| 摘要 |
PROBLEM TO BE SOLVED: To extract desired contour from image data independently of an exposure condition and a density of a background, a character or a line. SOLUTION: A 4-direction edge detection filter is used to obtain a density peak of all pixels in image data. Maximum density peaks of respective pixels are compared among adjacent pixels in an edge direction and a pixel with a maximum density peak is extracted as a pixel at a high density end. Minimum density peaks of respective pixels are compared among pixels adjacent in the edge direction and a pixel with a minimum density peak is extracted as a pixel at a low density end. Thus, distances (B1, B2) between the high density end pixel and the contour pixels obtained by using a prescribed threshold through binary processing and distances (A1, A2) between the low density end pixels and the contour pixels are obtained and the threshold is decided so that ratios of the obtained distances are prescribed values.
|
