I'm not judging which is better or worse as it would indeed be nice if the calibration could be controlled by the OS. I'm just saying that adjusting the monitor hardware directly is what's being done in the pro linux content creation world. Also, I imagine that certain brightness and color gamut controls could only happen from the bezel controls. Dreamcolors can switch between srgb & P3 for example.
it's good to know that you've found the controls sufficient on the systems you have adjusted!
When it comes time to implement the color management stuff into Wayland, it's declared out of scope for the core Wayland protocol, but don't worry guys -- someday, somehow, a consortium led by GNOME will implement it on a DBUS interface that all compositors will understand. At least two, mutually incompatible, such protocols emerge, neither of which fix the underlying issues, both of which are tied to particular compositors.
Meanwhile, we are told that X11 is still horribly, irredeemably broken in this regard and if we haven't yet switched to Wayland, we really should by now.
The professional colorist industry goes on using Xorg on Linux.
Then the layers up the stack like Wayland/X/GNOME/KDE are just messengers to/from the bottom @ drm.
We also need floating point frame buffers to be first-class citizens at the KMS level. I don't want to be forced into OpenGL/Vulkan just to be able to have the hardware apply gamma correction on a software-rendered frame buffer, and if I have the hardware do color correction, it kind of needs the HDR of floats - not uchars, which I don't think libdrm supports with dumb buffers of today. If not floats, at least more bits than 8 per color component.
Programs like Plymouth or other embedded style applications running directly on libdrm should be able to have color-corrected output without needing bespoke software implementations and their own calibration tables. I should be able to tell the kernel the correction table, maybe compile it in, or another payload on the boot parameters cmdline.
Hell there are fairly well-known simple algorithms for generating approximate color tables from a single gamma value. If I only want to make things look "better" in my linux kiosk, and care not about absolute color correctness, let me stick a drm.gamma=.55 field on the kernel commandline to generate the correction table in lieu of a full calibrated table.
Or is your point that it's substantially more complicated than it appears, and I'd know that if I tried doing it myself?
(not challenging, just asking, I know next to nothing about color correction)
If by "video LUT" you mean something at the CRTC or even after it on some external device, if the software producing the visuals has already reduced the pixels down to 8-bits-per-component before they hit the LUT, then you've lost accuracy particularly in the small values.
This is why it's desirable to do one of the following:
1. inform the software of the LUT and let it perform the transform before it packs the pixels for display
2. change the entire system to have more bits per color component all the way down to the framebuffer, then the per-component LUTs at the CRTC can profitably contain > 256 entries.
I'm not an expert in this field at all, just play with graphics hacks. But this is what I've come to understand is the nature of the issue.
edit:
To clarify, the reality implied by the need for correction is that some areas of the 0-256 range of values are more significant than others. When you do a naive linear conversion of whatever precision color the application is operating in down to the 24-bit rgb frame buffer, you've lost the increased accuracy in the regions that happen to actually be more significant on a given display. So you'd much rather do the conversion before throwing away the extra precision, assuming the application was working in greater than 24-bit pixels.
Thus your software has to know what your display is capable of. It can use this information to show you which parts of the photograph you edit are not shown accurately.
Sounds like an easy thing to fix. I'd suggest the author to try and make some patches - don't know about GNOME, but KDE is pretty friendly and easy to contribute to.
It's not just saying "Hey you, go fix that." , it's saying "Hey everyone viewing this comment on a public page : this exists and needs to be fixed. Someone grab a wrench."
Well, at least when ignoring the UI/UX mention that has absolutely nothing to do with the discussion here (color correction is required in many fields, but UI and UX aren't really those ones).
The author seems to be technical enough to make a nice analysis of what's done and what needs to be done. I suspect he might be able to provide this particular fix himself - or, if he isn't, then he might be able to contribute by providing a well-detailed feature request for others to implement (with that even I might be able to go and fix it, while without it I surely won't, as I lack the knowledge, hardware and in fact even awareness of this problem; only reading this post put some light on it for me).
