Wesley Snyder - Academia.edu (original) (raw)

Papers by Wesley Snyder

Hairong Qi, Wesley E. Snyder

In this paper, we propose the concept of content-based image retrieval (CBIR) and demonstrate its... more In this paper, we propose the concept of content-based image retrieval (CBIR) and demonstrate its potential use in picture archival and communication system (PACS). We address the importance of image retrieval in PACS and highlight the drawbacks existing in traditional textual-based retrieval. We use a digital mammogram database as our testing data to illustrate the idea of CBIR, where retrieval is carried based on object shape, size, and brightness histogram. With a user-supplied query image, the system can find images with similar characteristics from the archive, and return them along with the corresponding ancillary data which may provide a valuable reference for radiologists in a new case study. Furthermore, CBIR can perform like a consultant in emergencies when radiologists are not available. We also show that content-based retrieval is a more natural approach to man-machine communication.

Mosaicking and Demosaicking in the Design of Multispectral Digital Cameras

Image Processing Series, 2008

A generic method for generating multispectral filter arrays

2004 International Conference on Image Processing, 2004. ICIP '04.

The technology of color filter arrays (CFA) has been widely used in the digital camera industry s... more The technology of color filter arrays (CFA) has been widely used in the digital camera industry since it provides sev- eral advantages like low cost, exact registration, and stro ng robustness. The same motivations also drive the design of multi-spectral filter arrays (MSFA), in which more than thre e color bands are used (e.g. visible and infrared). Although considerable research

Center for Advanced Computing and Communication North Carolina State University

Page 1. The E ects of LAN-like Input Tra c on a Switch Access Node Steven W. Hunter* Ricardo M. F... more Page 1. The E ects of LAN-like Input Tra c on a Switch Access Node Steven W. Hunter* Ricardo M. Fricks Center for Advanced Computing and Communications Department of Electrical and Computer Engineering Duke University Durham, NC 27708-0291 ...

Infrared imaging learns from camera industry

Efficient approach to segment man-made targets from unmanned aerial vehicle imagery

Optical Engineering, 2000

... to those of methods that use image enhancement, and the computation time for imageenhancement... more ... to those of methods that use image enhancement, and the computation time for imageenhancement can be ... where he does research in computational statistics and pattern recognition, primarily applied to image processing and ... Steps of the proposed segmentation approach. ...

IEEE International Conference on Acoustics Speech and Signal Processing, 1993

In this paper, the problem of motion estimation is formalired aa a problem in nonlinear opthisati... more In this paper, the problem of motion estimation is formalired aa a problem in nonlinear opthisation. The algorithm is baaed on modeling the displacement fields as Markov Random Fields. The Markov Random Fields-Gibbs distribution equivalence is used to convert the problem into one of finding an appropriate energy function that describes the motion fields. Mean field annealing, a technique for finding the global minima in nonconvex opthisation problem, is used to minimise the Hamiltonian. The estimated displacement vector fielda are accurate, even for scenes containing noiae or intenaity discontinuities.

Segmentation-based motion estimation and residual coding for packet video: a goal-oriented approach

In this project, we explore a new approach to two-dimensional shape recognition. The method draws... more In this project, we explore a new approach to two-dimensional shape recognition. The method draws from literature on the Hough transform and its extensions. The methods is shown to be invariant to zoom, translation, rotation, and partial occlusion, although not zoom and partial occlusion simultaneously. The method is shown to be robust to distortions which smooth the contour shape (scale space changes). Furthermore, when the method misclassifies a shape, it chooses a shape which is most "similar" (in a human-intuitive sense) to the original. The method is developed and evaluated on a data base of tank silhouettes and a data base of fish silhouettes. The computer-based version of the algorithm is shown to have a reasonable implementation in neural hardware, and a neural-network implementation is described.

Lecture Notes in Computer Science, 1997

The project we are working on is to help develop and test a low cost, large area, high resolution... more The project we are working on is to help develop and test a low cost, large area, high resolution X-ray detection system with a high dynamic range. The large area is achieved by butting two or more scintillator/fiber/CCD combinations together. An algorithm is thus required to compensate the defects come from the detector induced errors including missing single pixel due to individual defective detectors or missing column(s)/row(s) due to misalignment of adjacent CCD's in the blurred and noise corrupted images. Mean field annealing, as a global optimization technique, is the proposed algorithm. This paper, however, proposes a new approach based on multiresolution analysis where the defect compensation is implemented by removing the characteristics created by the missing columns/rows from the detail images of lower resolution. Experiments will be carried out to compare the performance of these two approaches. Future research directions are discussed at last.

