An optimal deformable contour approximation algorithm using a cardinal-form piecewise cubic spline (PCS) curve representation is presented. The approximation is optimal in the sense of least square errors in both loca...
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An optimal deformable contour approximation algorithm using a cardinal-form piecewise cubic spline (PCS) curve representation is presented. The approximation is optimal in the sense of least square errors in both location and orientation. The knots are set automatically at high curvature positions. The sample data are generated by a robust edge fragment detection algorithm which is optimal in the sense of a weighted absolute error. An initial contour placement algorithm uses a penalized maximum likelihood algorithm to group the edge fragments together for an initial contour. A controlled deformable contour algorithm refines the initial contour to cover meaningful edge features.< >
An edge-based trinocular stereovision algorithm is presented. The primitives it works on are cubic B-spline approximations of the 2-D edges. This allows one to deal conveniently with curvature and to extend to some no...
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An edge-based trinocular stereovision algorithm is presented. The primitives it works on are cubic B-spline approximations of the 2-D edges. This allows one to deal conveniently with curvature and to extend to some nonpolyhedral scenes to previous stereo algorithms. To build a matching primitive, the principle of the algorithm is, first, to find a triplet of corresponding points on three splines. This is provided by the bootstrapping part. Second, the algorithm propagates along the three supporting splines to find other matching points. This provides a set of ordered point triplets along these three splines, for which all the matching constraints are verified. This primitive constitutes a trinocular hypothesis. The set of all hypotheses is obtained by propagating from all the point triplets provided by the bootstrapping process. A criterion based on the size of the hypotheses is then used to choose among them a compatible set with respect to the uniqueness constraint. Results of several 3-D reconstructed scenes are shown.< >
Two patternrecognition algorithms are proposed to detect two types of knots in lumber, lumped and surface knots, using an optical scanner. It is shown that lumped knots can be recognized by a log profile approach and...
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Two patternrecognition algorithms are proposed to detect two types of knots in lumber, lumped and surface knots, using an optical scanner. It is shown that lumped knots can be recognized by a log profile approach and surface knots can be detected by an imageprocessing.approach. A mathematical model for describing the geometry of the knots inside the log based on the surface parameters of the knots is presented. By a log breakdown strategy, the log can be cut into a maximum number of boards with prescribed dimensionalities. The mathematical knot model can be used to predict the locations, sizes, orientations, and shapes of the knots on these boards, whereby their lumber grades can be determined. Summing up the value yields of all the boards gives the value yield of the log. By computing all the possible value yields of the log from different log orientations, one can determine a maximum value yield of a log.< >
A vision system to operate in a greenhouse environment designed Tor tomato cultivation is presented. The signals sent by two PAL colour cameras are processed by a Graphic Workstation using a bit-slice microprocessor c...
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A novel memory system is proposed for imageprocessing. Latin squares, which are well known combinatorial objects, are used as the skew function of the memory system. A Latin square with desired properties for image-a...
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ISBN:
(纸本)081861952x
A novel memory system is proposed for imageprocessing. Latin squares, which are well known combinatorial objects, are used as the skew function of the memory system. A Latin square with desired properties for image-array access is introduced. The resulting memory system provides access to various subsets of image data (rows, columns, diagonals, main subsquares, etc.) without memory conflict. The memory modules are fully utilized for most frequently used subsets of image data. The address generation can be performed in constant time. This memory system achieves constant-time access to rows, columns, diagonals, and subarrays using a minimum number of memory modules.
The proceedings contains 97 papers. The following topics are dealt with: edge detection;shape derivation;feature extraction;motion;morphology and neural networks;range data;image and texture segmentation;polarization ...
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ISBN:
(纸本)081861952x
The proceedings contains 97 papers. The following topics are dealt with: edge detection;shape derivation;feature extraction;motion;morphology and neural networks;range data;image and texture segmentation;polarization cues;stereo vision;methodology and standards;object recognition;navigation;preprocessing.and computer architectures.
Square and hexagonal spatial samplings, because of their processing.ease, are used most widely in image and signal processing. The authors developed mathematical tools for estimating quantization error in hexagonal se...
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ISBN:
(纸本)081861952x
Square and hexagonal spatial samplings, because of their processing.ease, are used most widely in image and signal processing. The authors developed mathematical tools for estimating quantization error in hexagonal sensory configurations. These include analytic expressions for the average error and the error distribution of a function of an arbitrarily large number of hexagonally quantized variables. The two quantities (the average error and the error distribution) are essential in assessing the reliability of a given algorithm. The corresponding expressions for square spatial sampling are presented for comparison;they can be used to determine which sampling technique would result in less quantization error for a particular algorithm. Such a comparison is important due to the paramount role that quantization error plays in computational approaches to computer vision. Some general observations in regard to the relative accuracy of hexagonal vs. square quantization are also presented.
Using a model of an edge's motion through a sequence of images, the problem of its localization can be formulated as a stochastic filtering problem. The extended Kalman filter for such a system is considered in de...
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ISBN:
(纸本)081861952x
Using a model of an edge's motion through a sequence of images, the problem of its localization can be formulated as a stochastic filtering problem. The extended Kalman filter for such a system is considered in detail and is shown to be interpretable as a sequence of oriented special convolutions. Results are presented which show that the edge localization obtained using this filter is substantially better than that obtained using the either the Sobel or Canny edge operators on each image individually.
A set of array processors with optical interconnection networks for fine-grain imageprocessing.is considered. The unit-time interconnection made possible with the use of free-space optics results in efficient solutio...
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ISBN:
(纸本)081861952x
A set of array processors with optical interconnection networks for fine-grain imageprocessing.is considered. The unit-time interconnection made possible with the use of free-space optics results in efficient solutions to communication-intensive image computations. Using these models, a summary of results in designing O(log N) pointer-based algorithms for several tasks in low- and medium-level vision are presented, along with a generic subroutine that can be used to simulate algorithms for image computations on the proposed electrooptical arrays.
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