Enhancement of fingerprint using FFT×|FFT|n filter

Abstract

Fingerprint enhancement is an indispensable task in the Automatic Fingerprint Identification System. In this paper, a simple method for the enhancement of fingerprint images is presented, which is based on FFT. The FFT is found out after the fingerprint image is partitioned into blocks. It is then multiplied with |FFT|n, where n is obtained by trial and error as 2.2. The best enhancement results were obtained for a block size of 4×4. In this approach, patching of pore holes in the ridges and joining discontinuous ridges were achieved. This method was compared with the different conventional enhancement techniques.