Abstract: Fingerprint enhancement has important functions in fingerprint identification, such as reducing noise and emphasizing key features. As a result, ridge distance estimation is a key step in AFIX (automated fingerprint identification system). However, it is still a difficult task to accurately and reliably estimate the ridge distance. Two methods for estimating the ridge distance, namely, the method based on multipeak detection and the method based on energy weight, were put forth. In addition, the performance of these two methods is verified by applying ridge distance estimation results to fingerprint enhancement and minutiae extraction. Experimental results indicate that these two methods have a good impact on ridge distance estimation.

Key words: spectrum analysis , ridge distance estimation, fingerprint enhancement, fingerprint identification, fingerprint