Survey Paper on Visibility Restoration of Underwater Optical Images and Enhancement Techniques

Abstract

We have investigated the problem of underwater hazy image enhancement and restoration in this paper studied. Underwater image processing has several applications in the field of oceanic research work and scientific applications such as archaeology, geology, underwater environmental assessment, laying of long distance gas pipelines and communication links across the continents which demand geo-referential surveying of the oceanic bed and prospection of ancient shipwreck. There are many difficulties for undersea optical imaging. To submerging a camera in underwater enough space is required. The maneuvering of the camera with the help from remote place or in person at the site is likewise a complex task. However, the major challenge is imposed by underwater medium properties. Underwater haze image enhancement has gained widespread importance with the rapid development of modern imaging equipment. Though, the contrast enhancement of single underwater hazy image is a cumbersome task for scientific exploration and computational application. At extreme depth, because of attenuation in light propagation, the underwater images are susceptible to inferior visibility.

The development and usability test of an automated fish counting system based on CNN and contrast limited histogram equalization

“…Underwater images often suffer from distortion and light attenuation due to the scattering of light as it passes through the water [13], [14]. Thus, image enhancement is important for accurately detecting the presence of fish in a single image.…”