  Auto white balance (AWB) is applied by camera hardware at capture time to
remove the color cast caused by the scene illumination. The vast majority of
white-balance algorithms assume a single light source illuminates the scene;
however, real scenes often have mixed lighting conditions. This paper presents
an effective AWB method to deal with such mixed-illuminant scenes. A unique
departure from conventional AWB, our method does not require illuminant
estimation, as is the case in traditional camera AWB modules. Instead, our
method proposes to render the captured scene with a small set of predefined
white-balance settings. Given this set of rendered images, our method learns to
estimate weighting maps that are used to blend the rendered images to generate
the final corrected image. Through extensive experiments, we show this proposed
method produces promising results compared to other alternatives for single-
and mixed-illuminant scene color correction. Our source code and trained models
are available at https://github.com/mahmoudnafifi/mixedillWB.
