Beyond HDTV

The future of television got a test-drive recently in New York City. While consumers around the globe are just now getting acquainted with the vivid picture quality of high-definition television, or HDTV, a far more advanced super-high-resolution system is in the works. NHK, Japan's public broadcaster, is working on what it has dubbed Super Hi-Vision: a TV technology—not expected to be commercialized for a decade or more—that produces live video with a resolution 16 times that of today's HDTV and twice that of 70-millimeter movies. The New York City test was recorded for display at a convention of broadcasters who were meeting in Las Vegas.

Last November, NHK conducted its first live test in the field, when it transmitted an uncompressed 24-gigabit-per-second SHV video signal for several hours, producing a picture with a resolution of 7680 by 4320 pixels. The live video was relayed over 260 kilometers of optical fiber and viewed on a screen measuring 10 meters by 5.5 meters. The transmission also included a technically swank audio scheme, with more than 22 channels, to match the video's high resolution. To shoot the live transmission, the researchers used two custom-built cameras equipped with four 8-megapixel CMOS sensors.

Months before, NHK had shown off an 8-minute SHV video to visitors at the 2005 World Expo held near Nagoya, from March to September last year. After postproduction the movie weighed in at 1.4 terabytes and had to be stored on a hard-disk array.

"The typical reaction of the audience was 'Sugoii!' ('Wow!')," says Masaru Kanazawa, a senior researcher engineer in NHK's Science & Technical Research Laboratories, in western Tokyo. He says some 1.6 million Expo attendees watched the video, and many were astonished with the heightened sense of reality it evoked. He attributes this in part to the video's clarity; the system's wide viewing angle of 100 degrees, as opposed to HDTV's 30 degrees and the 15 degrees for standard television; and the advanced audio system. "They felt they were a part of the same scenes," he says.

Despite making such technological progress, NHK's researchers are quick to caution that commercialization of SHV is years—and maybe decades—away. And there are lots of technical and political hurdles left to leap. For instance, the company is working to have the format accepted as an international standard by the International Telecommunication Union-Radiocommunications, which regulates radio spectrum. If an agreement is reached, Kanazawa says the proposed standard could be published as early as this year, and then member countries would get to vote on it.

Perhaps a much greater hurdle SHV faces is further developing the technology so that it can be used for broadcasting. Because of the huge amount of data involved, today it only works over optical fiber. But NHK is looking to one day transmit it via satellite in the 21-gigahertz band range. To do this, NHK's researchers will likely need to come up with some form of algorithm-based digital compression that will bring the data rate down from 24 Gb/s to a somewhat more manageable 200 to 400 megabits per second.

Of course, none of it will matter unless consumers have affordable displays that can reproduce the camera's high resolution. And broadcasters need the cameras to be less complex as well as smaller. Given such obstacles, NHK is targeting 2025, the company's 100th anniversary, for the actual commercial launch of SHV.

[ Editor's note: Technical reasons prevent the proper display of the high-resolution digital images from NHK's new Super Hi-Vision TV camera. We apologize for any inconvenience.]

Related Stories

Advertisement
Advertisement