3D Acquisition of Occluded Surfaces from Scattering in Participating Media

Most vision-based 3D acquisition methods including both passive and active methods have a limitation in that cameras must be able to observe the surface to be measured. If this is not possible, that is to say, if the surface is occluded, most of the methods cannot acquire the surface shape. In this paper, we present a method that can acquire the 3D points on the occluded surfaces. The main idea is to observe the scattering of reflected light in a participating medium instead of observing only the reflected light. We place the target in a participating medium, specifically a liquid tank filled with a participating medium, and irradiate a laser beam on it. Even if the reflecting point is occluded, our method can acquire the 3D position of occluded reflecting points from the scattering. Experimental results showed that our method can measure 3D reflecting points on several objects even if the objects are completely occluded.