Research On Method Of Ship Target Detection Under Complex Harbor Background

Harbor is an important civil and martial facility, and ship target detection in harbor is strategic important. The key problem is how to detect and locate ship target quickly and accurately. The offshore ship target can be located quickly by segmentation in local region. But because of the similar gray level between ship and the harbor, this method cannot segment the ship target docked on harbor. This paper studies on the method of ship detection in complex harbor background, the main content including the following:Take a measure of harbor-template matching by Hausdorff distance algorithm to locate the harbor and extract the sea area. The template is a binary image of coast line which contains two different gray level representing the sea area and land area respectively. This method can extract the sea area from background efficiently.For the problem of small angle rotation existing between the template and the real-time image which causes partial dock remain and stick to ship and leads to false detection. This paper presents a method of using line information by Hough transform to find the corresponding rotate angle. Then template is renewed by this angle and match again under the restriction of the first match's result which can receive a better matching result.Analyze the character feature by information of smallest minimum bounding rectangle, and the separation of linking ship is also based on this information. The peak-valley-peak pattern existing in rectangle's projection indicates that the ships are linking, and the valley point indicates the ships'connection position.