Algorithm of weld seam feature detection for remote welding

An algorithm of weld seam feature detection was presented, which was applied to stereo matching of stereo vision system for remote welding. Firstly, the bottom-hat transformation in grey-scale morphology was used to preprocess the image, making the weld seam section more distinctive, and Canny edge detection and close operation were employed to obtain a pixel level closed edge of weld seam; secondly, the edge data was filtered according to continuity and limited width of the weld seam edge; finally, the sub-pixel weld seam edge data was gained by fitting a cubic smoothing spline to the filtered edge data. With the detected sub-pixel weld seam, stereo matching and 3D reconstruction experiments were performed. The results show that the algorithm is rapid, exact and robust to noises.