Background elimination technique in the structured light system for dynamic environment

The utilization of structured light system is increasing not only in industrial areas but also in dynamic environment including the motion recognition for Xbox 360 based on the motion sensor kinect and the obstruction recognition for mobile robot navigation. In this paper, we presented a method to estimate the background at t₂ (projector on) by using the background images at t₃ (projector off) and t₁ (projector off) in the dynamic environment where there exists a motion of structured light system or an object. Differentiation of the estimated background image from the image at t₂ where the signal and the background are mixed can not only increase the signal-to-noise ratio between the projected pattern and the noise but also eliminate the noise similar to the signal that is detected in the background range. The experimental result not only provided the three-dimensional data from which the actual noise range was removed but also suggested the correlation between the size of interpolation area and the estimated error.