Enhancing structured light range imaging by adaptation of color, exposure and focus

This paper presents a series of enhancements to a color-coded structured light range sensor that increases the adaptability to complex and unconstrained scenes. First, the projected pattern is made more visible on colored objects by replacing the unique colored pattern with time-multiplexed pseudo-color channels. Second, an exposure fusion algorithm is used when acquiring images to allow the detection of regions with low and high reflectance characteristics. Finally, the focus planes of the scene are automatically detected and imaged separately, enlarging the sensor's depth of field. Each improvement is detailed and integrated into a custom acquisition procedure. Experimental results demonstrate the improved robustness of the structured light range sensor and validate the proposed design.