A single-shot structured light means by encoding both color and geometrical features

Color encoded structured light is an important means for single-shot 3D reconstruction. In this article, we present a pseudorandom array-based structured light method. The proposed pattern is composed with four colors, and one geometric shape is inlaid to the color elements to extend the coding element from four to eight. As a result, a relatively small coding window with the size of 2×2 can be obtained. Grid-point between each two adjacent pattern elements is defined as the pattern feature. And an improved feature detector is proposed for the robust and accurate grid-point localization. The grid-points are divided into two types and represented by a topological structure. The decoding procedure is performed in two steps, the shape decoding and color decoding. Finally, the epipolar constraint and neighboring constraint are introduced to improve the decoding reliability. Accuracy and robustness of the proposed method are evaluated in the experiments. Some real objects including human face are reconstructed to demonstrate the 3D reconstruction quality of the proposed structured light method. Compared with conventional color SL pattern, a novel 'color+geometrical' pattern was proposed.The pattern consists of four colors and one embedded geometrical feature.With a coding capacity of 65×63, a relative small unique window size of 2×2 was obtained.The decoding procedure was implemented as color decoding and geometrical decoding.A robust and accurate pattern feature detection algorithm was also presented.