Simulating the effect of illumination using color transformations
We investigate design and estimation issues for using the standard color management profile architecture for general custom image enhancement. Color management profiles are a flexible architecture for describing a mapping from an original colorspace to a new colorspace. We investigate use of this same architecture for describing color enhancements that could be defined by a non-technical user using samples of the mapping, just as color management is based on samples of a mapping between an original colorspace and a new colorspace. As an example enhancement, we work with photos of the 24 color patch Macbeth chart under different illuminations, with the goal of defining transformations that would take, for example, a studio D65 image and reproduce it as though it had been taken during a particular sunset. The color management profile architecture includes a look-up-table and interpolation. We concentrate on the estimation of the look-up-table points from minimal number of color enhancement samples (comparing interpolative and extrapolative statistical learning techniques), and evaluate the feasibility of using the color management architecture for custom enhancement definitions.