This paper presents an overview of HyperLecture, a hypertextual, gesturally-controlled lecture presentation system originally designed for teaching introductory computer programming. HyperLecture provides genuinely us...
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Many biological objects are elongated. This research addresses the issue of recognizing elongated objects from both 2D intensity images and 3D volumes. A mathematical model, called tube model, is developed for this cl...
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The problem of egomotion recovery has been treated by using as input local image motion, with the published algorithms utilizing the geometric constraint relating 2-D local image motion (optical flow, correspondence, ...
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The issue of recognizing 3D elongated objects from 2D intensity images is addressed. A tube model, locally similar to generalized cones, is developed for the class of elongated objects. A recognition strategy that com...
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The issue of recognizing 3D elongated objects from 2D intensity images is addressed. A tube model, locally similar to generalized cones, is developed for the class of elongated objects. A recognition strategy that combines 2D contour properties and surface shading information is used to exploit the power of the 3D model. Reliable contours provide constraints for localizing the objects of interest. The theory of optimal filters is adopted in verifying the shading of hypothesized objects. Object recognition is achieved through optimizing the signal-to-noise response with respect to model parameters. A sweeping operation is proposed as a further stage of identifying objects so that the overall performance of the system does not heavily rely on the quality of local feature detection.< >
作者：
C.F. HarrisJ.W. ModestinoElectrical
Computer and Systems Engineering Department Center for Image Processing Research Rensselaer Polytechnic Institute Troy NY USA
A new perceptually relevant entropy-constrained coding scheme based on the just-noticable-distortion (JND) level of the human observer is described and its properties demonstrated. The JND at each pixel location is de...
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A new perceptually relevant entropy-constrained coding scheme based on the just-noticable-distortion (JND) level of the human observer is described and its properties demonstrated. The JND at each pixel location is defined as the threshold of detectability of the human visual system (HVS) to errors in reproducing that pixel. Because of the masking effect of the HVS, errors below the JND are rendered imperceptible. The JND is determined empirically as a function of spatial frequency, local texture and local contrast. A distortion measure is developed, making essential use of the JND, for a subband coding environment which attempts to mimic the subjective evaluation effects of the HVS. This distortion measure employs a weighted squared-error metric, where the weighting depends upon the JND value at each pixel position. It essentially assigns near-zero distortion to subthreshold errors and approximately squared-error distortion to superthreshold errors. This perceptual distortion measure was incorporated into a previously developed design procedure for entropy-constrained subband coding (ECSBC) schemes based upon training data. We demonstrate that, compared to use of the conventional squared-error distortion, significant improvements in subjective image reconstruction quality can be achieved at low average bit rates using this perceptual distortion measure.
In this paper, we investigate the discrepancy between a serìal version and a parallel version of zero-knowledge protocols, and clarify the information "leaked" in the parallel version, which is not zero...
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An empirical measure for the selection of the edge-enhancement Gaussian filter is developed. The Gaussian filter is specified by its standard deviation sigma ; the filter's spatial support is a function of sigma ....
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An empirical measure for the selection of the edge-enhancement Gaussian filter is developed. The Gaussian filter is specified by its standard deviation sigma ; the filter's spatial support is a function of sigma . An estimation procedure for sigma using Fourier analysis is described. The measure is easy to implement and is based totally on the image at hand. Experimental results suggest that this measure can be used as an aid in deciding the Gaussian filter's spatial support, which is needed to enhance the edges. Other equivalent bandwidth definitions can be used to obtain a measure of the frequency spread in the smoothed image (e.g., the mean-square bandwidth).< >
The problem of egomotion recovery has been treated by using as input local image motion, with the published algorithms utilizing the geometric constraint relating 2-D local image motion (optical flow, correspondence, ...
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The problem of egomotion recovery has been treated by using as input local image motion, with the published algorithms utilizing the geometric constraint relating 2-D local image motion (optical flow, correspondence, derivatives of the image flow) to 3-D motion and structure. Since it has proved very difficult to achieve accurate input (local image motion), a lot of effort has been devoted to the development of robust techniques. A new approach to the problem of egomotion estimation is taken, based on constraints of a global nature. It is proved that local normal flow measurements form global patterns in the image plane. The position of these patterns is related to the three dimensional motion parameters. By locating some of these patterns, which depend only on subsets of the motion parameters, through a simple search technique, the 3-D motion parameters can be found. The proposed algorithmic procedure is very robust, since it is not affected by small perturbations in the normal flow measurements. As a matter of fact, since only the sign of the normal flow measurement is employed, the direction of translation and the axis of rotation can be estimated with up to 100% error in the image measurements.< >
The FLAI’93 workshop "Industrial and Commercial Applications of Fuzzy Logic" will provide an informal forum to conference participants to address key issues in industrial and commercial applications of fuzz...
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