Patent ID: 8249359

Claim:
A detector for detecting a specified image in an input image, comprising: an area determination unit operable to determine, in the input image, a detection target area in which the specified image potentially exists; a setting unit operable to set positions of a plurality of matching target ranges in the detection target area, each of the matching target ranges being a predetermined size, so that the matching target ranges cover the detection target area, and each matching target range of the plurality of matching target ranges overlaps a neighboring matching target range by a predetermined overlap width; a matching unit operable to detect the specified image by matching a portion of the input image encompassed by each matching target range set by the setting unit and a template image for detecting the specified image; and a scaling ratio determination unit operable to determine a ratio for the portion of the input image encompassed by each matching target range of the plurality of matching target ranges, wherein the setting of the position of each matching target range of the plurality of matching target ranges by the setting unit is performed so that the predetermined overlap width corresponds to the ratio determined by the scaling ratio determination unit, and the matching of the portion of the input image encompassed by each matching target range of the plurality of matching target ranges and the template image is performed by the matching unit after a size of the portion of the input image encompassed by the matching target range of the plurality of matching target ranges has been changed according to the ratio determined by the scaling ratio determination unit.