Even though we still have the playoffs and Super Bowl to look forward to, fans of American football are (really, really) disappointed that the regular season ended yesterday. Since there's not much else to do but kill time until the 2009 season starts nine long months from now, let's have a look at some of the technology behind those cool onscreen graphics the NFL uses during televised games.
There's a surprising amount of wizardry that goes into the first down lines that bisect the tv screen during most plays. The heart of the technology is along the same lines as the green screen meteorologists use when delivering the weather forecast. Unlike an unchanging news studio, however, every NFL playing field has subtle differences so a one-size-fits-all approach isn't the answer.
Every single field must be carefully measured with special lasers in order to create a 3D map. It's those dimensions that tell the computer where to place the lines atop the onscreen field. The next consideration is to make sure the image can be seen against the mish-mash of colors and changing lighting conditions on the field.
"To account for that problem, all of the known shades of green that make up the field are entered into the computer before game day so that the line only covers the field, and nothing else. This allows for the illusion of players running over the yellow stripe. Team uniform colors, such as the Green Bay Packers, can also be tough, as the computer has to be told not to paste the yellow line over the shades of green in players’ clothing," writes Science Line's Katherine Tweed.
The technology used to create first down lines may seem relatively simple once explained but, as always, the devil is in the details. In fact, the number of different issues that need to be addressed during a given game is staggering.
As this article points out, in addition to monitoring the color and dimensions of the field, the computer (and its techs) must also calculate camera angles, player movement, and other graphics superimposed on the tv screen at the same time.
I remember watching professional football back in the day and often wondering, "did he get the first down or is it 3rd and inches?" so this new technology thrills me. The only thing cooler would be to see the games in 3D. Apparently, that option is right around the corner.