Binocular ray mapping reconstruction method for cross-media via fringe projection.

We introduce a ray mapping method for a binocular fringe projection system to fulfill a high-accurate measurement in the unknown refractive cross-media scenarios. This method builds the pixel-level ray mapping implicitly rather than launch the binocular calibration in pure air pinhole model and rectification for cross-media elaborately. We demonstrate how to use the orthogonal fringe patterns to fulfill the pixel-height mapping with the degraded epipolar constraint and parasitic reflections of multi-interface. Experimental results demonstrate that the proposed method enables high-precision 3D reconstruction in two typical cross-media scenarios, i.e., a glass box with and without water, with standard plane measurement errors consistently below 0.03 mm in all cases.