Phase-Shifting Temporal Phase Unwrapping Algorithm for High-Speed Fringe Projection Profilometry

Fringe projection profilometry based on temporal phase unwrapping (TPU) without error propagation has been widely used to measure the three-dimensional (3-D) shape of the complex scene. This paper develops a phase-shifting temporal unwrapping (PS-TPU) algorithm to ensure the measuring robustness and speed at the same time. In this method, a series of phase shifts are set as the cue of fringe order, and then embedded into the different periods of the single quasi-cosine pattern. High-quality wrapped phase and coded phase obtained from three conventional phase-shifting patterns and the single coded pattern can be utilized to generate fringe order pixel-by-pixel using the parallel and symmetrical relationship. Compared with the classical TPU algorithms, the number of projecting extra patterns is minimized to 1, while guaranteeing high noise immunity and less computational complexity. The static and dynamic experiments verify that the proposed PS-TPU is powerful for reconstructing 3-D shapes in our daily life.