Colored Structured Light Patterns with Binocular Cameras for Fast and Low-cost 3-D Reconstruction

Gray code is a commonly used coding strategy in structured light techniques. However, projecting the large number of patterns required by it slows down the reconstruction. In this paper, a colored Gray code was generated to reduce the number of projected patterns and cut down the projecting time, which appeared to be a major time-consuming part especially for low-cost projectors. Meanwhile, two cameras were used to improve the performance of color stripes matching. Therefore, the complex considerations about the spectral characteristics of devices and the calibration of projectors could be avoided, making the system easy to use. Inverse colored patterns were also projected to assist the decoding procedure. The effects of the combination of colored line-shifting methods and different threshold parameters were also studied. A 130mm*100mm statue was reconstructed into a dense point cloud with 214,4848 points using our approach. Evaluations showed that the system had an average deviation of 0.02mm, and its speed can be further elevated with GPUs.