[youtube]http://www.youtube.com/watch?v=cVyIRQk8hCc[/youtube]
Researchers in the US have created a buoy-mounted CCTV surveillance system that uses video analytics software to automatically identify and track passing vessels.
CCTV cameras mounted on buoys would be an ideal means of securing ports and harbours and could also be used further out to sea to combat smuggling and people trafficking. There are mature surveillance systems designed specifically for ports and harbour surveillance but they rely on being mounted to a fixed object.
Deploying cameras at sea has apparently been tried before, but the obvious problem with mounting a CCTV camera on a buoy is the constant and unpredictable motion as it’s tossed about on the waves. Mounting the camera on gimbals stabilised by gyroscopes might be one way to deal with the problem, but the system would require significant amounts of power and be prone to corrosion and other maintenance issues.
Now researchers at the University of South Florida in St Petersburg have overcome this problem with an algorithm that compensates for the random motion of the sea by following advice familiar to any sailor who suffers from sea-sickness: keep your eyes fixed on the horizon.
By identifying the horizon and using it as a fixed reference point, the algorithm can normalise each image to frame it around common reference points. Video analytic software is then used to pick out anything that sticks above the horizon.
In an article in Ocean Engineering, the authors claim to have achieved an 88 per cent success rate in over 500 tests in identifying ships at up to 300 metres from the buoy.
Sergiy Fefilatyev, who has done the majority of the work on the system as part of his PhD, told us in an email that there were limitations in the test apparatus. The data was recorded in reduced resolution and frame rate – 800 x 600 pixels at 10-15 frames per second. “Higher frame rate and higher resolution would make detection and tracking more reliable and would increase the effective range of the system,” he said.
Chad Lembke told us they have been working for a number of years to combine oceanographic systems that he works with in the College of Marine Science with “the software wizardry that Dr. Goldgof’s [a co-author of the article] group does in a way that may have port security applications”.
In these videos and captions supplied by Fefilatyev, you can see how the system works:
[youtube]http://www.youtube.com/watch?v=byYIjS4d7rE[/youtube]
The first clip is the original video taken by a camera installed on a buoy.
[youtube]http://www.youtube.com/watch?v=q1mc2pZHSww[/youtube]
the second is the same video registered in a global coordinate system to neutralize the buoy’s motion
[youtube]http://www.youtube.com/watch?v=KRv8eqYUDvU[/youtube]
Detection results on the original video
[youtube]http://www.youtube.com/watch?v=hxgB158fdRM[/youtube]
More detection on easy data
[youtube]http://www.youtube.com/watch?v=_p459jSHauI[/youtube]
Video showing our buoy submerging (by regulating buoyancy)
[youtube]http://www.youtube.com/watch?v=cVyIRQk8hCc[/youtube]
Multiple targets detection (without tracking)
