INDIAN WELLS, CALIF. –
Why bother with 4KTV, or UHDTV, or Ultra-HD, or
whatever name implies the developing generation of higher-resolution
television? One of the key questions is whether or not anyone will notice the
difference, and if it’s significant enough for people to go out and drop a dime
on a new TV set after just paying off the HDTV. The European Broadcasting Union
set about to find out.
“The first think the EBU tried to determine is if viewers could see the
difference,” said Hans Hoffmann, EBU’s head of fundamentals and production.
The EBU assembled 72 volunteers at one of its own conferences to test UHDTV,
using what Hoffmann referred to as UHD-1 material—3,840x2,160 pixel resolution
images collected at 50 frames per second collected from Sony F65 test shoots.
It was cropped from 4K to 3,840 pixels horizontally. Copies were down-converted
to make the HD-UHDTV/4KTV comparison. HD resolutions used included 1080p/50,
720p/50 and a conversion of the 1080p/50 to 1080i/25 using an HHI filter and
Test footage was run on a 56-inch “UHD-1” monitor that was not, “Grade 1,”
Hoffmann said. Six sequences were shown of the four resolutions, including
UHD-1. Two viewing distances were used—1.5 times picture height, the standard
distance for viewing UHD-1, and 2.7 meters, the average domestic viewing
distance in the United Kingdom.
Samples were shown in 12-second sequences. Participants were asked to rate them
bad, poor, fair, good or excellent.
Between 720p, 1080i and 1080p, there was no conclusion of perceptual difference.
There was a “statistically relevant, but very small,” perceived improvement of native
4K content when it was presented on a UHDTV screen,” Hoffmann said.
“The results are only applicable for uncompressed sources,” he said. “Transmission
compression may change results significantly…. In order to create an immersive
impact, resolution alone will not make the difference… to make consumers go
into shops and buy theses screens.”
More frames are also necessary for motion portrayal, and so the full
distribution eco-system must be able to handle higher frame rates. There are
cameras and displays for 60 fps, but nothing in the middle, he said. The same
goes for higher dynamic ranges.
Motion-blur improvement with a higher frame rate would still be perceived at
higher viewing distances,” he said. Object high-dynamic range improvements
likely would be perceived, as well as object color improvements and higher bit
For now, he provided the following advice: Relax. HDTV investments remain
“UHDTV is a mid-longer term development,” he said.