Hawkeye Technology and Umpire's Call




Cricket was the first sport to introduce a review of the on-field umpire's decision. This system called the <b>Decision Review System (DRS)</b> in cricket, was made possible using the Hawkeye system. Though the system has proved to be very useful, it has been part of many controversial decisions in the past. We will discuss how the DRS system works and why we sometimes need to consider the umpire's call in decision-making. <b><h2><center>What is DRS?</b></h2></center> DRS, or Decision Review System, has a very self-explanatory name. It consists of 3 main components: hawkeye, slow motion, reverse technology, and Sneeko. <b>Paul Hawkins and David Sherry</b> developed Hawkeye developed it in the United Kingdom. It is a 6-camera setup that allows the 3rd-umpire to see the predicted trajectory of the ball (generally after hitting the pads). Sneeko is another vital technology that helps the umpire catch some of the most miniature bat and ball connections the on-field umpire might miss. Both Sneeko and Hawkeye have been involved in some of the controversial decisions in the past. But they have been very impactful in making the correct decisions as well. The DRS system was introduced in cricket in 2009 after it was tested in different matches. According to a report and review of the system in 2012, DRS proved the umpire's decision to be correct 75% of the time, correcting 25% of decisions. <br><a href="https://ibb.co/xjG7W64" target="_blank" rel="noopener noreferrer"><img src="https://i.ibb.co/hWHmbVq/DRS-Dhoni-review-system.jpg" alt="DRS-Dhoni-review-system" border="0"></a> <b><h2><center>How Does Hawkeye Work?</b></h2></center> All Hawkeye systems are based on the <b>principles of triangulation</b> using visual images and timing data provided by several high-speed video cameras located at different locations and angles around the play area. In cricket, six cameras are involved in the form of a spider web, also called <b>Spidercam</b>. It also uses the data from the speed gun to estimate the ball's path. The system rapidly processes the video feeds from the cameras and ball tracker. A data store contains a predefined playing area model and data on the game's rules. In each frame sent from each camera, the system identifies the pixel group corresponding to the image of the ball. It then calculates the ball's position for each frame by simultaneously comparing its position on at least two physically separate cameras. A succession of frames builds up a record of the ball's path. It also "predicts" the future flight path of the ball and where it will interact with any of the playing area features already programmed into the database. In the following image provided by Cricket Australia on Twitter, you can see the predicted path of the cricket ball using Hawkeye in blue. <br><a href="https://ibb.co/S0RhGsC target="_blank" rel="noopener noreferrer""><img src="https://i.ibb.co/XpShM2R/hawkeye-in-action.jpg" alt="hawkeye-in-action" border="0"></a> <b><h2><center>Triangulation</b></h2></center> The Hawkeye system is based on the principle of 'triangulation.' Triangulation is a system that finds the area of a point by measuring the angle from the element to the point detected at any end of the fixed baseline rather than directly measuring the distance to the component. This point can be specified as the third point in a triangle with a recognized edge and angle. <br><a href="https://ibb.co/mTJxBdP" target="_blank" rel="noopener noreferrer"><img src="https://i.ibb.co/zxsk5Ct/hawkeye-camera-setup.png" alt="hawkeye-camera-setup" border="0"></a> The Hawkeye requires two inputs. Six special cameras provide video from 6 unique locations. They help us find the tempo of the ball and the ball's speed. Gadgets quickly route video feeds through a high-speed video processor. It detects pixels of the ball in 6 specific locations. This part of the gadget can also be broken down into essential elements: 1) <b><i>To detect the pixels representing the cricket ball of each image captured by each video camera:</b></i> captured using an algorithm. Search for ball-like pixels in the captured image. The recording is an excellent way to record the size and shape of the ball. After this degree, the x and y coordinates of the ball in each frame are output. Using the formula in the following image, you can find the ball's position. <br><a href="https://ibb.co/QcC8Ld3 target="_blank" rel="noopener noreferrer""><img src="https://i.ibb.co/g7PvNVL/triangulation.png" alt="triangulation" border="0"></a> 2) <b><i>Geometric algorithm</b></i>: Facts and coordinates from each camera are received using the attached geometric algorithm. Work inside the Hawkeye machine. Now that we know the exact position of the cameras in the area and the coordinates of the ball are larger than any of the images captured by those cameras, we can correctly determine the ball's placement. 3D ball trajectories are created from photographic statistics using <b>Kalman filtering</b>. From this 3D orbital, you can determine the velocity, position, and deviation of the ball's flight. <b><h2><center>The margin of Error in DRS and Umpire's Decision</b></h2></center> Since the DRS system (Hawkeye, more specifically) is nothing but a Machine Learning model, it has a margin of error. According to the developers, Hawkeye Innovations Ltd., based in England, the technology has a mild flaw. They say that the margin of error in Hawkeye is about 3.6 mm. While many commentators have stated that the margin is too large for any sport, some believe it is extraordinarily accurate. One of the drawbacks of the Hawkeye is that it doesn't consider real-time weather conditions, wind speed, etc. It traces the ball's path in predefined conditions, which can also lead to a higher margin of error. That's why the umpire's call is given more significance only when an edge case is involved, like when more than 50% of the ball is not hitting the stumps in the Hawkeye review. Though, based on a 3.6 mm margin of error, this rule can be relaxed more; I guess it is for states like this so that it's easier for umpires and players to understand who might not be as technical to understand the concepts of margin of error.

- Ojas Srivastava, 04:47 PM, 14 Apr, 2024


Next Read: Hot and Cold