Structured Light 3D Measurement Based on Quaternary Gray Code

To improve the efficiency of fringe projection and measurement accuracy in optical 3D measurement systems, this chapter proposes an efficient structured light 3D measurement method based on a four-gray-level Gray code. By employing a combination of the Quaternary Gray code and a three-step phase-shifting technique, the number of projected patterns required for reconstruction is reduced to five, thereby shortening the image acquisition time. Using the principles of triangulation and dual-camera calibration, depth information and 3D data of the measured object are obtained. Experimental results demonstrate that the proposed method can reconstruct a 3D model using only five fringe patterns, substantially reducing the number of images required compared to traditional binary Gray code or multistep phase-shifting methods.