| 摘要 |
PROBLEM TO BE SOLVED: To extract a characteristic valid to recognition even from a picture with low resolution. SOLUTION: Picture data in a grey level generated from a document original picture are analyzed as three-dimensional curved surface data by judging grey level information in a height direction. A triangle approximating means 104 triangle-approximates the curved surface data, a polygon synthesizing means 105 synthesizes the adjacent approximating triangles into a polygon, and a feature extracting means 106 extracts a feature in the neighborhood of the boundary of the adjacent polygons. Also, an outline extracting means 207 extracts an outline feature by using the polygon and the extracted feature in the neighborhood of the boundary of the adjacent polygons, classifies the extracted outline feature into outside and inside outline based on the result, and generates a binary picture by using a vector/raster converting method. |
