Optimization Design of Projection Grating Wavelength for Robust 3D Imaging

For three-dimensional (3D) imaging based on fringe projection profilometry (FPP), maximum fringe frequency selection and fringe frequencies allocation have a significant impact on the accuracy and robustness of 3D imaging. In this paper, we conduct a detailed analysis of the wrapped phase error, and analyze the phase unwrapping reliability in the three-frequency temporal phase unwrapping (TPU). Since different measurement systems and scenes having different maximum sampling frequencies, we introduce a maximum frequency selection approach in this work. In order to ensure the overall phase unwrapping reliability, we introduce an optimal frequencies allocation approach. Experimental results show the valid of the proposed approach. The research in this paper will help to improve the accuracy and robustness of FPP in practical 3D measurement.