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142
Iterative point matching for registration of free-form curves and surfaces
, 1994
"... A heuristic method has been developed for registering two sets of 3-D curves obtained by using an edge-based stereo system, or two dense 3-D maps obtained by using a correlation-based stereo system. Geometric matching in general is a difficult unsolved problem in computer vision. Fortunately, in ma ..."
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Cited by 660 (8 self)
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A heuristic method has been developed for registering two sets of 3-D curves obtained by using an edge-based stereo system, or two dense 3-D maps obtained by using a correlation-based stereo system. Geometric matching in general is a difficult unsolved problem in computer vision. Fortunately, in many practical applications, some a priori knowledge exists which considerably simplifies the problem. In visual navigation, for example, the motion between successive positions is usually approximately known. From this initial estimate, our algorithm computes observer motion with very good precision, which is required for environment modeling (e.g., building a Digital Elevation Map). Objects are represented by a set of 3-D points, which are considered as the samples of a surface. No constraint is imposed on the form of the objects. The proposed algorithm is based on iteratively matching points in one set to the closest points in the other. A statistical method based on the distance distribution is used to deal with outliers, occlusion, appearance and disappearance, which allows us to do subset-subset matching. A least-squares technique is used to estimate 3-D motion from the point correspondences, which reduces the average distance between points in the two sets. Both synthetic and real data have been used to test the algorithm, and the results show that it is efficient and robust, and yields an accurate motion estimate.
Matching Hierarchical Structures Using Association Graphs
- IEEE Transactions on Pattern Analysis and Machine Intelligence
, 1998
"... this article, please send e-mail to: tpami@computer.org, and reference IEEECS Log Number 108453 ..."
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Cited by 212 (24 self)
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this article, please send e-mail to: tpami@computer.org, and reference IEEECS Log Number 108453
Model-Based Recognition in Robot Vision
- ACM Computing Surveys
, 1986
"... This paper presents a comparative study and survey of model-based object-recognition algorithms for robot vision. The goal of these algorithms is to recognize the identity, position, and orientation of randomly oriented industrial parts. In one form this is commonly referred to as the “bin-picking ” ..."
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Cited by 192 (0 self)
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This paper presents a comparative study and survey of model-based object-recognition algorithms for robot vision. The goal of these algorithms is to recognize the identity, position, and orientation of randomly oriented industrial parts. In one form this is commonly referred to as the “bin-picking ” problem, in which the parts to be recognized are presented in a jumbled bin. The paper is organized according to 2-D, 2&D, and 3-D object representations, which are used as the basis for the recognition algorithms. Three
Smoothed local symmetries and their implementation
, 1984
"... We introduce a novel representation of two-dimensional shape that we call smoothed local symmetries (SLS). Smoothed local symmetries represent both the bounding contour of a shape fragment and the region that it occupies. In this paper we develop the main features of the SLS repre-sentation and desc ..."
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Cited by 137 (3 self)
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We introduce a novel representation of two-dimensional shape that we call smoothed local symmetries (SLS). Smoothed local symmetries represent both the bounding contour of a shape fragment and the region that it occupies. In this paper we develop the main features of the SLS repre-sentation and describe an implemented algorithm that com-putes it. The performance of the algorithm is illustrated for a set of tools. We conclude by sketching a method for deter-mining the articulation of a shape into subshapes. 1.
Flexible Syntactic Matching of Curves and its Application to Automatic Hierarchical Classification of Silhouettes
- IEEE Transactions on Pattern Analysis and Machine Intelligence
"... Curve matching is one instance of the fundamental correspondence problem. Our exible algorithm is designed to match curves under substantial deformations and arbitrary large scaling and rigid transformations. A syntactic representation is constructed for both curves, and an edit transformation which ..."
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Cited by 131 (2 self)
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Curve matching is one instance of the fundamental correspondence problem. Our exible algorithm is designed to match curves under substantial deformations and arbitrary large scaling and rigid transformations. A syntactic representation is constructed for both curves, and an edit transformation which maps one curve to the other is found using dynamic programming. We present extensive...
Stereo correspondence through feature grouping and maximal cliques
- IEEE Transactions on Pattern Analysis and Machine Intelligence
, 1989
"... Abstract-In this paper we propose a method to solve the stereo cor-respondence problem. The method matches features and feature rela-tionships and can be paraphrased as follows. Linear edge segments are extracted from both the left and right images. Each such segment is characterized by its position ..."
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Cited by 115 (0 self)
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Abstract-In this paper we propose a method to solve the stereo cor-respondence problem. The method matches features and feature rela-tionships and can be paraphrased as follows. Linear edge segments are extracted from both the left and right images. Each such segment is characterized by its position and orientation in the image as well as its relationships with the nearby segments. A relational graph is thus built from each image. For each segment in one image a set of potential assignments in the other image is determined. These assignments are represented as nodes in a correspondence graph. Arcs in this graph rep-resent compatible assignments established on the basis of segment re-lationships. Stereo matching becomes equivalent to searching for sets of mutually compatible nodes in this graph. These sets are found by looking for maximal cliques. The maximal clique the best suited to rep-resent a stereo correspondence is selected using a benefit function. Fi-nally we show numerous results obtained with this method. Index Terms-Feature-based matching, feature grouping, geometric constraints, maximal cliques, stereo vision, subgraph isomorphism. T I.
ASSERT: A Physician-in-the-loop Content-Based Retrieval System for HRCT Image Databases
, 1999
"... It is now recognized in many domains that content-based image retrieval (CBIR) from a database of images cannot be carried out by using completely automated approaches. One such domain is medical radiology for which the clinically useful information in an image typically consists of gray level varia ..."
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Cited by 84 (8 self)
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It is now recognized in many domains that content-based image retrieval (CBIR) from a database of images cannot be carried out by using completely automated approaches. One such domain is medical radiology for which the clinically useful information in an image typically consists of gray level variations in highly localized regions of the image. Currently, it is not possible to extract these regions by automatic image segmentation techniques. To address this problem, we have implemented a human-in-the-loop (a physician-in-the-loop, more specifically) approach in which the human delineates the pathology bearing regions (PBR) and a set of anatomical landmarks in the image when the image is entered into the database. From the regions thus marked, our approach applies low-level computer vision and image processing algorithms to extract attributes related to the variations in gray scale, texture, shape, etc. In addition, the system records attributes that capture relational information such...
Shapes, Shocks, and Deformations I: The Components of Two-Dimensional Shape and the Reaction-Diffusion Space
- International Journal of Computer Vision
, 1994
"... We undertake to develop a general theory of two-dimensional shape by elucidating several principles which any such theory should meet. The principles are organized around two basic intuitions: first, if a boundary were changed only slightly, then, in general, its shape would change only slightly. Th ..."
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Cited by 83 (5 self)
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We undertake to develop a general theory of two-dimensional shape by elucidating several principles which any such theory should meet. The principles are organized around two basic intuitions: first, if a boundary were changed only slightly, then, in general, its shape would change only slightly. This leads us to propose an operational theory of shape based on incremental contour deformations. The second intuition is that not all contours are shapes, but rather only those that can enclose "physical" material. A theory of contour deformation is derived from these principles, based on abstract conservation principles and Hamilton-Jacobi theory. These principles are based on the work of Sethian [82, 86], the Osher-Sethian level set formulation [65], the classical shock theory of Lax [53, 54], as well as curve evolution theory for a curve evolving as a function of the curvature and the relation to geometric smoothing of Gage-Hamilton-Grayson [32, 37]. The result is a characterization of th...
