. PMID:27483287

Reproducibility of the NEPTUNE descriptor-based scoring system on whole-slide images and histologic and ultrastructural digital images.

PubMed

Barisoni, Laura; Troost, Jonathan P; Nast, Cynthia; Bagnasco, Serena; Avila-Casado, Carmen; Hodgin, Jeffrey; Palmer, Matthew; Rosenberg, Avi; Gasim, Adil; Liensziewski, Chrysta; Merlino, Lino; Chien, Hui-Ping; Chang, Anthony; Meehan, Shane M; Gaut, Joseph; Song, Peter; Holzman, Lawrence; Gibson, Debbie; Kretzler, Matthias; Gillespie, Brenda W; Hewitt, Stephen M

2016-07-01

The multicenter Nephrotic Syndrome Study Network (NEPTUNE) digital pathology scoring system employs a novel and comprehensive methodology to document pathologic features from whole-slide images, immunofluorescence and ultrastructural digital images. To estimate inter- and intra-reader concordance of this descriptor-based approach, data from 12 pathologists (eight NEPTUNE and four non-NEPTUNE) with experience from training to 30 years were collected. A descriptor reference manual was generated and a webinar-based protocol for consensus/cross-training implemented. Intra-reader concordance for 51 glomerular descriptors was evaluated on jpeg images by seven NEPTUNE pathologists scoring 131 glomeruli three times (Tests I, II, and III), each test following a consensus webinar review. Inter-reader concordance of glomerular descriptors was evaluated in 315 glomeruli by all pathologists; interstitial fibrosis and tubular atrophy (244 cases, whole-slide images) and four ultrastructural podocyte descriptors (178 cases, jpeg images) were evaluated once by six and five pathologists, respectively. Cohen's kappa for inter-reader concordance for 48/51 glomerular descriptors with sufficient observations was moderate (0.40

Automatic identification of fault surfaces through Object Based Image Analysis of a Digital Elevation Model in the submarine area of the North Aegean Basin

NASA Astrophysics Data System (ADS)

Argyropoulou, Evangelia

2015-04-01

The current study was focused on the seafloor morphology of the North Aegean Basin in Greece, through Object Based Image Analysis (OBIA) using a Digital Elevation Model. The goal was the automatic extraction of morphologic and morphotectonic features, resulting into fault surface extraction. An Object Based Image Analysis approach was developed based on the bathymetric data and the extracted features, based on morphological criteria, were compared with the corresponding landforms derived through tectonic analysis. A digital elevation model of 150 meters spatial resolution was used. At first, slope, profile curvature, and percentile were extracted from this bathymetry grid. The OBIA approach was developed within the eCognition environment. Four segmentation levels were created having as a target "level 4". At level 4, the final classes of geomorphological features were classified: discontinuities, fault-like features and fault surfaces. On previous levels, additional landforms were also classified, such as continental platform and continental slope. The results of the developed approach were evaluated by two methods. At first, classification stability measures were computed within eCognition. Then, qualitative and quantitative comparison of the results took place with a reference tectonic map which has been created manually based on the analysis of seismic profiles. The results of this comparison were satisfactory, a fact which determines the correctness of the developed OBIA approach.

e-phenology: monitoring leaf phenology and tracking climate changes in the tropics

NASA Astrophysics Data System (ADS)

Morellato, Patrícia; Alberton, Bruna; Almeida, Jurandy; Alex, Jefersson; Mariano, Greice; Torres, Ricardo

2014-05-01

The e-phenology is a multidisciplinary project combining research in Computer Science and Phenology. Its goal is to attack theoretical and practical problems involving the use of new technologies for remote phenological observation aiming to detect local environmental changes. It is geared towards three objectives: (a) the use of new technologies of environmental monitoring based on remote phenology monitoring systems; (b) creation of a protocol for a Brazilian long term phenology monitoring program and for the integration across disciplines, advancing our knowledge of seasonal responses within tropics to climate change; and (c) provide models, methods and algorithms to support management, integration and analysis of data of remote phenology systems. The research team is composed by computer scientists and biology researchers in Phenology. Our first results include: Phenology towers - We set up the first phenology tower in our core cerrado-savanna 1 study site at Itirapina, São Paulo, Brazil. The tower received a complete climatic station and a digital camera. The digital camera is set up to take daily sequence of images (five images per hour, from 6:00 to 18:00 h). We set up similar phenology towers with climatic station and cameras in five more sites: cerrado-savanna 2 (Pé de Gigante, SP), cerrado grassland 3 (Itirapina, SP), rupestrian fields 4 ( Serra do Cipo, MG), seasonal forest 5 (Angatuba, SP) and Atlantic raiforest 6 (Santa Virginia, SP). Phenology database - We finished modeling and validation of a phenology database that stores ground phenology and near-remote phenology, and we are carrying out the implementation with data ingestion. Remote phenology and image processing - We performed the first analyses of the cerrado sites 1 to 4 phenology derived from digital images. Analysis were conducted by extracting color information (RGB Red, Green and Blue color channels) from selected parts of the image named regions of interest (ROI). using the green color channel. We analyzed a daily sequence of images (6:00 to 18:00 h). Our results are innovative and indicate the great variation in color change response for tropical trees. We validate the camera phenology with our on the ground direct observation in the core cerrado site 1. We are developing a Image processing software to authomatic process the digital images and to generate the time series for further analyses. New techniques and image features have been used to extract seasonal features from data and for data processing, such as machine learning and visual rhythms. Machine learning was successful applied to identify similar species within the image. Visual rhythms show up as a new analytic tool for phenological interpretation. Next research steps include the analyses of longer data series, correlation with local climatic data, analyses and comparison of patterns among different vegetation sites, prepare a compressive protocol for digital camera phenology and develop new technologies to access vegetation changes using digital cameras. Support: FAPESP-Micorsoft Research, CNPq, CAPES.

Pediatric chest imaging.

PubMed

Gross, G W

1992-10-01

The highlight of recent articles published on pediatric chest imaging is the potential advantage of digital imaging of the infant's chest. Digital chest imaging allows accurate determination of functional residual capacity as well as manipulation of the image to highlight specific anatomic features. Reusable photostimulable phosphor imaging systems provide wide imaging latitude and lower patient dose. In addition, digital radiology permits multiple remote-site viewing on monitor displays. Several excellent reviews of the imaging features of various thoracic abnormalities and the application of newer imaging modalities, such as ultrafast CT and MR imaging to the pediatric chest, are additional highlights.

Real-time out-of-plane artifact subtraction tomosynthesis imaging using prior CT for scanning beam digital x-ray system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Meng, E-mail: mengwu@stanford.edu; Fahrig, Rebecca

2014-11-01

Purpose: The scanning beam digital x-ray system (SBDX) is an inverse geometry fluoroscopic system with high dose efficiency and the ability to perform continuous real-time tomosynthesis in multiple planes. This system could be used for image guidance during lung nodule biopsy. However, the reconstructed images suffer from strong out-of-plane artifact due to the small tomographic angle of the system. Methods: The authors propose an out-of-plane artifact subtraction tomosynthesis (OPAST) algorithm that utilizes a prior CT volume to augment the run-time image processing. A blur-and-add (BAA) analytical model, derived from the project-to-backproject physical model, permits the generation of tomosynthesis images thatmore » are a good approximation to the shift-and-add (SAA) reconstructed image. A computationally practical algorithm is proposed to simulate images and out-of-plane artifacts from patient-specific prior CT volumes using the BAA model. A 3D image registration algorithm to align the simulated and reconstructed images is described. The accuracy of the BAA analytical model and the OPAST algorithm was evaluated using three lung cancer patients’ CT data. The OPAST and image registration algorithms were also tested with added nonrigid respiratory motions. Results: Image similarity measurements, including the correlation coefficient, mean squared error, and structural similarity index, indicated that the BAA model is very accurate in simulating the SAA images from the prior CT for the SBDX system. The shift-variant effect of the BAA model can be ignored when the shifts between SBDX images and CT volumes are within ±10 mm in the x and y directions. The nodule visibility and depth resolution are improved by subtracting simulated artifacts from the reconstructions. The image registration and OPAST are robust in the presence of added respiratory motions. The dominant artifacts in the subtraction images are caused by the mismatches between the real object and the prior CT volume. Conclusions: Their proposed prior CT-augmented OPAST reconstruction algorithm improves lung nodule visibility and depth resolution for the SBDX system.« less

How Digital Image Processing Became Really Easy

NASA Astrophysics Data System (ADS)

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.

The treatment of tendon injury with electromagnetic fields evidenced by advanced ultrasound image processing.

PubMed

Parker, Richard; Markov, Marko

2015-09-01

This article presents a novel modality for accelerating the repair of tendon and ligament lesions by means of a specifically designed electromagnetic field in an equine model. This novel therapeutic approach employs a delivery system that induces a specific electrical signal from an external magnetic field derived from Superconductive QUantum Interference Device (SQUID) measurements of injured vs. healthy tissue. Evaluation of this therapy technique is enabled by a proposed new technology described as Predictive Analytical Imagery (PAI™). This technique examines an ultrasound grayscale image and seeks to evaluate it by means of look-ahead predictive algorithms and digital signal processing. The net result is a significant reduction in background noise and the production of a high-resolution grayscale or digital image.

Digital image film generation: from the photoscientist's perspective

USGS Publications Warehouse

Boyd, John E.

1982-01-01

The technical sophistication of photoelectronic transducers, integrated circuits, and laser-beam film recorders has made digital imagery an alternative to traditional analog imagery for remote sensing. Because a digital image is stored in discrete digital values, image enhancement is possible before the data are converted to a photographic image. To create a special film-reproduction curve - which can simulate any desired gamma, relative film speed, and toe/shoulder response - the digital-to-analog transfer function of the film recorder is uniquely defined and implemented by a lookup table in the film recorder. Because the image data are acquired in spectral bands, false-color composites also can be given special characteristics by selecting a reproduction curve tailored for each band.

Proposed U.S. Geological Survey standard for digital orthophotos

USGS Publications Warehouse

Hooper, David; Caruso, Vincent

1991-01-01

The U.S. Geological Survey has added the new category of digital orthophotos to the National Digital Cartographic Data Base. This differentially rectified digital image product enables users to take advantage of the properties of current photoimagery as a source of geographic information. The product and accompanying standard were implemented in spring 1991. The digital orthophotos will be quadrangle based and cast on the Universal Transverse Mercator projection and will extend beyond the 3.75-minute or 7.5-minute quadrangle area at least 300 meters to form a rectangle. The overedge may be used for mosaicking with adjacent digital orthophotos. To provide maximum information content and utility to the user, metadata (header) records exist at the beginning of the digital orthophoto file. Header information includes the photographic source type, date, instrumentation used to create the digital orthophoto, and information relating to the DEM that was used in the rectification process. Additional header information is included on transformation constants from the 1927 and 1983 North American Datums to the orthophoto internal file coordinates to enable the user to register overlays on either datum. The quadrangle corners in both datums are also imprinted on the image. Flexibility has been built into the digital orthophoto format for future enhancements, such as the provision to include the corresponding digital elevation model elevations used to rectify the orthophoto. The digital orthophoto conforms to National Map Accuracy Standards and provides valuable mapping data that can be used as a tool for timely revision of standard map products, for land use and land cover studies, and as a digital layer in a geographic information system.

3D Digital Surveying and Modelling of Cave Geometry: Application to Paleolithic Rock Art.

PubMed

González-Aguilera, Diego; Muñoz-Nieto, Angel; Gómez-Lahoz, Javier; Herrero-Pascual, Jesus; Gutierrez-Alonso, Gabriel

2009-01-01

3D digital surveying and modelling of cave geometry represents a relevant approach for research, management and preservation of our cultural and geological legacy. In this paper, a multi-sensor approach based on a terrestrial laser scanner, a high-resolution digital camera and a total station is presented. Two emblematic caves of Paleolithic human occupation and situated in northern Spain, "Las Caldas" and "Peña de Candamo", have been chosen to put in practise this approach. As a result, an integral and multi-scalable 3D model is generated which may allow other scientists, pre-historians, geologists…, to work on two different levels, integrating different Paleolithic Art datasets: (1) a basic level based on the accurate and metric support provided by the laser scanner; and (2) a advanced level using the range and image-based modelling.

Effect of Different Tube Potential Settings on Caries Detection using PSP Plate and Conventional Film.

