Derivation Expression

Abstract: PROBLEM TO BE SOLVED: To decide whether or not two pieces of image data are image data based on the same kind of business form even if the business form is changed by the additon contents. SOLUTION: A characteristic amount is obtained about each of a plurality of small areas included in the two pieces of the image data, and similarity D between the small areas between the two pieces of the image data is obtained based on the characteristic amount of each small area of one of the two pieces of the image data and the characteristic amount of each small area of the other. About a combination of the small areas of the similarity D>th1, by the use of a first derivation expression wherein higher similarity is derived as the similarity D is higher, the similarity S different from the similarity D is obtained. About a combination between the small areas of the similarity D≤th1, by the use of a second derivation expression wherein lower non-similarity is derived as the similarity D is higher and wherein the non-similarity not a reciprocal of the similarity S derived by the use of the first derivation expression is derived, the non-similarity N is obtained. Based on the similarity S and the non-similarity N, it is decided whether or not the two pieces of the image data are the image data based on the same kind of business form. COPYRIGHT: (C)2010,JPO&INPIT