Surrounding adaptive color image enhancement based on CIECAM02

In this paper, we propose a CIECAM02-based color image enhancement method which is particularly robust to scenes with bright surrounding. The proposed method detects color edges using a distance metric based on the characteristics of a Human Visual System (HVS). The CIECAM02 is inherently strong considering both HVS and surrounding conditions. A major problem of HVS is that the dark region appears darker under a bright surrounding condition, leading to masking of details within the dark region. This phenomenon causes deterioration of edges which are among the most important and sensitive components for the HVS. To overcome this problem, we propose to weight the deteriorated edges at bright scenes. Adaptively, we estimate the surrounding image by the CIECAM02, and then use a vector gradient edge detector with a newly proposed distance metric to perform the weighting. The proposed method is seen to enhance edges without introducing unwanted color artifacts. We subjectively confirm the performance with clearly enhanced images.