Prototype at Swindon Greyhound Stadium (2004-2005)
Fig 1. One of the two system cabinets.
The Greyhound Tracking System automatically tracked 6 dogs, and the mechanical hare. It also automatically detected race launches by detecting the opening of the cage. These coordinates were streamed across the Internet in realtime in order to allow pundits to view racing on PCs.
Between December 2003 and April 2004 I built a live tracking system for tracking greyhound (dog) racing in Swindon. The system used 52 low grade video cameras evenly distributed around the track, and these required up to nine Pentium 4 class computers in two cabinets for computing power (you can imagine me looking like a bit of a mad scientist with all this computing gear at the race course). To my knowledge, this is the first ever sport tracking system which tracked all participants in realtime.
Fig 2. Example camera input - due to the speed of the dogs one would typically only get 2-3 frames of data per camera at 25 FPS. The low image quality increased the computational effort of accurately identifying vests.
Key lessons of this project:
Simplification of the problem is key - in this case I found it computationally advantageous to reproject the race course into a straight line (and perform necessary physics & predictions in this simplified space).
Certain materials are near-invisible to low end cameras equipped with IR sensors.
Keep your tracking cameras away from floodlights and other light sources, as these will attract moths at night.
Just like with the old Speedway system, these days one could recreate a system like this for a fraction of the cost.
Nine Pentium 4 class computers
52 QPAL camera feeds in CCTV enclosures
Automatic tracking of 6 dogs and 1 mechanical hare
Automatic identification of race launches
Fig 3. Track camera video is on the left, and the virtual output home viewers experienced on their home PCs on the right. The software application allowed home viewers to choose from 4 different viewing angles.