Sports fans who watch athletics, soccer or other events on TV are familiar with the long advertising boards on the sidelines. Organizers, advertising rights marketers and companies earn a lot of money by advertising their products or services to an audience of millions. However, this type of advertising also has a major disadvantage: all viewers – worldwide – see the same advertising.
The Fraunhofer Institute for Intelligent Analysis and Information Systems IAIS has therefore developed a technology that allows content on the boards to be customized for different target groups. This means that each TV broadcaster can show content on the boards that is targeted to a specific audience or country so that when a soccer match is broadcast worldwide, for example, people see the same boards but each with completely different content.
Chromakey technology with magenta
To achieve this, the scientists from Sankt Augustin near Bonn, Germany, combine the Chromakey process established in TV productions and an innovative technological in-house development. Chromakey – also known as blue screen or green screen – is used in TV studios when an image or video is played behind presenters. The viewer then sees the presenters standing on a beach, for example. The Fraunhofer team uses magenta as the background color for its solution. If the players’ jerseys do not stand out sufficiently against a magenta background, any other color is also possible, the researchers emphasize.
Modern perimeter advertising, however, works with electronically controlled LED panels that show changing content. So how does individualized advertising work? “The streams on the LED banners consist of a sequence of individual images, each displayed for 20 milliseconds,” says Ulrich Nütten, head of the Media Engineering department, explaining the process developed at the institute. “We shorten the display of the advertisement to 18 milliseconds, and for the remaining two milliseconds the band shows a magenta color area. This magenta flash is too short to be perceived by the human eye. The recording time and duration of the TV camera are set to record only this flash.”
The camera does not see the real advertising, but only the band with the colored area. “This is where Chromakey comes into play: in the image that the camera delivers from the stadium to the TV studio, new content is placed on the magenta color surface. This way, an advertising stream is created that seamlessly blends into the TV picture.” While viewers in the stadium now see the real perimeter advertising, people in front of their TV sets would be shown a different ad. But to them, he says, it looks as if the ads are playing on the boards in the stadium. Even if an athlete is standing in front of a perimeter or running back and forth in front of it, that’s not a problem, he said. “The technology is now so sophisticated that there are no hems, color distortions or blurring in such a situation,” says Nütten.
Correct perspective even with camera pans
But the researchers first had to eliminate one difficulty: changing camera perspectives or panning shots cause the perimeter elements to appear distorted in perspective. So the externally generated ad content had to be adjusted so that it always stayed within the boundaries of the perimeter. The solution was for the team to place tracking modules on the cameras that continuously register camera tilts and pans. This data is used by AI-powered software to continuously recalculate the angle to the perimeter and compensate for perspective distortion. Mainframes are not needed for these calculations, despite the significant computing power required to do so. “Two commercially available PCs with a powerful graphics card are all that is needed. One PC recognizes the magenta band in the TV picture, the other plays in the advertising content.”
The researchers are currently already working on ensuring that the technology will also support TV formats in the highest-resolution 8K format in the future. The technology is marketed by the Swiss company ViboTec AG.
Cover photo: Chromakey-based perimeter advertising opens up new marketing opportunities for TV broadcasts of soccer matches. Fraunhofer experts with equipment in front of the Bay Arena in Leverkusen. © Fraunhofer