RE: The HAWKEYE Technology
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Hawk-Eye is a complex computer system used in cricket, tennis and other sports to visually track the trajectory of the ball and display a record of its most statistically likely path as a moving image. In cricket and tennis, it is now part of the adjudication process. It was developed by engineers at Roke Manor Research Limited of Romsey, Hampshire in the UK, in 2001. A UK patent was submitted but withdrawn by Dr Paul Hawkins and David Sherry. Later, the technology was spun off into a separate company, Hawk-Eye Innovations Ltd., as a joint venture with television production company Sunset + Vine, which was bought outright by Sony in March 2011.
The game of cricket has attained great commercial importance and popularity over the past few years. As a result, there has been felt a need to make the game more interesting for the spectators and also to try and make it as fair as possible. The component of human error in making judgments of crucial decisions often turns out to be decisive. It is not uncommon to see matches turning from being interesting to being one sided due to a couple of bad umpiring decisions. There is thus a need to bring in technology to try and minimize the chances of human error in such decision making. Teams across the world are becoming more and more professional with the way they play the game. Teams now have official strategists and technical support staff which help players to study their past games and improve. Devising strategies against opponent teams or specific players is also very common in modern day cricket. All this has become possible due to the advent of technology. Technological developments have been harnessed to collect various data very precisely and use it for various purposes. The Hawk-Eye is one such technology which is considered to be really top notch in cricket. The basic idea is to monitor the trajectory of the cricket ball during the entire duration of play. This data is then processed to produce life like visualizations showing the paths which the ball took. Such data has been used for various purposes, popular uses including the LBW decision making software and colorful wagon wheels showing various statistics. This paper attempts to explain the intricate details of the technology which goes behind the Hawk-Eye. We first start off with general overview of the system and an outline of the challenges that we might face, then move on to the details of the technology and end with various applications where one sees this technology being put to use.
Hawk-Eye – a general overview
Cricket is a ball game played within a predetermined area. A system comprising of video cameras mounted at specific angles can be used to take pictures. These pictures are then used to locate the position of the ball. The images are then put together and superimposed on predetermined model to form a complete visualization of the trajectory of the ball. The model includes, in this case, the pitch, the field, the batsmen and fielders etc. For this to be possible, we need to sample images at a very high rate and thus need efficient algorithms which can process data in real time. Such technologies are widely used today in various sports such as Tennis, Billiards which also fall in the category of ball games played within a restricted area. Our discussion will mostly contain applications which specific to the game of cricket, however in some cases, we will mention how similar techniques are applied in other games.
What it can do?
1.Hawk-eye can track any type of bounce, spin, swing and seam movement of the ball.
2.Give a prediction as accurate as 99.99 percent
3.Hawk-Eye was used for referring decisions to the third umpire in LBW.
4.In tennis Hawk-Eye generates the impact of the ball whether the ball is “IN “or “OUT”.
HAWKEYE technology successfully treats each of the issues and provides a robust system to be used in practice. The top-level schematic picture of the system and its various parts is as shown below (each color represents a block of steps which are related)
The Hawk-eye technology, as with many recent developments, initially came about from military application. Initially Hawk-eye was used to track the movement and flight path of missiles, it was though soon realized that it could be used to track any independently moving projectile. Thus it was that Dr Paul Hawkins and his colleagues sought to adapt the military version of Hawk-eye to one that could be used in sports, and in particular cricket. It was developed by engineers at Roke Manor Research Limited of Romsey, Hampshire in the UK, in 2001. A UK patent was submitted by Dr Paul Hawkins and David Sherry. Later, the technology was spun off into a separate company, Hawk-Eye Innovations Ltd.,as a joint venture with television. The Hawkeye system was launched in2001.The system was first used during a Test match between Pakistan and England at Lord’s Cricket Ground, on 21 April 2001, in the TV coverage by Channel 4. It was first used in television coverage of sporting events such as Test cricket, and has now reached the stage of being used by officials in tennis to assist in adjudicating close line calls. The Nasdaq-100 Open in Miami was the first tour event to officially use the technology. The2006 US Open was the first Grand Slam event to feature the system, followed by the 2007Australian Open.
How does Hawk-Eye work?
For most sports fans it is not important to know how Hawk-eye works, but there is a lot of interesting science and technology behind the images that appear on the TV screen. In cricket matches Hawk-eye technology is based upon the images captured by six cameras, three on each side to the wicket. Through these six cameras, all round and 3D images can be captured, which allows for the path of the ball to be tracked. The prediction side comes about through the use of logarithms based on known laws of physics and trajectories. Hawk-Eye uses 6 high speed specialist vision processing cameras which are positioned around the ground and calibrated. In addition the system uses the two “Mat” broadcast cameras and calibrates them so that the graphic is always overlaid in the right place. All cameras have “anti wobble” software to deal with camera movement. When a ball is bowled By , the system is able to automatically find the ball within each frame of video from each camera. Combining the positions of the ball in each of the cameras, the 3d position of the ball is measured through-out the delivery. By measuring the position of the ball at multiple frames post bounce, the speed, direction of travel, swing and dip can be calculated for that specific delivery. Using these measured characteristics of the ball’s flight up to impact, the future path is predicted.