• Prakash S. Bodkhe
• Dr. Prafulla E. Ajmire

Recognition of Devanagari CAPTCHA script characters is yet a challenging problem. Many lingual character recognition systems have been developed since last few years. There are several techniques that are proposed to deal with problem of character recognition. This paper presents an efficient Devanagari character recognition scheme that implements effective feature extraction methods and use classifiers like SVM (Support Vector Machine) and PNN (Probabilistic Neural Network) for recognizing printed Devanagari characters. To prepare a database, 5 samples of each Devanagari character from 5 different Kruti Dev fonts have been considered. There are 34 consonants and 13 vowels in Devanagari script. These characters are classified based on their structural properties. The presence or absence of vertical bar plays vital role in the structure of Devanagari characters. The vertical bar is used in the middle of some characters. It is also used as a terminator of many characters. There are 2 consonants that have middle-bar, 9 consonants and 3 vowels that have no-bar. There are 9 consonants out of 34 and 3 vowels out of 13, which have no end-bar. Such specific characters and 10 numeric characters are chosen for experiments. The experiments are performed on a dataset having 14 alphabetic characters (which have middle-bar & no-bar) and 10 numeric characters together, using SVM and PNN classifiers respectively. So, in all 24 characters are used to prepare a dataset of 6000 (24 x 250) character images. The proposed scheme has given average character recognition rates of 96.47% using SVM and 97.54%using PNN which are comparatively higher than other techniques.

Keywords: SVM, PNN, Kruti Dev, Middle-bar characters, No-bar characters, End-bar characters, Dataset.

"Recognition of Devanagari CAPTCHA Script that comprises characters with Middle-bar, No-bar and Digits using SVM and PNN", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 1, page no.42-51, January-2019, Available :http://www.jetir.org/papers/JETIR1901E07.pdf

"Recognition of Devanagari CAPTCHA Script that comprises characters with Middle-bar, No-bar and Digits using SVM and PNN", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 1, page no. pp42-51, January-2019, Available at : http://www.jetir.org/papers/JETIR1901E07.pdf