1. An image matching apparatus which performs matching as to whether or not a first image and a second image match, comprising: a partial image segmentation unit segmenting a partial image of a predetermined size from the first image; a searching unit moving the partial image on the second image, and searching for a position of the partial image where the partial image and the second image having a portion overlapping the partial image indicate a largest overlap; an adjustment unit adjusting a relative position between the second image and the first image based on the position searched for by the searching unit; and a determination unit determining based on an adjustment result of the adjustment unit as to whether or not the first image matches the second image.