High-efficiency de-scattering 3D measurement with a single exposure based on polarization angle shifting

The issue of scattering effect is common in imaging and optical 3D measurements, which introduces global illumination into the classical geometrical optics model. Separating the interested information from complex global-direct illumination often poses significant challenges. However, to suppress the global illumination, the conventional polarized modulated method generally requires manual adjustment to obtain multiple signals, which strictly limits the real-time detection and adaptability. To solve this problem, based on our analysis for the intensity distribution of four channels of the polarization camera from Malus's law, we establish a polarization angle shifting (PAS) model and further propose a separation strategy to efficiently achieve global-direct light transmission component pixel-by-pixel separation with a single exposure. And the proposed method eliminates the limitation of the linear polarization of the light source. With the proposed method, we could obtain contamination-free phase of scattering interface and global information imaging. Experimental results in a structured light measurement system confirm the effectiveness of the method for separation imaging, and the final de-scattering 3D phase results are also shown.