, Volume 3, Issue 2, pp 187-203

Optimization approach to dichromatic images

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


A method for recovering the spectrum of both the interface and the body reflectance for images composed of dichromatic surfaces is presented. An important assumption is that the spectrum of the interface component is the same as that of the illuminant. It is also assumed that the image is presegmented into dichromatic patches, that surfaces possess specularities, and that these highlights change geometrically differently from the shading. The method is based on minimizing the sum of squares of deviations from the dichromatic model over all the patches in the image, by using finite-dimensional linear models to approximate spectral functions. We point out shortcomings in the accuracy of such models when specularities are present in images. Results are presented for synthesized images made up of shaded patches with highlights. It is shown that the method does reasonably well in recovering interface and body colors as well as the illuminant spectrum and body spectral reflectance function.

This work was supported in part by grants from the Centre for Systems Science of Simon Fraser University.