The organisation demoed its wares at an open house event at its Science & Technology Research Laboratories, including an 8K satellite link with a camera on Tokyo Bay.
8K - actually, 7,680 pixels by 4,320 pixels, has 16 times the resolution of standard HD and four times that of 4K TVs. Uncompressed signals can run about 24 gigabits per second (Gbps) or even 48 Gbps at 120 frames per second. It also has a 22.2 multichannel sound system.
NHK will conduct trial 8K broadcasts for the Olympics next year ahead of regular public programming in 2018. When Tokyo hosts the Games in 2020, however, viewers may be able to create their own custom broadcasts with a service called Hybridcast.
Launched in September 2013, the broadband service lets viewers see interactive graphics and information linked to a program they're watching, such as the map of a golf course and leader boards below live shots from a golf tournament. In a demo, NHK staffers showed the latest Hybridcast improvements for 8K in which viewers can create their preferred cuts of a given broadcast.
Viewers using HTML5 tablets linked to the Hybridcast service can record brief segments of 8K video at will and even choose their preferred angle when multiple cameras have been used. Four camera angles taken from a Japanese pop band concert were displayed on the tablet and, once selected, the preferred angle was seen on a large-screen TV nearby.
"The viewer is almost acting like a switcher in a TV studio," an NHK staffer said, adding the company hopes to begin test offerings of the service in 2018.
The broadcaster also demonstrated a Hybridcast video player that works with the MPEG-DASH streaming protocol. The player was linked to a Hybridcast TV, as well as browsers on some nearby mobile devices, such as tablets running Chrome and Explorer and a laptop running Safari, so that they all played the same content simultaneously. The technology is able to monitor the reception status of linked devices.
Another improvement to Hybridcast involves synchronizing real-time Internet data sent from sports events with the broadcast signal itself. While the data, such as real-time player stats, are usually quicker than the TV signal, they can be synchronized with it by aligning broadcast reference clocks with Coordinated Universal Time. That way, viewers see the stats as the action happens.
The NHK lab also tried to wow visitors with eye-popping 8K video of parrots and chameleons projected on a 450-inch movie theater screen. The 8K projector was developed by NHK and JVC and can take full-spec 8K signals at 144 Gbps through a single optical cable.
For smaller displays, however, the difference between 4K and 8K resolution becomes difficult to see, raising the question of whether there will ever be a 16K resolution standard.
"We've studied the human eye and find that it cannot distinguish resolution, in terms of 2D television, beyond 8K," said Kenichi Murayama, a senior manager at the lab. "So NHK isn't talking about going another step beyond 8K."
Tim Hornyak covers Japan and emerging technologies for The IDG News Service. Follow Tim on Twitter at @robotopia.