Unlocking the Mechanism of Devanagari Letter Identification Using Eye Tracking

Abstract

The present day computers can outperform the human in many complicated tasks very precisely and efficiently. However, in many scenarios like pattern recognition and more importantly, character recognition; a school going child can outperform the sophisticated machines available today. The modern machines present today find handwritten, calligraphic text difficult to recognize because such texts hardly contain rationalized straight lines or perfect loops or circles. Therefore, most of the optical character recognition systems fail to recognize the characters beyond certain levels of distortions and noise. On the other hand, the human brain has achieved a remarkable ability to recognize visual patterns or characters in various distortion conditions with high speed. The present work tries to understand how human perceive, process and recognize the Devanagari characters under various distortion levels. In order to achieve this objective, eye tracking experiment was performed on 20 graduate participants by presenting stimuli in decreasing level of distortions (from highly distorted to more normal one). The eye fixation patterns along with the time course of recognition gave us the moment-to-moment processing involved in letter identification. Upon understanding the level of distortion acceptable for correct letter recognition and the processes involved in the identification of the letters, the OCR can be made more robust and the gap between human reading and machine reading can be narrowed down.