Reduction of Phase Error Caused by Overexposure in Phase Measurement Profilometry

Abstract

When using phase measurement profilometry (PMP) for three dimensional (3D) detection, the surface specular reflection of the object can easily cause the captured fringe pattern image to become overexposed and non-sinusoidal, which leads to a phase error. In this paper, based on the analysis of the phase error model in the overexposed region, a double four-step phase-shifting method is proposed to measure the phase in the overexposure regions of fringe pattern images. A simulation and an experiment show that the phase measurement accuracy of the overexposed region can be effectively improved using the proposed algorithm while maintaining the high-speed of the PMP.