PRE-PROCESSING THE BRAILLE IMAGE FOR IMPROVING OPTICAL BRAILLE RECOGNITION PERFORMANCE

Abstract

Optical Braille Recognition (OBR), the automated software processes that are used in capturing and converting the Braille documents into text. The image data of embossed Braille plate captured using mobile camera or scanner is the input to OBR. Preprocessing is the first stage performed by OBR system. The Considerable troubles in Image captured using camera, mobile or scanners include low-quality image due to irregular lightness during scanning, relatively low resolution of camera, impulse noise in the image, diverse gray-level values, introduce an elevated spatial frequency, angled or slanted image captured as a result of human error, deformation or warp of image document that continue deprivation or disability of the dots, manifestation of uninvited dots, irregular gap in connecting dots and the cells representing character. These impulse noises are eliminated by applying various image enhancement techniques under preprocessing stage of OBR. The main mission of the paper is to study and provide a proportional learning of diverse preprocessing techniques that are applied to the Braille image by various researchers.