High-speed three-dimensional shape measurement for dynamic scenes using bi-frequency tripolar pulse-width-modulation fringe projection

► We introduce a high-speed three-dimensional shape measurement technique for dynamic scenes. ► Two wrapped phase maps can be obtained simultaneously by bi-frequency phase-shifting algorithm. ► Two phase maps are unwrapped using a simple look-up-table based number-theoretical approach. ► Tripolar pulse-width-modulation technique is employed to generate ideal fringe patterns. ► Our method can achieve a speed of 1250 frames per second for fast, and accurate 3-D measurements.