Static and Gradient Field Inhomogeneity Compensation for Low-Cost MRI Machines

Compensation for Low-Cost MRI Machines. (Under the direction of Larry Silverberg and

The ability to merge partial reconstructions into larger reconstructions is an important step use... more The ability to merge partial reconstructions into larger reconstructions is an important step used by many structure from motion systems. Merging is typically performed in metric space after autocalibration by solving an absolute orientation problem between structure point correspondences. However, autocalibration is an inherently sensitive procedure that is more reliable if delayed until the reconstruction is larger and more accurate. Additionally, the uncertainty of structure points triangulated in each partial reconstruction may prevent the accurate estimation of the proper orientation from corresponding structure points. In this paper we show how the orientation problem can be solved entirely in image space in a manner that is invariant to the potentially ill-estimated structure points, and is applicable to projective reconstructions because it does not require autocalibration. This method may be integrated into larger structure from motion systems for improved accuracy and reliability.

Reconstruction of positron emission tomography images using maximum a posteriori and mean field annealing techniques

Medical Imaging 1994: Physics of Medical Imaging, 1994

ABSTRACT

Applications of Digital Image Processing VIII, 1985

This paper presents a new technique for the detection of moving target tracks, where those tracks... more This paper presents a new technique for the detection of moving target tracks, where those tracks are linear paths or segments of circles[1.2]. The images used as input represent a time-varying sequence of noisy satellite images of terrain and a moving target(s). Preprocessing of the image sequence involves use of third order differencing to remove stationary points and produce a sequence of intermediate images containing only the target track(s) and noise from various sources[3]. The new procedure described in this paper begins by selection of a window from the preprocessed image sequence. A generalized Hough transform technique is then employed to obtain the equation for the line traveled by any target, and an extension of the linear technique is used to detect circular tracks. New strategies for reduction of the dimensionality of the Hough transformation are also described. The method has been shown to be robust when tested on simulated noisy target tracks.

Applications of Digital Image Processing V, 1983

A vision system has been developed at North Carolina State University to identify the orientation... more A vision system has been developed at North Carolina State University to identify the orientation and three dimensional location of steam turbine blades that are stacked in an industrial A-frame cart. The system uses a controlled light source for structured illumination and a single camera to extract the information required by the image processing software to calculate the position and orientation of a turbine blade in real time.* Background The development of the image processing /robot vision system that is the subject of this paper was begun in February of 1982 at North Carolina State University in Raleigh, North Carolina. The research is sponsored by the Westinghouse facility in Winston-Salem, North Carolina, in response to their need to automate specific portions of their steam turbine blade manufacturing facility. This system has been designed to provide "vision" to a Cincinnati Milacron HT3 industrial robot so that it can reliably unload turbine blades into various machines from transportation carts within the plant. The facilities that have been available for this research include a DEC VAX 11/780, an IKONAS color display system, and a laboratory robot.

Sherman, Michael, et al. "User-generated free-form gestures for authentication: Security and memo... more Sherman, Michael, et al. "User-generated free-form gestures for authentication: Security and memorability.". Retrieved from http:// dl.acm.org/citation.cfm?id=2594375. Proceedings of the 12th annual international conference on Mobile systems, applications, and services. ACM, 2014.

Proceedings. IEEE International Conference on Multimedia and Expo

We propose a new approach to steganography for information hiding in digital media. We refer to i... more We propose a new approach to steganography for information hiding in digital media. We refer to it as blind consistency-based steganography (BCBS). Our main concerns in designing BCBS is high imperceptibility, high security level, and large capacity. Steganography differs from digital watermarking because both the information and the very existence of the information are hidden. Even though the discussion focuses on digital images, BCBS can be applied to any digital media. While existing steganographic approaches all have different advantages for specific applications, they also suffer a similar problem: such systems are unable to handle subterfuge attacks, i.e., they cannot deal with the opponents who not only detect a message, but also render it useless, or even worse, modify it to the opponent's favor. The breakthrough of BCBS is that it not only decodes the message exactly, it also detects if the message has been tampered without using any extra error correction. The detection is integrated into the process of decoding. Another advantage of BCBS is the "blindness" of the decoding process, meaning the decoding can be operated without access to the cover image. The encoding and decoding process are detailed in the paper, along with the analysis on imperceptibility, security, and capacity. Experimental results are provided as well.