Phase error correction based on Inverse Function Shift Estimation in Phase Shifting Profilometry using a digital video projector

Fringe Pattern Profilometry (FPP) is 3D surface measuring technique based on triangulation. The utilization of digital projection in FPP system introduces significant phase distortion for Phase Shifting Profilometry (PSP), because of the nonlinear response of digital video projectors, which is referred as gamma distortion. Considering that the distorted phase has a stable function for a reference plane, this paper proposes an approach based on inverse function shift estimation (IFSE) to detect the spatial shift of the distorted phase caused by object height. This spatial shift is independent of projector’s gamma distortion and accurate surface can be reconstructed based it. The simulation results show that the proposed method can almost completely eliminate gamma distortion in reconstructed surface and we obtain more than 5 times improvement in practical experiments.