Design and decoding of an M-array pattern for low-cost structured light 3D reconstruction systems

3D shape reconstruction is one of the most important topics in computer vision due to its wide field of application. Among various technologies, structured light is considered to be one of the most reliable techniques. This paper addresses the problem of finding correspondences in a structured-light 3D shape reconstruction system. The work is based on the 3-symbol binary M-array encoded pattern proposed by Albitar. A new 6-symbol M-array pattern is designed with guaranteed minimum Hamming distance of three among all 3 × 3 windows. Improvements to the decoding algorithm are made, which allows successful identification of most symbols, and which corrects one possible error or missing symbol in each 3 × 3 window. Finally, refinements are made to the algorithm for finding correspondences, including back-projection of the captured structured light pattern to the projector plane to eliminate projective distortion.