Fingerprint enhancement based on non-separable wavelet

Fingerprint enhancement is necessary for low quality images. In this paper, we develop a new method for fingerprint enhancement based on non-separable filter banks. We first decompose the fingerprint image using the non-separable filter banks, which can decompose the fingerprint image efficiently and obtain wavelet coefficients, then modifies the coefficients by applying the adaptive approach to reduce the noises and increase the contrast between ridges and valleys according to the geometry feature of images. Then we apply the inverse wavelet transform to map the result and use a two-dimensional median filter to reduce noise and preserve edges. Experiments have been conducted on the fingerprint database FVC2002 in our study. The results demonstrate that the proposed method works well in fingerprint enhancement without under-enhancement and over-enhancement, and it is more effective and robust than other existing methods.