Dynamic Programming based elastic pattern matching method called Branched Reference Rubber String Matching was investigated. As in Rubber String Matching, the reference pattern is represented as a sequence of direction specified vectors and the input pattern as two dimensional dot pattern. In order to improve the coping of topological variations in input pattern, the reference patterns allow partial pattern alternatives and misses. Effect on the recognition time is almost negligible. Experimental results show the effectiveness of the proposed algorithm.

Dynamic programming based one dimensional-two dimensional adaptive pattern matching methods were investigated. In these methods, the reference pattern is represented as a sequence of directional vectors and the input pattern as two dimensional dot pattern. The input pattern needs no preskeletization or local feature analysis, and thus stroke order free top-down pattern matching is carried out. As the starting point, Rubber String Matching algorithm using fixed direction vectors was newly investigated. At latter stages, the reference pattern vectors were permitted some freedom in their directions to cope with abrupt aberrations in input pattern line segments, improving the flexibility of matching. Two cases were considered, allowing 45and approximately 20deviations from the vector directions. The 20version gave the best recognition score.