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...http://www.google.co.uk/patents/US6041138?utm_source=gb-gplus-sharePatent US6041138 - Method and device for extracting features from gray-scale image and generating boundaries of document elements
