Range imaging with adaptive color structured light

In range sensing with time-multiplexed structured light, there is a trade-off between accuracy, robustness and the acquisition period. The acquisition period is lower bounded by the product of the number of projection patterns and the time needed for acquiring a single image. In this paper a novel structured light method is described. Adaptation of the number and form of the projection patterns to the characteristics of the scene takes place as part of the acquisition process. Noise margins are matched to the actual noise level, thus reducing the number of projection patterns to the necessary minimum. Color is used for light plane labeling. The dimension of the pattern space (and the noise margins) are thus increased without raising the number of projection patterns. It is shown that the color of an impinging light plane can be identified from the image of the illuminated scene, even with colorful scenes. Identification is local and does not rely on spatial color sequences. Therefore, in comparison to other color structured light techniques, assumptions about smoothness and color neutrality of the scene can be relaxed. The suggested approach has been implemented and the theoretical results are supported by experiments.