Auto White-Balance Correction for Mixed-Illuminant Scenes

Abstract

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.

Color Constancy Beyond Standard Illuminants

“…Overall, the traditional algorithms Gray-World [11], max-RGB [10], Shades-of-Gray [12], Gray-Edge [13], Weighted Gray-Edge [14], MSGP [15], DOCC [17], PCA-CC [16] and the proposed method are compared against the learning-based methods; Deep-WB [20], AWB-MIS [21], C5 [22], C3A [19] and the data-driven technique; WB-sRGB [18]. In order to evaluate the performance of each method, the mean, the median, the mean of the best 25% and the mean of the worst 25% of the angular error, and ΔE 2000 [28] are reported in Table 1.…”

“…The model is a deep neural network and it is trained in an end-to-end manner. The auto white-balance algorithm [21] does not require an illuminant estimation process to correct the illumination in images. Instead, it renders the input image with certain whitebalance settings multiple times and extracts weight maps via a deep neural network to form the final image.…”