A device has means for computing and obtaining blood vessel extraction images by extracting blood vessel portions from two or more fundus images, means for computing and obtaining a corner data image (T n+1 ) having corner portions of the blood vessel portions detected from the obtained blood vessel extraction image, means for computing and obtaining a probability distribution diagram (Pn) for the corner data image by convolving the corner data image with a window function, means for computing a matching probability score when executing a matching processing between two or more fundus images on the basis of the probability distribution diagram corresponding to each fundus image obtained and the corner data image, and means for creating a retinal fundus map by superimposing two or more fundus images on the basis of the obtained matching probability score.