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:
May. 30, 1995
Filed:
Sep. 01, 1993
Phillip S Davis, Carthage, MO (US);
The Phoenix Group, Inc., Pittsburg, KS (US);
Abstract
A method for minutia extraction from a digitized fingerprint array by twin tracker border line analysis includes scanning the array to detect ridge pixels, setting up a pair of tracker pixels or trackers on opposite borders of the ridge, moving the trackers along the borders of the ridge, periodically calculating the midpoint between the trackers to generate a centerline between the borders, calculating an average slope of the centerline, and periodically testing between the trackers for the presence of valley pixels. When such a valley pixel is detected, a sequence of aberration tests is conducted to identify the type of aberration. If the aberration tests all fail, the aberration is identified as a ridge diversion, the location and slope of which are stored as a minutia in a minutia location table. Ridge endings are detected by comparing the coordinates of the trackers after each move. If a ridge ending is detected, an attempt is made to jump to another ridge within a given proximity to the current ridge. When all the ridges have been processed, the valleys of the fingerprint are processed in a similar manner to locate valley minutiae, the locations and slopes of which are stored in the minutia location table associated with the fingerprint.