1. An image processor comprising: a reference point detection unit that extracts a first plurality of bright spots in a first fluorescent image of a predetermined surface of a sample which is obtained using a first microscope, extracts a second plurality of bright spots in a second fluorescent image of the predetermined surface of the sample, which is obtained using a second microscope, and extracts at least three corresponded bright spots as first and second groups of reference points from each of the first and second pluralities of bright spots, respectively, based on angles formed among the first plurality of bright spots in the first fluorescent image and angles formed among the second plurality of bright spots in the second fluorescent image; and a calculation unit that calculates transformation coefficients for matching the at least three corresponded bright spots of the first group of reference points in the first fluorescent image and the at least three corresponded bright spots of the second group of reference points in the second fluorescent image.