A fast three-dimensional shape measurement method based on color phase coding

Gray code plus phase-shifting method embed the codeword into intensity to reconstruct complex three-dimensional shape. Owing to surface reflectivity and noise, it is less robust for measuring the surfaces of object with low contrast. In order to solve the problem, the codeword is embedded into phase to determine fringe order for obtaining the unwrapped phase. However, measurement speed is limited. Therefore, a fast three-dimensional shape measurement method based on color phase coding is proposed. As it adopts a color sinusoidal fringe to obtain wrapped phase and an additional color phase coding fringe to determine fringe order, the method can achieve fast complex three-dimensional shape measurement with different contrast. Color crosstalk and gamma nonlinearity are compensated to improve the measurement accuracy. The experiment results confirm the effectiveness and robustness of the proposed method.