抄録
In personal authentication systems (PAS) using fingerprints, there is a decline in authentication accuracy because of the dirt on the contact surface with the present input equipment. We have already examined the possibility of noncontact fingerprint authentication to address these problems. In this paper, we propose an improvement for the extraction of a fingerprint and a compensation method for a rotation error for the noncontact fingerprint authentication. In the preprocessing, the compensation of a rotation error from two dimensions to three dimensions. In the proposed rotation compensation technique, the front view and side view of a fingertip are used. Moreover, we examined the cause of decreasing the quality of the principal line in our technique. The extraction error is caused by the change in a red component of the skin caused in blood circulation. Then we propose the technique for correcting an input image by using the approximation image obtained by the wavelet transform. As a result of the experiment, the quality of the output image has improved greatly that the extraction errors of the principal lines are decreased.