Some people don't do the mental switch between "I'll wait for fix" and "I'll fix it" if they're not used to it, even if they are perfectly capable of fixing it and have time for it. I see it on my own example, as there were some parts of the stack I never really considered digging into to fix stuff by myself, and when I finally tried, turned out there was no reason to keep myself restrained. It's just a friendly reminder that you can often fix such stuff by yourself and it might be not as hard as it seems.
Source: colord author.
At the other end of the spectrum, when the target audience is comprised of a small number of professionals that don't code, for example advanced graphic or music editors or an engineering toolbox, open source struggles to keep up with proprietary because the economic model is less adequate: each professional would gladly pay, say, $200 each to cover the development costs for a fantastic product they could use forever, but there is a prisoner dilema that your personal $200 donation does not make others pay and does not directly improve your experience. Because the userbase is small and non-software oriented, the occasional contributions from outside are rare, so the project is largely driven by the core authors who lack the resources to compete with proprietary software that can charge $200 per seat. And once the proprietary software becomes entrenched, there is a strong tendency for monopolistic behavior (Adobe) because of the large moat and no opportunity to fork, so people will be asked to pay $1000 per seat every year by the market leader simply because it can.
A solution I'm brainstorming could be a hybrid commercial & open source license with a limited, 5 year period where the software, provided with full source, is commercial and not free to copy (for these markets DRM is not necessary, license terms are enough to dissuade most professionals from making or using a rogue compile with license key verification disabled).
After the 5 year period, the software reverts to an open source hybrid, and anyone can fork it as open source, or publish a commercial derivative with the same time-limited protection. The company developing the software gets a chance to cover it's initial investment and must continue to invest in it to warant the price for the latest non-free release, or somebody else might release another free or cheap derivative starting from a 5-year old release. So the market leader could periodically change and people would only pay to use the most advanced and inovative branch, ensuring that development investment is paid for and then redistributed to everybody else.
I've wanted to know whether two colors I'm displaying actually get distinguished by the monitor or if the LIST maps then to the same output value.
What platforms do they all use? Not Macintosh, despite its reputation for being the platform for "graphics professionals" (it was missing 10 bit/channel color until very recently). And not Linux, despite its use in render farms.
They use Windows 10 and HP DreamColor monitors. That's the only platform that works and works well for people who need to care about color.
Further, HP Dreamcolors have tons of problems and aren't considered solid for color critical work (but are fine for semi color accurate stuff like intermediate comps etc). Color accurate work is done over SDI with dedicated LUT boxes handling the color transforms and the cheapest monitors being $7500 Flanders Scientific Inc 25" OLED panels.
A while ago I had a look at Eizo's 10 bit / channel TFTs, which looked impressive to me (from a layman's perspective), do you have any opinions of those?
This sounds pretty interesting. What do you actually do, in layperson-y terms?
That's for rendering, where the OS and Desktop experience doesn't really matter, and the cheaper it is the better.
Few pros do the actual editing and color work (where the decisions are made, not the rendering part) on Linux.
I currently work for a media conglomerate where colour tends to matter a lot to both the print and digital channels. I'm not sure which monitors they use as I tend to work rather separate from that group, but they all work on Macs—that's been the case since the late 80's early 90's in publishing and there seems to be no move to stray.
Higher end displays are already pretty decently calibrated out of the factory, but if you want to be exact you will need to buy an external piece of hardware that will measure your display’s colors and tell you how off they might be.
The author bought a piece of color calibrating hardware that was meant to be open in design and work with Linux, as presumably he wants to support these efforts.
But he encountered a bevy of problems, ranging from packages not updated in a while to things that just plain don’t work as documented, and got frustrated.
Understandable, since on macOS or Windows with proprietary hardware, this would have been a 5 minute process. The author is sad and frustrated that the open source alternatives aren’t there.
This is true with even the highest quality color critical displays like we use in film/tv color correction ($5-$50k+ for 25" panels).
Spending €100 also isn't an insignificant amount, and for that price I would expect what I'm buying to work properly.
