"Settings Dialog" Page in Documentation: Color Management: Ensuring Accuracy When Using "sRGB mode"

[digpz]

The "Setting Dialog" page in the documentation says if the user is using a non-HDR monitor, "accuracy is only assured if the display itself is also configured for sRGB color display."

 

If the user configured their monitor for sRGB colors by changing settings in the display's hardware and telling the operating system to use a color profile, does that fulfill the requirement to configure the display for sRGB color display?

 

Or, is something else necessary such as using a display with built-in LUT storage (e.g. the DM160 from Flanders Scientific Inc.)?

 

In case it helps, here is a specific scenario.

 

I have a Dell P2418D connected to a Windows 10 (Version 22H2) computer. The display has been configured to expect an "Input Color Format" of RGB and the whitepoint is 6499K. The target whitepoint was 6500K. The brightness is 120.3 candelas per square meter (cd/m2). These settings were set by following the instructions in the user manual in conjunction with a spectrophotometer (ColorMunki Photo).

 

Next, a display profile was made using the same spectrophotometer. The profile targets sRGB. The profile is loaded automatically in the background by the DisplayCal Profile Loader.

 

Applications such as Firefox (gfx.color_management.mode = 1) and GIMP accurately show colors using the profile that was created with the process described above.

[Rick Brewster]

1 hour ago, digpz said:

If the user configured their monitor for sRGB colors by changing settings in the display's hardware and telling the operating system to use a color profile, does that fulfill the requirement to configure the display for sRGB color display?

 

It depends on a lot of factors, and it's actually very difficult to give you a correct answer. This is the big reason why I've been pushing towards HDR/WCG mode: a lot of those factors just go away. In these modes Windows will color manage the entire desktop. All apps will display correctly and you won't have to configure color management for each one separately. Apps will either output pure sRGB, or if they use Advanced Color (like PDN, Chrome, and many games) they will get access to the full color gamut of the display without having to load and parse and deal with "color profiles" (these apps will render with either the scRGB or BT.2084/HDR10 color space). The display will tell Windows about its native color space, and then you can also load an MCH2 color profile for calibration purposes. Windows will then do the right thing for the entire pixel pipeline (app -> GPU -> display), automatically converting from sRGB, scRGB, or BT.2084/HDR10 to the display's actual color space. (Paint.NET uses scRGB)

 

If you want a properly color managed workflow in Paint.NET then you really do want to use Windows 11 v24H2 and to then enable Wide Color Gamut (WCG) mode. Instructions for enabling WCG mode are in PDN's Settings -> Color Management. HDR is its own bag of craziness, it's so difficult to configure properly that I can't give any solid, generalized advice for it. But WCG mode is usually just enable it and forget about it. (WCG is still "SDR", but with access to the display's full color gamut, and auto color management for the whole desktop just like in HDR mode.)

 

Paint.NET will not load or use the display's color profile that you have in the Windows Color Management control panel. I'm not familiar with DisplayCal Profile Loader so I don't know if it's expecting apps to do their own color management, or if it's modifying the later stages of the hardware display pipeline in a way that affects all apps. My Lenovo P16 had some X-Rite software that does the latter.

 

My best guess is: your monitor appears to be a pure sRGB display (it lists "99% sRGB"), so it will probably work the way you're hoping even with the display configured for "SDR mode". The color profile you're using seems to be for calibration, not for describing the display's color gamut and other factors. If your monitor was using a native color space of, e.g., Display P3, then this would be an entirely different discussion. So I would load up some images and compare how they appear in other apps whose color management you already trust.

[digpz]

On 11/28/2024 at 3:25 PM, Rick Brewster said:

Paint.NET will not load or use the display's color profile that you have in the Windows Color Management control panel.

Thank you for the lengthy response, especially the bit I quoted.

 

The DisplayCal loader is meant to act almost exactly the same way as the Windows Color Management control panel's profile loader.

 

I will not expect Paint .NET to use the profile.

 

Although I cannot upgrade to Windows 11 right now, others who are running Windows 11+ and have a DisplayCal-generated profile may find https://github.com/dantmnf/MHC2 useful. Users in a thread asking about generating Windows Advanced Color-compatible profiles reported that it allowed DisplayCal-generated profiles to be used with Windows Advanced Color.

[Rick Brewster]

Ultimately, the future of color management in Windows is via Automatic Color Management, Advanced Color, and MCH2 profiles. You want HDR or WCG mode, in other words. SDR mode should be considered legacy and deprecated. It will take years for the broader ecosystem to adapt and migrate in this direction, but eventually we'll all get there.

 

I did have support for display profiles in SDR mode in an early beta of PDN 5.1, but I threw it away because it was an unmaintainable mess. Win32's legacy APIs for color profiles and color management are a nightmare full of bugs, inconsistencies, poor documentation, and things just never seem to work right. Deferring all color management to the OS is a much simpler direction to go in.