Patent ID: 8385612

Claim:
A fingerprint image background detection apparatus which discriminates background regions and impressing regions in an input fingerprint image, the fingerprint image background detection apparatus comprising: an impressing feature extraction unit that calculates an impressing feature quantity for every small region obtained by dividing the input fingerprint image, the impressing feature quantity being calculated based on spatial variation quantities of pixel values in each small region in a direction parallel to streak-like noise in the input fingerprint image, the input fingerprint image having been generated by a fingerprint pattern on a finger when the finger is slid on a fingerprint sensor, and the streak-like noise having been caused by dragging matter adhered to the finger when the finger is slid on the fingerprint sensor; a tentative impressing region decision unit that judges whether each small region is an impressing region or not by comparing with a threshold the impressing feature quantity calculated by the impressing feature extraction unit, and the impressing region being a region where a part or all of a fingerprint patter is present; and an impressing region shaping unit that shapes the impressing regions judged by the tentative impressing region decision unit to obtain a convex shaped figure by modifying a part of the judgments made by the decision unit about whether each small region is an impressing region or not and obtains regions other than the impressing regions as background regions.