High-speed 3-D shape measurement using composite structured-light patterns and multi-view system

In this paper, we propose a high-speed 3-D shape measurement technique based on composite structured-light patterns and a multi-view system. Benefiting from the multi-view system, stereo phase unwrapping, as a novel method for the phase unwrapping algorithm, can eliminate the phase ambiguities and obtain absolute phase map without projecting any additional patterns. However, in order to ensure the stability of phase unwrapping, the period of fringe is generally around 20, which leads to the limited accuracy of 3D measurement. To solve the precision-limited problem reasonably, we mathematically developed an optimized design method of the composite pattern. By skillfully embedding speckles without compromising the phase measurement accuracy, we can realize phase unwrapping with high-frequency fringes. In addition, a computational framework will be provided to further achieve the robust and high-performance 3D acquisition. It is demonstrated by several experiments that our method can achieve a high-speed, dense, and accurate 3-D shape measurement with 64-period fringe patterns at 5000 frames per second.