The problem of symbolization is avoided, the structure is expressed in an analog way and matching with a reference can be performed flexibly and simply. Each stroke of a hand-written character string is grasped in a parameter expression. The each stroke is approximated to a broken line. The broken line drawn by broken-line approximation is treated as a vector from the starting point to the end point. The angles between a reference axis and the broken lines are determined as a broken line angle sequence. The exterior angle sequence of the vertices of the obtained broken lines is determined. The sum of the exterior angles of the continuous same sign + or - of the exterior angle sequence is defined as a winding angle sequence. ON the basis of the feature extraction by the determined sequences and nodes to be used as reference points are determined. A graph expression is given from the attributes of the positions of the nodes and the attributes of the sides between the nodes. Matching with a template having an open mask structure in which the starting point and the end point are not especially defined is so performed that character recognition is flexible and robust over the noise at the ends and deformation even if the character is one that holds normal up-down and left-right relations and even if rotation invariance is required.
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