Joint transform correlation for fingerprint identification

Abstract

The pattern matching for fingerprints requires a large amount of data and computation time. Practical fingerprint identification systems require minimal errors and ultrafast processing time to perform real time verification and identification. By utilizing the two-dimensional processing capability, ultrafast processing speed and noninterfering communication of optical processing techniques, fingerprint identification systems can be implemented in real time. Among the various pattern matching systems, the joint transform correlator (JTC) has been found to be inherently suitable for real time matching applications. Among the various JTCs, the fringeadjusted JTC has been found to yield significantly better correlation output compared to alternate JTCs. In this paper, we review the latest trends and advancements in fingerprint identification system based on the fringeadjusted JTC. Since all pattern matching systems suffer from high sensitivity to distortions, the synthetic discriminant function concept has been incorporated in fringe-adjusted JTC to ensure distortion-invariant fingerprint identification. On the other hand a novel polarization-enhanced fingerprint verification system is described where a polarized coherent light beam is used to record spatially dependent response of the scattering medium of the fingerprint to provide detailed surface information, which is not accessible to mere intensity measurement. It is shown that polarization-enhanced database improves the accuracy of the fingerprint identification or verification system significantly. Keywords: Fringe-adjust joint transform correlation, finger print identification, polarization, synthetic discriminant function