The Markov line process that has been used in some image segmentation and restoration studies is investigated. Realizations from this model are presented for a wide range of parameter values, and the effects of certai...
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The Markov line process that has been used in some image segmentation and restoration studies is investigated. Realizations from this model are presented for a wide range of parameter values, and the effects of certain parameters are studied. The maximum pseudolikelihood (MPL) estimation procedure is implemented for the Markov line process. The MPL procedure is applied to several images generated from the model as well as to a hand-drawn image and the edge-detector output of a natural image. It is expected that improved segmentation and restoration results can be obtained, if the Markov line process model is fine-tuned to the class of images under consideration, by estimating the parameters of some typical images in that class.
An approach to object recognition using cross correlation (CC) is presented. The CC utilizes samples of distances defined from a major axis to points located on the boundary of the object image (sampled boundary dista...
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ISBN:
(纸本)0818690275
An approach to object recognition using cross correlation (CC) is presented. The CC utilizes samples of distances defined from a major axis to points located on the boundary of the object image (sampled boundary distances, or SBDs). With this approach (CCSBD), the recognition of an object under translation, rotation, and uniform scaling can be achieved. The recognition of an object under stretching may also be achieved under the condition that the major axis of the image is not changed after transformation. The generalization of this approach is discussed. In particular, one of the generalizations is the use of axis of symmetry for symmetric images to measure SBDs. This can achieve recognition invariant under translation, rotation, uniform scaling, and stretching along the axis of symmetry and/or the direction perpendicular to it. The experimental results of using CCSBD to recognize some sampling objects are presented. The capability of recognizing objects under a certain type of nonaffine transformation using CCSBD is also investigated.
The mechanics of occlusion of one surface by another are described by a set of integer linear constraints. These constraints insure that the output of a contour grouping process is physically valid and consistent with...
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ISBN:
(纸本)0818620579
The mechanics of occlusion of one surface by another are described by a set of integer linear constraints. These constraints insure that the output of a contour grouping process is physically valid and consistent with the image evidence. Among the many feasible solutions, the most compelling is the solution which best explains the presence and form of image structure. The problem of computing a complete and consistent surface boundary representation is reduced to solving an integer linear program.
A system is described for real-time motion tracking of 3-D objects, including those with variable internal parameters. Unlike most previous work on model-based motion tracking, this system provides for the integrated ...
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ISBN:
(纸本)0818620579
A system is described for real-time motion tracking of 3-D objects, including those with variable internal parameters. Unlike most previous work on model-based motion tracking, this system provides for the integrated treatment of matching and measurement errors during motion tracking. These two sources of error have very different distributions and must be handled by separate computational mechanisms. These errors can be treated in an integrated way by using the computation of variance in predicted feature measurements to greatly decrease the amount of search required for subsequent matching. In return, the search process is used to eliminate the need to treat outliers during the analysis of measurement errors. The resulting system can robustly track models with many degrees of freedom while running on relatively inexpensive hardware. These same techniques can be used to speed verification during model-based recognition, and they point the way to merging of systems for recognition and motion tracking.
Discontinuities have been important in visual reconstruction to avoid oversmoothing. This work raises the question as to whether location of discontinuities is necessary in this process. The author proposes a class of...
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ISBN:
(纸本)0818620579
Discontinuities have been important in visual reconstruction to avoid oversmoothing. This work raises the question as to whether location of discontinuities is necessary in this process. The author proposes a class of adaptive regularizers (ARs) for reconstruction in the framework of regularization, in an attempt to solve the conflict between 'oversmoothing across discontinuities' and 'finding discontinuities'. The proposal differs from existing methods in the way it controls continuity, in which true discontinuities are considered in the mathematical sense only. A simple analog neuron-like circuit for hardware implementation is suggested. Experimental results are presented.
The problem of finding a path for a mobile robot in two dimensions among stationary obstacles using a free-space graph representation of the robot's workspace is examined. One problem with solutions of this type h...
