Improving Optical Braille Recognition in Pre-processing Stage

Abstract

Braille documents are captured and processed and converted into natural text using Optical Braille Recognition (OBR) system. Braille data or information which is embossed on Braille plate is most commonly captured by mobile camera or scanner into Braille image is the input to OBR. Preprocessing is the first stage performed by OBR system. The Noise introduced while Image captured using camera, mobile or scanners involve irregular lightness, low quality image due to less pixel camera, impulse noise, diverse gray-level values, angled or slanted image captured as a result of human error, deformation or warp of image document, deprived or disabled dots, appearance of unwanted dots, irregular gap between adjacent dots that represent a character. Various image enhancement techniques are applied in preprocessing stage to abolished or reduce such impulse noises. The main mission of the paper is to understand and apply a proportional learning of diverse preprocessing techniques on the Braille image and identify the best method to improve quality of Braille image.