Mutual Information Re-Registration of Sensitive Region in Forward-Looking Sonar Images Combined With Particle Swarm Optimization Algorithm

In order to meet the needs of complex seafloor scenes target detection, an image registration method based on sensitive region is proposed which considering the fuzzy boundary, poor contrast and low overall gray value of forward-looking sonar image. In this method, gradient enhancement algorithm is used to enhance the boundary of the target region in forward-looking sonar(FLS) image, and morphological operation method is used to remove a large number of noise points in the image background. And then, the coordinates and the sensitive region which contains a part of obvious grayscale changes is located in the floating image. The combined method of particle swarm optimization(PSO) algorithm and mutual information(MI) algorithm are used for initial registration, and the re-registration method of mutual information is used to optimize the registration error and improve the registration accuracy. The experimental results show that this method has the advantages of accurate location of the sensitive region, low computation time and high registration accuracy.