Light Transport Matrix recovery for nearly planar objects

The light transport matrix has become a powerful tool for scene relighting, owing to the versatility of its representational power of various light transport phenomenon. We argue that scenes with an almost planar surface geometry, even with significant amounts of surface roughness, have a banded structure in the light transport matrix. In this paper, we propose a method that exploits this structure of the light transport matrix and provide significant savings in terms of both acquisition time and computation time, while retaining a high accuracy. We validate the proposed algorithm, by recovering the light transport of real objects that exhibit multiple scattering and with rendered scenes exhibiting inter-reflections.