Phase Unwrapping-Free Fringe Projection Profilometry for 3D Shape Measurement

Phase unwrapping is always the necessary procedure in fringe projection profilometry (FPP). This letter presents an efficient phase unwrapping-free FPP method. Both the wrapped phase maps of the measured object and the reference plane are extracted by phase-shifting algorithm. If the depth range of the measured object is within
$2\pi $
in phase domain, the three-dimensional (3D) shape can be directly reconstructed by converting the wrapped phase difference into absolute phase difference without phase unwrapping process. Simulations and experiments are carried out, and their results demonstrate the effectiveness and robustness of the proposed method.