Snapshot polarizer modulated polarization imaging high dynamic range structured light 3D measurement

Abstract In structured light three-dimensional (3D) measurement, the high dynamic range (HDR) imaging for varying reflectivity objects with snapshot and with high accuracy is still a great challenge. This paper proposes a snapshot HDR structured light method based on polarizer modulated polarization imaging technology. In our snapshot HDR 3D reconstruction method, a linear polarizer is placed in front of the four channels polarization camera, which allows the polarization camera to capture four images with different brightness levels in a single exposure for both metal and non-metallic objects in our developed structured light system. The optimal rotation angle is investigated and determined to maximize the accuracy of the polarization structured light 3D measurement system for complex varying reflectivity objects. Experimental results demonstrate that our proposed method can perform snapshot HDR imaging for fringe projection structured light 3D measurement and outperform four-exposure HDR fusion method, which requires less acquisition time, making it more suitable for dynamic measurements.