The Library of Congress has been conducting the Braille digitization to preserve its tactile braille music collection electronically. In this project we scan braille papers with a 3D laser sensor to obtain the coordinates of the recto/front and verso/back dots, which are fed into our digitization program for dots pattern recognition. Our software groups the dots in different lines and further into different characters. Specifically, each dot in a character is identified according to the relative positions to its local neighbors in the same character, based on which the character is recognized and the corresponding ASCII glyph code is written into the final output file. Experiments on different collections show the robustness of our system.