Wide-angle laser structured light system calibration with a planar object

In this paper, we proposed a calibration method for a structured light system composed of a wide-angle line laser and a camera using a planar object. Instead of directly calibrating the camera with a planar object, we separated the radial distortion estimation from the camera calibration step to improve accuracy. Firstly, we corrected the lens radial distortion and then computed the camera´s intrinsic and extrinsic parameters. For line laser calibration, the line laser´s position was extracted from the distorted image. The laser´s sub-pixel position was then calculated using the proposed normalized weighted average method, and forward-mapped to the rectified image. The corresponding 3D point of the extracted laser was estimated by computing the intersecting point of the camera ray and the calibration plane. The experimental results show the superiority of the proposed method.