Recovering three-dimensional shape through a small hole using three laser scatterings

An approach was proposed and developed to recover the 3D shape concealed in a shelter with a small hole only using three laser scatterings. This approach extends reconstruction of concealed 3D shape from "around a corner" to "through a small hole". Based on principle of rectilinear propagation of light, a simple geometric mapping tentative theoretical frame independent of scene was proposed to extract 3D information of concealed objects. Experimental setup mainly consists of a nanosecond laser and a single-photon APD, both of which are commercially available. The 3D reconstructions of three hidden objects were acquired with a resolution of centimeters.