Posts Tagged ‘football’

The yellow first down lines in football games

Monday, February 4th, 2008

Every time I watch a football game, someone asks “How do they make those yellow lines on the field that mark the first down?” And no one ever knows the answer. Yesterday, watching the (disappointing) Super Bowl, my sister-in-law asked the question and suggested that I write about it, so I thought I would oblige.

Sportvision LogoIt turns out that the “First and 10″ lines have been appearing on your screen since 1998 and are the invention of a company called Sportvision. The simplicity of the yellow lines, which show up on the ground to mark the first down line, and appear to be painted on the ground, with players and refs and the football able to walk over the lines, belies how complicated it actually is to create them on your television screen. I would love to simplify this for you, but it’s beyond me – so here’s the description from the Sportvision Web site:

“A laser placed in the center of the field is used to collect data on elevation points. That information is used to draw a computer map of the contours of the field, and the map is adjusted and overlaid onto the camera’s view of the actual field. Anywhere from three to five separate broadcast cameras are outfitted with custom Sportvision sensors and encoders to capture camera data so that the 1st and Ten Computers can enhance one camera “live” with the yellow line, and any of the others for use in replay. As cameras pan, tilt and zoom, this data enables the virtual line to follow suit, staying in perspective and getting larger and smaller, as needed.

“Drawing the yellow line so that it appears to be painted on field underneath the players is accomplished through a sophisticated process of color keying that allows the operators to tell the computers what colors to draw on (grass, dirt) and what not to draw on (skin, uniforms). And finally, after adding the precise location of the first down marker to the system and… voila … The Yellow Line appears like magic on your TV screen.”

It also turns out that we aren’t the only ones who think that the yellow lines are cool – they have a 98% approval rating from fans, and the company has won multiple Emmy’s for the technology. Sportvision also has other technology solutions that are used in baseball, basketball, golf, horseracing and motorsports, among others.