Underwater Image Devignetting and Colour Correction

This paper describes a novel method to recover underwater images by devignetting and colour correction. Scattering and colour distortion are two major problems of degradation for underwater imaging. Scattering is caused by large suspended particles. Colour distortion corresponds to the varying degrees of attenuation encountered by light traveling in water with different wavelengths, rendering ambient underwater environments dominated by a bluish tone. To this end, we propose a novel underwater imaging model, which is much closer to the light propagation model in underwater environment. We remove the noise by dual-tree complex wavelet transform. Then, solve the non-uniform illumination of artificial lights by devignetting. Finally, we recover the image colour through camera spectral responses. The corrected images are characterized by reduced noised level, better exposedness of the dark regions, improved global contrast while the finest details and edges preserving.