Vision now integral to professional sport
Any follower of sport on TV would at the very least expect ‘slow motion replay’ and multiple angle view analysis of key action sequences. However, vision technology is now used extensively by sports officials, coaches, developers and amateur performers alike. Applications fall into 3 main categories: tracking the trajectories of moving items, such as balls and people, high-speed imaging to allow frame by frame motion analysis and the use of infra-red imaging to reveal information that could not be obtained from conventional cameras.
Geometrical systems
Ball tracking systems such as ‘Hawk-Eye’ (part of Sony) are used extensively in many sports including international tennis, cricket and football, to help the officials verify borderline decisions. The system uses a number of cameras at key locations around the particular arena to track the movement of the ball and a sophisticated image processing system calculates the trajectory of the ball relative to the particular playing area. Other examples include the tracking of a player’s movement during football matches for analysis. The systems monitor the position coordinates for every player, the ball and the referee at all times during the game to allow calculation of players’ total running performance including average and maximum speeds, number and intensity of sprints and the distance covered, allowing the production of socalled ‘heat maps’. A very recent application is a vision based scoring system in a social darts environment using multiple cameras and 3D fitting algorithms to measure the precise position and score of the dart in the board.
Infrared imaging
In cricket, a system called ‘Hot Spot’ uses infrared cameras to help adjudicate disputed catches since the impact of the ball against bat results in a localised heat spot, which appears bright on the IR image. Infrared cameras have been used in the development of ventilation and cooling systems in athletics footwear. Infrared technology can reveal the thermal performance of Formula 1 tyres under race conditions and in different weathers. It can also be used to provide a detailed understanding of how the complex materials used in disc brakes react under load and how heat is dissipated in exhaust systems.
High Speed Analysis
High frame rate and high resolution imaging allow complex movements to be filmed and slowed down for analysis. Applications include analysis of racehorses in motion, the analysis of athletes’ techniques for sports science and the analysis of golf swings both for professionals and amateurs.
