Flexible and fast calibration method for uni-directional multi-line structured light system

Multi-line Shift Profilometry (MLSP) is widely used to measure the high-reflectivity object by projecting high-contrast binary stripe image. However, in the calibration of a MLSP system, the lens distortion of the projector makes the most existing calibration methods fail in obtaining high accurate result. Therefore, to avoid the influence of lens distortion, we propose a novel flexible and fast calibration method for MLSP, which requiring only uni-directional patterns. In this method, for each bending light plane, lens distortion is avoided by establishing a polynomial model between three-dimensional (3D) coordinates and camera sub-pixel coordinates. Because the position of calibration planar targets is placed freely without any constraint, this method is flexible and convenient to operate. Experimental results demonstrate that the proposed method achieves high-precision 3D reconstruction.