PubMed

De Melo, Daniela Pita; Cruz, Adriana Dibo; Melo, Saulo Leonardo Sousa; De Farias, Julyanna Filgueiras GonçAlves; Haiter-Neto, Francisco; De Almeida, Solange Maria

2015-04-01

To compare intraoral Phosphor Stimulable Plate digital system and intraoral film using different tube settings on incipient proximal caries detection. Five blocks, with five teeth each, were radiographically examined using phosphor plates and F-speed films. The images were acquired in 07 different tube potentials from 50-80 kV. The films were digitized. Three oral radiologists scored the images for the presence of caries using a 5-point rating scale. The areas under ROC curve were calculated. The influence of tube kilovoltage was verified by ANOVA and pair wise comparisons performed using Tukey test. Mean ROC curve areas varied from 0.446-0.628 for digital images and 0.494-0.559 for conventional images. The tube setting of 70 kV presented the best result both for digital and conventional images. Considering the image type separately, 70 kV scored highest followed by 75 and 65 kV for digital images (p=0.084). For conventional image modality, even though 70 kV presented the best result, it did not differ significantly from 80 kV, not differing from 60 and 55 kV, which did not differ from 75, 65 and 50 kV (p=0.53). Phosphor plate digital images seem to be more susceptible to tube setting potential variations then digitized film images.

The Artist, the Color Copier, and Digital Imaging.

ERIC Educational Resources Information Center

Witte, Mary Stieglitz

The impact that color-copying technology and digital imaging have had on art, photography, and design are explored. Color copiers have provided new opportunities for direct and spontaneous image making an the potential for new transformations in art. The current generation of digital color copiers permits new directions in imaging, but the…

76 FR 59737 - In the Matter of Certain Digital Photo Frames and Image Display Devices and Components Thereof...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-27

... Frames and Image Display Devices and Components Thereof; Notice of Institution of Investigation... United States after importation of certain digital photo frames and image display devices and components... certain digital photo frames and image display devices and components thereof that infringe one or more of...

Measurement of Full Field Strains in Filament Wound Composite Tubes Under Axial Compressive Loading by the Digital Image Correlation (DIC) Technique

DTIC Science & Technology

2013-05-01

Measurement of Full Field Strains in Filament Wound Composite Tubes Under Axial Compressive Loading by the Digital Image Correlation (DIC...of Full Field Strains in Filament Wound Composite Tubes Under Axial Compressive Loading by the Digital Image Correlation (DIC) Technique Todd C...Wound Composite Tubes Under Axial Compressive Loading by the Digital Image Correlation (DIC) Technique 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c

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

NASA Astrophysics Data System (ADS)

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.

Limitations and requirements of content-based multimedia authentication systems

NASA Astrophysics Data System (ADS)

Wu, Chai W.

2001-08-01

Recently, a number of authentication schemes have been proposed for multimedia data such as images and sound data. They include both label based systems and semifragile watermarks. The main requirement for such authentication systems is that minor modifications such as lossy compression which do not alter the content of the data preserve the authenticity of the data, whereas modifications which do modify the content render the data not authentic. These schemes can be classified into two main classes depending on the model of image authentication they are based on. One of the purposes of this paper is to look at some of the advantages and disadvantages of these image authentication schemes and their relationship with fundamental limitations of the underlying model of image authentication. In particular, we study feature-based algorithms which generate an authentication tag based on some inherent features in the image such as the location of edges. The main disadvantage of most proposed feature-based algorithms is that similar images generate similar features, and therefore it is possible for a forger to generate dissimilar images that have the same features. On the other hand, the class of hash-based algorithms utilizes a cryptographic hash function or a digital signature scheme to reduce the data and generate an authentication tag. It inherits the security of digital signatures to thwart forgery attacks. The main disadvantage of hash-based algorithms is that the image needs to be modified in order to be made authenticatable. The amount of modification is on the order of the noise the image can tolerate before it is rendered inauthentic. The other purpose of this paper is to propose a multimedia authentication scheme which combines some of the best features of both classes of algorithms. The proposed scheme utilizes cryptographic hash functions and digital signature schemes and the data does not need to be modified in order to be made authenticatable. Several applications including the authentication of images on CD-ROM and handwritten documents will be discussed.

Toward a perceptual video-quality metric

NASA Astrophysics Data System (ADS)

Watson, Andrew B.

1998-07-01

The advent of widespread distribution of digital video creates a need for automated methods for evaluating the visual quality of digital video. This is particularly so since most digital video is compressed using lossy methods, which involve the controlled introduction of potentially visible artifacts. Compounding the problem is the bursty nature of digital video, which requires adaptive bit allocation based on visual quality metrics, and the economic need to reduce bit-rate to the lowest level that yields acceptable quality. In previous work, we have developed visual quality metrics for evaluating, controlling,a nd optimizing the quality of compressed still images. These metrics incorporate simplified models of human visual sensitivity to spatial and chromatic visual signals. Here I describe a new video quality metric that is an extension of these still image metrics into the time domain. Like the still image metrics, it is based on the Discrete Cosine Transform. An effort has been made to minimize the amount of memory and computation required by the metric, in order that might be applied in the widest range of applications. To calibrate the basic sensitivity of this metric to spatial and temporal signals we have made measurements of visual thresholds for temporally varying samples of DCT quantization noise.

Remote measurement methods for 3-D modeling purposes using BAE Systems' Software

NASA Astrophysics Data System (ADS)

Walker, Stewart; Pietrzak, Arleta

2015-06-01

Efficient, accurate data collection from imagery is the key to an economical generation of useful geospatial products. Incremental developments of traditional geospatial data collection and the arrival of new image data sources cause new software packages to be created and existing ones to be adjusted to enable such data to be processed. In the past, BAE Systems' digital photogrammetric workstation, SOCET SET®, met fin de siècle expectations in data processing and feature extraction. Its successor, SOCET GXP®, addresses today's photogrammetric requirements and new data sources. SOCET GXP is an advanced workstation for mapping and photogrammetric tasks, with automated functionality for triangulation, Digital Elevation Model (DEM) extraction, orthorectification and mosaicking, feature extraction and creation of 3-D models with texturing. BAE Systems continues to add sensor models to accommodate new image sources, in response to customer demand. New capabilities added in the latest version of SOCET GXP facilitate modeling, visualization and analysis of 3-D features.

Estimation of breast percent density in raw and processed full field digital mammography images via adaptive fuzzy c-means clustering and support vector machine segmentation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keller, Brad M.; Nathan, Diane L.; Wang Yan

Purpose: The amount of fibroglandular tissue content in the breast as estimated mammographically, commonly referred to as breast percent density (PD%), is one of the most significant risk factors for developing breast cancer. Approaches to quantify breast density commonly focus on either semiautomated methods or visual assessment, both of which are highly subjective. Furthermore, most studies published to date investigating computer-aided assessment of breast PD% have been performed using digitized screen-film mammograms, while digital mammography is increasingly replacing screen-film mammography in breast cancer screening protocols. Digital mammography imaging generates two types of images for analysis, raw (i.e., 'FOR PROCESSING') andmore » vendor postprocessed (i.e., 'FOR PRESENTATION'), of which postprocessed images are commonly used in clinical practice. Development of an algorithm which effectively estimates breast PD% in both raw and postprocessed digital mammography images would be beneficial in terms of direct clinical application and retrospective analysis. Methods: This work proposes a new algorithm for fully automated quantification of breast PD% based on adaptive multiclass fuzzy c-means (FCM) clustering and support vector machine (SVM) classification, optimized for the imaging characteristics of both raw and processed digital mammography images as well as for individual patient and image characteristics. Our algorithm first delineates the breast region within the mammogram via an automated thresholding scheme to identify background air followed by a straight line Hough transform to extract the pectoral muscle region. The algorithm then applies adaptive FCM clustering based on an optimal number of clusters derived from image properties of the specific mammogram to subdivide the breast into regions of similar gray-level intensity. Finally, a SVM classifier is trained to identify which clusters within the breast tissue are likely fibroglandular, which are then aggregated into a final dense tissue segmentation that is used to compute breast PD%. Our method is validated on a group of 81 women for whom bilateral, mediolateral oblique, raw and processed screening digital mammograms were available, and agreement is assessed with both continuous and categorical density estimates made by a trained breast-imaging radiologist. Results: Strong association between algorithm-estimated and radiologist-provided breast PD% was detected for both raw (r= 0.82, p < 0.001) and processed (r= 0.85, p < 0.001) digital mammograms on a per-breast basis. Stronger agreement was found when overall breast density was assessed on a per-woman basis for both raw (r= 0.85, p < 0.001) and processed (0.89, p < 0.001) mammograms. Strong agreement between categorical density estimates was also seen (weighted Cohen's {kappa}{>=} 0.79). Repeated measures analysis of variance demonstrated no statistically significant differences between the PD% estimates (p > 0.1) due to either presentation of the image (raw vs processed) or method of PD% assessment (radiologist vs algorithm). Conclusions: The proposed fully automated algorithm was successful in estimating breast percent density from both raw and processed digital mammographic images. Accurate assessment of a woman's breast density is critical in order for the estimate to be incorporated into risk assessment models. These results show promise for the clinical application of the algorithm in quantifying breast density in a repeatable manner, both at time of imaging as well as in retrospective studies.« less

Estimation of breast percent density in raw and processed full field digital mammography images via adaptive fuzzy c-means clustering and support vector machine segmentation

PubMed Central

Keller, Brad M.; Nathan, Diane L.; Wang, Yan; Zheng, Yuanjie; Gee, James C.; Conant, Emily F.; Kontos, Despina

2012-01-01

Purpose: The amount of fibroglandular tissue content in the breast as estimated mammographically, commonly referred to as breast percent density (PD%), is one of the most significant risk factors for developing breast cancer. Approaches to quantify breast density commonly focus on either semiautomated methods or visual assessment, both of which are highly subjective. Furthermore, most studies published to date investigating computer-aided assessment of breast PD% have been performed using digitized screen-film mammograms, while digital mammography is increasingly replacing screen-film mammography in breast cancer screening protocols. Digital mammography imaging generates two types of images for analysis, raw (i.e., “FOR PROCESSING”) and vendor postprocessed (i.e., “FOR PRESENTATION”), of which postprocessed images are commonly used in clinical practice. Development of an algorithm which effectively estimates breast PD% in both raw and postprocessed digital mammography images would be beneficial in terms of direct clinical application and retrospective analysis. Methods: This work proposes a new algorithm for fully automated quantification of breast PD% based on adaptive multiclass fuzzy c-means (FCM) clustering and support vector machine (SVM) classification, optimized for the imaging characteristics of both raw and processed digital mammography images as well as for individual patient and image characteristics. Our algorithm first delineates the breast region within the mammogram via an automated thresholding scheme to identify background air followed by a straight line Hough transform to extract the pectoral muscle region. The algorithm then applies adaptive FCM clustering based on an optimal number of clusters derived from image properties of the specific mammogram to subdivide the breast into regions of similar gray-level intensity. Finally, a SVM classifier is trained to identify which clusters within the breast tissue are likely fibroglandular, which are then aggregated into a final dense tissue segmentation that is used to compute breast PD%. Our method is validated on a group of 81 women for whom bilateral, mediolateral oblique, raw and processed screening digital mammograms were available, and agreement is assessed with both continuous and categorical density estimates made by a trained breast-imaging radiologist. Results: Strong association between algorithm-estimated and radiologist-provided breast PD% was detected for both raw (r = 0.82, p < 0.001) and processed (r = 0.85, p < 0.001) digital mammograms on a per-breast basis. Stronger agreement was found when overall breast density was assessed on a per-woman basis for both raw (r = 0.85, p < 0.001) and processed (0.89, p < 0.001) mammograms. Strong agreement between categorical density estimates was also seen (weighted Cohen's κ ≥ 0.79). Repeated measures analysis of variance demonstrated no statistically significant differences between the PD% estimates (p > 0.1) due to either presentation of the image (raw vs processed) or method of PD% assessment (radiologist vs algorithm). Conclusions: The proposed fully automated algorithm was successful in estimating breast percent density from both raw and processed digital mammographic images. Accurate assessment of a woman's breast density is critical in order for the estimate to be incorporated into risk assessment models. These results show promise for the clinical application of the algorithm in quantifying breast density in a repeatable manner, both at time of imaging as well as in retrospective studies. PMID:22894417

Estimation of breast percent density in raw and processed full field digital mammography images via adaptive fuzzy c-means clustering and support vector machine segmentation.

