An intrinsic coordinate system for fingerprint matching

Abstract

In this paper, an intrinsic coordinate system is proposed for fingerprints. First the fingerprint is partitioned in regular regions, which are regions that contain no singular points. In each regular region, the intrinsic coordinate system is defined by the directional field. When using the intrinsic coordinates instead of pixel coordinates, minutiae are defined with respect to their position in the directional field. The resulting intrinsic minutiae coordinates can be used in a plastic distortion-invariant fingerprint matching algorithm. Plastic distortions, caused by pressing the 3-dimensional elastic fingerprint surface on a flat sensor, now deform the entire coordinate system, leaving the intrinsic minutiae coordinates unchanged. Therefore, matching algorithms with tighter tolerance margins can be applied to obtain better performance. © Springer-Verlag 2001.