Recognition method for letter patterns

Claim 1

A letter pattern recognition method comprising the steps of: preprocessing character patterns; extracting characteristic data for the character patterns according to elements including a loop, a straight line and an arc which have branches and nodes; obtaining a center of gravity for each of the respective elements; normalizing the character patterns by using the extracted characteristic data; comparing the normalized character patterns with pre-registered classification codes by allotting relative positions of the loop, straight line and arc elements in accordance with information on the center of gravity thereof and determining if a return check is required depending upon the result of the comparison, and performing a return check and returning to the extracting step if a return check is required; performing balance and stroke checking for the normalized patterns in the absence of the requirement for the return check, wherein the balance checking is performed by using a relationship of weight on the relative position and wherein the stroke checking is performed by checking a direction of the straight line elements, a rotational direction of the arc elements and a link structure of the elements; and detail-classifying the normalized patterns in such a manner that an orientation of the arc elements, and a length ratio of the elements so as to thereby recognize the character patterns.