Phoenix Group, Inc.

Phillip S Davis

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.

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Carthage, MO, United States of America

Phillip S Davis