David Chelberg | Ohio University (original) (raw)

Papers by David Chelberg

W e discuss the use of stereo imayiny tecliniqiies as a low cost and low radiation dosage means t... more W e discuss the use of stereo imayiny tecliniqiies as a low cost and low radiation dosage means to provide physicians with three-dimensional (3 0) infoririation for diagnosis and follow-up care of paticrits. Iiistrud of using a pair of images obtained from perpcndicdar directions (as in the case of biplane ruclioyruphy), W E show that if a puir of small-anyle s t e r w x-ray iinuyes are obtained, observers can vividly perceive the iiriayes in 3 0 during acquisition, i. e. real-time stcreo visiiulitation is possible. In addition, quantitative inforination such as blood p o w measurements and the ainouiit of arterial narrowing can be extractcd off-line by iisiriy co mp ut at i o n a1 st e reo aly o ri tli rns. Th f : pot e n t i (1 1 a (1 1111 niages of using u small-anyle sfereo-bascd approuch u s opposed to biplane anyioyraphy are disciisscd. 'This work was supported i n part by a Purrlue University Trask Fund Grant, a Digital Equipment Corporatioii Faculty Incentives for Excellence Grant and an Iritliana Elks Fellowsliip. Address all correspondence to Edward J. Drrlp at aceQecn.purdue. edu.

Abstract A design for a system to perform object recognition from a large model data base is pres... more Abstract A design for a system to perform object recognition from a large model data base is presented, focusing on efficient indexing. The authors propose a decision-theoretic approach using a Bayesian framework to achieve efficient indexing of model objects. A ...

CVGIP: Graphical Models and Image Processing, Sep 1, 1994

A new algorithm for ray tracing generalized cylinders whose axis is an arbit:rary three dimension... more A new algorithm for ray tracing generalized cylinders whose axis is an arbit:rary three dimensional space curve and whose cross-sectional contour can be varied accortding to a general sweeping rule is presented. The only restriction placed on the class of generalized cylinders that can be ray-traced is that the sweeping rule of the generalized cylinder must be invertible. This algorithm handles a broader class of generalized cylinders than ainy other reported ray tracer. It has been integrated into a general geometric modeling systenn that can render objects utilizing visible light as well as simulated X-rays. Generalized cylinders are often used in modeling systems because they cornpactly represent objects. Many commonly occurring objects including snakes, horses, airplanes, flower vases, and organ,s of the human abdomen such as the stomach and liver can be described naturally and conveniently in terms of one or more generalized cylinder primitives. :By extending the class of generalized cylinders that can be conveniently modeled, the presented algorithm enhances .the utility of modeling systems based on generalized cylinders. X-ray images of the internal bone structure of a knee joint, and a visible light image of a fan blade assembly are presented.

Srmng image .seginerifation i.s a v e y challerigirig problem in conzpufer vision research. Borh ... more Srmng image .seginerifation i.s a v e y challerigirig problem in conzpufer vision research. Borh the data-driveri and rnodel-driven approaches have been irivestizafed in the pa.sf nm decades. and ntariy approaches w r e ~~mpo.sed. Alrlroirgli rnodel-based upiiroaches are rnore pmrrii.~irig iri oddr-easing simrig imu,qe .se,qrrieiifarioii, dafa-driven approache,s prrserir inore gene,ul ,fm,neworks which could poreririally be adoprrd fo srgrrierir general sceiies wirhoirf urry pi-ioi-rrrodd i1f~ir-1rlario11. lrr tt1i.s paper: file pmblerns of strvrrg irriajie .se,qwerifurian frorn a dura-driseii pr>r?perrhe are discussed, mid a ,nodeling rechuiyue de-.scribiq UII ohjecf uirh hofh i f s segrnenfs arid a hierarchical relario~i,slrip ~iiii(~iig rhe segmerifs is presenfed. The focus oj this paper uill he dei,ored ro the discussion of fhe Jeosibilif? (fdara-di-iwi appmac1ie.s fiir .sfmng irnage segl l i~l l f U~i / J l i .

