Rough classification of handwritten characters by divide‐and‐unify method

A new method is proposed in which all the characteristic vectors are classified into subvectors. Then a rough classification of handwritten characters is performed by unifying classification information obtained in each subvector all over again. In rough classification, “soundness” of classification and “quickness” of processing are required. To perform rough classification effectively, it is necessary to store considerable classification information in a dictionary. On the other hand, to implement processing quickly, it is necessary to decrease the amount of computation by condensing the classification information. The method herein not only realizes efficient rough classification through decreased redundancy by condensing classification information independently for each subvector of the characteristic vector, but also realizes a sounder rough classification by unifying classification information obtained in each subvector all over again. In the classification experiments, the amount of processing could be reduced to one‐fourth or one‐fifth that in the previous method to examine all the character classes without reducing a successful classification rate; this demonstrates the effectiveness of the method.