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 3-D shape of the complex scene. This article 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 PS 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.