What is this sports digital-imaging trick?

The TV networks can now make ads appear on the outfield walls in baseball, on the court in basketball, or seemingly under the ice in hockey. The ads don’t appear, of course, to those actually attending these games. How do they do that? Is there a name for the process? Is it trademarked or patented?

It appears to me to be a sophisticated method of chroma keying. Not too different conceptually from weatherpersons who stand in front of virtual weather maps.

I think you are right, but with the addition of a camera that is made to record the exact direction it is pointed and the amount of zoom. This information is used by a computer to calculate how to draw the added image. I think this was originally used a few years ago to highlight the hockey puck for TV. Now used to draw first down marker lines and such for football games.

ETA, sportvision seems to hold a trademark on the process.

The trick is that there are reference points around the field, court, etc to which the graphic can be related.

“If this point appears here in relation to this point, then apply this perspective distortion to this graphic.” The output from this is then overlayed (with chroma-key, as mentioned) over the source video, in real time.

Ninja edit: Here ya go, detail.

(Oh, hi RedSwinglineOne. Heh.)

The other key is that they aren’t foolproof. I’ve seen lots of goofs when someone decided to change camera angles at a time when, apparently, the computer had its eye on the ball instead of the wall.

Howstuffworks explains how it works.

While this appears to be relatively new in American sports, i remember this technology being used for advertising delivery during rugby games in Australia in the late 1990s.

Given that America is usually ahead of the curve in terms of advertising saturation, it’s interesting how long it’s taken this technology to catch on here in the US. It’s clearly not a technological deficiency, because i’m sure that American companies knew how to do this at least as early as Australian companies, so there must have been some cultural issue, such as fear of alienating the viewing audience.


It might also be that American sports like football and baseball tend to already have a lot of breaks for advertising, whereas sports like rugby and soccer are more continuous, and it’s harder to squeeze in commercial breaks.

I saw all these ads for booze under the ice in a sport I thought was above putting something like the distracting ads under the ice. I turned it off because seeing booze ads continuously was distracting. Now I find out it was the stinking station screwing with the event, and ruining what I turned off. At least the fans at the event didn’t have to put up with it.

Yes, I think you are right, to some extent. But you will notice that American professional sports haven’t taken to advertising on their uniforms, yet, either*. So at some level it’s also about the way Americans hate tradition screwing with their sports.

  • Well, except for the logo of the unifor manufacturer, of course. Swoosh!

The exception, of course, being motor sports, NASCAR & IRL most predominantly in the US.

Of course, this confuses the daylights out of me at the start of every season, as the Silly Season sponsor changes make the cars just a little different each year.

L-VIS was being used here around that time as well, pretty much exclusively on the advertising panel behind home plate.

Um, those are not professional “sports”, regardless what NASCAR would love us to believe. :stuck_out_tongue:

The actual counter-example is professional golf, which is getting worse every day. <sigh>

Small hijack on logos at sporting events:

In August 2000 I was in Sydney, Australia on business and was invited to a rugby match in Olympic Stadium. Painted onto the field (pitch?) were sponsor logos, but they were modified so that the image captured by upper-deck TV cameras would look normal. From my viewpoint from the opposite side of the field they looked like comic strip images lifted with Silly Putty and stretched to look, well, silly. Interesting the ingenuity of advertisers trying to make a living.

You get these “anamorphic” adverts painted onto the rugby pitch at Twickenham as well. And a lot of cricket matches have similar physical adverts skewed for perspective, but they are usually on tarpaulins as far as I can tell. Some cricket broadcasters use the digital version too.

I’m pretty sure I’ve seen this on San Francisco Giants broadcasts in the late 90s.

Thanks, everybody!