Journal of Machine Vision and Applications, Feb 1, 2005

In this paper, a novel machine vision application is presented for analyzing and visualizing conf... more In this paper, a novel machine vision application is presented for analyzing and visualizing confocal microscopy images of biological preparations. The proposed system is divided into three subsystems: a 3D curved surface extraction subsystem that generates 3D surfaces passing through selected key points in confocal image stacks; a 2D image projection subsystem that produces a flattened projection of the extracted curved surface; and an image mosaic subsystem that concatenates a series of image projections to form a view of an entire biological preparation. A combination of cubic interpolation and boundary matching is employed to reconstruct the 3D curved surface that passes through selected key points. The projection process integrates data fidelity and local smoothness constraints, producing a color or intensity projection along the desired 3D surface. Registration is achieved by aligning and minimizing the sum of the squared distances (SSD) between the intensities of the corresponding pixels. Two biological applications of the proposed system are reported to illustrate how the vision system could aid in biological research.

The paper proposes an adaptive framework for shape-based image retrieval with relevance feedback.... more The paper proposes an adaptive framework for shape-based image retrieval with relevance feedback. The motivation is to find an adjustable shape representation scheme that can account for feedback information. Relevance feedback is modeled as a dynamic eigenspace decomposition, and is used to classify the database into relevant and irrelevant groups with respect to the query. Eigenvectors of the subspace are updated by optimizing a linear transform with respect to the J3 class separability criterion. Experimental results show that the proposed approach can effectively capture a user's perceptual subjectivity

Springer eBooks, Nov 21, 2007

Automatic segmentation of sub-cortical structures has great use in studying various neurodegentat... more Automatic segmentation of sub-cortical structures has great use in studying various neurodegentative diseases. In this paper, we propose a fully automatic solution to this problem through the utilization of a distribution atlas built from a set of training MR images. Our model consists of two major components: a local likelihood based active contour (LLAC) model and a guiding probabilistic atlas. The former has a very strong ability in standing out the structures that are in low contrast with the surrounding tissues. The latter has the functionality of defining and leading the segmentation procedure to capture the structure of interest. Formulated under the maximum a posterior framework, probabilistic atlas for the structure of interest, e.g. caudate, putamen, can be seamlessly integrated into the level set evolution procedure, and no thresholding step is needed for capturing the target.

Society for Information Technology & Teacher Education International Conference, Mar 2, 2009

... Dr. Chang Liu College of Engineering Ohio University United States liuc@ohio.edu Dr. TeresaFr... more ... Dr. Chang Liu College of Engineering Ohio University United States liuc@ohio.edu Dr. TeresaFranklin College of Education Ohio University United States franklit@ohio.edu Dr. David Chelberg College of Engineering Ohio University United States chelberg@ohio.edu ...

This research features the rapid recognition of three dimensional objects, focusing on efficient ... more This research features the rapid recognition of three dimensional objects, focusing on efficient indexing. A major concern in practical vision systems is how to retrieve the best matched models without exploring all possible object matches. We have employed a Bayesian framework to achieve efficient indexing of model objects. A decision-theoretic measure of the discriminatory power of a feature for a model object is defined in terms of posterior probability. Domain-specific knowledge compiled off-line from CAD model data is used in order to estimate posterior probabilities that define the discriminatory power of features for model objects. Detectability of a feature (defined as a function of the feature itself, viewpoint, sensor characteristics and the feature detection algorithm(s)) is also considered in the computation of discriminatory power. In order to speed up the indexing or selection of correct objects, we generate and verify the object hypotheses for features detected in a scene in the order of the discriminatory power of these features for model objects. Based on the principles described above, we have implemented a working prototype vision system using a feature structure called an LSG (Local Surface group) for generating object hypotheses. Our object recognition system can employ a wide class of features for generation of object hypotheses. In order to verify an object hypothesis, we estimate the view of the hypothesized model object and render the model object for the computed view. The object hypothesis is then verified by finding additional features in the scene that match those present in the rendered image.

