Bao Qingkang, Zhang Tianyu, Liu Faheng, Zhao Hong, Zhang Chunwei
Opt Express. 2022 Feb 28;30(5):7551-7565. doi: 10.1364/OE.453682.
Phase unwrapping is an essential procedure for fringe projection profilometry (FPP). To improve measurement efficiency and reduce phase unwrapping errors (PUEs) in dynamic measurement, a phase unwrapping algorithm based on phase edge tracking is proposed, which unwraps the current wrapped phase map with the aid of the previously unwrapped one. The phase edges are accurately tracked and their trajectories are used to divide the phase map into several regions, each of which is unwrapped either temporally or spatially according to its properties. It doesn't require extra patterns for phase unwrapping once the initial unwrapped phase map is obtained, thus significantly increasing the frame rate of the 3D result. Meanwhile, it greatly reduces the PUEs caused by noise amplification and motion-induced misalignment of phase edges. Experiments prove that it is capable of retrieving the absolute phase maps of complex dynamic scenes with high unwrapping accuracy and efficiency.
相位展开是条纹投影轮廓术（FPP）中的一个重要步骤。为了提高动态测量中的测量效率并减少相位展开误差（PUE），提出了一种基于相位边缘跟踪的相位展开算法，该算法借助先前展开的相位图来展开当前的包裹相位图。精确跟踪相位边缘，并利用其轨迹将相位图划分为几个区域，每个区域根据其特性在时间上或空间上进行展开。一旦获得初始展开的相位图，就不需要额外的图案进行相位展开，从而显著提高了三维结果的帧率。同时，它大大减少了由噪声放大和相位边缘的运动引起的未对准所导致的PUE。实验证明，它能够以高展开精度和效率检索复杂动态场景的绝对相位图。
