Underwater image restoration method based on scene depth estimation and white balance

Due to the absorption and scattering of the light, underwater images often have the problems of low contrast, detail blurring and color distortion. An underwater image restoration method based on scene depth estimation and white balance is proposed. First, the underwater image is divided to the scene depth related patches by using Sobel edge detection and morphological closed operation. Regression analysis of the relationship between the KGB channel and the scene depth is carried out to obtain scene depth images and to estimate the background light underwater. Second, for the heavily attenuated color channel, its inverse channel is used for correcting the transmission estimation. Third, the backscattering is eliminated by inversely calculating the underwater optical imaging model. Finally, the improved white balance algorithm is utilized to achieve better color correction of underwater images and the restored underwater images are obtained. Compared with four kinds of typical underwater image restoration methods, the experimental results demonstrate that the proposed method can effectively improve the detail clarity and color fidelity of underwater images with low quality and low illumination, while restoring the natural visual effects.