Method and device for extracting features from gray-scale image and generating boundaries of document elements
First Claim
Patent Images
1. A method of extracting features from a gray-scale image, said method comprising the steps of:
- a) generating polygons which approximate a curved surface represented by said gray-scale image;
b) extracting features with respect to common edges of adjoining polygons; and
c) generating boundaries of document elements based on said features,wherein said step b) comprises the steps ofb1) cutting said surface by a horizontal plane to generate intersection lines between said horizontal plane and said polygons around each one of said common edges,b2) extracting directional features with respect to each one of said common edges based on said intersection lines, andb3) extracting convex/concave features with respect to each one of said common edges based on said intersection lines.
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Abstract
A method of extracting features from a gray-scale image includes the steps of generating polygons which approximate a curved surface represented by the gray-scale image, and extracting features with respect to common edges of adjoining polygons. The method further includes the step of generating boundaries of document elements based on the features.
26 Citations
13 Claims
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1. A method of extracting features from a gray-scale image, said method comprising the steps of:
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a) generating polygons which approximate a curved surface represented by said gray-scale image; b) extracting features with respect to common edges of adjoining polygons; and c) generating boundaries of document elements based on said features, wherein said step b) comprises the steps of b1) cutting said surface by a horizontal plane to generate intersection lines between said horizontal plane and said polygons around each one of said common edges, b2) extracting directional features with respect to each one of said common edges based on said intersection lines, and b3) extracting convex/concave features with respect to each one of said common edges based on said intersection lines. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A device for extracting features from a gray-scale image, said device comprising:
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approximation means for generating polygons which approximate a curved surface represented by said gray-scale image; feature-extraction means for extracting features with respect to common edges of adjoining polygons; and boundary-extraction means for generating boundaries of document elements based on said features, wherein said feature-extraction means comprises, means for cutting said surface by a horizontal plane to generate intersection lines between said horizontal plane and said polygons around each one of said common edges, means for extracting directional features with respect to each one of said common edges based on said intersection lines, and means for extracting convex/concave features with respect to each one of said common edges based on said intersection lines. - View Dependent Claims (11)
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12. A computer usable medium having program code means embodied therein for causing a computer to extract features from a gray-scale image, said program code means comprising:
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approximation means for generating polygons which approximate a curved surface represented by said gray-scale image; feature-extraction means for extracting features with respect to common edges of adjoining polygons; and boundary-extraction means for generating boundaries of document elements based on said features, wherein said feature-extraction means comprises, means for cutting said surface by a horizontal plane to generate intersection lines between said horizontal plane and said polygons around each one of said common edges; means for extracting directional features with respect to each one of said common edges based on said intersection lines; and means for extracting convex/concave features with respect to each one of said common edges based on said intersection lines. - View Dependent Claims (13)
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Specification