Optical 3-D surface reconstruction with color binary speckle pattern encoding

This paper proposes a novel 3-D surface profile measurement scheme by only a single-shot color binary speckle pattern (CBSP) and a temporal-spatial correlation matching algorithm, which can be applied to measurements of dynamic and static objects. R/G/B channels of CBSP are coupled with three carefully designed black and white binary speckle patterns (BWBSPs), whose physical features are associated with the system configuration parameters. We mathematically deduce the concrete details of how to design such a pattern and its relationship with the system parameters selected in the experiment. During 3-D reconstruction, we develop an extended temporal-spatial correlation framework to determine the correspondence between two stereo images sequences that are composed of R/G/B images separated from a captured color stereo image pair. Comparative experiments and analysis are implemented to assess the measurement accuracy using standard workpieces (dumbbell and optical flat). The results indicate that the proposed approach enjoys better performance than the conventional BWBSP-based method in terms of spatial resolution, accuracy, and efficient reconstructed points. An experiment of applying CBSP to measuring a moving A4 paper is also presented, demonstrating the success of our computational framework. Finally discussions concerning the limitations of this method are implemented. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement