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:
Dec. 05, 1978
Filed:
Dec. 30, 1977
Noel M Herbst, Mount Kisco, NY (US);
Chao N Liu, Yorktown Heights, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
Method and apparatus are disclosed for verifying a sample signature based on comparison of the dynamics of a reference and a sample signature. More particularly, second derivative values of pen displacements (i.e. acceleration) and continuous pressure pattern signals are periodically sampled for both a reference and sample signature and a comparison of these second derivative values and pressure patterns is made. To effect the comparisons the two groups (reference and sample) of both second derivative and pressure pattern signals are segmented and corresponding segments are individually correlated. Successive comparisons of the same segment pairs are performed utilizing successive shifting of the phases between the two segments being correlated to find regions of highest possible correlation. A running account of the maximum cross correlation values for all of the segment pairs of the two signatures are kept. Finally, these maximum values obtained for each segment pair comparison are combined and this resultant correlation value is utilized as a verification indicator.