Fingerprint ridges frequency

This work is a study about the fingerprint ridge distance and presents an efficient algorithm to estimate the values of local ridge frequency. Most of fingerprint image enhancement algorithms use an anisotropic filters with frequency response. Therefore, ridges frequency, as a global feature of fingerprint, is very important to image preprocessing methods used in automatic fingerprint identification system (AFIS). In proposed algorithm, through the use of fingerprint direction image, the frequency values are calculated directly, without the use of computationally expensive spectral analysis.