Palmprint indexing based on ridge features

In recent years, law enforcement agencies are increasingly using palmprint to identify criminals. For law enforcement palmprint identification systems, efficiency is a very important but challenging problem because of large database size and poor image quality. Existing palmprint identification systems are not sufficiently fast for practical applications. To solve this problem, a novel palmprint indexing algorithm based on ridge features is proposed in this paper. A palmprint is pre-aligned by registering its orientation field with respect to a set of reference orientation fields, which are obtained by clustering training palmprint orientation fields. Indexing is based on comparing ridge orientation fields and ridge density maps, which is much faster than minutiae matching. Proposed algorithm achieved an error rate of 1% at a penetration rate of 2.25% on a palm print database consisting of 13,416 palmprints. Searching a query palmprint over the whole database takes only 0.22 seconds.