Abstract: A three-step extraction method for the image feature of a light stripe in the structuredlight vision is proposed. The sub-pixel center of the light stripe can be obtained with Taylor series expansion in the normal direction which is determined by HESSIAN matrix. The curve can be linked with the sub-pixel center points of the light stripe subject to the continuity constraint in pixel position. The curve can be split into simple lines with line approximate method. The collinear center points on the different simple lines will be combined to one merged line. And then the equation of the line-stripe can be obtained by the least square line-fitting with the merged center points belong to the same merged line subject to the length constraint and angle constraint. The experiments conducted on some real structured-light vision images with complicated background reveal that the proposed three-step extraction method for line-stripe is characterized by high precision, automation and robustness. It advances the structured light vision to be applied widely on site.

Key words: Light stripe, Line extraction, Structured light vision, Sub-pixel