PubMed

Keller, Brad M; Nathan, Diane L; Wang, Yan; Zheng, Yuanjie; Gee, James C; Conant, Emily F; Kontos, Despina

2012-08-01

The amount of fibroglandular tissue content in the breast as estimated mammographically, commonly referred to as breast percent density (PD%), is one of the most significant risk factors for developing breast cancer. Approaches to quantify breast density commonly focus on either semiautomated methods or visual assessment, both of which are highly subjective. Furthermore, most studies published to date investigating computer-aided assessment of breast PD% have been performed using digitized screen-film mammograms, while digital mammography is increasingly replacing screen-film mammography in breast cancer screening protocols. Digital mammography imaging generates two types of images for analysis, raw (i.e., "FOR PROCESSING") and vendor postprocessed (i.e., "FOR PRESENTATION"), of which postprocessed images are commonly used in clinical practice. Development of an algorithm which effectively estimates breast PD% in both raw and postprocessed digital mammography images would be beneficial in terms of direct clinical application and retrospective analysis. This work proposes a new algorithm for fully automated quantification of breast PD% based on adaptive multiclass fuzzy c-means (FCM) clustering and support vector machine (SVM) classification, optimized for the imaging characteristics of both raw and processed digital mammography images as well as for individual patient and image characteristics. Our algorithm first delineates the breast region within the mammogram via an automated thresholding scheme to identify background air followed by a straight line Hough transform to extract the pectoral muscle region. The algorithm then applies adaptive FCM clustering based on an optimal number of clusters derived from image properties of the specific mammogram to subdivide the breast into regions of similar gray-level intensity. Finally, a SVM classifier is trained to identify which clusters within the breast tissue are likely fibroglandular, which are then aggregated into a final dense tissue segmentation that is used to compute breast PD%. Our method is validated on a group of 81 women for whom bilateral, mediolateral oblique, raw and processed screening digital mammograms were available, and agreement is assessed with both continuous and categorical density estimates made by a trained breast-imaging radiologist. Strong association between algorithm-estimated and radiologist-provided breast PD% was detected for both raw (r = 0.82, p < 0.001) and processed (r = 0.85, p < 0.001) digital mammograms on a per-breast basis. Stronger agreement was found when overall breast density was assessed on a per-woman basis for both raw (r = 0.85, p < 0.001) and processed (0.89, p < 0.001) mammograms. Strong agreement between categorical density estimates was also seen (weighted Cohen's κ ≥ 0.79). Repeated measures analysis of variance demonstrated no statistically significant differences between the PD% estimates (p > 0.1) due to either presentation of the image (raw vs processed) or method of PD% assessment (radiologist vs algorithm). The proposed fully automated algorithm was successful in estimating breast percent density from both raw and processed digital mammographic images. Accurate assessment of a woman's breast density is critical in order for the estimate to be incorporated into risk assessment models. These results show promise for the clinical application of the algorithm in quantifying breast density in a repeatable manner, both at time of imaging as well as in retrospective studies.

Why can't I manage my digital images like MP3s? The evolution and intent of multimedia metadata

NASA Astrophysics Data System (ADS)

Goodrum, Abby; Howison, James

2005-01-01

This paper considers the deceptively simple question: Why can't digital images be managed in the simple and effective manner in which digital music files are managed? We make the case that the answer is different treatments of metadata in different domains with different goals. A central difference between the two formats stems from the fact that digital music metadata lookup services are collaborative and automate the movement from a digital file to the appropriate metadata, while image metadata services do not. To understand why this difference exists we examine the divergent evolution of metadata standards for digital music and digital images and observed that the processes differ in interesting ways according to their intent. Specifically music metadata was developed primarily for personal file management and community resource sharing, while the focus of image metadata has largely been on information retrieval. We argue that lessons from MP3 metadata can assist individuals facing their growing personal image management challenges. Our focus therefore is not on metadata for cultural heritage institutions or the publishing industry, it is limited to the personal libraries growing on our hard-drives. This bottom-up approach to file management combined with p2p distribution radically altered the music landscape. Might such an approach have a similar impact on image publishing? This paper outlines plans for improving the personal management of digital images-doing image metadata and file management the MP3 way-and considers the likelihood of success.

Why can't I manage my digital images like MP3s? The evolution and intent of multimedia metadata

NASA Astrophysics Data System (ADS)

Goodrum, Abby; Howison, James

2004-12-01

This paper considers the deceptively simple question: Why can"t digital images be managed in the simple and effective manner in which digital music files are managed? We make the case that the answer is different treatments of metadata in different domains with different goals. A central difference between the two formats stems from the fact that digital music metadata lookup services are collaborative and automate the movement from a digital file to the appropriate metadata, while image metadata services do not. To understand why this difference exists we examine the divergent evolution of metadata standards for digital music and digital images and observed that the processes differ in interesting ways according to their intent. Specifically music metadata was developed primarily for personal file management and community resource sharing, while the focus of image metadata has largely been on information retrieval. We argue that lessons from MP3 metadata can assist individuals facing their growing personal image management challenges. Our focus therefore is not on metadata for cultural heritage institutions or the publishing industry, it is limited to the personal libraries growing on our hard-drives. This bottom-up approach to file management combined with p2p distribution radically altered the music landscape. Might such an approach have a similar impact on image publishing? This paper outlines plans for improving the personal management of digital images-doing image metadata and file management the MP3 way-and considers the likelihood of success.

Design and clinical evaluation of a high-capacity digital image archival library and high-speed network for the replacement of cinefilm in the cardiac angiography environment

NASA Astrophysics Data System (ADS)

Cusma, Jack T.; Spero, Laurence A.; Groshong, Bennett R.; Cho, Teddy; Bashore, Thomas M.

1993-09-01

An economical and practical digital solution for the replacement of 35 mm cine film as the archive media in the cardiac x-ray imaging environment has remained lacking to date due to the demanding requirements of high capacity, high acquisition rate, high transfer rate, and a need for application in a distributed environment. A clinical digital image library and network based on the D2 digital video format has been installed in the Duke University Cardiac Catheterization Laboratory. The system architecture includes a central image library with digital video recorders and robotic tape retrieval, three acquisition stations, and remote review stations connected via a serial image network. The library has a capacity for over 20,000 Gigabytes of uncompressed image data, equivalent to records for approximately 20,000 patients. Image acquisition in the clinical laboratories is via a real-time digital interface between the digital angiography system and a local digital recorder. Images are transferred to the library over the serial network at a rate of 14.3 Mbytes/sec and permanently stored for later review. The image library and network are currently undergoing a clinical comparison with cine film for visual and quantitative assessment of coronary artery disease. At the conclusion of the evaluation, the configuration will be expanded to include four additional catheterization laboratories and remote review stations throughout the hospital.

Mapping of Polar Areas Based on High-Resolution Satellite Images: The Example of the Henryk Arctowski Polish Antarctic Station

NASA Astrophysics Data System (ADS)

Kurczyński, Zdzisław; Różycki, Sebastian; Bylina, Paweł

2017-12-01

To produce orthophotomaps or digital elevation models, the most commonly used method is photogrammetric measurement. However, the use of aerial images is not easy in polar regions for logistical reasons. In these areas, remote sensing data acquired from satellite systems is much more useful. This paper presents the basic technical requirements of different products which can be obtain (in particular orthoimages and digital elevation model (DEM)) using Very-High-Resolution Satellite (VHRS) images. The study area was situated in the vicinity of the Henryk Arctowski Polish Antarctic Station on the Western Shore of Admiralty Bay, King George Island, Western Antarctic. Image processing was applied on two triplets of images acquired by the Pléiades 1A and 1B in March 2013. The results of the generation of orthoimages from the Pléiades systems without control points showed that the proposed method can achieve Root Mean Squared Error (RMSE) of 3-9 m. The presented Pléiades images are useful for thematic remote sensing analysis and processing of measurements. Using satellite images to produce remote sensing products for polar regions is highly beneficial and reliable and compares well with more expensive airborne photographs or field surveys.

System Integration Issues in Digital Photogrammetric Mapping

DTIC Science & Technology

1992-01-01

elevation models, and/or rectified imagery/ orthophotos . Imagery exported from the DSPW can be either in a tiled image format or standard raster format...data. In the near future, correlation using "window shaping" operations along with an iterative orthophoto refinements methodology (Norvelle, 1992) is...components of TIES. The IDS passes tiled image data and ASCII header data to the DSPW. The tiled image file contains only image data. The ASCII header

Advanced Topics in Space Situational Awareness

DTIC Science & Technology

2007-11-07

34super-resolution." Such optical superresolution is characteristic of many model-based image processing algorithms, and reflects the incorporation of...Sampling Theorem," J. Opt. Soc. Am. A, vol. 24, 311-325 (2007). [39] S. Prasad, "Digital and Optical Superresolution of Low-Resolution Image Sequences," Un...wavefront coding for the specific application of extension of image depth well beyond what is possible in a standard imaging system. The problem of optical

Image-Based Reconstruction and Analysis of Dynamic Scenes in a Landslide Simulation Facility

NASA Astrophysics Data System (ADS)

Scaioni, M.; Crippa, J.; Longoni, L.; Papini, M.; Zanzi, L.

2017-12-01

The application of image processing and photogrammetric techniques to dynamic reconstruction of landslide simulations in a scaled-down facility is described. Simulations are also used here for active-learning purpose: students are helped understand how physical processes happen and which kinds of observations may be obtained from a sensor network. In particular, the use of digital images to obtain multi-temporal information is presented. On one side, using a multi-view sensor set up based on four synchronized GoPro 4 Black® cameras, a 4D (3D spatial position and time) reconstruction of the dynamic scene is obtained through the composition of several 3D models obtained from dense image matching. The final textured 4D model allows one to revisit in dynamic and interactive mode a completed experiment at any time. On the other side, a digital image correlation (DIC) technique has been used to track surface point displacements from the image sequence obtained from the camera in front of the simulation facility. While the 4D model may provide a qualitative description and documentation of the experiment running, DIC analysis output quantitative information such as local point displacements and velocities, to be related to physical processes and to other observations. All the hardware and software equipment adopted for the photogrammetric reconstruction has been based on low-cost and open-source solutions.

High Res at High Speed: Automated Delivery of High-Resolution Images from Digital Library Collections

ERIC Educational Resources Information Center

Westbrook, R. Niccole; Watkins, Sean

2012-01-01

As primary source materials in the library are digitized and made available online, the focus of related library services is shifting to include new and innovative methods of digital delivery via social media, digital storytelling, and community-based and consortial image repositories. Most images on the Web are not of sufficient quality for most…

Simulation of Image Performance Characteristics of the Landsat Data Continuity Mission (LDCM) Thermal Infrared Sensor (TIRS)

NASA Technical Reports Server (NTRS)

Schott, John; Gerace, Aaron; Brown, Scott; Gartley, Michael; Montanaro, Matthew; Reuter, Dennis C.

2012-01-01

The next Landsat satellite, which is scheduled for launch in early 2013, will carry two instruments: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). Significant design changes over previous Landsat instruments have been made to these sensors to potentially enhance the quality of Landsat image data. TIRS, which is the focus of this study, is a dual-band instrument that uses a push-broom style architecture to collect data. To help understand the impact of design trades during instrument build, an effort was initiated to model TIRS imagery. The Digital Imaging and Remote Sensing Image Generation (DIRSIG) tool was used to produce synthetic "on-orbit" TIRS data with detailed radiometric, geometric, and digital image characteristics. This work presents several studies that used DIRSIG simulated TIRS data to test the impact of engineering performance data on image quality in an effort to determine if the image data meet specifications or, in the event that they do not, to determine if the resulting image data are still acceptable.

Lunar Terrain and Albedo Reconstruction from Apollo Imagery

NASA Technical Reports Server (NTRS)

Nefian, Ara V.; Kim, Taemin; Broxton, Michael; Moratto, Zach

2010-01-01

Generating accurate three dimensional planetary models and albedo maps is becoming increasingly more important as NASA plans more robotics missions to the Moon in the coming years. This paper describes a novel approach for separation of topography and albedo maps from orbital Lunar images. Our method uses an optimal Bayesian correlator to refine the stereo disparity map and generate a set of accurate digital elevation models (DEM). The albedo maps are obtained using a multi-image formation model that relies on the derived DEMs and the Lunar- Lambert reflectance model. The method is demonstrated on a set of high resolution scanned images from the Apollo era missions.

Use of a digital camera to monitor the growth and nitrogen status of cotton.

PubMed

Jia, Biao; He, Haibing; Ma, Fuyu; Diao, Ming; Jiang, Guiying; Zheng, Zhong; Cui, Jin; Fan, Hua

2014-01-01

The main objective of this study was to develop a nondestructive method for monitoring cotton growth and N status using a digital camera. Digital images were taken of the cotton canopies between emergence and full bloom. The green and red values were extracted from the digital images and then used to calculate canopy cover. The values of canopy cover were closely correlated with the normalized difference vegetation index and the ratio vegetation index and were measured using a GreenSeeker handheld sensor. Models were calibrated to describe the relationship between canopy cover and three growth properties of the cotton crop (i.e., aboveground total N content, LAI, and aboveground biomass). There were close, exponential relationships between canopy cover and three growth properties. And the relationships for estimating cotton aboveground total N content were most precise, the coefficients of determination (R(2)) value was 0.978, and the root mean square error (RMSE) value was 1.479 g m(-2). Moreover, the models were validated in three fields of high-yield cotton. The result indicated that the best relationship between canopy cover and aboveground total N content had an R(2) value of 0.926 and an RMSE value of 1.631 g m(-2). In conclusion, as a near-ground remote assessment tool, digital cameras have good potential for monitoring cotton growth and N status.

