Distortion of normal vectors when approximating shape data with normal vectors is restrained. At step ST1, original polygon date is input. At step ST2, each edge is evaluated for performing removal of an edge. At step ST3, the evaluation values are sorted by magnitude and the edge having the minimum...http://www.google.ca/patents/US6326968?utm_source=gb-gplus-sharePatent US6326968 - Image data approximation considering normal vectors
