CHARACTER IMAGE FEATURE DICTIONARY PREPARATION APPARATUS, DOCUMENT IMAGE PROCESSING APPARATUS HAVING THE SAME, CHARACTER IMAGE FEATURE DICTIONARY PREPARATION PROGRAM, RECORDING MEDIUM ON WHICH CHARACTER IMAGE FEATURE DICTIONARY PREPARATION PROGRAM IS RECORDED, DOCUMENT IMAGE PROCESSING PROGRAM, AND RECORDING MEDIUM ON WHICH DOCUMENT IMAGE PROCESSING PROGRAM IS RECORDED

摘要

An image of a character string composed of M pieces of characters is clipped from a document image, and the image is divided character by character, and image features of each character image are extracted. On the basis of the image features, N (N>1, integer) pieces of character images in descending order of degree of similarity are selected as candidate characters from a character image feature dictionary which stores the image features of character image in units of character, and the first index matrix of MxN cells is prepared. A candidate character string composed of a plurality of candidate characters constituting the first column of the first index matrix, is subjected to a lexical analysis according to a predetermined language model, whereby a second index matrix adjusted into a character string which makes sense is prepared to he utilized for searching.