The use of UAV to document sloping landscapes to produce digital elevation models to examine environmental degradation

NASA Astrophysics Data System (ADS)

Themistocleous, K.; Agapiou, A.; Papadavid, G.; Christoforou, M.; Hadjimitsis, D. G.

2015-10-01

This paper focuses on the use of Unmanned Aerial Vehicles (UAVs) over the study area of Pissouri in Cyprus to document the sloping landscapes of the area. The study area has been affected by overgrazing, which has led to shifts in the vegetation patterns and changing microtopography of the soil. The UAV images were used to generate digital elevation models (DEMs) to examine the changes in microtopography. Next to that orthophotos were used to detect changes in vegetation patterns. The combined data of the digital elevation models and the orthophotos will be used to detect the occurrence of catastrophic shifts and mechanisms for desertification in the study area due to overgrazing. This study is part of the "CASCADE- Catastrophic shifts in dryland" project.

Modulation transfer function cascade model for a sampled IR imaging system.

PubMed

de Luca, L; Cardone, G

1991-05-01

The performance of the infrared scanning radiometer (IRSR) is strongly stressed in convective heat transfer applications where high spatial frequencies in the signal that describes the thermal image are present. The need to characterize more deeply the system spatial resolution has led to the formulation of a cascade model for the evaluation of the actual modulation transfer function of a sampled IR imaging system. The model can yield both the aliasing band and the averaged modulation response for a general sampling subsystem. For a line scan imaging system, which is the case of a typical IRSR, a rule of thumb that states whether the combined sampling-imaging system is either imaging-dependent or sampling-dependent is proposed. The model is tested by comparing it with other noncascade models as well as by ad hoc measurements performed on a commercial digitized IRSR.

A Medical Image Backup Architecture Based on a NoSQL Database and Cloud Computing Services.

PubMed

Santos Simões de Almeida, Luan Henrique; Costa Oliveira, Marcelo

2015-01-01

The use of digital systems for storing medical images generates a huge volume of data. Digital images are commonly stored and managed on a Picture Archiving and Communication System (PACS), under the DICOM standard. However, PACS is limited because it is strongly dependent on the server's physical space. Alternatively, Cloud Computing arises as an extensive, low cost, and reconfigurable resource. However, medical images contain patient information that can not be made available in a public cloud. Therefore, a mechanism to anonymize these images is needed. This poster presents a solution for this issue by taking digital images from PACS, converting the information contained in each image file to a NoSQL database, and using cloud computing to store digital images.

Digital data base application to porphyry copper mineralization in Alaska; case study summary

USGS Publications Warehouse

Trautwein, Charles M.; Greenlee, David D.; Orr, Donald G.

1982-01-01

The purpose of this report is to summarize the progress in use of digital image analysis techniques in developing a conceptual model for assessing porphyry copper mineral potential. The study area consists of approximately the southern one-half of the 1? by 3? Nabesna quadrangle in east-central Alaska. The digital geologic data base consists of data compiled under the Alaskan Mineral Resource Assessment Program (AMRAP) as well as digital elevation data and Landsat spectral reflectance data from the Multispectral Scanner System. The digital data base used to develop and implement a conceptual model for porphyry-type copper mineralization consisted of 16 original data types and 18 derived data sets formatted in a grid-cell (raster) structure and registered to a map base in the Universal Transverse Mercator (UTM) projection. Minimum curvature and inverse distance squared interpolation techniques were used to generate continuous surfaces from sets of irregularly spaced data points. Processing requirements included: (1) merging or overlaying of data sets, (2) display and color coding of maps and images, (3) univariate and multivariate statistical analyses, and (4) compound overlaying operations. Data sets were merged and processed to create stereoscopic displays of continuous surfaces. The ratio of several data sets were calculated to evaluate relative variations and to enhance the display of surface alteration (gossans). Factor analysis and principal components analysis techniques were used to determine complex relationships and correlations between data sets. The resultant model consists of 10 parameters that identify three areas most likely to contain porphyry copper mineralization; two of these areas are known occurrences of mineralization and the third is not well known. Field studies confirmed that the three areas identified by the model have significant copper potential.

Research on hyperspectral dynamic scene and image sequence simulation

NASA Astrophysics Data System (ADS)

Sun, Dandan; Liu, Fang; Gao, Jiaobo; Sun, Kefeng; Hu, Yu; Li, Yu; Xie, Junhu; Zhang, Lei

2016-10-01

This paper presents a simulation method of hyperspectral dynamic scene and image sequence for hyperspectral equipment evaluation and target detection algorithm. Because of high spectral resolution, strong band continuity, anti-interference and other advantages, in recent years, hyperspectral imaging technology has been rapidly developed and is widely used in many areas such as optoelectronic target detection, military defense and remote sensing systems. Digital imaging simulation, as a crucial part of hardware in loop simulation, can be applied to testing and evaluation hyperspectral imaging equipment with lower development cost and shorter development period. Meanwhile, visual simulation can produce a lot of original image data under various conditions for hyperspectral image feature extraction and classification algorithm. Based on radiation physic model and material characteristic parameters this paper proposes a generation method of digital scene. By building multiple sensor models under different bands and different bandwidths, hyperspectral scenes in visible, MWIR, LWIR band, with spectral resolution 0.01μm, 0.05μm and 0.1μm have been simulated in this paper. The final dynamic scenes have high real-time and realistic, with frequency up to 100 HZ. By means of saving all the scene gray data in the same viewpoint image sequence is obtained. The analysis results show whether in the infrared band or the visible band, the grayscale variations of simulated hyperspectral images are consistent with the theoretical analysis results.

A Hierarchical Building Segmentation in Digital Surface Models for 3D Reconstruction

PubMed Central

Yan, Yiming; Gao, Fengjiao; Deng, Shupei; Su, Nan

2017-01-01

In this study, a hierarchical method for segmenting buildings in a digital surface model (DSM), which is used in a novel framework for 3D reconstruction, is proposed. Most 3D reconstructions of buildings are model-based. However, the limitations of these methods are overreliance on completeness of the offline-constructed models of buildings, and the completeness is not easily guaranteed since in modern cities buildings can be of a variety of types. Therefore, a model-free framework using high precision DSM and texture-images buildings was introduced. There are two key problems with this framework. The first one is how to accurately extract the buildings from the DSM. Most segmentation methods are limited by either the terrain factors or the difficult choice of parameter-settings. A level-set method are employed to roughly find the building regions in the DSM, and then a recently proposed ‘occlusions of random textures model’ are used to enhance the local segmentation of the buildings. The second problem is how to generate the facades of buildings. Synergizing with the corresponding texture-images, we propose a roof-contour guided interpolation of building facades. The 3D reconstruction results achieved by airborne-like images and satellites are compared. Experiments show that the segmentation method has good performance, and 3D reconstruction is easily performed by our framework, and better visualization results can be obtained by airborne-like images, which can be further replaced by UAV images. PMID:28125018

Calibration and Validation of Airborne InSAR Geometric Model

NASA Astrophysics Data System (ADS)

Chunming, Han; huadong, Guo; Xijuan, Yue; Changyong, Dou; Mingming, Song; Yanbing, Zhang

2014-03-01

The image registration or geo-coding is a very important step for many applications of airborne interferometric Synthetic Aperture Radar (InSAR), especially for those involving Digital Surface Model (DSM) generation, which requires an accurate knowledge of the geometry of the InSAR system. While the trajectory and attitude instabilities of the aircraft introduce severe distortions in three dimensional (3-D) geometric model. The 3-D geometrical model of an airborne SAR image depends on the SAR processor itself. Working at squinted model, i.e., with an offset angle (squint angle) of the radar beam from broadside direction, the aircraft motion instabilities may produce distortions in airborne InSAR geometric relationship, which, if not properly being compensated for during SAR imaging, may damage the image registration. The determination of locations of the SAR image depends on the irradiated topography and the exact knowledge of all signal delays: range delay and chirp delay (being adjusted by the radar operator) and internal delays which are unknown a priori. Hence, in order to obtain reliable results, these parameters must be properly calibrated. An Airborne InSAR mapping system has been developed by the Institute of Remote Sensing and Digital Earth (RADI), Chinese Academy of Sciences (CAS) to acquire three-dimensional geo-spatial data with high resolution and accuracy. To test the performance of the InSAR system, the Validation/Calibration (Val/Cal) campaign has carried out in Sichun province, south-west China, whose results will be reported in this paper.

Tri-stereo Pleiades images-derived digital surface models for tectonic geomorphology studies

NASA Astrophysics Data System (ADS)

Ferry, Matthieu; Le Roux-Mallouf, Romain; Ritz, Jean-François; Berthet, Théo; Peyret, Michel; Vernant, Philippe; Maréchal, Anaïs; Cattin, Rodolphe; Mazzotti, Stéphane; Poujol, Antoine

2014-05-01

Very high resolution digital elevation models are a key component of modern quantitative geomorphology. In parallel to high-precision but time-consuming kinematic GPS and/or total station surveys and dense coverage but expensive LiDAR campaigns, we explore the usability of affordable, flexible, wide coverage digital surface models (DSMs) derived from Pleiades tri-stereo optical images. We present two different approaches to extract DSM from a triplet of images. The first relies on the photogrammetric extraction of 3 DSMs from the 3 possible stereo couples and subsequent merge based on the best correlation score. The second takes advantage of simultaneous correlation over the 3 images to derive a point cloud. We further extract DSM from panchromatic 0.5 m resolution images and multispectral 2 m resolution images to test for correlation and noise and determine optimal correlation window size and achievable resolution. Georeferencing is also assessed by comparing raw coordinates derived from Pleiades Rational Polynomial Coefficients to ground control points. Primary images appear to be referenced within ~15 m over flat areas where parallax is minimal while derived DSMs and associated orthorectified images show a much improved referencing within ~5 m of GCPs. In order to assess the adequacy of Pleiades DSMs for tectonic geomorphology, we present examples from case studies along the Trougout normal fault (Morocco), the Hovd strike-slip fault (Mongolia), the Denali strike-slip fault (USA and Canada) and the Main Frontal Thrust (Bhutan). In addition to proposing a variety of tectonic contexts, these examples cover a wide range of climatic conditions (semi-arid, arctic and tropical), vegetation covers (bare earth, sparse Mediterranean, homogeneous arctic pine, varied tropical forest), lithological natures and related erosion rates. The capacity of derived DSMs is demonstrated to characterize geomorphic markers of active deformation such as marine and alluvial terraces, stream gullies, alluvial fans and fluvio-glacial deposits in terms of vertical (from DSMs) and horizontal (from orthorectified optical images) offsets. Values extracted from Pleiades DSMs compare well to field measurements in terms of relief and slope, which suggests effort and resources necessary for field topography could be significantly reduced, especially in poorly accessible areas.

A perceptual metric for photo retouching.

PubMed

Kee, Eric; Farid, Hany

2011-12-13

In recent years, advertisers and magazine editors have been widely criticized for taking digital photo retouching to an extreme. Impossibly thin, tall, and wrinkle- and blemish-free models are routinely splashed onto billboards, advertisements, and magazine covers. The ubiquity of these unrealistic and highly idealized images has been linked to eating disorders and body image dissatisfaction in men, women, and children. In response, several countries have considered legislating the labeling of retouched photos. We describe a quantitative and perceptually meaningful metric of photo retouching. Photographs are rated on the degree to which they have been digitally altered by explicitly modeling and estimating geometric and photometric changes. This metric correlates well with perceptual judgments of photo retouching and can be used to objectively judge by how much a retouched photo has strayed from reality.

Reconstituted Three-Dimensional Interactive Imaging

NASA Technical Reports Server (NTRS)

Hamilton, Joseph; Foley, Theodore; Duncavage, Thomas; Mayes, Terrence

2010-01-01

A method combines two-dimensional images, enhancing the images as well as rendering a 3D, enhanced, interactive computer image or visual model. Any advanced compiler can be used in conjunction with any graphics library package for this method, which is intended to take digitized images and virtually stack them so that they can be interactively viewed as a set of slices. This innovation can take multiple image sources (film or digital) and create a "transparent" image with higher densities in the image being less transparent. The images are then stacked such that an apparent 3D object is created in virtual space for interactive review of the set of images. This innovation can be used with any application where 3D images are taken as slices of a larger object. These could include machines, materials for inspection, geological objects, or human scanning. Illuminous values were stacked into planes with different transparency levels of tissues. These transparency levels can use multiple energy levels, such as density of CT scans or radioactive density. A desktop computer with enough video memory to produce the image is capable of this work. The memory changes with the size and resolution of the desired images to be stacked and viewed.

