Patent ID: 6961453

Claim:
A method for extracting fingerprint feature data using a ridge orientation model, comprising: dividing a digital fingerprint image of a predetermined format into a plurality of regions, each region with a predetermined size; calculating ridge orientations in the regions; calculating qualities of ridges according to regions; separating the fingerprint image into a fingerprint region and a background region according to the calculated ridge qualities; extracting at least one position of at least one core or delta in the fingerprint region; determining a candidate position of a core or a delta outside the fingerprint region and a candidate position of each of the at least one core or delta in the fingerprint region from the extracted at least one position of the at least core or delta in the fingerprint region; setting the determined candidate positions both in and outside the fingerprint region as initial parameters of a ridge orientation model; setting a quality threshold for fingerprint regions; calculating parameters of a ridge orientation function by minimizing errors between ridge orientation values of the ridge orientation model and ridge orientation values of fingerprint regions with quality higher than the quality threshold; calculating ridge orientation values in all regions based on the ridge orientation function; and deciding at least one final position of the at least one core or delta in the fingerprint region from one or more of the parameters of the ridge orientation function.