Simulating Deep Sea Underwater Images Using Physical Models for Light Attenuation, Scattering, and Refraction

Abstract

When adapting computer vision algorithms to underwater imaging, two major differences in image formation occur. While still traveling through the water, light rays are scattered and absorbed depending on their wavelength, creating the typical blue hue and low contrast in underwater images. When entering the underwater housing of the camera, light rays are refracted twice upon passing from water into glass and into air. We propose a simulator for both effects based on physical models for deep sea underwater images captured by cameras in underwater housings with glass port thicknesses in the order of centimeters. Hence, modeling refraction by explicitly computing the correct path of the rays allows to accurately simulate distortions induced by underwater housings. The Jaffe- McGlamery model for effects on color is often used in computer vision algorithms as a base for simplification. We extend this model to incorporate color images, shadows, and several light sources.