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...http://www.google.com.hk/patents/US5420937?utm_source=gb-gplus-share專利 US5420937 - Fingerprint information extraction by twin tracker border line analysis
