A Three-Dimensional Reconstruction Method Based on Telecentric Epipolar Constraints

When calibrating a microscopic fringe projection profile system with a telecentric camera, the orthogonality of the camera causes an ambiguity in the positive and negative signs of its external parameters. A common solution is to introduce additional constraints, which often increase the level of complexity and the calibration cost. Another solution is to abandon the internal/external parameter models derived from the physical imaging process and obtain a numerically optimal projection matrix through the least squares solution. This paper proposes a novel calibration method, which derives a telecentric epipolar constraint model from the conventional epipolar constraint relationship and uses this constraint relationship to complete the stereo calibration of the system. On the one hand, since only the camera's intrinsic parameters are needed, there is no need to introduce additional constraints. On the other hand, the solution is optimized based on the full consideration of the imaging model to make the parameters confirm to the physical model. Our experiments proved the feasibility and accuracy of the method.