Fast phase unwrapping algorithm for 3D measurement

Reducing the number of fringe patterns for fringe projection profilometry (FPP) has been a hot topic in the field. The traditional temporal phase unwrapping algorithm generally requires additional fringe information to determine the fringe order, which leads to the excessive number of fringe patterns.A fast phase unwrapping algorithm for three-dimensional (3D) measurement is proposed. Only N-step standard phase-shifting sinusoidal fringe patterns are needed to calculate the absolute phase. Firstly, the standard phase-shifting algorithm is used to calculate the wrapped phase and the mask to eliminate the background. Then, the wrapped phase and mask are used to solve the fringe level according to the connected component labeling theorem, and then the absolute phase is obtained. The proposed method needs a minimum of three fringe patterns to complete the 3D measurement, and the data processing speed is fast. Computer simulation and experimental results verify the effectiveness and robustness of the proposed method.