An update on HDR and color management in KWin
zamundaaa.github.io
zamundaaa.github.io
The title however made my brain react negatively because too many corporations use “an update on…” to announce cancellations or similar negative news. Not the case here though!
It's just sad that we're days from 2024 and it's still impossible to create a web page with HDR photos in it that'll actually display correctly on... anything really.
There you go, HDR photos that display correctly everywhere. Bunch more information on this here https://gregbenzphotography.com/hdr-images/jpg-hdr-gain-maps...
It's what Pixel now captures by default as well.
I can’t use this technique to publish my photos to them.
I can use an Apple format to send HDR images to my friends and relatives with Apple devices.
I can use some other Adobe or Google formats to send pictures to my friends with Android (=Google) phones.
Etc…
We don’t have any new widely adopted open standards any more in today’s FAANG era of mutually antagonistic fiefdoms.
At best one of them muscles out the competing formats and that becomes a defacto standard.
For everything else we’re stuck with pre-FAANG standards established at a time when companies were smaller, didn’t “own” the whole stack top to bottom, and were forced to cooperate.
Google owns that hardware (Pixel), OS (Android), browser (Chrome), protocol (HTTP3, Brotli), codec (VP9, WEBM), and television itself (YouTube).
There’s an identical stack for Apple.
Why do you imagine it’ll ever be possible for Google user to send a full fidelity photo to an Apple user?
They live on opposite sides of a new iron curtain.
They’re not even permitted to text each other properly!
It's possible today. Apple may just not give you the ability to actually view the image though.
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
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.
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.
“Note for Safari / iPhone users: The top image on this page (the building with the before/after slider) uses a workaround which shows an HDR video as if it were a photo. This will let you get a sense of the HDR benefit, but you will fail the tests below as Safari / WebKit (which means all iPhone/iPad browsers) only supports HDR video and not HDR photos at this time.” :-(
What is the penetration rate? I mean is it a gimmick only wealthy people in the US use or will you find lower and middle class use HDR all over the world?
There are two competing implementations on the software side. Apple has theirs and Google has theirs. Since Apple will just quietly ship whatever they want forever, and Google has the attention span of a gnat, I suspect Apple's stack is here to stay and Google's version will be the HD-DVD to Apple's Blu-ray.
But our brains are also good at adapting for lower dynamic range images. We have no trouble recognizing a smudge of white with the same luminosity as a white wall as a sun glint, despite the real sun glint being thousand times more luminous.
I had trouble noticing that an HDR video is playing as SDR (due to player or browser limitations). Yes, something feels a bit off, but it's not that pronounced until you play the same video in HDR. Then the contrast (hehe) makes you see the difference clearly.
Not my experience at all. Maybe it depends on the content (as I previously said), but I discovered my Raspberry Pi firmware didn't support HDR yet because the reds were washed out. It looked plain wrong.
One nice side effect of HDR is that it forces the industry to tackle color management head first. This means going beyond sRGB as the default and often only option that had been the norm for decades.
And by HDR I don't mean "LCD screens that have huge segments of backlighting that are made to shine more". I mean actual HDR like iPhones have.
People are still buying laptops with 1366x768 screens in 2023. People still buy things because they are the cheapest available with no concern for features.
For phones, OLED is already in the mid-range market. It won't be that long until there are more HDR-capable screens than non-HDR screens.
Yes, but no.
It's a gimmick because invariably it becomes over-used in some streaming TV shows as a "special effect", which breaks the immersion.
However, it's not a gimmick as used by hundreds of millions of people.
Something I noticed with the new HDR support in Adobe Lightroom is that proper HDR "simply works" by default, whereas it is actually SDR that takes a lot of manual "color grading" and general fiddling about with sliders to not look terrible.
HDR is essentially more faithfully representing the light as it is in reality, whereas SDR is a combination of aggressive tone mappings to make it "fit" into a tiny gamut.
I went back to look at some Nikon RAW[1] photos from as far back as 2013 and turned HDR mode on. Those photos instantly looked not just better, but more correct, as if I had spent an hour adjusting them in Lightroom!
This is why Apple iPhone photos just look better (on other iDevices!). They're not using AI magic[2] to colour grade them like a Lightroom professional, they're instead leaning on the HDR mode to simply show the photos accurately, without the need to aggressively tone map them.
This is why HDR photography is actually the vast majority of photography now, easily outnumbering professional photographers (and videographers). It's the path of low resistance to a good quality outcome, which makes it very attractive as a consumer image capture/display technology, especially mobile phones. The vast, vast majority of mobile phone users tap the shutter button, and will never adjust the colours, contrast, or any other image setting. It is HDR mode that enables this to "just work" and not result in photos that look like they were made with a potato.
[1] Most professional photographers and serious hobbyists shoot in RAW format, which has always been a "HDR" format in all but name, typically capturing about 12 bits per channel instead of the 8 bits typical of SDR.
[2] iPhones do actually use a lot of computation photography and AI magic, but the point is that for tone mapping and colour grading they need a lot less than they would have without HDR.
> Most professional photographers and serious hobbyists shoot in RAW format, which has always been a "HDR" format in all but name, typically capturing about 12 bits per channel instead of the 8 bits typical of SDR.
While RAW captures do have a greater dynamic range than your typical 8-bit sRGB image, they are still fairly limited compared to lighting conditions in the real world. There are plenty of scenes you won't be able to accurately capture in a single exposure even on high end cameras.
Also it's worth pointing out that using 12-bit RAW formats doesn't mean that there is 12 bits of useful information per pixel. At some point all you are doing is storing more precise noise. This is even more of a problem for phones with tiny lenses and image sensors - which is why they often take many exposures and magic them together into one image.
monitors no, but displays yes. A huge number of phones from the past few years all have HDR displays. This is largely driven by the need for bright displays independent of HDR (ie, sunlight viewing), so HDR comes along "for free" and you might as well enable it.
IMO it would be really nice if one could easily profile one’s actual screen with a colorimeter and this were integrated with HDR support. Presumably one would separately profile in HDR and SDR mode. This ought to allow a compositor to give good SDR results in HDR mode.