The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 2002
Filed:
Sep. 30, 1999
Hiroyasu Takahashi, Yokohama, JP;
International Business Machines Corporation, Armonk, NY (US);
Abstract
One or more contours of a picture element (PEL) array pattern are detected and, then, a strength of concavity/convexity on each contour (acuteness) and a direction of concavity/convexity are determined. Using an acuteness value of a contour point of interest, its curvature is classified into a group of strong curvatures or another group of weak curvatures such that the definitions of a direction of the concavity/convexity (contour direction) is appropriately switched from one to another for calculation. In a preferred aspect of this invention, using an acuteness value of a contour point of interest, its contour curvature is classified into either one of five curvature groups, comprising “strong concavity,” “weak concavity,” “straight line/inflection point,” “weak convexity,” and “strong convexity.” If its contour curvature is classified into either “strong concavity” or “strong convexity,” then calculation of a normal line direction will be made for deriving a contour direction. On the other hand, if its contour curvature is classified into “straight line/inflection point,” then calculation of a tangent line direction will be made. In so doing, it is possible to improve image recognition rates compared to those of the prior schemes utilizing conventional feature values.