Maritime surveillance: Tracking ships inside a dynamic background using a fast level-set

Surveillance in a maritime environment is indispensable in the fight against a wide range of criminal activities, including pirate attacks, unlicensed fishing trailers and human trafficking. Computer vision systems can be a useful aid in the law enforcement process, by for example tracking and identifying moving vessels on the ocean. However, the maritime domain poses many challenges for the design of an effective maritime surveillance system. One such challenge is the tracking of moving vessels in the presence of a moving dynamic background (the ocean). We present techniques that address this particular problem. We use a background subtraction method and employ a real-time approximation of level-set-based curve evolution to demarcate the outline of moving vessels in the ocean. We report promising results on both small and large vessels, based on two field trials.