High-contrast 3D surface measurement without changing camera exposures

This paper proposes a method that does not require to change exposure time of the camera for high-quality surface measurement when the surface contrast is large. The idea is that three phase-shifted inverted fringe patterns are used to complement regular three phase-shifted fringe patterns for phase retrieval. For saturated pixels, the inverted fringe patterns will be used in lieu of the original patterns for phase computation. Though not as robust as some of previously proposed time-consuming methods, experimental data showed that the proposed method can substantially increase measurement quality for high-contrast surfaces.