Abstract:
A sensor receives a print image from an authorized person to form a template (21), and a candidate to form test data (11). Power spectral density (PSD) data for a template (21) and a candidate (11) are compared, to read out rotation and dilation; these are used to adjust the template or candidate preparatory to a correlation to find translation (51). After applying the translation, and refinement of the rotation and dilation, normalized spatial correlation values (NSCSVs) are used to measure the quality of the match (36) and thresholded (41) to make an early rejection (42) or acceptance (43) decision in very clear cases. Where the question is closure, isomorphic adjustment is applied to the entire template or candidate for a fairer comparison in their overlap area.
Abstract:
Our invention is a device for acquiring fingerprint data using a capacitive sensor in an orientation which maximizes the amount of interesting fingerprint data gathered to increase the reliability of any fingerprint verification system. It also includes several indicia which facilitate proper alignment of the fingerprint on the sensor. The sensor can include additional circuitry to perform the verification itself. Our invention also includes apparatus for configuring the electronic circuitry and sensor in a highly compact conformation which increases the applicaitons of the verificaiton system. Such additional applicaitons include placing the verificaiton system in a remote device, or mounted in a weapon. The configuring apparatus includes plural circuit boards and an interconnection, which is both electrical and flexible, between the plural circuit boards. Further the plural circuit boards and the interconnections are made from a unitary part. Our invention further includes a method for configuring plural electronic elements which are used to acquire and process fingerprints. Interactive enrollment procedures are enabled by a pair of bar graph display for viewing by the enrollee to optimuze template contrast and information content, and train the enrollee.