Jointly correcting lens distortion of structured light systems

In structured light illumination, lens distortions in both the camera and the projector compromise the accuracy of 3D reconstruction. Typically, existing methods separately compensate for camera and projector lens distortion. In this paper, we report a novel joint distortion model that analytically relates distorted 3D coordinate to its undistorted counterpart, thereby directly recovering distortion-free 3D coordinate from distorted one. First, we conduct a typical 3D scanning to have the distorted 3D coordinate. Second, we derive a set of linear equations of undistorted coordinate, whose coefficient matrix is represented by the distorted 3D coordinate and calibration parameters. Finally, we straightforwardly compute the corrected 3D coordinate using the least square method. Extensive experiments show that, compared with the distorted point cloud, our method effectively reduces the lens distortion of the system by a factor of 5 in root mean squared error, outperforming the existing methods in terms of accuracy.