Towards Highlight Based Illuminant Estimation in Multispectral Images

We review the physics based illuminant estimation methods, which extract information from highlights in images. Such highlights are caused by specular reflection from the surface of dielectric materials, and according to the dichromatic reflection model, provide cues about the illumination. This paper analyzes different categories of highlight based illuminant estimation techniques for color images from the point of view of their extension to multispectral imaging. We find that the use of chromaticity space for multispectral imaging is not straightforward and imposing constraints on illuminants in the multispectral imaging domain may not be efficient either. We identify some methods that are feasible for extension to multispectral imaging, and discuss the advantage of using highlight information for illuminant estimation.