Distortion Localization and Restoration Method in Water Column Area of Side-scan Sonar Image

Side-scan sonar is equipped on two sides of AUV to obtain underwater information. Due to the interference of the changing marine environment and the limitation of the measurement principle of sonar equipment, there are obvious distortion, noise interference and contrast imbalance in the real side-scan sonar image, which needs to be geometric correction and preprocessed before being used. However, the distortion problem in the water column area due to the geometric correction process is present in all sonar image and contains many useless features. To solve this problem, firstly, this paper analyzes the distortion problem in the water column area, and then proposes a method to automatically determine the area to be restored of distortion problem. Finally, a method to restore the side-scan sonar image using its self-similarity is presented. Comparing experiment is given and the results show that the proposed method can restore side-scan sonar image and make the texture structure more coherent.