Abstract: When processing the structured light stripes with obstructions and shadows,the conventional decoding algorithms can lead to erroneous decoding and cause problems that stripes with different coded values overlapped.In this paper an improved Canny edge-detection method to extract the boundaries between the black and white stripes is proposed,and a precise coding and decoding algorithm for structured light based on the boundaries information is presented.Considering the features of the stripes,the Canny edge-detection algorithm is improved to extract the stripes boundaries precisely.The proposed coding and decoding methods for structured light include following steps.Firstly,build codec binary tree to describe the structured light image sequence stripes boundary.Then design boundary location and decoding algorithm to solve the unknown boundary code value.Thirdly,design boundary matching algorithm to eliminate different code value stripes overlapped.Finally,decode the disconnected boundaries caused by obstructions and shadows.The experiments show that the good results can be obtained by the algorithm.It has higher decoding accuracy,fewer errors,and better robustness when processing the stripes of complex shape.