Mutual Illumination Correction for Compositing and Material Editing

This work introduces a new approach to material editing and to mutual illumination correction in edited or composited scenes. Lambertian reflectance values from a static reference set are transfered across a dynamic sequence using non-parametric statistics. Both original and edited reflectance values are transfered from the reference set. Dividing out the original reflectance from the dynamic sequence gives an illumination-shading map. This illumination-shading map is corrected for the changes in mutual illumination caused by the material edit and composite before being combined with the edited reflectance values giving the material edited and mutual illumination corrected result. The correction is made by splitting the illumination-shading map into direct and mutual illumination components and replacing the mutual illumination component. Results show that given reflectance values for a surface mutual illumination can be detected and modified giving a greater degree of photorealism to composites and material edits.