A Perceptual Measure of Illumination Estimation Error

The goal of color constancy is to keep colors invariant to illumination. An important group of color constancy methods are the global illumination estimation methods. Numerous such methods have been proposed and their accuracy is usually described by using statistical descriptors of illumination estimation angular error. In order to demonstrate some of their fallacies and shortages, a very simple learning-based global illumination estimation dummy method is designed for which the values of statistical descriptors of illumination estimation error can be interpreted in contradictory ways. To resolve the paradox, a new performance measures is proposed that focuses on perceptual difference between different illumination estimation errors. The effect of ground-truth illumination distribution of the benchmark datasets on method evaluation is also demonstrated.