Reconstruction of hidden 3D shapes using diffuse reflections
This work addresses the challenge of seeing around corners for applications in robotics and surveillance, representing a novel method rather than an incremental improvement.
The paper tackles the problem of reconstructing hidden 3D shapes by analyzing multi-bounce light reflections, demonstrating that reflected light contains enough information to recover hidden scene structures, and shows that using a 2D streak camera or 1D high-speed time-of-flight camera can achieve this reconstruction.
We analyze multi-bounce propagation of light in an unknown hidden volume and demonstrate that the reflected light contains sufficient information to recover the 3D structure of the hidden scene. We formulate the forward and inverse theory of secondary and tertiary scattering reflection using ideas from energy front propagation and tomography. We show that using careful choice of approximations, such as Fresnel approximation, greatly simplifies this problem and the inversion can be achieved via a backpropagation process. We provide a theoretical analysis of the invertibility, uniqueness and choices of space-time-angle dimensions using synthetic examples. We show that a 2D streak camera can be used to discover and reconstruct hidden geometry. Using a 1D high speed time of flight camera, we show that our method can be used recover 3D shapes of objects "around the corner".