Abstract: Due to the absorption and scattering of light by floating particles in water, and the different attenuation degrees of light at different wavelengths under water, the underwater images generally have the problems of fuzzy details, low contrast and color distortion. Aiming to improve the quality of underwater images, an underwater image restoration method based on color attenuation prior and white balance is proposed. Firstly, the scene depth map is obtained according to the color attenuation prior in HSV color space of the image. Secondly, the underwater optical attenuation characteristic is used to estimate the corresponding background light intensity and underwater transmittance of RGB channels in order to realize image clarity. Finally, the improved white balance method is adopted for the color correction of the clear underwater image. The experimental results show that the proposed method can significantly improve the detail sharpness and color fidelity of underwater images, and the visual effects are more similar to images captured in natural scenes.

Key words: underwater imaging, image restoration, color attenuation prior, scene depth estimation, white balance