IEEE transactions on systems, man, and cybernetics, 1998

Parallel Computing, May 1, 1999

Parallel processing methods are a means to achieve signi®cant speedup of computationally expensiv... more Parallel processing methods are a means to achieve signi®cant speedup of computationally expensive image understanding algorithms, such as those applied to range images. Practical implementations of these algorithms must deal with the problems of selecting an appropriate parallel architecture and mapping the algorithm onto that architecture. The parallel implementation approaches for range image segmentation that are presented here are applicable to many low-level image understanding algorithms in a variety of parallel architectures. An evaluation of initial data distribution is presented to determine whether a square subimage or a striped subimage distribution would result in the greatest overall reduction in execution time for the given range image segmentation problem. Novel implementations that consider each data distribution's treatment of edge pixels in window operations yield a trade-o between the number of data transfers versus the amount of computation. This trade-o is examined both analytically and experimentally. Additionally, using the same initial data distributions, a

International Journal of Tomography and Simulation, 2009

Automatic segmentation of brain structures in MR images is of great importance in studying neurod... more Automatic segmentation of brain structures in MR images is of great importance in studying neurodegenerative disease quantitatively. In this paper, we propose a fully automatic solution to this problem through the utilization of a probabilistic atlas built from a set of training MR images. As a generalization of the Chan-Vese piecewise-constant model, our model uses Bayesian a posterior probabilities as the driving forces for curve evolution. Prior intensity distribution can be seamlessly integrated into the level set evolution procedure. Unlike other region-based active contour models, our solution relaxes the global piecewise constant assumption, and uses locally varying Gaussians to better account for intensity inhomogeneity and local variations existing in many brain MR images. Our model shows particular strength in distinguishing low contrast structures from surrounding tissues. Accurate and robust segmentation is therefore achieved. Experiments conducted on synthetic and real ...

The Asian Journal of Kinesiology, 2018

OBJECTIVES Athletic performance and injury prevention are important for athletes and coaches. Dif... more OBJECTIVES Athletic performance and injury prevention are important for athletes and coaches. Different types of movement analyses have been created to aid in injury prevention and performance. The reliability of the Microsoft Kinect™ for movement analysis has not been widely tested. If reliable and accurate it could decrease the cost and time necessary for movement analysis. The purpose of this study was to determine if the Microsoft Kinect™ is an accurate measure of knee displacement during the parallel squat when compared to the Dartfish Team Pro Software 6.0. METHODS Twenty nine healthy recreational athletes participated in the study and used the Dartfish Team Pro Software 6.0 to validate the Microsoft Kinect™ as a tool to measure knee displacement. Subjects performed a parallel squat with a 2.1m long dowel rod. This exercise was used to compare value between systems. The intraclass correlation coefficient and paired-samples t-test were used to compare Dartfish Team Pro Software 6.0 and Microsoft Kinect™. Intrarater reliability of each system was also assessed. RESULTS There were 29 participants in the study. The interclass correlation coefficient for Dartfish Team Pro Software 6.0 and Microsoft Kinect™ showed that the Microsoft Kinect™ had a high-reliability ICC = 0.96. Intrarater reliability for Kinect™ and Dartfish were .98 and .99, respectively. The mean difference between systems for measured knee displacement was 1.06 cm. The mean for the Microsoft Kinect™ was 49.11 ± 1.9 and 50.16 ± 96 for the Dartfish (p > 0.05).

In most object recognition systems, features are extracted from an image, grouped into hypotheses... more In most object recognition systems, features are extracted from an image, grouped into hypotheses, and matched against a model database. The constructed hypotheses are usually formed in a multi-level hierarchy of features from the lower level pixels into higher level geometric features. Many existing systems include a statistical or heuristic measure of the hypothesized features formed at a given level but do not consider the measure of the underlying features of lower levels in the hierarchy. By incorporating a statistical likelihood measure at each level of the hierarchy from the lower level to higher level features, the overall accuracy and speed of the system can be improved. The system can also provide a final measure representing the strength of a match between the image and a given model object that cannot be calculated accurately in other systems. The feature extraction task has been divided into several steps. The first step extracts a set of edge pixel hypotheses from an image using a statistical model of edges. The edge pixel hypotheses are then grouped into straight line edge hypotheses, or curves represented by splines using a unified statistical model. Using the edge model, the features can not only be evaluated but can also be improved to increase the accuracy of the system. The benefits of statistically measuring the features at each step is demonstrated with a OCR program for Korean Hangul

... Stephen P. Carroll College of Engineering Ohio University United States stephen.p.carroll.1@ ... more ... Stephen P. Carroll College of Engineering Ohio University United States stephen.p.carroll.1@ ohio.edu Dr. Teresa Franklin College of Education Ohio University United States franklit@ohio.edu Dr. Chang Liu College of Engineering Ohio University United States liuc@ ...

