UNDERWATER IMAGE ENHANCEMENT USING GUIDED TRIGONOMETRIC BILATERAL FILTER AND FAST AUTOMATIC COLOR CORRECTION

This paper describes a novel method to enhance underwater optical images by guided trigonometric bilateral filters and color correction. Scattering and color distortion are two major problems of distortion for underwater optical imaging. Scattering is caused by large suspended particles, like fog or turbid water which contains abundant particles. Color distortion corresponds to the varying degrees of attenuation encountered by light traveling in the water with different wavelengths, rendering ambient underwater environments dominated by a bluish tone. Our key contributions are proposed a new underwater model to compensate the attenuation discrepancy along the propagation path, and to propose a fast guided trigonometric bilateral filtering enhancing algorithm and a novel fast automatic color enhancement algorithm. The enhanced images are characterized by reduced noised level, better exposedness of the dark regions, improved global contrast while the finest details and edges are enhance significantly. In addition, our enhancement method is comparable to higher quality than the state-of-the-art methods by assuming in the latest image evaluation systems.