Photometric Stereo in Participating Media Using an Analytical Solution for Shape-Dependent Forward Scatter.

Images captured in participating media such as murky water, fog, or smoke are degraded by scattered light. Thus, the use of traditional three-dimensional (3D) reconstruction techniques in such environments is difficult. In this paper, we propose a photometric stereo method for participating media. The proposed method differs from prvious studies with respect to modeling shape-dependent forward scatter. In the proposed model, forward scatter is described as an analytical form using lookup tables and is represented by spatially-variant kernels. We also propose an approximation of a large-scale dense matrix as a sparse matrix, which enables the removal of forward scatter. We discuss the approximation in the proposed method using synthesized data. Then, experiments with real data demonstrate that the proposed method improves 3D reconstruction in participating media.