Display colour profile

[ygoe]

Hello,

I think I already know what colour management and colour profiles are about and how they work in theory. But I'm having trouble putting this into practice.

Until now I've only used (almost) sRGB displays and sRGB images, so there wasn't ever much of a difference to be seen. My focus was more on the CMYK side. Now I've got a new laptop from Lenovo that has a "DCI-P3" display. But it behaves really weird. I've done a fresh installation of Windows 11 with all updates from all sources, including drivers and a display colour profile named "Notebook PC Internal Display". The device produces really warm colours. Comparing with my sRGB desktop monitor and a custom blue light filter app, it could be around 5000 to 5500 K. According to the EIZO online monitor test, the gamma is around 1.7. The reds and greens are really intense. So this looks like a wide-gamut non-calibrated display to me.

Then I took my Spyder 5 colorimeter and the DisplayCAL software like I used to in the past. It has created a profile for me with the desired whitepoint of 6500 K. The white now looks good, it all got a bit darker (I probably lost some of the contrast, too). Colours are still very intense though and the gamma is unchanged at 1.7.

I've exported a photo I took with Lightroom and set the export colour profile once to sRGB and once to Display-P3. In IrfanView, differences are visible on both computers. When using both as Windows desktop wallpaper on the laptop, they look identical though. Still intense colours, with or without my new profile from DisplayCAL.

When I open both images in Affinity Photo, they look good either way. Some profile even seems to be applied for display when I deselect the new profile from Windows settings. I have no clue what's going on here. Can somebody please explain what all these settings are for? Colour profiles can be set in Affinity Photo settings but have no effect. I can reassign a profile to an image, that's visible then but probably wrong. What is the effect of setting the profile in Windows display settings? Either by using Windows or DisplayCAL to "load" the profile. It has the same effect, but in incomprehensible ways.

What I want is: correct sRGB colours everywhere and the wide gamut in supporting apps where I want it. Can this be achieved at all or will I have to live with a randomly-calibrated display that's far from sRGB and P3 (despite being advertised as "100% DCI-P3") because Windows has no idea about colour profiles? I could manually hack my desktop wallpaper but what about all images in Firefox, Word and other applications?

[lacerto]

Obsolete.

[RichardMH]

Bit hard for me to understand what your problem is, but I suspect this

 

 

[NotMyFault]

Still valid

https://affinityspotlight.com/article/display-colour-management-in-the-affinity-apps/

[v_kyr]

See also for Win ...

• https://pcmonitors.info/articles/using-icc-profiles-in-windows/

[ygoe]

Alright, thanks for the explanations. Meanwhile I made some progress.

So I understood that a wide gamut stays a wide gamut unless an application really fully understands a colour profile. Only select apps can do that, like Affinity, Chrome, Firefox (under certain circumstances), IrfanView (when options are enabled). But not Explorer. Explorer even does it all wrong. It seems to interpret embedded profiles and intentionally break the rendering. So desktop wallpapers are never correct (unless manually hacking the file with a wrong profile, as described in the video).

The colour profiles I can select in Windows might be a nice hint for colour-managed apps, but Windows itself can only apply a little portion of it (the R/G/B gamma curves). This can basically change the white point but not how the primary colours red, green and blue look like, i.e. their wavelengths and saturation.

My display and vendor profile and apps were so off that I didn't know what is wrong or right. But after some asking and exploring, I found out that the AMD software seems to have some sRGB simulation mode. It's labelled as something completely different and generic, and it's not completely there yet. But it does the gamut conversion for the entire desktop and all apps, probably by instructing the GPU or DWM (desktop window manager) or something like that. I could correct the white point with DisplayCAL from there. A verification suggests that my display is now well calibrated to sRGB. This shows a correct desktop wallpaper and all other apps do the same.

BTW, the wrong gamma value was a wrong measurement. The test pattern was disturbed by the display scaling to 250%, and the test warned me about that. At 100% scaling all is correct around 2.2 to 2.3.

I know that I cannot access the wide gamut of my display anymore in this state. If I need it again, I'll have to disable the setting in the AMD software and recalibrate my display to that mode.

Windows 11 22H2 seems to have some experimental feature called "ACM" that would do the gamut correction and all else for the entire desktop. (There was a Microsoft blog post from October 2022 somewhere.) It could interfere with colour-managed apps so it's not publicly available yet. But it wasn't working at all on my system, so maybe it was removed again. Hopefully, one day Windows will completely support colour profiles. Until then, I'm fine with the sRGB gamut as I've been for the past decades. I have no other content sources anyway.

[lacerto]

Obsolete.

[ygoe]

Unfortunately, this laptop doesn't have any monitor buttons. The last laptop that I've seen with monitor sliders (not buttons) had a monochrome slow LCD panel with some VGA resolution and I think a 286 CPU.