With the Super Bowl being this weekend lots of people like me (who can’t stand not knowing how something works) will be sitting around wondering “How do they paint the first-down line on the TV?”
Since 1998, Sportvision has provided many of the major networks with the technology called “1st & Ten” to paint the first-down line on the screen.
How does the line get there?
Well, the short answer is a computer analyzes the position of the camera on the field, takes into account zoom and the angle the camera is at, and where the first down line is, and draws the line on the image.
Why doesn’t the line cover the players?
There is a carefully calibrated color pallet of all the colors on the field, and another color pallet of all the colors of players’ uniforms, skin, the ball, and anything else which the line should not be painted on.
Before the line is drawn, very pixel on screen is then compared against these two color pallets. If the pixel matches a color in the field pallet the line is drawn on that pixel, if it matches the non-field pallet the line is not drawn.
Of course all of this has to happen 30 times a second to keep up with moving cameras and players, so as you can imagine it takes some serious computer power.