Structured light codec and phase analysis based on Gray code and four-step phase shift

In the process of workpiece contour measurement, when the surface structure of the workpiece is too complex or the texture information is insufficient, it is often difficult to collect enough workpiece feature information, which increases the difficulty of subsequent feature matching. Therefore, this paper investigates a structured light coding technique, which can increase the texture data on the appearance of the workpiece and reduce the complexity of later matching. It centers on projecting specific patterns onto the surface of the workpiece to be measured, and these patterns carry unique information codes. Because these projections contain special data formats, they can be parsed and decoded with the help of a computer program. In this paper, a combination of Gray code and four-step phase shift is used for encoding. The absolute phase information thus generated can provide new matching primitives for stereo matching between images later. At the same time, in order to improve the decoding efficiency and accuracy, this paper proposes a number of processing methods including image denoising, background phase removal, periodic misalignment correction, etc. Finally, the simulation experiments are carried out through the MATLAB software to verify that the obtained image correction effect is good.