On-field testing and evaluation of a goal-line technology system

Goal-LineTechnology (GLT) is a system used in football game to establish if the ball has completely crossed the goal line and contextually assisting referee in awarding a goal or not. The first aim of GLT is not to replace the institutional role of the officials, but rather to help them in highly critical situations where making the correct decision is difficult. This work is focused on a real case study on a Goal-Line Technology system. The chapter details the ball detection algorithm that analyzes candidate ball regions in order to recognize the ball pattern. In order to decide about the goal event occurrence, a decision-making approach by means of camera calibration is developed. Differently from other GLT systems present in the literature, this one has two main strengths: (i) it gives, as unquestionable proof, the image video sequence that records the goal event when it occurs; (ii) it is noninvasive: it does not require any change in the typical football devices (ball, goal posts, and so on). Extensive sessions of experiments were performed on both real matches acquired during the Italian Serie A championship, and specific evaluation tests by using an artificial impact wall and a shooting machine for shot simulation. The obtained experimental results are encouraging and confirm that the system could help humans in ambiguous goal-line event detection.