18 SPORT 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 so- called ‘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.
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.
TRAFFIC & TRANSPORT
Keeping us moving An area that now benefits from vision, that affects us all, is transportation and traffic. Monitoring of traffic and in particular Automatic Number Plate Recognition (ANPR), has changed the face of our roads, but there has also been considerable use in railway applications.
Controlling traffic
Traffic applications are many and varied and can include ANPR, toll booth control, multi-lane monitoring, automatic toll licence validation, red light violation, traffic enforcement systems, vehicle recognition and identification, vehicle occupancy and speed monitoring. Although many will comment on speed detection, ANPR is actually greatly increasing the effectiveness of our homeland security with image data, networked throughout the UK, to detect or find vehicles of interest. This wide range of applications have been made possible by developments in lighting and lighting control technology, the versatility in functionality and triggering offered by modern image sensors and sophisticated soſtware. In particular, high dynamic range cameras are available which can provide more than 1000x the dynamic range of conventional sensors. These cameras can produce high quality images of moving objects in widely varying lighting conditions, for example in the open air where the sun may come in and out at random times, underground car parks, tunnels or traffic monitoring at night (for example checking registration number plates without interference from the vehicle headlights). Cameras can accept trigger signals from motion detectors, barriers being raised, pressure sensors etc. A wide choice of image sensors allow the most suitable resolution to be chosen for the application. For example, resolution choice could be influenced by the field of view necessary, such as the number of traffic lanes to be covered, different sizes of number plates etc. Line scan technology is also used in vehicle inspection applications such as high integrity under vehicle surveillance. This can be used at airports, prisons, border control, and other high security facilities to detect foreign objects such as explosives hidden under vehicles.
Keeping on track
There are many examples of the use of vision technology on the railways both trackside and mounted on the trains themselves, even though the operational conditions are demanding. Cameras and imaging systems can be exposed to extremes of weather, vibration and physical wear. Line scan technology is being used to inspect the rails, sleepers and ballast for early detection of failure at speeds over 100 MPH, to a resolution of 0.8mm. Used in conjunction with cutting-edge pattern recognition soſtware, this can automate the detection of track defects to help increase the safety of the railway network in a way that was previously impossible.
Cycling posture analysis - Courtesy IDS 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.
www.ukiva.org
104 industrial camera assemblies on London Underground passenger trains check the condition of the wheel/rail interface and the track - Courtesy Stemmer Imaging
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96
