Optical recognition of Braille writing

The authors describe the way they solved the optical recognition of Braille characters (OBR). Braille is a relief writing for the blind and partially sighted. Its characters consist of punched dots that are placed in a fixed matrix. Double sided (recto-verso) Braille is obtained by punching dots at both sides, using interleaved matrices. As a consequence, an optical reading system will see both sides of the printed material simultaneously. Reading this relief writing with machine vision needs special conditions of illumination. It is shown that this writing can be read using standard equipment and that the recognition can be solved with image processing techniques