Re:An update on HDR and color management in KWin
by amluto on Wednesday December 20, 2023 @03:27PM
(#38713176)
Something is utterly busted about the spec and the patent system. Look at the Swift code for decoding the headroom! It stinks — maybe Apple tried a few different transfer functions or for size and didn’t bother to mark which version was in use? And now Apple is kindly offering to license the patent if this goes into an ISO standard?
I’m sorry, but a system to decide old nonsensical formats should not require a license.
Also… the gain map is subsampled 1:2. Surely this will cause annoying artifacts at sharp edges where one side is much brighter.
Re:An update on HDR and color management in KWin
by kllrnohj on Wednesday December 20, 2023 @05:57PM
(#38714766)
> And now Apple is kindly offering to license the patent if this goes into an ISO standard?
The one that's likely to go to an ISO standard is the Adobe spec here: https://helpx.adobe.com/camera-raw/using/gain-map.html (which is the same as Google's "UltraHDR")
And that has a blanket public grant for usage.
> Also… the gain map is subsampled 1:2.
Subsampling is optional, you can do 1:1 if you want.
Switch your iPhone to use "high compatibility" or something like that and it'll spit out jpegs with hdr gainmaps that chrome and Android understand as well now. It's not the Adobe spec, but given Apple is now publicly talking about gainmaps ( https://developer.apple.com/documentation/appkit/images_and_... ) and the Adobe spec is a superset of capabilities with a patent-free license and an ISO draft proposal it doesn't seem unimaginable that Apple will move it.
But if Apple won't ever support it, that doesn't mean iPhones can't view it. You already can today with the latest version of Lightroom. And of course Chrome on MacOS already lets you view them. Apple's iOS browser monopoly is hurting you here, but that's very obviously an exclusively Apple created problem