Detecting Illumination in Images

In this paper we present a surprisingly simple yet powerful method for detecting illumination--determining which pixels are lit by different lights--in images. Our method is based on the chromagenic camera, which takes two pictures of each scene: one is captured as normal and the other through a coloured filter. Previous research has shown that the relationship between the colours, the RGBs, in the filtered and unfiltered images depends strongly on the colour of the light and this can be used to estimate the colour of the illuminant. While chromagenic illuminant estimation often works well it can and does fail and so is not itself a direct solution to the illuminant detection problem. In this paper we dispense with the goal of illumination estimation and seek only to use the chromagenic effect to find out which parts of a scene are illuminated by the same lights. The simplest implementation of our idea involves a combinatorial search. We precompute a dictionary of possible illuminant ...

• Type: Conference
• Year: 2007
• Where: ICCV
• Authors: Clément Fredembach, Graham D. Finlayson, Mark S. Drew
• Keywords: Chromagenic Illuminant Estimation, Computer Vision, ICCV 2007, Illuminant Detection Problem, Minimum Prediction Error, Possible Illuminant Relations--that, Simple Search Algorithm