Practical Spectral Imaging for Realistic Appearance Modeling

This talk will provide an overview of some of the research we have been conducting in the Realistic Graphics and Imaging group at Imperial College London on spectral imaging for appearance modelling. The talk will span techniques focusing both on material and facial appearance capture and modelling. The talk will first present our work on practical imaging of surface diffraction to model the complex iridescence seen on manufactured materials such LCD screens and holographic samples, and cover both practical spectral and polarization imaging techniques for modeling homogeneous as well as spatially varying surface diffraction. The second part of the talk will then focus on high quality facial capture with a multi-spectral Light Stage apparatus. Here, the talk will first cover our work on efficient facial reflectance separation using binary spherical gradient illumination, as well as further color multiplexing of illumination for a two-shot capture of facial reflectance and photometric normals. The talk will conclude with our latest work on practical measurement and reconstruction of spectral skin reflectance for achieving photo-realistic rendering of a face driven by a bio-physically based spectral BSSRDF. Here, we will present optimal spectral measurements suitable for facial capture and estimation of detailed spatially varying skin chromophore concentrations for reconstructing spectral skin appearance.