To automatically acquire an optimum model image by extracting a section suitable as a model out of an arbitrarily shaped area.

A model candidate extracting means 201 designates the area desired to be registered as model image as a window on an image containing an object, scans the area corresponding to the inside of the window and extracts the coordinates of the area that a feature amount satisfies fixed conditions as an optimum model candidate. A model registering means 202 registers rotary models provided by successively rotating the image inside the extracted model coordinate each by a fixed angle. A pattern matching position acquiring means 203 scans this image, performs pattern matching between each image area and the rotary model image, calculates a normalized cross correlation value between the both and acquires the coordinate of the area in which the maximum cross correlation value is obtd. A model verification means 204 verifys, whether the model image at the position obtd. by pattern matching is a model image at the optimumly satisfied position for registration or not.