Multi-projector Calibration and Alignment Using Flatness Analysis for Irregular-Shape Surfaces

A multi-projector calibration and alignment method, which has no assumptions on projection surfaces' shape, is presented. Based on surface flatness analysis, the method will automatically partition the projection surface into pieces, more at none flat regions and less at flat ones, as flat region will cause less distortions. Corresponding to these pieces, an image will first be cut into some sub-images, and then projected onto the surfaces using texture warping method. The principle which ensures the inner projector distortion correction is proved, that is if a camera captures an undistorted projected image, human eye will also observe an undistorted one at that spot. Multi-projector alignment is achieved by projecting images which are rendered according to the camera's extrinsic parameters during the course of coded structured light capturing. Because the camera can capture a wide field of view area by moving and rotating itself, the alignment method has a build-in support for scalability in view filed. The whole work of calibration and alignment can be done in a single camera capture process. Results show that the proposed method is efficient and robust.