Patent ID: 7254269

Claim:
A character recognition system comprising: a computer that performs character recognition by comparing distances between a feature vector extracted from an input pattern and reference vectors of previously stored target characters, wherein all characters are classified into plurality of classes based on occurrence frequencies of the target characters, a dictionary storage device for storing the reference vectors for each of the classes, wherein the computer is programmed to calculate distances between the feature vector and the reference vectors of a plurality of characters belonging to a class having a highest character occurrence frequency among the plurality of classes, and to select, when there is a distance smaller than a class threshold determined for the class, a character of a reference vector corresponding to the distance as a character candidate, and a list indicating order of average distance of features of a number of reference vectors, wherein the computer is programmed such that after features of the feature vector extracted from the input pattern are sorted in accordance with the list in descending order of average distance, first, with respect to features up to an n-th feature and with respect to one of the reference vectors, a distance as to the corresponding features is calculated, (1) the distance is compared with a character candidate selection threshold, (2) if the distance is not larger than the threshold, a distance including next n features is calculated, procedures of (1) and (2) are repeated, and when the distance exceeds the character candidate selection threshold, a comparison with a next reference vector is started.