Sonar image segmentation based on implicit active contours

Sonar images are susceptible to noise pollution and the image intensities are often inhomogeneous. So there are many difficulties in sonar image segmentation. When apply the current popular region-based active contour models to sonar image segmentation, the objects we interested may be segmented inaccurately sometimes, especially for the image with shadows. To solve the problem, a simple algorithm was proposed in this paper. Firstly we analyzed the initial contour action in level set evolution, and then combined with a strict local binary fitting energy we segmented sonar images selectively by changing the initial contour. Computer experiment results show that our method is very suitable for sonar image segmentation. Target regions with weak border can be obtained perfectly. And for the sonar image with shadows, interested objects and the shadows could be distinguished separately, avoiding the boundary leaking problems caused by the shadows´ existing.