A method of pitch-variation moiré fringes is proposed to realize the temporal phase unwrapping for three-dimensional profilometry. On the basis of the principle of moiré pattern,we achieve variable spatial frequencies of fringes in a moiré pattern by rotating two gratings. Furthermore a five-point fitting method is used to automatically compute the central position of side-lobe spectrum of the moiré fringes. Finally,a generalized temporal phase unwrapping algorithm is intro-duced to process the three-dimensional reconstruction. The theoretical analysis and experimental results show the validity of the proposed method.
This letter addresses several key issues in the process of model-based optical metrology, including three dimensional (3D) sensing, calibration, registration and fusion of range images, geometric representation, and visualization of reconstructed 3D model by taking into account the shape measurement of 3D complex structures,and some experimental results are presented.
LIU Xiao-liLI A-mengZHAO Xiao-boGAO Peng-dongTIAN Jin-dongPENG Xiang
