Single image visibility enhancement in gradient domain

This study proposes a novel algorithm for visibility enhancement from a single degraded image in the gradient domain. The algorithm is based on the fact that the smaller the transmission value, the larger the coefficient multiplied by the gradient to enhance the visibility. A multi-scale method is employed to highly restore the visibility in regions with very small transmission and maintain the contrast in close-range regions. Experimental results show that the algorithm can effectively enhance the visibility from a degraded image even in very low-contrast regions, and avoid the halo effect.