The term HDR has become public knowledge, but creating a single standard to define image dynamic range to add to what Rec. 2020 gave to UHD, and perhaps offer the longevity of Rec.709, is the immense responsibility of ITU-R RG 24 and its chairman Andy Quested, head of technology at BBC UHD and HD.
“All eyes are turned on me. They are, I know it,” he said. “I am not a chairman. I am a referee.”
Quested started with four different proposals for HDR TV, submitted through national administrations (like OFCOM and the FCC), which have the power of veto, or sector members who do not. Those four technologies came from Dolby, NHK and Philips (all at the show) and Technicolor.
“You cannot have a standard with four options. What we are trying to do is merge the proposals into a document with a single proposal but with one or two applications,” said Quested. “OETF is essentially how you set a camera up, and EOTF is how you set up a display. We are looking at trying to combine the signal path into something called an OOTF (Opto Optical Transfer Function). If we can get a single definition of an OOTF the camera can be what’s called informative.”
How did Quested whistle in the obvious vested interests? “Fundamentally I have to get everybody to agree. It is not about putting one system against another and making a decision,” he said. “It is about putting up a proposal that is not objected to by any admin. Any ITU standard is agreed worldwide, which means it takes a long time to ratify. But it will last a long time and the industry will build to it.”
RG 24 is working on a flexible standard. “I don’t believe we will replace 2020 but it could be an extension to it. The group is within a meeting of having a framework document, but I think there will be objections coming from certain admins,” said Quested.
“I hope they are not objections on the grounds of ‘ you didn’t use our technology’, which is always a risk. I think it will just be a change demanded to slow everything up,” he added.