1. An image recognition method comprising the steps of: (I) taking a first image including a character composed of plural elements; (II) extracting said plural elements in said first image to obtain a second image, in which each of said plural elements is enclosed by a rectangular frame; (III) forming a composite image with respect to a combination of said rectangular frames in said second image; (IV) calculating a characteristic amount of said elements included in said composite image; (V) inputting said characteristic amount in a back-propagation network, in which learning about a reference character(s) to be included in said first image has already finished, to provide a degree of agreement between the characteristic amount of said composite image and the reference character; and (VI) determining said composite image having a highest degree of agreement between the characteristic amount of said composite image and the reference character from results obtained by repeating the steps (III) to (V) with respect to different combinations of said rectangular frames in said second image, to output it as a recognition data.