Watermarking and copyright labeling of printed images

NASA Astrophysics Data System (ADS)

Hel-Or, Hagit Z.

2001-07-01

Digital watermarking is a labeling technique for digital images which embeds a code into the digital data so the data are marked. Watermarking techniques previously developed deal with on-line digital data. These techniques have been developed to withstand digital attacks such as image processing, image compression and geometric transformations. However, one must also consider the readily available attack of printing and scanning. The available watermarking techniques are not reliable under printing and scanning. In fact, one must consider the availability of watermarks for printed images as well as for digital images. An important issue is to intercept and prevent forgery in printed material such as currency notes, back checks, etc. and to track and validate sensitive and secrete printed material. Watermarking in such printed material can be used not only for verification of ownership but as an indicator of date and type of transaction or date and source of the printed data. In this work we propose a method of embedding watermarks in printed images by inherently taking advantage of the printing process. The method is visually unobtrusive to the printed image, the watermark is easily extracted and is robust under reconstruction errors. The decoding algorithm is automatic given the watermarked image.

Coupled Physical and Digital Cadaver Dissection Followed by a Visual Test Protocol Provides Insights into the Nature of Anatomical Knowledge and Its Evaluation

ERIC Educational Resources Information Center

Hisley, Kenneth C.; Anderson, Larry D.; Smith, Stacy E.; Kavic, Stephen M.; Tracy, J. Kathleen

2008-01-01

This research effort compared and contrasted two conceptually different methods for the exploration of human anatomy in the first-year dissection laboratory by accomplished students: "physical" dissection using an embalmed cadaver and "digital" dissection using three-dimensional volume modeling of whole-body CT and MRI image sets acquired using…

Comparison of a digital retinal imaging system and seven-field stereo color fundus photography to detect diabetic retinopathy in the primary care environment.

PubMed

Schiffman, Rhett M; Jacobsen, Gordon; Nussbaum, Julian J; Desai, Uday R; Carey, J David; Glasser, David; Zimmer-Galler, Ingrid E; Zeimer, Ran; Goldberg, Morton F

2005-01-01

Because patients with diabetes mellitus may visit their primary care physician regularly but not their ophthalmologist, a retinal risk assessment in the primary care setting could improve the screening rate for diabetic retinopathy. An imaging system for use in the primary care setting to identify diabetic retinopathy requiring referral to an ophthalmologist was evaluated. In a masked prospective study, images were obtained from 11 patients with diabetes mellitus using both the digital retinal imaging system and seven-field stereo color fundus photography. The ability to obtain gradable images and to identify diabetic retinal lesions was compared. Of all images, 85% of digital retinal imaging system images and 88% of seven-field images were gradable. Agreement based on "no retinopathy" versus "any retinopathy" was excellent (Kappa = 0.96). Agreement based on "microaneurysms or less retinopathy" versus "retinal hemorrhages or worse retinopathy" was very good (Kappa = 0.83). The agreement between the digital retinal imaging system and seven-field photography indicates that the digital retinal imaging system may be useful to screen for diabetic retinopathy.

The influence of software filtering in digital mammography image quality

NASA Astrophysics Data System (ADS)

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.

Digital Image Access & Retrieval.

ERIC Educational Resources Information Center

Heidorn, P. Bryan, Ed.; Sandore, Beth, Ed.

Recent technological advances in computing and digital imaging technology have had immediate and permanent consequences for visual resource collections. Libraries are involved in organizing and managing large visual resource collections. The central challenges in working with digital image collections mirror those that libraries have sought to…

Photo-editing in Orthodontics: How Much is Too Much?.

PubMed

Kapoor, Priyanka

2015-01-01

Digital photography and radiology are the mainstay of orthodontic records but current image editing software programs nave led to increase in instances of digital forgery and scientific misconduct. In the present study, digital image data of orthodontic study casts and photographs were altered using software such as [Microsoft Paint6 1, Picasa3.1, Adobe Photoshop3.6]. Based on ethical guidelines on digital image manipulations, cropping or intensity adjustments in moderation to entire image were considered permissible while cloning or color adjustments were deemed unethical.

Quantitative comparison and reproducibility of pathologist scoring and digital image analysis of estrogen receptor β2 immunohistochemistry in prostate cancer.

PubMed

Rizzardi, Anthony E; Zhang, Xiaotun; Vogel, Rachel Isaksson; Kolb, Suzanne; Geybels, Milan S; Leung, Yuet-Kin; Henriksen, Jonathan C; Ho, Shuk-Mei; Kwak, Julianna; Stanford, Janet L; Schmechel, Stephen C

2016-07-11

Digital image analysis offers advantages over traditional pathologist visual scoring of immunohistochemistry, although few studies examining the correlation and reproducibility of these methods have been performed in prostate cancer. We evaluated the correlation between digital image analysis (continuous variable data) and pathologist visual scoring (quasi-continuous variable data), reproducibility of each method, and association of digital image analysis methods with outcomes using prostate cancer tissue microarrays (TMAs) stained for estrogen receptor-β2 (ERβ2). Prostate cancer TMAs were digitized and evaluated by pathologist visual scoring versus digital image analysis for ERβ2 staining within tumor epithelium. Two independent analysis runs were performed to evaluate reproducibility. Image analysis data were evaluated for associations with recurrence-free survival and disease specific survival following radical prostatectomy. We observed weak/moderate Spearman correlation between digital image analysis and pathologist visual scores of tumor nuclei (Analysis Run A: 0.42, Analysis Run B: 0.41), and moderate/strong correlation between digital image analysis and pathologist visual scores of tumor cytoplasm (Analysis Run A: 0.70, Analysis Run B: 0.69). For the reproducibility analysis, there was high Spearman correlation between pathologist visual scores generated for individual TMA spots across Analysis Runs A and B (Nuclei: 0.84, Cytoplasm: 0.83), and very high correlation between digital image analysis for individual TMA spots across Analysis Runs A and B (Nuclei: 0.99, Cytoplasm: 0.99). Further, ERβ2 staining was significantly associated with increased risk of prostate cancer-specific mortality (PCSM) when quantified by cytoplasmic digital image analysis (HR 2.16, 95 % CI 1.02-4.57, p = 0.045), nuclear image analysis (HR 2.67, 95 % CI 1.20-5.96, p = 0.016), and total malignant epithelial area analysis (HR 5.10, 95 % CI 1.70-15.34, p = 0.004). After adjusting for clinicopathologic factors, only total malignant epithelial area ERβ2 staining was significantly associated with PCSM (HR 4.08, 95 % CI 1.37-12.15, p = 0.012). Digital methods of immunohistochemical quantification are more reproducible than pathologist visual scoring in prostate cancer, suggesting that digital methods are preferable and especially warranted for studies involving large sample sizes.

Using Digital Imaging in Classroom and Outdoor Activities.

ERIC Educational Resources Information Center

Thomasson, Joseph R.

2002-01-01

Explains how to use digital cameras and related basic equipment during indoor and outdoor activities. Uses digital imaging in general botany class to identify unknown fungus samples. Explains how to select a digital camera and other necessary equipment. (YDS)

Earth analog image digitization of field, aerial, and lab experiment studies for Planetary Data System archiving.

NASA Astrophysics Data System (ADS)

Williams, D. A.; Nelson, D. M.

2017-12-01

A portion of the earth analog image archive at the Ronald Greeley Center for Planetary Studies (RGCPS)-the NASA Regional Planetary Information Facility at Arizona State University-is being digitized and will be added to the Planetary Data System (PDS) for public use. This will be a first addition of terrestrial data to the PDS specifically for comparative planetology studies. Digitization is separated into four tasks. First is the scanning of aerial photographs of volcanic and aeolian structures and flows. The second task is to scan field site images taken from ground and low-altitude aircraft of volcanic structures, lava flows, lava tubes, dunes, and wind streaks. The third image set to be scanned includes photographs of lab experiments from the NASA Planetary Aeolian Laboratory wind tunnels, vortex generator, and of wax models. Finally, rare NASA documents are being scanned and formatted as PDF files. Thousands of images are to be scanned for this project. Archiving of the data will follow the PDS4 standard, where the entire project is classified as a single bundle, with individual subjects (i.e., the Amboy Crater volcanic structure in the Mojave Desert of California) as collections. Within the collections, each image is considered a product, with a unique ID and associated XML document. Documents describing the image data, including the subject and context, will be included with each collection. Once complete, the data will be hosted by a PDS data node and available for public search and download. As one of the first earth analog datasets to be archived by the PDS, this project could prompt the digitizing and making available of historic datasets from other facilities for the scientific community.

D Digitization of AN Heritage Masterpiece - a Critical Analysis on Quality Assessment

NASA Astrophysics Data System (ADS)

Menna, F.; Nocerino, E.; Remondino, F.; Dellepiane, M.; Callieri, M.; Scopigno, R.

2016-06-01

Despite being perceived as interchangeable when properly applied, close-range photogrammetry and range imaging have both their pros and limitations that can be overcome using suitable procedures. Even if the two techniques have been frequently cross-compared, critical analysis discussing all sub-phases of a complex digitization project are quite rare. Comparisons taking into account the digitization of a cultural masterpiece, such as the Etruscan Sarcophagus of the Spouses (Figure 1) discussed in this paper, are even less common. The final 3D model of the Sarcophagus shows impressive spatial and texture resolution, in the order of tenths of millimetre for both digitization techniques, making it a large 3D digital model even though the physical size of the artwork is quite limited. The paper presents the survey of the Sarcophagus, a late 6th century BC Etruscan anthropoid Sarcophagus. Photogrammetry and laser scanning were used for its 3D digitization in two different times only few days apart from each other. The very short time available for the digitization was a crucial constraint for the surveying operations (due to constraints imposed us by the museum curators). Despite very high-resolution and detailed 3D models have been produced, a metric comparison between the two models shows intrinsic limitations of each technique that should be overcome through suitable onsite metric verification procedures as well as a proper processing workflow.

Taking digital imaging to the next level: challenges and opportunities.

PubMed

Hobbs, W Cecyl

2004-01-01

New medical imaging technology, such as multi-detector computed tomography (CT) scanners and positron emission tomography (PET) scanners, are creating new possibilities for non-invasive diagnosis that are leading providers to invest heavily in these new technologies. The volume of data produced by such technology is so large that it cannot be "read" using traditional film-based methods, and once in digital form, it creates a massive data integration and archiving challenge. Despite the benefits of digital imaging and archiving, there are several key challenges that healthcare organizations should consider in planning, selecting, and implementing the information technology (IT) infrastructure to support digital imaging. Decisions about storage and image distribution are essentially questions of "where" and "how fast." When planning the digital archiving infrastructure, organizations should think about where they want to store and distribute their images. This is similar to decisions that organizations have to make in regard to physical film storage and distribution, except the portability of images is even greater in a digital environment. The principle of "network effects" seems like a simple concept, yet the effect is not always considered when implementing a technology plan. To fully realize the benefits of digital imaging, the radiology department must integrate the archiving solutions throughout the department and, ultimately, with applications across other departments and enterprises. Medical institutions can derive a number of benefits from implementing digital imaging and archiving solutions like PACS. Hospitals and imaging centers can use the transition from film-based imaging as a foundational opportunity to reduce costs, increase competitive advantage, attract talent, and improve service to patients. The key factors in achieving these goals include attention to the means of data storage, distribution and protection.

Mars digital terrain model

NASA Technical Reports Server (NTRS)

Wu, Sherman S. C.; Howington, Annie-Elpis

1987-01-01

The Mars Digital Terrain Model (DTM) is the result of a new project to: (1) digitize the series of 1:2,000,000-scale topographic maps of Mars, which are being derived photogrammetically under a separate project, and (2) reformat the digital contour information into rasters of elevation that can be readily registered with the Digital Image Model (DIM) of Mars. Derivation of DTM's involves interpolation of elevation values into 1/64-degree resolution and transformation of them to a sinusoidal equal-area projection. Digital data are produced in blocks corresponding with the coordinates of the original 1:2,000,000-scale maps, i.e., the dimensions of each block in the equatorial belt are 22.5 deg of longitude and 15 deg of latitude. This DTM is not only compatible with the DIM, but it can also be registered with other data such as geologic units or gravity. It will be the most comprehensive record of topographic information yet compiled for the Martian surface. Once the DTM's are established, any enhancement of Mars topographic information made with updated data, such as data from the planned Mars Observer Mission, will be by mathematical transformation of the DTM's, eliminating the need for recompilation.