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ISBN:
(纸本)0818620617
The problem of finding a path for a mobile robot in two dimensions among stationary obstacles using a free-space graph representation of the robot's workspace is examined. One problem with solutions of this type has been the time it takes to construct a graph from the image of the workspace. Two solutions are presented which seek to resolve this situation by constructing the graph representation 'on the fly' in a scanline fashion by processing the image one line at a time from top to bottom. Each method consists of three processes: one which breaks the obstacles in the image into pseudo-obstacles, another which analyzes the pseudo-obstacles and locates regions in the free space which represent nodes in the graph, and a third which completes the graph by locating similarities of the free space regions and uses them as edges. The modularity lends itself toward pipelined processing to reach the solution. Discussions are presented and results given of the graph construction process and the paths found on sample images as well as comparative times.
The issues of integration in a vision and imageprocessing system (VIPS) which has found an increasing number of applications in manufacturing are analyzed. It is pointed out that, to achieve fully integrated systems ...
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ISBN:
(纸本)0818690275
The issues of integration in a vision and imageprocessing system (VIPS) which has found an increasing number of applications in manufacturing are analyzed. It is pointed out that, to achieve fully integrated systems which are seamless and have a uniform occurrence of data and ways to process the data, it is essential that the semantics of components be identified and captured in advance. The semantics of a VIPS are identified in terms of data, processes, and knowledge. The system should have the features of handling large and heterogeneous knowledge bases, the ability to integrate knowledge and data, and a generic knowledge representation scheme. The basic system architecture to meet these features is discussed.
A method is described for segmenting edge data into a combination of straight lines and elliptic arcs. The two-stage process first segments the data into straight line segments. Ellipses are then fitted to the line da...
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ISBN:
(纸本)0818620579
A method is described for segmenting edge data into a combination of straight lines and elliptic arcs. The two-stage process first segments the data into straight line segments. Ellipses are then fitted to the line data. This is much faster than curve fitting directly to pixel data since the lines provide a great reduction in data. Segmentation is performed in the paradigm suggested by D. G. Lowe (1987). A measure of significance is defined that produces a scale-invariant description and allows the replacement of sequences of line segments by ellipses without requiring any thresholds. A method for fitting ellipses to arbitrary curves, essential for this algorithm, has been developed, based on an iterative Kalman filter. This is guaranteed to produce an elliptical fit even though the best conic fit may be a hyperbola or parabola.
The authors propose a hierarchical approach to solving the surface and the vertex correspondence problems in multiple-view-based 3-D object recognition systems. The proposed scheme is a coarse-to-fine search process, ...
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The authors propose a hierarchical approach to solving the surface and the vertex correspondence problems in multiple-view-based 3-D object recognition systems. The proposed scheme is a coarse-to-fine search process, and a Hopfield network is employed at each stage. Compared with the conventional object matching schemes, the proposed technique provides a more general and compact formulation of the problem and a solution more suitable for parallel implementation. At the coarse search stage, the surface matching rates between the input image and each object model in the database are computed through a Hopfield network and used to select the candidates for further consideration. At the fine search stage, the object models selected from the previous stage are fed into another Hopfield network for vertex matching. The object model that has the best surface and vertex correspondences with the input image is finally singled out as the best matched model. Results of experiments using both line drawings and real range images to corroborate the proposed theory are also reported.
A technique is introduced for 3-D surface reconstruction and graphic animation using elastic, deformable models. The basic structure used is an imaginary elastic grid, which is made of membranous, thin-plate type mate...
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ISBN:
(纸本)0818620579
A technique is introduced for 3-D surface reconstruction and graphic animation using elastic, deformable models. The basic structure used is an imaginary elastic grid, which is made of membranous, thin-plate type material. This elastic grid is bent, twisted, compressed, and stretched into any desirable 3-D shape, or from one flexible state to another. The desired shape can be specified by the shape constraints derived automatically from images of a real 3-D object, or by an analytic surface function. Shape reconstruction is guided by a set of imaginary springs that enforce the consistency in the position, orientation, and/or curvature measurements of the elastic grid and the desired shape. The dynamics of a reconstruction process is regulated by Hamilton's principle or the principle of the least action. Implementation results using simple analytic shapes and images of real free-form objects are presented. The authors believe that their model is widely applicable in many surface reconstruction and graphic animation processes.
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