Spatially varying white balancing for mixed and non-uniform illuminants

TL;DR

This paper introduces a spatially varying white balancing method that effectively corrects colors under mixed and non-uniform lighting conditions, outperforming traditional methods while maintaining comparable results under uniform illumination.

Contribution

The paper presents a novel white balancing technique using multiple diagonal matrices and weights to handle complex lighting conditions, addressing limitations of existing methods.

Findings

Effective under mixed and non-uniform illuminants

Comparable performance to conventional white balancing under single illuminant

Reduces lighting effects on all spatially varying colors

Abstract

In this paper, we propose a novel white balance adjustment, called "spatially varying white balancing," for single, mixed, and non-uniform illuminants. By using n diagonal matrices along with a weight, the proposed method can reduce lighting effects on all spatially varying colors in an image under such illumination conditions. In contrast, conventional white balance adjustments do not consider the correcting of all colors except under a single illuminant. Also, multi-color balance adjustments can map multiple colors into corresponding ground truth colors, although they may cause the rank deficiency problem to occur as a non-diagonal matrix is used, unlike white balancing. In an experiment, the effectiveness of the proposed method is shown under mixed and non-uniform illuminants, compared with conventional white and multi-color balancing. Moreover, under a single illuminant, the proposed method has almost the same performance as the conventional white balancing.