Many image compression techniques involve segmentation of a gray level image. With such techniques, information is extracted that describes the regions in the segmented image, and this information is then used to form...
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A new class of morphological filters is proposed for smoothing an image contaminated with noise. A multiple model that includes the combination of linear and nonlinear operations is used in the design of the new filte...
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A new class of morphological filters is proposed for smoothing an image contaminated with noise. A multiple model that includes the combination of linear and nonlinear operations is used in the design of the new filter. The performance of the averaging version of this new filter is similar to that of the alpha-trimmed mean filter. The structure-preserving properties of this new filter depend on the values assigned to the coefficients in the filter. The idempotent property is obtained when a closing-min and opening-max version of the filter is used. The root structure of the output signal is also investigated.< >
This study addresses a problem that arises in the early stages of visual processing. Low-level visionprocessing tasks generate information describing distances and orientations at sparse locations of visible surfaces...
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This study addresses a problem that arises in the early stages of visual processing. Low-level visionprocessing tasks generate information describing distances and orientations at sparse locations of visible surfaces in a scene. The information from these various low-level tasks need to be combined to form an estimate of the visual surface for all points in the scene. This step is commonly referred to as the surface reconstruction problem. The problem is cast as an ill-posed inverse problem, which must be stabilized using a priori information relative to image and constraint formation. A desirable property of any reconstruction algorithm is invariance with respect to rigid transformations of the surface in three-dimensional space. Two surface reconstruction algorithms that are based on invariant surface characteristics are proposed. These algorithms are studied in detail, and an example is presented to demonstrate their effectiveness. The discrete realization of the algorithms is also briefly discussed.< >
Edge detection is analyzed as a problem in cost minimization. A cost function is formulated that evaluates the quality of edge configurations. A mathematical description of edges is given, and the cost function is ana...
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Edge detection is analyzed as a problem in cost minimization. A cost function is formulated that evaluates the quality of edge configurations. A mathematical description of edges is given, and the cost function is analyzed in terms of the characteristics of the edges in minimum-cost configurations. The cost function is minimized by the simulated annealing method. A novel set of strategies for generating candidate states and a suitable temperature schedule are presented. Sequential and parallel versions of the annealing algorithm are implemented and compared. Experimental results are presented.< >
An efficient iterative method is proposed to grow and prune classification trees. This method divides the data sample into two subsets and iteratively grows a tree with one subset and prunes it with the other subset, ...
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An efficient iterative method is proposed to grow and prune classification trees. This method divides the data sample into two subsets and iteratively grows a tree with one subset and prunes it with the other subset, successively interchanging the roles of the two subsets. The convergence and other properties of the algorithm are established. Theoretical and practical considerations suggest that the iterative tree growing and pruning algorithm should perform better and require less computation than other widely used tree growing and pruning algorithms. Numerical results on a waveform recognition problem are presented to support this view.< >
Summary form only given, as follows. A necessary requirement of a strategic defense system is the detection of incoming nuclear warheads in an environment that may include nuclear detonations of undetected or missed t...
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Summary form only given, as follows. A necessary requirement of a strategic defense system is the detection of incoming nuclear warheads in an environment that may include nuclear detonations of undetected or missed target warheads. A computer model that simulates incoming warheads as distant endoatmospheric targets is described. A model of the expected electromagnetic noise present in a nuclear war environment is developed using estimates of the probability distributions. Predicted atmospheric effects are also included. Nonlinear morphological image enhancement algorithms are presented, and their ability to suppress the noise and atmospheric effects of the nuclear environment is discussed. Particular attention is given to the design of structure elements to mitigate the noise effects. These algorithms are then tested, using the combined target and noise models, and evaluated in terms of noise removal and the ability to resolve closely spaced targets.
A technique to guide landmark matching known as hopping dynamic programming is described. The location of the model in the scene is estimated with a least-squares fit. A heuristic measure is then computed to decide if...
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A technique to guide landmark matching known as hopping dynamic programming is described. The location of the model in the scene is estimated with a least-squares fit. A heuristic measure is then computed to decide if the model is in the scene. The shape features of an object are the landmarks associated with the object. The landmarks of an object are defined as the points of interest of the object that have important shape attributes. Examples of landmarks are corners, holes, protrusions, and high-curvature points.< >
It is noted that a necessary requirement of a strategic defense system is the detection of incoming nuclear warheads in an environment that may include nuclear detonations of undetected or missed target warheads. A co...
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It is noted that a necessary requirement of a strategic defense system is the detection of incoming nuclear warheads in an environment that may include nuclear detonations of undetected or missed target warheads. A computer model is described which simulates incoming warheads as distant endoatmospheric targets. A model of the expected electromagnetic noise present in the nuclear environment is developed; predicted atmospheric effects are included. Various morphological-based image-enhancement algorithms are examined with regard to their ability to suppress the noise and atmospheric effects of the nuclear environment. These algorithms are then tested, using the combined target and noise models, and evaluated in terms of noise removal and the ability to resolve closely spaced targets.< >
Cardiac function is often evaluated quantitatively using two-dimensional echocardiography to analyze shape attributes, such as the heart wall thickness or the shape change of the heart wall boundaries. A review of pre...
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Cardiac function is often evaluated quantitatively using two-dimensional echocardiography to analyze shape attributes, such as the heart wall thickness or the shape change of the heart wall boundaries. A review of previous work in detecting the heart wall boundaries is presented, along with how this problem can be viewed from a computervision perspective. The principles of echo image sequence analysis and high-level analysis are described. It is suggested that one promising approach is to use multiple-resolution processing by using a large window smoothed image for the initial detection of major edge segments, followed by smaller and smaller windows until a complete boundary is found.< >
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