78 FR 16707 - Certain Digital Photo Frames and Image Display Devices and Components Thereof; Issuance of a...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

... Image Display Devices and Components Thereof; Issuance of a Limited Exclusion Order and Cease and Desist... within the United States after importation of certain digital photo frames and image display devices and...: (1) The unlicensed entry of digital photo frames and image display devices and components thereof...

An instructional guide for leaf color analysis using digital imaging software

Treesearch

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...

A COMPARISON OF ILLUMINATION GEOMETRY-BASED METHODS FOR TOPOGRAPHIC CORRECTION OF QUICKBIRD IMAGES OF AN UNDULANT AREA

USDA-ARS?s Scientific Manuscript database

The high spatial resolution of QuickBird satellite images makes it possible to show spatial variability at fine details. However, the effect of topography-induced illumination variations become more evident, even in moderately sloped areas. Based on a high resolution (1 m) digital elevation model ge...

Spatio-temporal Variability of Albedo and its Impact on Glacier Melt Modelling

NASA Astrophysics Data System (ADS)

Kinnard, C.; Mendoza, C.; Abermann, J.; Petlicki, M.; MacDonell, S.; Urrutia, R.

2017-12-01

Albedo is an important variable for the surface energy balance of glaciers, yet its representation within distributed glacier mass-balance models is often greatly simplified. Here we study the spatio-temporal evolution of albedo on Glacier Universidad, central Chile (34°S, 70°W), using time-lapse terrestrial photography, and investigate its effect on the shortwave radiation balance and modelled melt rates. A 12 megapixel digital single-lens reflex camera was setup overlooking the glacier and programmed to take three daily images of the glacier during a two-year period (2012-2014). One image was chosen for each day with no cloud shading on the glacier. The RAW images were projected onto a 10m resolution digital elevation model (DEM), using the IMGRAFT software (Messerli and Grinsted, 2015). A six-parameter camera model was calibrated using a single image and a set of 17 ground control points (GCPs), yielding a georeferencing accuracy of <1 pixel in image coordinates. The camera rotation was recalibrated for new images based on a set of common tie points over stable terrain, thus accounting for possible camera movement over time. The reflectance values from the projected image were corrected for topographic and atmospheric influences using a parametric solar irradiation model, following a modified algorithm based on Corripio (2004), and then converted to albedo using reference albedo measurements from an on-glacier automatic weather station (AWS). The image-based albedo was found to compare well with independent albedo observations from a second AWS in the glacier accumulation area. Analysis of the albedo maps showed that the albedo is more spatially-variable than the incoming solar radiation, making albedo a more important factor of energy balance spatial variability. The incorporation of albedo maps within an enhanced temperature index melt model revealed that the spatio-temporal variability of albedo is an important factor for the calculation of glacier-wide meltwater fluxes.

Simulation of the modulation transfer function dependent on the partial Fourier fraction in dynamic contrast enhancement magnetic resonance imaging.

PubMed

Takatsu, Yasuo; Ueyama, Tsuyoshi; Miyati, Tosiaki; Yamamura, Kenichirou

2016-12-01

The image characteristics in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) depend on the partial Fourier fraction and contrast medium concentration. These characteristics were assessed and the modulation transfer function (MTF) was calculated by computer simulation. A digital phantom was created from signal intensity data acquired at different contrast medium concentrations on a breast model. The frequency images [created by fast Fourier transform (FFT)] were divided into 512 parts and rearranged to form a new image. The inverse FFT of this image yielded the MTF. From the reference data, three linear models (low, medium, and high) and three exponential models (slow, medium, and rapid) of the signal intensity were created. Smaller partial Fourier fractions, and higher gradients in the linear models, corresponded to faster MTF decline. The MTF more gradually decreased in the exponential models than in the linear models. The MTF, which reflects the image characteristics in DCE-MRI, was more degraded as the partial Fourier fraction decreased.

Evolution of digital angiography systems.

PubMed

Brigida, Raffaela; Misciasci, Teresa; Martarelli, Fabiola; Gangitano, Guido; Ottaviani, Pierfrancesco; Rollo, Massimo; Marano, Pasquale

2003-01-01

The innovations introduced by digital subtraction angiography in digital radiography are briefly illustrated with the description of its components and functioning. The pros and cons of digital subtraction angiography are analyzed in light of present and future imaging technologies. In particular, among advantages there are: automatic exposure, digital image subtraction, digital post-processing, high number of images per second, possible changes in density and contrast. Among disadvantages there are: small round field of view, geometric distortion at the image periphery, high sensitivity to patient movements, not very high spatial resolution. At present, flat panel detectors represent the most suitable substitutes for digital subtraction angiography, with the introduction of novel solutions for those artifacts which for years have hindered its diagnostic validity. The concept of temporal artifact, reset light and possible future evolutions of this technology that may afford both diagnostic and protectionist advantages, are analyzed.

Photoplus: auxiliary information for printed images based on distributed source coding

NASA Astrophysics Data System (ADS)

Samadani, Ramin; Mukherjee, Debargha

2008-01-01

A printed photograph is difficult to reuse because the digital information that generated the print may no longer be available. This paper describes a mechanism for approximating the original digital image by combining a scan of the printed photograph with small amounts of digital auxiliary information kept together with the print. The auxiliary information consists of a small amount of digital data to enable accurate registration and color-reproduction, followed by a larger amount of digital data to recover residual errors and lost frequencies by distributed Wyner-Ziv coding techniques. Approximating the original digital image enables many uses, including making good quality reprints from the original print, even when they are faded many years later. In essence, the print itself becomes the currency for archiving and repurposing digital images, without requiring computer infrastructure.

The Lunar Mapping and Modeling Portal: Capabilities and Lunar Data Products to support Return to the Moon

NASA Astrophysics Data System (ADS)

Law, E.; Bui, B.; Chang, G.; Goodale, C. E.; Kim, R.; Malhotra, S.; Ramirez, P.; Rodriguez, L.; Sadaqathulla, S.; Nall, M.; Muery, K.

2012-12-01

The Lunar Mapping and Modeling Portal (LMMP), is a multi-center project led by NASA's Marshall Space Flight Center. The LMMP is a web-based Portal and a suite of interactive visualization and analysis tools to enable lunar scientists, engineers, and mission planners to access mapped lunar data products from past and current lunar missions, e.g., Lunar Reconnaissance Orbiter, Apollo, Lunar Orbiter, Lunar Prospector, and Clementine. The Portal allows users to search, view and download a vast number of the most recent lunar digital products including image mosaics, digital elevation models, and in situ lunar resource maps such as iron and hydrogen abundance. The Portal also provides a number of visualization and analysis tools that perform lighting analysis and local hazard assessments, such as, slope, surface roughness and crater/boulder distribution. In this talk, we will give a brief overview of the project. After that, we will highlight various key features and Lunar data products. We will further demonstrate image viewing and layering of lunar map images via our web portal as well as mobile devices.

Utilization of MatPIV program to different geotechnical models

NASA Astrophysics Data System (ADS)

Aklik, P.; Idinger, G.

2009-04-01

The Particle Imaging Velocimetry (PIV) technique is being used to measure soil displacements. PIV has been used for many years in fluid mechanics; but for physical modeling in geotechnical engineering, this technique is still relatively new. PIV is a worldwide growth in soil mechanics over the last decade owing to the developments in digital cameras and laser technologies. The use of PIV is feasible provided the surface contains sufficient texture. A Cambridge group has shown that natural sand contains enough texture for applying PIV. In a texture-based approach, the only requirement is for any patch, big or small to be sufficiently unique so that statistical tracking of this patch is possible. In this paper, some of the soil mechanic's models were investigated such as retaining walls, slope failures, and foundations. The photographs were taken with the help of the high resolution digital camera, the displacements of soils were evaluated with free software named as MatPIV and the displacement graphics between the two images were obtained. Nikon D60 digital camera is 10.2 MB and it has special properties which makes it possible to use in PIV applications. These special properties are Airflow Control System and Image Sensor cleaning for protection against dust, Active D-Lighting for highlighted or shadowy areas while shooting, advanced three-point AF system for fast, efficient and precise autofocus. Its fast and continuous shooting mode enables up to 100 JPEG images at three frames per second. Norm Sand (DIN 1164) was used for all the models in a glass rectangular box. For every experiment, MatPIV was used to calculate the velocities from the two images. MatPIV program was used in two ways such as easy way and difficult way: In the easy way, the two images with 64*64 pixels with 50% or 75% overlap of the interrogation windows were taken into consideration and the calculation was performed with a single iteration through the images and the result consisted of four matrices measured in pixels and pixels/second. At the end of the iteration, the results were visualized. In the application of difficult way of MatPIV, a grid of points into the research model was inserted and the first image was taken with the Nikon D60 digital camera. Afterwards, how large a pixel in the image and the orientation of the coordinate system were calculated. If there are no particles to perform PIV calculations in the investigated region, the best way is to mask out this empty region. The crucial step in PIV is the particle image analysis, which is to determine the displacements between two successive images. The first image was divided into a grid of test patches. Each test patch consisted of a sample of the image matrix of size L * L pixels. To find the displacement of the test patch between images 1 and 2, a search patch was extracted from the second image. The cross-correlation of test patch and search patch was evaluated. The resulting normalized correlation plane indicated the "degree of match" between the test and search patch. The highest peak in the normalized correlation plane indicated the displacement vector of the test patch. The procedure described above for evaluation a single displacement vector was repeated for the entire grid of test patches, producing the displacement field between the image pair. After having performed the calculations, there were so many wild vectors due to low image quality in some parts of the images to be removed with the help of the different filters. There are four different filters in MatPIV, these are: signal-to-noise ratio filter, peak height filter, global filter, and local filter. The filters were used step by step to decide which filter could give the best result for the related images. As a last step, both of the ways were compared in each geotechnical model.

Comparison of glass slides and various digital-slide modalities for cytopathology screening and interpretation.

PubMed

Hanna, Matthew G; Monaco, Sara E; Cuda, Jacqueline; Xing, Juan; Ahmed, Ishtiaque; Pantanowitz, Liron

2017-09-01

Whole-slide imaging in cytology is limited when glass slides are digitized without z-stacks for focusing. Different vendors have started to provide z-stacking solutions to overcome this limitation. The Panoptiq imaging system allows users to create digital files combining low-magnification panoramic images with regions of interest (ROIs) that are imaged with high-magnification z-stacks. The aim of this study was to compare such panoramic images with conventional whole-slide images and glass slides for the tasks of screening and interpretation in cytopathology. Thirty glass slides, including 10 ThinPrep Papanicolaou tests and 20 nongynecologic cytology cases, were digitized with an Olympus BX45 integrated microscope with an attached Prosilica GT camera. ViewsIQ software was used for image acquisition and viewing. These glass slides were also scanned on an Aperio ScanScope XT at ×40 (0.25 μm/pixel) with 1 z-plane and were viewed with ImageScope software. Digital and glass sides were screened and dotted/annotated by a cytotechnologist and were subsequently reviewed by 3 cytopathologists. For panoramic images, the cytotechnologist manually created digital maps and selected representative ROIs to generate z-stacks at a higher magnification. After 3-week washout periods, panoramic images were compared with Aperio digital slides and glass slides. The Panoptiq system permitted fine focusing of thick smears and cell clusters. In comparison with glass slides, the average screening times were 5.5 and 1.8 times longer with Panoptiq and Aperio images, respectively, but this improved with user experience. There was no statistical difference in diagnostic concordance between all 3 modalities. Users' diagnostic confidence was also similar for all modalities. The Aperio whole-slide scanner with 1 z-plane scanning and the Panoptiq imaging system with z-stacking are both suitable for cytopathology screening and interpretation. However, ROI z-stacks do offer a superior mechanism for overcoming focusing problems commonly encountered with digital cytology slides. Unlike whole-slide imaging, the acquisition of representative z-stack images with the Panoptiq system requires a trained cytologist to create digital files. Cancer Cytopathol 2017;125:701-9. © 2017 American Cancer Society. © 2017 American Cancer Society.

Bilateral Contrast-enhanced Dual-Energy Digital Mammography: Feasibility and Comparison with Conventional Digital Mammography and MR Imaging in Women with Known Breast Carcinoma

PubMed Central

Dershaw, D. David; Sung, Janice S.; Heerdt, Alexandra S.; Thornton, Cynthia; Moskowitz, Chaya S.; Ferrara, Jessica; Morris, Elizabeth A.

