DxO Photolab color management on Windows

mjdl · January 7, 2025, 5:42am

I have submitted a support request with the following text, but I also want to see if anyone in the Windows Photolab forum can clear up my confusion:

I don’t understand the logic in support article https://support.dxo.com/hc/en-us/articles/7063819737501-Why-is-the-ICC-profile-used-for-display-option-missing-from-the-Preferences-Common-options-Windows-only?input_string=multiple+screen+display+profiles which has the title

Normally in every other professional editing software, the display profile assigned by the user to a particular screen display in the relevant Windows operating system display setting is used by by the editing software to translate the image color values represented in the internal working color space used by the software to the equivalent color values of the individual display screen, i.e. the familiar ICC model of how display profiles function.

In the case of a person using two or more display screens on Windows, each having a distinct calibrated display profiles, either (1) the photo editing application queries the operating system for the display profile used on the display screen where the user started the application, or, much better, (2) offers the user (in the program’s preferences) a drop-down list of current display profiles installed on the user’s machine, so that the user cam move the application window to another non-primary screen and select the proper calibrated profile for that screen, after starting the program (the two methods can obviously be combined for convenience).

Photolab’s main program window will start up and open on a user selected non-primary screen only when the user has initially moved it to that non-primary screen and exited the program one time. On the next start of Photolab, the little start-up window stills opens on the primary screen, followed by the main program window on the user-selected non-primary screen. The user still has no way of determining which ICC display profile is being used by the main window, is it the profile used by the primary screen where the little start-up window appeared, or the one used by the screen on which the main application window appeared?

As I understand soft-proofing with ICC profiles made for a particular output device, soft-proofing is a subsequent transformation which works in conjunction with display profiles in order to simulate the colors of the output device.

So, In Photolab’s case, the internal working space is “DxO Wide Gamut”; image data is transformed from that color space to the display color space while editing an image so that colors are correctly displayed; Photolab offers an option to mark image colors that exceed the gamut of the display device; Photolab also can soft-proof an image using a particular output device’s ICC profile, and here can also can optionally mark image colors that exceed the output device gamut.

What confuses me in the cited DxO support article is the statement “With the introduction of the new Wide Gamut color space in DxO PhotoLab 6, this option has been dropped. You can achieve the same result using the soft prooﬁng tool, which is intended to replace the functionality of this option in an easier and more widely applicable way since it lets you choose a display proﬁle directly from the palette.”

So does Photolab perform standard ICC image display color management only when using the “soft-proofing” feature with the display profiles I have created for each of my screens? In other words, normal image editing without using that feature just sends un-transformed, un-managed internal color values to the screen, i.e. disables any ICC color management for the display screen?

KeithRJ · January 7, 2025, 6:48am

What option has been dropped? From your text I cannot tell what function no longer exists. I can’t think of any function DxO dropped when introducing their wide gamut colour space.

Everything you have said indicates you have a good understanding of colour management and how PL works in the windows environment.

John-M · January 7, 2025, 10:08am

The heading of the article referred to by the OP is: Why is the “ICC profile used for display” option missing from the “Preferences/Common” options? (Windows only)

Followed by;

With the introduction of the new Wide Gamut color space in DxO PhotoLab 6, this option has been dropped.

That is; prior to PLv6 there was a Preferences option to allow the user to specify the ICC profile used (by PL) to display the image being worked on - with the following choices;

Now, with PLv6 +, the first option (“Current profile of the display device”) is the default … and any other choice of ICC Profile is handled by the Soft Proofing tool.

The key question being asked by the OP is;

I’m not definitely sure about the answer, but I’m pretty sure that PL adapts to whichever display is being used by the main window … as the default option states.

For more info on the Colour Management pipeline, see here.

John7 · January 7, 2025, 10:33am

I wish I was confident in that’s what they do. The article was basically saying nothing on what happen from V6 on color management which is why most readers of it marked it as unhelpful. My primary screen is an old calibrated Dell but my working screen is a Benq hardware calibrated to Adobe RGB so yes it is of interest where PL takes its calibration from. At one stage PL couldn’t deal with hardware calibration, I think they over came that but if its taking it from the opening screen who knows what they use as they do not appear to really be saying what they do.

mjdl · January 7, 2025, 1:46pm

Thanks for the reference to the user created color management document and the subsequent long thread about PL color management, something I didn’t know about. I’ll read them over the coming days. Also, perhaps the DxO support article/FAQ was originally in French, poorly or only partially translated and I should read the original version.

