An Improvement Approach for Pixel-based Illumination Estimation Algorithms

Illumination estimation algorithms are aimed to estimate the RGB of scene illumination color when the image was taken, which is a significant way to achieve color constancy. They can be divided into three categories: pixel-based algorithms, learning-based algorithms and combination algorithms. Compared with other two kinds of illumination estimation algorithms, pixel-based algorithms are relatively poorly performing. In this paper, we add a L-0-norm smoothing preprocessing to pixel-based algorithms to improve the performance. The L-0-norm smoothing can suppress insignificant details and maintain major edges of an image. Experimental results show that our optimization approach is effective to enhance the performance of pixel-based algorithms.