’s VAR system uses Delta-offside VOL technology

  • 14 July, 2022


USA: VAR technology in football is an extra set of eyes for the officiating crew on the pitch. Video match officials (VMO) monitor the game “through the camera lenses”, check any controversial or missed moments, and provide the main referee with the opportunity to review it in detail.

The VAR system does an excellent job in checking the facts, e.g., goal, handball, identity of the player. However, during the match it may be necessary to deal with offside situations. That requires determining the position of defensive and offensive players in relation to each other at the exact moment of passing.

In most cases the situation is quite obvious and can be solved by the standard use of VAR-procedures. However, in order to make the right decision in complicated moments, referees can benefit from using the specialized Virtual Offside Line (VOL) technology.

Based in Ans, Belgium, Deltacast company offers a wide range of professional solutions for the video and TV production market, including 2D and 3D Virtual Offside Line technology for football - Delta-offside system. has successfully collaborated with Deltacast to integrate its videoReferee® (VAR) and Delta-offside (VOL). Since both systems meet FIFA Quality standards and are FIFA-certified, the joint solution can be used at any football competition.

Using specialized image processing technology and a 3D model of the football pitch, the VOL system overlays special reference lines on the broadcasted image to determine the position of players in space.

The 2D VOL processes an image from a single camera. Two lines, parallel to the goal, drawn through the outermost body parts of the nearest to the goal defender and the potentially in offside attacking player are superimposed on the image. The referee makes an offside decision based on the position of the lines on the pitch.

Should the 2D analysis be non-indicative due to objective reasons, the 3D analysis is used. It involves processing the images from 2 different cameras. Аn operator marks players’ body parts nearest to the goal оn both images, and the VOL system projects these points in space onto virtual lines parallel to the goal line.

The cameras used for 3D VOL, as well as for VAR in general, must be absolutely synchronous. This is ensured by the broadcaster and the VAR server.

As a result of the integration work, the's VAR server and the Deltacast's VOL system can now exchange the video-information via a local 1GbE network.

The Control-VR control panel has received additional functionality for working with the Delta-offside system. A dedicated "VOL" button was added to transfer all the necessary data and images of a potential offside position to the VOL system.

After VOL processing, the image with lines and visualization of the players' positions is sent back to the videoReferee® server. The "VOL" button lights up in green, indicating that the moment has been processed, and the image can be displayed on VAR-monitor and outputted to the RRA.

The bypassing of SDI connections for video transmission accelerated the process of offside checks, as well as simplified the installation by eliminating the coaxial SDI cables. and Deltacast are offering a complete certified solution allowing the football clubs, leagues and Federations for comprehensive implementation of Video Assistant Referee technology.

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