In any case, there has to be a clearer and more complete official explanation of the PL color management and its relation to the usual ICC concepts. The manual & whitepaper are a bit summary in that respect, I think.

mjdl · January 7, 2025, 1:57pm

I have edited the original post to clarify this, as well as correct a few other late-night deficiencies.

George · January 7, 2025, 2:08pm

May I post this copy out of The Manual of Photography again.

Examine the diagram and read the text under it.

The only thing I can’t place is the position of color management of the OS. Does PL use the icc profile of the OS, does it disable color management when sending the image to the screen?

George

mjdl · January 7, 2025, 2:36pm

I didn’t go into all the details (PCS space, gamut mapping transforms, etc.) depicted in the diagram you referred to, too complicated to explain in a forum posting, or so I thought, so inevitably I may have further confused matters by a badly simplified explanation of the relationship of the soft-proofing profile and the display profile!

Egregius · January 7, 2025, 2:51pm

This has been discussed with DxO in the past. PhotoLab does rely on the OS to manage the display profile. (You want it to when you have a software-calibrated display.) PhotoLab will override the default display profile when Soft Proofing is enabled. That’s why the option in question was removed in PL6.

mjdl · January 7, 2025, 3:12pm

OK, but what happens when the user has more than one display screen and a specific display profile for each one? Does moving the PL main window from one to the other screen (in the case where the second screen extends the display of the primary screen) automatically recalculate the display data with the color profile of the screen the PL window has just been moved to? Or is the active display profile set only of the screen on which PL is first started? And what happens when the second (larger) screen simply duplicates the primary screen (e.g. a laptop screen)?

This must be explained somewhere, I’m just missing it.

George · January 7, 2025, 4:02pm

That’s what I was asking in another thread to. PL is not aware of different monitors.

George

Egregius · January 7, 2025, 5:52pm

I also wish DxO would explain this better. I suspect that if you keep PhotoLab’s image viewer on the primary display it’ll work alright. But it seems to be unable to color-manage multiple displays.

George · January 7, 2025, 5:59pm

I’m pretty sure it’s not a PL problem. Google on windows color management 2 monitors

George

George · January 7, 2025, 6:14pm

And thinking further the monitor profile is used by the OS, not PL. So PL sends an image to the monitor and includes somehow the used color profile so the OS can convert it to the monitors profile.

George

Prem · January 7, 2025, 7:31pm

You are absolutely right. I myself have two monitors. An EIZO 2740 calibrated for Adobe RGB and an Asus sRGB of which I cannot remember the number. That’s also calibrated. The EIZO is my default monitor for photography and is set up under the colour management. So if I wish to use the Asus I need to set that up under the coLour management. Hope that makes sense.

KeithRJ · January 7, 2025, 11:03pm

I have two hardware calibrated monitors and the profiles are correctly specified as the default profile in the windows colour settings.

Visually the monitors display colour correctly and match each other. If I disable the profile on one or both monitors I can see a definite difference between them.

Now, moving the PL main window between monitors you can see the difference. Turn on the correct profiles and the difference is gone.

To me, this indicates that PL does not use the profile but let’s windows handle colour management and you can move the main PL window to any screen without issue as long as the monitors are calibrated.

This diagram may help understand what is happening:

Stenis · January 8, 2025, 12:13am

John a couple of years back I bought a Benq SW271. It is my first hardware calibrated monitor. I write this because that confused me a bit at first. I calibrated/profiled it for sRGB, Adobe RGB and even for Display P3.

The reason it confused me was that when I had all these three profiles to switch between with my “control puck” I realized after a while that what we see on the screen depends both on the calibration we have active in the monitor (with Photolab for example) but also what application we use.

When I installed Display P3 or any other of my three colorspaces using Palette Master that software also created an ICM matching my hardware calibrated profiles for each one of them and that was fine.

… but a problem with that solution was that if I then switched to say sRGB on the monitor , that system did not switch the standard profile in Windows Color Management automatically to that corresponding SW271 -profile for sRGB. Are you with me? Looking at sRGB through an P3 ICC or ICM confused me and I also made a lot of printing to try to understand this. Finally I did så now I know how to handle all this.

So, this confused me a lot before I understood that I had to switch that profile manually in Windows in order to get older software depending on that ICM-file to work properly.

There is also a difference between how “Working color space” and Rendering works for Classic (basically Adobe RGB) and Wide Gamut that is wider. Classic also specifies which Camera profile was used explicitly. In my case Sony 7M4 which is a short for Sony A7 IV. (You are free to select another profile of your liking if you want (yes even a Canon profile!

