Two Novel Directional Filter Banks with Diamond Structure for Fingerprint Enhancement

Fingerprint enhancement is important for improving the accuracy of the minutiae extraction, even for the total automated fingerprint identification system (AFIS). Directional filter bank (DFB) is frequently used to enhance fingerprint images. Based on the famous Fibonacci sequences, two novel DFBs with diamond structure are proposed. The especial structure can ensure the consistency of all the filter orientations' structure. The two DFBs not only solve the overflow problem of filter orientations, but also ensure that the coefficients on the rotated masks distribute more regularly. The performance of the two DFBs is evaluated with some typical low quality images of FVC database. Experimental results indicate that the proposed DFBs have dramatic effect on low quality fingerprint images. Compared with the DFB reported in the literature the proposed DFBs can reduce the noise, connect the broken fingerprint and enhance the ridges more efficiently. They can cause less pseudo minutiae in the course of enhancement.