Fingerprint Image Enhancement by Diffusion Processes

Fingerprint enhancement is one of the most important steps in automatic fingerprint identification system. In this paper, based on nonlinear diffusion processes, we present an enhancement method which is able to adaptively enhance the ridge and valley structures in fingerprint images using the local ridge orientation information. Instead of using conventional gradient-based orientation estimation method, an anisotropic diffusion scheme is used to improve the estimation accuracy. Experimental results show a significant performance improvement of the fingerprint identification system by incorporating the proposed enhancement method.