Handwritten Bangla Compound character recognition: Potential challenges and probable solution

A novel technique is presented here for recognition of handwritten compound characters of Bangla alphabet. It advocates for incrementally expanding the number of learned character classes from more frequently occurred to less frequently occurred ones. The work is preceded by a survey for finding the frequencies of occurrences of all Bangla characters in the standard literature. One important finding of the survey is that only 4.27 percent of characters in a standard text piece are on average compound characters. Out of the 160 compound character classes, characters of 55 classes constitute 90 percent of the compound characters occurring on average in a standard text piece. For the time being, handwritten characters from these classes are considered here. The average recognition rate, as observed under this work, is 84.67 percent after 3 fold cross validation of results. It is more or less comparable with the performance reported in another related work[3]. The work presented here can be considered as an important step for the development of OCR for handwritten Bangla characters, including complex shaped compound characters.