An Improved Air-Light Estimation Scheme for Single Haze Images Using Color Constancy Prior

Hazy environment attenuates the scene radiance and causes difficulty in distinguishing the color and texture of the scene. A crucial step in dehazing is the recovery of the global air-light vector. Traditional methods usually interpret the RGB value of the brightest region in haze images as the air-light. In this letter, a new prior called ‘color constancy prior’ has been proposed to improve the robustness of air-light estimation when varicolored illumination exists. The prior utilizes the statistical observation that distant scenery objects become the most haze-opaque due to the pixel escalation towards the higher intensity side. The comparative evaluation on a variety of haze images manifests that the proposed prior perform better than existing air-light recovery methods and can be used for subsequent dehazing applications.