Omnidirectional Scene Illuminant Estimation Using a Multispectral Imaging System

摘要

A method is developed for estimating an omnidirectional distribution of the scene illuminant spectral distribution, including spiky fluorescent spectra. First, we show a measuring apparatus, consisting of the mirrored ball system and the imaging system using a LCT filter (or color filters), a monochrome CCD camera, and a personal computer. Second, the measuring system is calibrated and images representing the omnidirectional light distribution are created. Third, we present an algorithm for recovering the illuminant spectral-power distribution from the image data. Finally, the feasibility of the proposed method is demonstrated in an experiment on a classroom scene with different illuminant sources such as fluorescent light, incandescent light, and daylight. The accuracy of the estimated scene illuminants is shown in the cases of the 6-channel multi-band camera, 31-channel spectral camera, and 61-channel spectral camera.