Polarimetric target depth sensing in ambient illumination based on polarization-coded structured light

Appl Opt. 2017 Sep 20;56(27):7741-7748. doi: 10.1364/AO.56.007741.

Abstract

Depth sensing is a basic issue in three-dimensional computer vision, and structured light is one of the most prevailing methods for it. However, complex surroundings and strong ambient illumination are fairly unfavorable to depth sensing based on structured light. Complex surroundings increase computation overhead and require extra effort to be separated from the target object. Strong ambient illumination is unfavorable to the signal-noise ratio of structured light and, thus, increases the difficulty of decoding. In this paper, we propose that the polarization-coded structured light is capable of target enhanced depth sensing in ambient illumination. We present the polarimetric principle, an improved algorithm of polarization-coded structured light, and signal-noise-ratio analysis in ambient illumination. Experimental results show that polarization-coded structured light is efficient and robust for target depth sensing of a complicated environment. The polarization-coded structured light is promising to the target depth sensing in an outdoor scenario and industrial inspection.