HOW DO THEY DO THAT?

The game itself is not enough anymore. Fans now demand more from sports television than just the action, and two high-tech companies have positioned themselves to meet that demand.

Sportvision of New York, N.Y., and Princeton Video Image (PVI) of Lawrenceville, N.J., offer technology that is changing the look of sports broadcasting - for the fan and the advertiser.

Sportvision, which brought the glowing puck to hockey a few years ago, now seeks to enrich the experience of viewing other sports. It originated the electronic first-down line for NFL football (ESPN and Fox) and added pitch/bat speed for major league baseball, Internet content (Ironman Triathlon series) and other “enhanced television” features that accompany many game broadcasts.

PVI also offers its own first-down line (CBS) and produced special graphics for last year’s Super Bowl, but it focuses most of its efforts on virtual advertising - placing electronic ads directly into a broadcast.

Here’s a look at how some of these technologies work:

END ZONE POP-UP

1) Creating the animation - Fox Sports produced four video animations for the 1999 SuperBowl to introduce the offenses and defenses of each team with giant billboard-like graphics. These were broadcast just after kickoff. PVI’s technology was used to make these images appear to actually be in the broadcast.

2) Select camera and perspective - An end zone camera at the stadium was selected as the broadcast camera and the four videos were rendered from this perspective in advance. This view was chosen to allow the animation to appear to pop up out of the end zone.

Fox and PVI knew there was a good chance that the line of scrimmage would be far enough away from the end zone - and the camera angle high enough - that no players would be “in front” of the animation. If they had been, the animation would have blocked them out.

3) Inserting the animations - PVI set up separate graphics files for the animations to be inserted into the broadcast video.

Each file is made up of four channels - red, green and blue channels that contain the actual color images, and an alpha channel. This black-and-white alpha channel creates a white “mask” wherever there is an image and a black area where there is to be no image and the video passes right through. This allows the animation to block out the grandstands and the end zone grass.

The alpha channel allows PVI’s computers to analyze the animation and send to the live broadcast video only those areas that are “masked,” or contain images. Computers keep the insertion stable and in correct perspective even as the camera moves. This is done 30 times a second, or once for each frame of video.

FIRST-DOWN LINE

1) On Camera - Regular network broadcast cameras on the 20-, 50- and 20-yard lines (25, 50 and 25 for PVI system) have computers attached to them that measure the pan, zoom, tilt and focus.

2) Production feed - Video streams from these three first-down cameras are sent to the network’s production truck where decisions are made on which camera feed to air.

3) First-down feed - Video - along with data from the three first-down cameras - then is sent to the production equipment facilities of Sportvision or PVI, whichever is on site. There, a central computer examines each frame of video and analyzes the action in real time at 1/30th of a second so that electronic decisions as to placement of the first-down line can be made.

4) Surveying the field - Other information has been fed into the facilities’ computers regarding the color of the field, the players’ and officials’ uniforms, shoes, skin tones, etc.

After each play of the game (as needed), an employee types in the yard number of the new first-down line. This information is combined with data from a 3-D model of the field (gathered at the site before the game) to determine the exact placement of a first-down line so that it appears correctly on your television.

5) ‘Painting’ the line - The actual line is created by changing the color of electronic pixels on the video that is received from the first-down cameras.

With the new yard line marker typed in, the computer looks for pixels along that line that match the grass - the background - but not the players and referees - the foreground.

This “occlusion” process makes the line look as if it were on top of the grass but underneath the players.

6) At home - TV viewers see the electronic line that the team needs to cross for a first down. The line is not visible to fans in the stadium.

VIRTUAL SIGNAGE

PVI has found a potentially huge niche in sports television with virtual advertising. The ads appear to be standard stadium billboards, but are actually inserted electronically. This allows advertisers to cater ads to a variety of markets reached by a broadcast. Ad space - and revenue - is not limited to static signage within a stadium.

In Europe and Mexico, PVI technology is used for ad insertion into soccer telecasts.

It also specializes in placing virtual ad products into movies an TV shows.

1) In baseball - Used in this country in some major league baseball broadcasts, the process is similar to that used to insert the virtual first-down line into a football game. Players “occlude” the ad/logo so that they appear to move in front of it.

The ad is usually placed in a blank spot on a backstop pad and viewed from the center-field camera. Pitch speeds, game time or other stats can also be used in conjunction with ad logos that appear to flip over.

2) Placing the ad - Video from the center-field camera is fed to the PVI computers on site where it is analyzed in real time. The insertion is adjusted to match the camera movement (pan, zoom and tilt). In some stadiums, camera data are also used to analyze the video.

A graphic file of each ad is prepared in advance, and when it is time for insertion computers determine which pixels of the ad to allow into the scene and which will be occluded.

PITCH/BAT SPEED

1) Tracking the pitch - Sportvision uses seven radars, similar to those police use, in an array around the backstop. Radar No. 1 tracks the pitch and when it detects movement of at least 50 mph, it triggers data capture from the other radars.

2) Tracking the bat - Radars aimed at the batter send microwaves out and receive a reflected signal back based on bat movement.

3) Processing - Data from the radars are filtered to reduce signal “noise,” then consolidated and sent over a single digital cable to a Windows NT workstation inside the Sportvision production truck on site.

4) Determining speeds - Sophisticated software then analyzes data from all radars and speed is determined based on the Doppler effect. The reflected signal has a higher frequency for incoming (the pitch) than outgoing (bat swing, batted ball) objects.

The difference in frequency between the radar gun’s signal and the return signal reflected off the pitched ball, bat or batted ball determines the actual speeds.

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Sources: Sportvision, Princeton Video Image, Times staff

Researched by Matt Moody / Los Angeles Times