APPARATUS FOR CALCULATING ROTATIONAL ANGLE OF FINGERPRINT IMAGE, APPARATUS FOR ROTATING FINGERPRINT IMAGE, FINGERPRINT COLLATION APPARATUS, PROGRAM FOR CALCULATING ROTATIONAL ANGLE OF FINGERPRINT IMAGE, PROGRAM FOR ROTATING FINGERPRINT IMAGE, AND FINGERPRINT COLLATION PROGRAM

摘要

PPROBLEM TO BE SOLVED: To provide an apparatus for calculating the rotational angle of a fingerprint image to accurately calculate the angle of an inclination from the reference position of a fingerprint image even if the contour of a fingerprint area is imperfect. PSOLUTION: A painted-out image 200 is created out of an input fingerprint image 100. Boundaries 401, 402 between a fingerprint area 202 and a background area 201 in the painted-out image 200 are extracted (boundary image 400). Boundary approximate straight lines 411, 412, which are straight lines approximating portions of the boundaries 401, 402, are calculated (explanatory boundary image 410). A rotational angle is calculated on the basis of the boundary approximate straight lines 411, 412 (explanatory boundary image 420). The reliability of the two approximate straight lines is determined, and the rotational angle is calculated not on the basis of an unreliable approximate straight line but on the basis of a reliable approximate straight line. If neither of the straight lines is reliable, the rotational angle is calculated on the basis of an area approximate straight line 221, i.e., a straight line approximating the fingerprint area 202 in the painted-out image 200 (illustration 220). PCOPYRIGHT: (C)2008,JPO&INPIT