2013-01-01

Purpose To determine feasibility of performing bilateral dual-energy (DE) contrast agent–enhanced (CE) digital mammography and to evaluate its performance compared with conventional digital mammography and breast magnetic resonance (MR) imaging in women with known breast cancer. Materials and Methods This study was approved by the institutional review board and was HIPAA compliant. Written informed consent was obtained. Patient accrual began in March 2010 and ended in August 2011. Mean patient age was 49.6 years (range, 25–74 years). Feasibility was evaluated in 10 women with newly diagnosed breast cancer who were injected with 1.5 mL per kilogram of body weight of iohexol and imaged between 2.5 and 10 minutes after injection. Once feasibility was confirmed, 52 women with newly diagnosed cancer who had undergone breast MR imaging gave consent to undergo DE CE digital mammography. Positive findings were confirmed with pathologic findings. Results Feasibility was confirmed with no adverse events. Visualization of tumor enhancement was independent of timing after contrast agent injection for up to 10 minutes. MR imaging and DE CE digital mammography both depicted 50 (96%) of 52 index tumors; conventional mammography depicted 42 (81%). Lesions depicted by using DE CE digital mammography ranged from 4 to 67 mm in size (median, 17 mm). DE CE digital mammography depicted 14 (56%) of 25 additional ipsilateral cancers compared with 22 (88%) of 25 for MR imaging. There were two false-positive findings with DE CE digital mammography and 13 false-positive findings with MR imaging. There was one contralateral cancer, which was not evident with either modality. Conclusion Bilateral DE CE digital mammography was feasible and easily accomplished. It was used to detect known primary tumors at a rate comparable to that of MR imaging and higher than that of conventional digital mammography. DE CE digital mammography had a lower sensitivity for detecting additional ipsilateral cancers than did MR imaging, but the specificity was higher. © RSNA, 2012 PMID:23220903

Integrated Digital Platform for the Valorization of a Cultural Landscape

NASA Astrophysics Data System (ADS)

Angheluţǎ, L. M.; Ratoiu, L.; Chelmus, A. I.; Rǎdvan, R.; Petculescu, A.

2017-05-01

This paper presents a newly started demonstrative project regarding the implementation and validation of an interdisciplinary research model for the Aluniş-Bozioru (Romania) cultural landscape, with the development of an online interactive digital product. This digital product would provide complementary data about the historical monuments and their environment, and also, constant updates and statistical comparison in order to generate an accurate evaluation of the state of conservation for this specific cultural landscape. Furthermore, the resulted information will contribute in the decision making process for the regional development policies. The project is developed by an interdisciplinary joint team of researchers consisted of technical scientists with great experience in advanced non-invasive characterization of the cultural heritage (NIRD for Optoelectronics - INOE 2000) and a group of experts from geology and biology (Romanian Academy's "Emil Racoviţǎ" Institute of Speleology - ISER). Resulted scientific data will include: 3D digital models of the selected historical monuments, microclimate monitoring, Ground Penetrating Radar survey, airborne LIDAR, multispectral and thermal imaging, soil and rock characterization, environmental studies. This digital product is constituted by an intuitive website with a database that allows data corroboration, visualization and comparison of the 3D digital models, as well as a digital mapping in the GIS system.

Analysis of discrepancies observed between digital and analog images during a clinical trial of IRIS

NASA Astrophysics Data System (ADS)

Goldberg, Morris; Coristine, Marjorie; Currie, Shawn; Belanger, Garry; Ahuja, J.; Dillon, Richard F.; Robertson, John G.

1990-08-01

A clinical trial of an Integrated Radiological Information System (IRIS) was conducted at the Ottawa Civic Hospital with the Department of Emergency Medicine and the Department of Radiological Sciences between April 4, and May 12, 1989. During the trial, 319 active Emergency Department cases (905 films) were processed using IRIS. Radiologists examined the digital images on the image screen to formulate a diagnosis, then before dictating a report, they examined the analog films. In 30 cases there was a discrepancy between the information obtained while viewing the digital images on IRIS and the information obtained from the analog films. These anomalous cases were used in an independent study of the discrepancies. In the study, each case was reviewed in both digital and analog form by three physicians who provided a comparative rating of diagnostic quality. Any perceived differences between the digital and analog media were noted. Particular attention was paid to rating the relevance of the IRIS enhancement capabilities. Although ratings for digital images were high, the comparative ratings for the film are in general better. An analysis of the individual cases shows that: (i) most of the discrepancies probably resulted from physician inexperience in reading radiographs in digital form, (ii) the IRIS enhancement facilities significantly increase the ratings of satisfaction or perceived quality of digital images and (iii) an appropriate choice of enhancement may make visible the required diagnostic features for cases where some reviewers did not find the image/digital discrepant.

New Geologic Map of the Scandia Region of Mars

NASA Technical Reports Server (NTRS)

Tanaka, K. L.; Rodriquez, J. A. P.; Skinner, J. A., Jr.; Hayward, R. K.; Fortezzo, C.; Edmundson, K.; Rosiek, M.

2009-01-01

We have begun work on a sophisti-cated digital geologic map of the Scandia region (Fig. 1) at 1:3,000,000 scale based on post-Viking image and to-pographic datasets. Through application of GIS tools, we will produce a map product that will consist of (1) a printed photogeologic map displaying geologic units and relevant modificational landforms produced by tectonism, erosion, and collapse/mass wasting; (2) a landform geoda-tabase including sublayers of key landform types, attributed with direct measurements of their planform and to-pography using Mars Orbiter Laser Altimeter (MOLA) altimetry data and High-Resolution Stereo Camera (HRSC) digital elevation models (DEMs) and various image datasets; and (3) a series of digital, reconstructed paleostratigraphic and paleotopographic maps showing the inferred distribution and topographic form of materi-als and features during past ages

CR digital mammography: an affordable entry.

PubMed

Fischer, Cathy

2006-01-01

CR full-field digital mammography (FFDM) has been used extensively in other countries, and it was one of the 4 digital mammography technologies employed in the Digital Mammographic Imaging Screening Trial. Affordability and easy integration with pre-existing mammography systems makes CR FFDM an attractive way to secure the advantages of filmless mammography imaging. CR mammography is true digital mammography--it is merely a different way of acquiring the image. The FDA has recently approved the first CR FFDM system for sale in the United States. At Gundersen Lutheran Health System (La Crosse, Wisconsin), CR FFDM is the most practical technology for realizing the potential everyday clinical benefits of filmless mammography imaging.

Accuracy and precision of computer-assisted analysis of bone density via conventional and digital radiography in relation to dual-energy x-ray absorptiometry.

PubMed

Vaccaro, Calogero; Busetto, Roberto; Bernardini, Daniele; Anselmi, Carlo; Zotti, Alessandro

2012-03-01

To evaluate the precision and accuracy of assessing bone mineral density (BMD) by use of mean gray value (MGV) on digitalized and digital images of conventional and digital radiographs, respectively, of ex vivo bovine and equine bone specimens in relation to the gold-standard technique of dual-energy x-ray absorptiometry (DEXA). Left and right metatarsal bones from 11 beef cattle and right femurs from 2 horses. Bovine specimens were imaged by use of conventional radiography, whereas equine specimens were imaged by use of computed radiography (digital radiography). Each specimen was subsequently scanned by use of the same DEXA equipment. The BMD values resulting from each DEXA scan were paired with the MGVs obtained by use of software on the corresponding digitalized or digital radiographic image. The MGV analysis of digitalized and digital x-ray images was a precise (coefficient of variation, 0.1 and 0.09, respectively) and highly accurate method for assessing BMD, compared with DEXA (correlation coefficient, 0.910 and 0.937 for conventional and digital radiography, respectively). The high correlation between MGV and BMD indicated that MGV analysis may be a reliable alternative to DEXA in assessing radiographic bone density. This may provide a new, inexpensive, and readily available estimate of BMD.

MRI for transformation of preserved organs and their pathologies into digital formats for medical education and creation of a virtual pathology museum. A pilot study.

PubMed

Venkatesh, S K; Wang, G; Seet, J E; Teo, L L S; Chong, V F H

2013-03-01

To evaluate the feasibility of magnetic resonance imaging (MRI) for the transformation of preserved organs and their disease entities into digital formats for medical education and creation of a virtual museum. MRI of selected 114 pathology specimen jars representing different organs and their diseases was performed using a 3 T MRI machine with two or more MRI sequences including three-dimensional (3D) T1-weighted (T1W), 3D-T2W, 3D-FLAIR (fluid attenuated inversion recovery), fat-water separation (DIXON), and gradient-recalled echo (GRE) sequences. Qualitative assessment of MRI for depiction of disease and internal anatomy was performed. Volume rendering was performed on commercially available workstations. The digital images, 3D models, and photographs of specimens were archived into a workstation serving as a virtual pathology museum. MRI was successfully performed on all specimens. The 3D-T1W and 3D-T2W sequences demonstrated the best contrast between normal and pathological tissues. The digital material is a useful aid for understanding disease by giving insights into internal structural changes not apparent on visual inspection alone. Volume rendering produced vivid 3D models with better contrast between normal tissue and diseased tissue compared to real specimens or their photographs in some cases. The digital library provides good illustration material for radiological-pathological correlation by enhancing pathological anatomy and information on nature and signal characteristics of tissues. In some specimens, the MRI appearance may be different from corresponding organ and disease in vivo due to dead tissue and changes induced by prolonged contact with preservative fluid. MRI of pathology specimens is feasible and provides excellent images for education and creating a virtual pathology museum that can serve as permanent record of digital material for self-directed learning, improving teaching aids, and radiological-pathological correlation. Copyright © 2012 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Accuracy Assessment of Digital Surface Models Based on WorldView-2 and ADS80 Stereo Remote Sensing Data

PubMed Central

Hobi, Martina L.; Ginzler, Christian

2012-01-01

Digital surface models (DSMs) are widely used in forest science to model the forest canopy. Stereo pairs of very high resolution satellite and digital aerial images are relatively new and their absolute accuracy for DSM generation is largely unknown. For an assessment of these input data two DSMs based on a WorldView-2 stereo pair and a ADS80 DSM were generated with photogrammetric instruments. Rational polynomial coefficients (RPCs) are defining the orientation of the WorldView-2 satellite images, which can be enhanced with ground control points (GCPs). Thus two WorldView-2 DSMs were distinguished: a WorldView-2 RPCs-only DSM and a WorldView-2 GCP-enhanced RPCs DSM. The accuracy of the three DSMs was estimated with GPS measurements, manual stereo-measurements, and airborne laser scanning data (ALS). With GCP-enhanced RPCs the WorldView-2 image orientation could be optimised to a root mean square error (RMSE) of 0.56 m in planimetry and 0.32 m in height. This improvement in orientation allowed for a vertical median error of −0.24 m for the WorldView-2 GCP-enhanced RPCs DSM in flat terrain. Overall, the DSM based on ADS80 images showed the highest accuracy of the three models with a median error of 0.08 m over bare ground. As the accuracy of a DSM varies with land cover three classes were distinguished: herb and grass, forests, and artificial areas. The study suggested the ADS80 DSM to best model actual surface height in all three land cover classes, with median errors <1.1 m. The WorldView-2 GCP-enhanced RPCs model achieved good accuracy, too, with median errors of −0.43 m for the herb and grass vegetation and −0.26 m for artificial areas. Forested areas emerged as the most difficult land cover type for height modelling; still, with median errors of −1.85 m for the WorldView-2 GCP-enhanced RPCs model and −1.12 m for the ADS80 model, the input data sets evaluated here are quite promising for forest canopy modelling. PMID:22778645

Accuracy assessment of digital surface models based on WorldView-2 and ADS80 stereo remote sensing data.

PubMed

Hobi, Martina L; Ginzler, Christian

2012-01-01

Digital surface models (DSMs) are widely used in forest science to model the forest canopy. Stereo pairs of very high resolution satellite and digital aerial images are relatively new and their absolute accuracy for DSM generation is largely unknown. For an assessment of these input data two DSMs based on a WorldView-2 stereo pair and a ADS80 DSM were generated with photogrammetric instruments. Rational polynomial coefficients (RPCs) are defining the orientation of the WorldView-2 satellite images, which can be enhanced with ground control points (GCPs). Thus two WorldView-2 DSMs were distinguished: a WorldView-2 RPCs-only DSM and a WorldView-2 GCP-enhanced RPCs DSM. The accuracy of the three DSMs was estimated with GPS measurements, manual stereo-measurements, and airborne laser scanning data (ALS). With GCP-enhanced RPCs the WorldView-2 image orientation could be optimised to a root mean square error (RMSE) of 0.56 m in planimetry and 0.32 m in height. This improvement in orientation allowed for a vertical median error of -0.24 m for the WorldView-2 GCP-enhanced RPCs DSM in flat terrain. Overall, the DSM based on ADS80 images showed the highest accuracy of the three models with a median error of 0.08 m over bare ground. As the accuracy of a DSM varies with land cover three classes were distinguished: herb and grass, forests, and artificial areas. The study suggested the ADS80 DSM to best model actual surface height in all three land cover classes, with median errors <1.1 m. The WorldView-2 GCP-enhanced RPCs model achieved good accuracy, too, with median errors of -0.43 m for the herb and grass vegetation and -0.26 m for artificial areas. Forested areas emerged as the most difficult land cover type for height modelling; still, with median errors of -1.85 m for the WorldView-2 GCP-enhanced RPCs model and -1.12 m for the ADS80 model, the input data sets evaluated here are quite promising for forest canopy modelling.

