High precision 3D measurement using area modulated phase-shifting binary patterns

This paper presents a novel area-modulated phase-shifting binary method for three-dimensional (3D) shape measurement. First, the defocused triangular binary pattern is introduced to obtain the high-quality sinusoidal fringe without gamma correction. Then, the modified three steps phase-shifting algorithm which includes an average intensity image is adopted to get the wrapped phase and the object mask. After that, a multi-frequency method is used to obtain the unwrapped phase. Finally, a two-step matching method is applied to get the corresponding matching points. The experiments show that the proposed method is more precise and efficient compared with the previous methods.