Proceedings of SPIE, Feb 1, 1992

This paper describes the application of regularization techniques to the problem of segmenting ra... more This paper describes the application of regularization techniques to the problem of segmenting range images. We propose a new energy functional that varies the amount of smoothing according to the gradient of the data. An iterative application of reconstruction using this new functional improves the signal/noise ratio of the noisy input image with good preservation of discontinuities. By employing reconstruction using this new energy functional, the difficulty in applying regularization techniques to the segmentation problem due to smoothing over discontinuities is circumvented. The results indicate that the algorithm performs especially well on noisy range images. Reconstruction using the new energy functional shows the possibility of its application to the problem of image enhancement. An algorithm is described for the detection of zeroth order discontinuities and surface reconstruction. We also discuss how the same algorithm can be applied to detect first order discontinuities and be applied to gradient reconstruction.

STEREO MAMMOGRAPHY Elabbady et al. 2 The objective of this study was to explore and document the ... more STEREO MAMMOGRAPHY Elabbady et al. 2 The objective of this study was to explore and document the diagnostic utility of digital stereo mammography for the detection of localized breast cancer in women. In it we character ized the ability of experienced mammographers, general radiologists, and non-radiologists to detect three types of tumor masses embedded within a heterogeneous background of normal tis sue elements in numerically simulated digital mammograms. The simulated mammograms were displayed to the subjects on a high resolution video display, both in stereo mode and in mono mode. Half of the mammograms contained a single tumor, ranging from 0.3 to 0.8 cm in maxi mal diameter. Each reader rated 120 images (60 in stereo and 60 in mono) as to the probability of abnormality on scale of 1-5. Observer responses were evaluated using receiver operating characteristic (ROC) analysis to characterize any difference in diagnostic performance between the two viewing modes. The synthesiz...

this paper, we report on a study of the effectiveness of stereo perception in aiding the detectio... more this paper, we report on a study of the effectiveness of stereo perception in aiding the detection of shape and density abnormalities in simulated x-ray images. Results from the study suggest that digital stereomammography may permit easier detection of certain tissue abnormalities, perhaps providing a route to earlier tumor detection in cases of breast cancer. A computational algorithm for reconstruction of stereo mammograms is also presented, demonstrating the potential use of digital stereo mammograms in automating the detection and/or characterization of breast tumors. STEREO PERCEPTION To study the hypothesis that stereo perception can enhance the ability to detect abnormalities, it is important to understand what gives humans the ability to perceive in three dimensions. By alternately opening one eye and closing the other, we note that our left and right eyes obtain slightly different views of nearby objects. The left and right images, when fused by the visual system, produce depth perception or stereo vision in humans. This depth information is lost in ordinary two-dimensional pictures which are depicted from only one viewpoint. The fact that humans can see well with only one eye indicates that monocular cues such as linear perspective, occultation, shading, shadow, and texture can also provide a sense of depth. However, in the domain of x-ray imaging, radiologists have minimal monocular depth cues. In mammography in particular, the exact shape of a possible tumor may not be known. Binocular stereo vision could be of great benefit in such applications since it is the most powerful depth cue for scenes viewed close at hand and it is sufficient for perception of objects even in the absence of other cues such as color and contour [7]. Stereo vision can help in resol...

Educational video games are an effective medium for teaching in modern middle school classrooms. ... more Educational video games are an effective medium for teaching in modern middle school classrooms. The Science and Technology Enrichment for Appalachian Middle-schoolers (STEAM) project at Ohio University has developed multiple computer games in Second Life to provide a more enjoyable learning experience. This paper is a report on development issues, effectiveness, and future suggestions for using Second Life in the