Material and shape perception based on two types of intensity gradient information
Fig 6
(a) Probability density distributions in the HDR environment map. The correlation in the direction of the intensity gradient is reduced for some material combinations. (b) The correlation of the image in the HDR environment map was calculated after applying the compressive tone-mapping of Eq (1) to the surface image. As a consequence, the correlation in the direction of the intensity gradient is markedly improved.