Called SkyMap, the system relies on an additional datastream sent from the helicopter with the live video. The data includes the current GPS position of the helicopter, the direction in which the camera is facing, and it's zoom level.
The data coming from the helicopter is processed by computer mapping software, which then generates a virtual map giving the same view as the real camera. The mapping software is already programmed to place labels over landmarks on the map, just as Google Earth does over its images.
NHK takes the label layer from the map image and overlays that on the live video image. (A video showing the system in-use and other new broadcasting technologies from NHK .)
If the system is precise enough, they should match up.
In a demonstration of the system at the broadcaster's headquarters on Monday, the system worked well. The demo fed recorded images to the system, but the mapping overlay was being done live in real time over the images.
Slight delays or inaccuracies in the GPS data meant the labels sometimes strayed, but usually only by a few meters from the intended location.
NHK expects SkyMap to be useful during live news, especially when covering earthquakes.
The broadcaster frequently relies on helicopter images during immediate broadcasting after quakes, and the location shown in the live video is sometimes not immediately obvious.
The system was demonstrated alongside other recent innovations by the broadcaster.
One, called Twinscam, provides a new view of watersports like synchronized swimming.
Traditional coverage of the sport switches between cameras above and underwater. It's not possible to use a single camera to capture all the action because of the different way light refracts in air and water.
With Twinscam two cameras, one underwater and one above the water, have their zoom and focus synchronized to produce a single, realistic image. The result is an image that perfectly matches the above and underwater shots for a complete view of the performance.
NHK used the system at last year's Japan Open synchronized swimming championship and hopes it will be used at next year's London Olympics.
It also showed a Mitsubishi iMiev electric vehicle equipped for live broadcasting. The car has all the equipment needed to support and switch up to four video sources, and send back a live signal. The car's main battery provides a 100-kilometer range and a second battery can power the equipment for up to 2 hours.
Calling it cramped might be an understatement, but the car will allow NHK to broadcast from residential areas where trucks can't go because of noise or narrow streets.
The IDG News Service