Automatic signature verification

US5251265A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Lothar Dohle · Herrenberg, DE
• Volker Rudolph
• Werner Ruppert · Schönaich, DE

Key dates

• Filing date: Oct 25, 1991
• Grant date: Oct 5, 1993
• Expiry date: Oct 25, 2011

Classification

• Technology area (CPC G): Physics
• CPC primary: G07C9/35
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A method and apparatus for automatically verifying a signature of an individual is described. The apparatus digitizes an image of the signature and provides a grey scale representation of each pixel. Next, the apparatus determines parameters of this digitized image and compares them to corresponding reference parameter values which were determined from a valid signature. The results of the comparison indicate if the signature to be verified is valid. The parameters include a center of gravity of the pixels within each row and columns of the digitized image, a center of gravity line for the centers of gravity for the rows or columns and the center of gravity for all pixels of the image. Other parameters include the positions of maximum grey scale pixels within each row or column, sums of grey scale values per column or row and the shape of a bow within the signature image.