Spatially varying white balancing for mixed and non-uniform illuminants
This addresses the issue of color correction in images under complex lighting conditions for computer vision and photography applications, representing an incremental improvement over existing white and multi-color balancing techniques.
The paper tackles the problem of white balance adjustment under mixed and non-uniform illuminants by proposing a spatially varying method that uses diagonal matrices and weights to reduce lighting effects on all colors in an image, showing effectiveness in experiments compared to conventional methods while maintaining similar performance under single illuminants.
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.