High-dynamic-range 3D shape measurement based on time domain superposition

Fringe projection is a widely used approach for 3D shape measurements. However, it is ineffective for scenarios with a wide range of reflectivity. In this paper, we propose a technique that can measure high-dynamic-range surfaces without changing camera exposure or projected light intensity. With the strategy of time domain superposition, we can use noisy fringe images to recover phase and geometric shapes accurately for low-reflection and high-reflection regions. The measurement accuracy of low-reflection regions obtained by the proposed method is about three times higher than that of the traditional phase-shifting method. Both simulations and experiments are performed to verify the proposed method.