PURPOSE: To improve the collation precision of the stripe pattern of a fingerprint, etc., by deciding on such a threshold value that the difference in the number of collation points between the identical stripe pattern and an approximate stripe pattern is maximum, and updating the threshold value on the basis of the collation result.
CONSTITUTION: A stripe pattern is inputted on an image input device 1, digitized by an A/D converter 2, and converted into a 1/0 picture by a binary coding device. A registering device 4 extracts feature points, which are registered in a registration file 5; and a collating device 6 performs collation. When the threshold value of the collation is determined, the combination of the initial value and gradient of such a threshold value that the difference in the number of picture element point when the registered stripe pattern is collated with an approximate stripe pattern is maximum is determined as the smallest threshold value. The threshold value of a point where the collation result is good is updated by updatig the threshold value by a determined value.
NISHIKAWA YOSHIHIRO
YAMAGATA NOBUTAKE
KONDOU AKIHIRO
