4-D light field reconstruction by irradiance decomposition

Common light sources such as an ordinary flashlight with lenses and/or reflectors make complex 4-D light field that cannot be represented by conventional isotropic distribution model nor point light source model. This paper describes a new approach to estimate 4-D light field using an illuminated diffuser. Unlike conventional works that capture a 4-D light field directly, our method decomposes observed intensities on the diffuser into intensities of 4-D light rays based on inverse rendering technique with prior knowledge. We formulate 4-D light field reconstruction problem as a non-smooth convex optimization problem for mathematically finding the global minimum.