Sunday, October 28, 2007

My favorite yellow line

Last week, I got an e-mail from the TAMU Telcommunication Media Association saying that Sportvision and ESPN needed a student to work with a technician to help build and calibrate the cameras that paint the digital first down marker that shows up on live broadcasts of football games for Saturday's game against Kansas. The job included a day of set-up on Friday as well, and since I'm not a huge fan of actually going to class anyway, I called and applied for the position and was hired. When my brother found out what I would be doing, he insisted that I take some pictures and write something about how they do it, because it's a very cool process. Hopefully I don't screw this explanation up too badly.

They start with a laser. This part was done before I got there. In fact, it was done several years ago, and now they keep the data from each stadium to use the next time they come. The laser is placed in the center of the field and collects data on elevation points. This information is used to draw a map of the contours of the field on the computer.

The next step in hardware set-up is the sticks, or the tripod the camera sits on. This tripod has to be completely level for the process to work, and can't be moved after everything is set up and calibrated. Incidentally, Adam (my boss and the rock star behind this game's yellow line) said the cameras get moved almost every week after they have been calibrated. This week was no exception: one of the first things they did Saturday morning was move one of the cameras, which was quite frustrating for Adam, who had spent the entire day before setting them up. After the camera is set up and level, it is chained down so it won't move during the game.

Next, we have the pan/tilt head, which sits on top of the sticks. This particular head has been modified to hold a box on the front that sends information to the 1st and Ten computers downstairs about that camera's view of the field so they can add the yellow line to the live broadcast when that camera is in use. This particular broadcast had three such cameras with 1st and Ten capabilities. Usually, there are four, but Adam was more than ecstatic that Camera 4 would not be a 1st and Ten camera for the rest of the season (Camera 4 is an end-zone camera, for this game placed on top of the 12th Man TV. Apparently it's difficult to set-up and even more difficult to make the yellow line look good from that perspective because the technology was originally designed for sideline shots.)

On top of the head we have the actual camera (with a $100,000 lens, by the way). This is where I actually got to play with the technology (aside from helping build the cameras...oh, who are we kidding; I watched Adam do most of that too). Before the game my job was to listen to Adam, who was in the ESPN trailer at the 1st and Ten computer, over the headset and do what he told me to with the cameras (zoom in on a yard line, pan, tilt, etc.) so that he could collect the necessary data about the field so the virtual line would stay in perspective as the cameras pan, tilt and zoom during the game. Adam now has a really precise map of the field on his computer, and the system now knows where in each frame of the video the line should appear.

Next, Adam creates a blue screen (yellow, rather) of the parts of the field he wants to draw on by selecting the colors of those parts. He selects the different shades of green on the field and then determines how strong that color should be replaced: a higher percentage means a brighter yellow line over that color. During day games, the shadows change, so Adam has to monitor his blue screen to make sure the appropriate colors are still being replaced as the game goes on. He also has to make sure that he's not drawing on skin, logos, or uniforms so that it appears that the line is actually painted on the grass.

Now that the computers know where the field is and which colors to replace, Adam can select the yard line he wants to put the line of scrimmage and the yellow down line on during the game (far left screen). He watches the three cameras to make sure the line is showing up properly on all three cameras (center screens) and the action on the field to find out where to put the line next.

I came away very impressed with the technology, process, and end result of this little feature. No wonder Sportvision has won multiple Emmys for this advancement.

Here are a few other things I observed during the experience:

Their cables are really freaking long. (These go from their cameras under the press box to the trailers)


These are the graphics guys. They create the lower third graphics that go on the screen when they show a player on TV and other stats graphics. They get really mad when a graphic doesn't get up on time or if there's a mistake in the text of a graphic.


It's fun to have one of these. This is the first of what I hope will be many TV Crew credentials.


The view of the Aggie Band is even better from here.

Special thanks to Adam for letting me follow him around all weekend, and the whole crew for letting me take their money in the pool (I put in $10 and won $80 back because I drew "0" and therefore won 3 quarters). An Aggie loss is a Mandy win, apparently.

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