State of the art of the underwater image processing methods

Underwater images often suffer from color-distortion and low contrast, because light is scattered and absorbed when traveling through water. Scattering is caused by large suspended particles, like fog or turbid water which contains abundant particles etc. Color change corresponds to the varying degrees of attenuation encountered by light traveling in the water with different wavelengths. In the past decades, underwater image processing area has attracted considerable attention and also received important achievements. This paper we review some of the most recent methods that have been successfully applied in the underwater environment. These techniques mainly focus on improving image contrast, better exposedness of the dark regions while the finest details and edges are enhanced significantly. The conditions of which of methods could be used will be introduced in this paper as well as the quality assessment used to evaluate their performance.