Lifting The Veil: Enhancing Images In Turbid Aqueous Environments

Water turbidity is a frequent impediment for achieving satisfactory imaging clarity in underwater video and inhibits the extraction of information concerning the condition of submerged structures. Ports, rivers, lakes and inland waterways are notoriously difficult spots for camera inspections due to poor visibility. This problem motivated us to study methods to extract a cleaner image/video from the one acquired in an almost real-time setting (delay of the order of 6-7 secs). This type of problem arises in image post-processing as an illumination neutralization problem. and, it can also be viewed as a blind deconvolution problem. We present a mathematical method which enables the derivation of a cleaner image from a poor visibility original by means of a combination of linear and non-linear deterministic mathematical transformations for illumination neutralization. Moreover, we propose a new stochastic model for the effects of water turbidity in sub-aquatic video and and still images. In the light of this model, illumination neutralization does not offer the full solution to this dehazing problem.