Abstract:Image enhancement is an important procedure in an automatic fingerprint recognition system. An item called gray-level phase is defined, and a gray-level phase based image enhancement approach is proposed. In this approach, gray-level phase of each pixel is obtained firstly; then a filter is designed for gray-level phase; finally, the enhanced image is obtained according to the filtered gray-level phase. The experimental results show that the proposed approach is promising for low quality fingerprint image.