Enhancement of Underwater Images

Underwater photography becomes an important research area in Ocean Engineering, Computer Graphics and Surveillance. But underwater images appear blue-green and hazy since the longer wavelength of sunlight cannot penetrate deep in the water due to salinity and high concentration of dissolve impurities in the seawater. The paper proposes Multi-scale Fusion technique in order to remove hazing effects and to enhance visibility of such images. An input underwater image is processed for deriving two images from Gamma Correction and sharpening filter. The associated weight maps are then computed and merged together using Gaussian and Laplacian pyramids. Patch-based Contrast Quality Index (PCQI) and Underwater Color Image Quality Evaluation (UCIQE) are used for determining the quality of recovered underwater images. The experimental results indicate that the final image has better visibility and contrast than the original image.