Structured Light System Based On Waveband Separation

Three-dimensional shape measurement of space objects has been an important topic on engineering, it has significant impact on reverse engineering, product quality testing, identification and 3D modeling areas.Due to its stability, high accuracy, large-scale, etc., structured light projection is widely used in the area of three-dimensional measurement. With three separated color channels, Color structured light system can expand the capacity of data which is obtained in one shot. In this paper, the key technologies about color structured light system are discussed.Firstly, stripe encoding strategy of color structured light was discussed. Continuous encoded sinusoidal structured light pattern was combined with three color channels of the system. A color contours of a object can be obtained in only two shot which contain a color pattern and a uniform lighting pattern.Secondly, crosstalk elimination method was studied, a detailed analysis of the crosstalk was made. The waveband separation principle of projector and the single-chip color video camera was discussed. By measuring a crosstalk matrix in advance, the crosstalk can be eliminated by software method. To improve the efficiency and reduce the noise in each color channels, a novel structure of waveband separation system was designed. By the use of color separation prism and a specially designed filter, the crosstalk can be eliminated.At the end, calibration method of the structured light system was discussed, a two-step calibration method was used, which calibrated the depth and position separately. Nonlinear effect of projector was compensated. And color reconstruction was achieved by the use of OpenGL...