The Research On Model-based Image Restoration For Underwater Laser Imaging

Underwater laser imaging technology has a very important role in the exploitation of deep-sea resources. But because of lots of medium and suspended particles in sea water, there are many serious degradation problems of underwater image, such as noise, blur and low resolution. Many scholars are doing research of underwater image restoration, but the recovery effect still need to improve. This dissertation studies and proposes an improved underwater image model and proposes an improved underwater blind image restoration algorithm based on this model.Firstly, considering the characteristics of the range-gated imaging system, this dissertation proposes an improved underwater image model for the lack of Jaffe model. For the forward scattered light component calculated based on the improved beam spatial broadening model, For the calculation of the backward scattered light component combines the characteristics of a range-gated imaging system. And Calculated the modulation transfer function and the point spread function of the imaging system according to the improved model.And then did comparative experiments of inverse filtering and Wiener filtering based on Wells model and the improved underwater image model, Which also joined the contrast of whether the initial image preprocessed. Experimental results show the better effectiveness of underwater image restoration based on the improved model.Secondly, research and did comparative experiments on underwater blind image restoration algorithm, proposes an improved underwater blind image restoration algorithm model based on improved underwater image model.This dissertation did a series of comparative tests using three different blind restoration algorithm based on the Wells model and the improved model,using the original image and the original image preprocessed as the initial image, using the Index criterion and Sobel criterion as image quality evaluation criterion. The experimental data show that using Deconvblind algorithm based on the improved underwater image model,using the original image preprocessed as the initial image,and using the smallest Index criterion as image quality evaluation criterion,the blind image restoration effect is best.