Morphogenic designer--an efficient tool to digitally design tooth forms.

PubMed

Hajtó, J; Marinescu, C; Silva, N R F A

2014-01-01

Different digital software tools are available today for the purpose of designing anatomically correct anterior and posterior restorations. The current concepts present weaknesses, which can be potentially addressed by more advanced modeling tools, such as the ones already available in professional CAD (Computer Aided Design) graphical software. This study describes the morphogenic designer (MGD) as an efficient and easy method for digitally designing tooth forms for the anterior and posterior dentition. Anterior and posterior tooth forms were selected from a collection of digitalized natural teeth and subjectively assessed as "average". The models in the form of STL files were filtered, cleaned, idealized, and re-meshed to match the specifications of the software used. The shapes were then imported as wavefront ".obj" model into Modo 701, software built for modeling, texturing, visualization, and animation. In order to create a parametric design system, intentional interactive deformations were performed on the average tooth shapes and then further defined as morph targets. By combining various such parameters, several tooth shapes were formed virtually and their images presented. MGD proved to be a versatile and powerful tool for the purpose of esthetic and functional digital crown designs.

WE-G-209-01: Digital Radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schueler, B.

Digital radiography, CT, PET, and MR are complicated imaging modalities which are composed of many hardware and software components. These components work together in a highly coordinated chain of events with the intent to produce high quality images. Acquisition, processing and reconstruction of data must occur in a precise way for optimum image quality to be achieved. Any error or unexpected event in the entire process can produce unwanted pixel intensities in the final images which may contribute to visible image artifacts. The diagnostic imaging physicist is uniquely qualified to investigate and contribute to resolution of image artifacts. This coursemore » will teach the participant to identify common artifacts found clinically in digital radiography, CT, PET, and MR, to determine the causes of artifacts, and to make recommendations for how to resolve artifacts. Learning Objectives: Identify common artifacts found clinically in digital radiography, CT, PET and MR. Determine causes of various clinical artifacts from digital radiography, CT, PET and MR. Describe how to resolve various clinical artifacts from digital radiography, CT, PET and MR.« less

Digitized radiographs in skeletal trauma: a performance comparison between a digital workstation and the original film images.

PubMed

Wilson, A J; Hodge, J C

1995-08-01

To evaluate the diagnostic performance of a teleradiology system in skeletal trauma. Radiographs from 180 skeletal trauma patients were digitized (matrix, 2,000 x 2,500) and transmitted to a remote digital viewing console (1,200-line monitor). Four radiologists interpreted both the original film images and digital images. Each reader was asked to identify, locate, and characterize fractures and dislocations. Receiver operating characteristic curves were generated, and the results of the original and digitized film readings were compared. All readers performed better with the original film when interpreting fractures. Although the patterns varied between readers, all had statistically significant differences (P < .01) for the two image types. There was no statistically significant difference in performance with the two images when dislocations were diagnosed. The system tested is not a satisfactory alternative to the original radiograph for routine reading of fracture films.

Radiation dose reduction in the evaluation of scoliosis: an application of digital radiography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kushner, D.C.; Cleveland, R.H.; Herman, T.E.

1986-10-01

This report documents the clinical testing of scanning beam digital radiography as an imaging method in patients with scoliosis. This type of digital imaging requires a skin exposure of only 2.4 mR (0.619 microC/kg) per image, compared with the lowest possible posteroanterior screen-film exposure of 10 mR (2.58 microC/kg) at the chest and 60 mR (15.48 microC/kg) at the lumbar spine. Digital radiographic and screen-film images were obtained on multiple test objects and 273 patients. Scoliosis measurements using screen-film radiographs and digital radiographs were comparable to within a mean difference of 1 degrees at many different degrees of severity. Themore » low-dose digital images were found to be useful and accurate for the detection and measurement of scoliosis after the first screen-film radiographs have excluded tumors and structural abnormalities.« less

An exposure indicator for digital radiography: AAPM Task Group 116 (executive summary).

PubMed

Shepard, S Jeff; Wang, Jihong; Flynn, Michael; Gingold, Eric; Goldman, Lee; Krugh, Kerry; Leong, David L; Mah, Eugene; Ogden, Kent; Peck, Donald; Samei, Ehsan; Wang, Jihong; Willis, Charles E

2009-07-01

Digital radiographic imaging systems, such as those using photostimulable storage phosphor, amorphous selenium, amorphous silicon, CCD, and MOSFET technology, can produce adequate image quality over a much broader range of exposure levels than that of screen/film imaging systems. In screen/film imaging, the final image brightness and contrast are indicative of over- and underexposure. In digital imaging, brightness and contrast are often determined entirely by digital postprocessing of the acquired image data. Overexposure and underexposures are not readily recognizable. As a result, patient dose has a tendency to gradually increase over time after a department converts from screen/film-based imaging to digital radiographic imaging. The purpose of this report is to recommend a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The intent is to facilitate the production of consistent, high quality digital radiographic images at acceptable patient doses. This should be based not on image optical density or brightness but on feedback regarding the detector exposure provided and actively monitored by the imaging system. A standard beam calibration condition is recommended that is based on RQA5 but uses filtration materials that are commonly available and simple to use. Recommendations on clinical implementation of the indices to control image quality and patient dose are derived from historical tolerance limits and presented as guidelines.

An exposure indicator for digital radiography: AAPM Task Group 116 (Executive Summary)

PubMed Central

Shepard, S. Jeff; Wang, Jihong; Flynn, Michael; Gingold, Eric; Goldman, Lee; Krugh, Kerry; Leong, David L.; Mah, Eugene; Ogden, Kent; Peck, Donald; Samei, Ehsan; Wang, Jihong; Willis, Charles E.

2009-01-01

Digital radiographic imaging systems, such as those using photostimulable storage phosphor, amorphous selenium, amorphous silicon, CCD, and MOSFET technology, can produce adequate image quality over a much broader range of exposure levels than that of screen/film imaging systems. In screen/film imaging, the final image brightness and contrast are indicative of over- and underexposure. In digital imaging, brightness and contrast are often determined entirely by digital postprocessing of the acquired image data. Overexposure and underexposures are not readily recognizable. As a result, patient dose has a tendency to gradually increase over time after a department converts from screen/film-based imaging to digital radiographic imaging. The purpose of this report is to recommend a standard indicator which reflects the radiation exposure that is incident on a detector after every exposure event and that reflects the noise levels present in the image data. The intent is to facilitate the production of consistent, high quality digital radiographic images at acceptable patient doses. This should be based not on image optical density or brightness but on feedback regarding the detector exposure provided and actively monitored by the imaging system. A standard beam calibration condition is recommended that is based on RQA5 but uses filtration materials that are commonly available and simple to use. Recommendations on clinical implementation of the indices to control image quality and patient dose are derived from historical tolerance limits and presented as guidelines. PMID:19673189

3-D Digitization of Stereoscopic Jet-in-Crossflow Vortex Structure Images via Augmented Reality

NASA Astrophysics Data System (ADS)

Sigurdson, Lorenz; Strand, Christopher; Watson, Graeme; Nault, Joshua; Tucker, Ryan

2006-11-01

Stereoscopic images of smoke-laden vortex flows have proven useful for understanding the topology of the embedded 3-D vortex structures. Images from two cameras allow a perception of the 3-D structure via the use of red/blue eye glasses. The human brain has an astonishing capacity to calculate and present to the observer the complex turbulent smoke volume. We have developed a technique whereby a virtual cursor is introduced to the perception, which creates an ``augmented reality.'' The perceived position of this cursor in the 3-D field can be precisely controlled by the observer. It can be brought near a characteristic vortex structure in order to digitally estimate the spatial coordinates of that feature. A calibration procedure accounts for camera positioning. Vortex tubes can be traced and recorded for later or real time supersposition of tube skeleton models. These models can be readily digitally obtained for display in graphics systems to allow complete exploration from any location or perspective. A unique feature of this technology is the use of the human brain to naturally perform the difficult computation of the shape of the translucent smoke volume. Examples are given of application to low velocity ratio and Reynolds number elevated jets-in-crossflow.

Low-Cost Photogrammetric Technique Used to Measure Dome Growth at Mount St. Helens Volcano, 2007-2007

NASA Astrophysics Data System (ADS)

Diefenbach, A. K.; Crider, J. G.; Schilling, S. P.; Dzurisin, D.

2007-12-01

We describe a low-cost application of digital photogrammetry using commercial grade software, an off-the-shelf digital camera, a laptop computer and oblique photographs to reconstruct volcanic dome morphology during the on-going eruption at Mount St. Helens, Washington. Renewed activity at Mount St. Helens provides a rare opportunity to devise and test new methods for better understanding and predicting volcanic events, because the new method can be validated against other observations on this well-instrumented volcano. Uncalibrated, oblique aerial photographs (snap shots) taken from a helicopter are the raw data. Twelve sets of overlapping digital images of the dome taken during 2004-2007 were used to produce digital elevation models (DEMs) from which dome height, eruption volume and extrusion rate can be derived. Analyses of the digital images were carried out using PhotoModeler software, which produces three dimensional coordinates of points identified in multiple photos. The steps involved include: (1) calibrating the digital camera using this software package, (2) establishing control points derived from existing DEMs, (3) identifying tie points located in each photo of any given model date, and (4) identifying points in pairs of photos to build a three dimensional model of the evolving dome at each photo date. Text files of three-dimensional points encompassing the dome at each date were imported into ArcGIS and three-dimensional models (triangulated irregular network or TINs) were generated. TINs were then converted to 2 m raster DEMs. The evolving morphology of the growing dome was modeled by comparison of successive DEMs. The volume of extruded lava visible in each DEM was calculated using the 1986 pre-eruption crater floor topography as a basal surface. Results were validated by comparing volume measurements derived from traditional aerophotogrammetric surveys run by the USGS Cascades Volcano Observatory. Our new "quick and cheap" technique yields estimates of eruptive volume consistently within 5% of the volumes estimated with traditional surveys. The end result of this project is a new technique that provides an inexpensive, rapid assessment tool for tracking lava dome growth or other topographic changes at restless volcanoes.

An initial study on the estimation of time-varying volumetric treatment images and 3D tumor localization from single MV cine EPID images

PubMed Central

Mishra, Pankaj; Li, Ruijiang; Mak, Raymond H.; Rottmann, Joerg; Bryant, Jonathan H.; Williams, Christopher L.; Berbeco, Ross I.; Lewis, John H.

2014-01-01

Purpose: In this work the authors develop and investigate the feasibility of a method to estimate time-varying volumetric images from individual MV cine electronic portal image device (EPID) images. Methods: The authors adopt a two-step approach to time-varying volumetric image estimation from a single cine EPID image. In the first step, a patient-specific motion model is constructed from 4DCT. In the second step, parameters in the motion model are tuned according to the information in the EPID image. The patient-specific motion model is based on a compact representation of lung motion represented in displacement vector fields (DVFs). DVFs are calculated through deformable image registration (DIR) of a reference 4DCT phase image (typically peak-exhale) to a set of 4DCT images corresponding to different phases of a breathing cycle. The salient characteristics in the DVFs are captured in a compact representation through principal component analysis (PCA). PCA decouples the spatial and temporal components of the DVFs. Spatial information is represented in eigenvectors and the temporal information is represented by eigen-coefficients. To generate a new volumetric image, the eigen-coefficients are updated via cost function optimization based on digitally reconstructed radiographs and projection images. The updated eigen-coefficients are then multiplied with the eigenvectors to obtain updated DVFs that, in turn, give the volumetric image corresponding to the cine EPID image. Results: The algorithm was tested on (1) Eight digital eXtended CArdiac-Torso phantom datasets based on different irregular patient breathing patterns and (2) patient cine EPID images acquired during SBRT treatments. The root-mean-squared tumor localization error is (0.73 ± 0.63 mm) for the XCAT data and (0.90 ± 0.65 mm) for the patient data. Conclusions: The authors introduced a novel method of estimating volumetric time-varying images from single cine EPID images and a PCA-based lung motion model. This is the first method to estimate volumetric time-varying images from single MV cine EPID images, and has the potential to provide volumetric information with no additional imaging dose to the patient. PMID:25086523