부산대학교 도서관

Fingerprint image enhancement is a key step in the Automated Fingerprint Identification System (AFIS). Because of different factors that affect the image, such as skin condition (very dry or moist, damaged or worn down skin, etc.), sensor noise, irregular print on the sensor, etc., the fingerprint image needs to be enhanced so that the structures of ridges and valleys are clearly visible. This paper presents fingerprint image enhancement with oriented linear anisotropic diffusion in the first stage and oriented local ridge compensation in the second stage. To control the process of oriented diffusion we have determined an orientation field from the previously established ridge orientation, which was additionally enhanced. Because the overall image contrast is decreased after the diffusion process, we have enhanced the contrast with block local normalization. In the second stage we have additionally enhanced ridge structure with oriented local ridge compensation. We have compared and combined our proposed algorithm with some of the state-of-the-art algorithms. The results of experiments, done on a public database FVC2004, show efficient fingerprint image enhancement. Index Terms--Image processing, image enhancement, fingerprint recognition, diffusion processes.
I. Introduction Fingerprint is a biometric physiological characteristic used for verification and identification of persons. Of all the biometric characteristics (iris, face, voice, hand), fingerprint has the highest degree of [...]