Optimizing Character Class Count for Devanagari Optical Character Recognition

Optical character recognition is a widely used technique for generating digital counterpart of printed or handwritten text. A lot of work has been done in the field of character recognition of Devanagari script. Devanagari script consists of several basic characters, half form of characters, vowel-modifiers and diacritics. From character recognition point of view only 78 character classes are sufficient for the identification of these characters. But in Devanagari the characters fuse with each other, which result in segmentation errors. Therefore to avoid such errors we shall consider such compound characters as separate recognizable unit. We have identified 864 such compound characters that make a total of 942 recognizable units. But it is very difficult to handle such a large number of classes; therefore we have optimized the character class count. We have found that the first 100 classes can contribute to 98.0898% of the overall recognition.