DXO Wide gamut was introduced because the system needed a wider data to handle both Adobe RGB and P3 that might have been beyond what Classic could manage. Sometimes if you don´t switch between Classic and Wide Gamut you will not even see the camera profile in the rendering section. It will just read “Default profile”.

But as I see it my point is that what I see on the screen even when having Wide Gamut as a “working color space” is actually seen through first my active Display P3 profile that happens to be totally independent of my Windows together with the camera-profile that happened to be dependent on the Sony model code in the files.

In other software dependent on the current ICM-profile used as standard in Windows Color Management that profile is used instead OR in some cases it uses an sRGB-profile as a default instead. On top of that some applications are not color managed at all.

… and I then export a JPEG-picture with a Display P3 ICC from Photolab that I have developed using my Display P3 profile stored in my monitors LUT-table. How that file looks in Photolab depends not on that ICC but on the corrections I have done to that file using the profile I have used on my monitor plus the profile and the camera profile driven rendering Photolab added then when I processed that RAW-file.

When printing that JPEG it looks like it does depending on the P3 bias I have given it in postprocessing plus the rendering the camera profile added plus eventual corrections via softproof with my Canson Etching Rag ICC-profile for my printer in Photolab. Just for me there might even be a slight slight impact from using another much cheaper “No name”-paper than the Etching Rag, but that is a very little differens in the results that are almost impossible to see with a side by side examination.

I managed to finally understand this when I understood that my monitor really is living it´s own life relative to Windows and Photolab. I have no problem at all now with color management in Windows, Photolab , my Benq monitor och with older applications depandent on Windows Monitor ICM-profiles.

Color Management for me is not anything I care about at all these days and that is because I use Display P3 for both displays and printer. People using both sRGB and Adobe RGB have a problem I have not and one of the most common mistakes occurs when people mix sRGB with Adobe RGB and Photolab is of no help either:slight_smile:

I want to know which ICC the file is exported with.

John7 · January 8, 2025, 2:05am

Thanks, not trusting programs like PL to use be able to switch profiles I have always just used the one calibration and profile. I dont know if PL ever moved on from just using the Windows profile, it was claimed they were going to add the ability to use hardware ones but I never saw any mention of it actually being done. An all too familiar story. I export as sRGB to check how they look on my old Dell. But the Dell is the moniter wiindows/PL uses as the main one. PL switching to the editing one as it opens so it’s of interest which moniter profile PL is using as I have little faith they have enabled the use of hardware calibration.

Oldjstein · January 8, 2025, 2:50am

Why would there be a problem displaying sRGB on a monitor calibrated in Adobe RGB (or P3)? Since both fully contain the sRGB space, it should display fine, under the influence of whatever gamma, black point, temperature and brightness you chose for your profile when calibrating? And never mind about the rest of what I wrote. I’m not sure what happens when you move the window from one monitor to the other, but the gamut warnings change and not in a way I might predict.

John-M · January 8, 2025, 5:47am

Yes, that’s my clear understanding … As also noted by @KeithRJ , when Soft Proofing is disabled ;

Yes, but effectively, no … because display-specific colour management is being handled via the OS.

This is Step#5 in the Colour Management pipeline diagram (as reproduced here).

At this point, with Soft Proofing disabled …

PL is rendering the image according to the capability of the display device, as determined/defined by the OS.
One can use the Toggle Gamut Warning feature (Ctrl+Alt+M for Windows) to highlight any areas of the image where colour(s) cannot be faithfully converted from DxO Wide Gamut to the capability of the display device … such as is often the case for “deep reds”.

Returning to your full quote (which I truncated above);

There’s no point in setting up Soft Proofing to render for the capabilities of your own monitor(s)- because;

a) That’s already done, by default (when SP is disabled) … See above.

b) That’s NOT the purpose of Soft Proofing - - which, instead, is to enable you to see a simulation of an ICC profile that’s different from the standard rendering capability of your display device (assuming, of course, that your device is capable of rendering that profile).

For example, you may be using a monitor that’s capable of rendering Adobe RGB … and, with SP disabled, that’s what you will see in PL’s main editing window.
However, your export target may be intended for the inter-webs or to share with friends … in which case you should use SP with ICC profile = sRGB … and then you will see (in PL’s main editing window) the same result as will be seen in those intended destinations (with caveats, of course, for your consumers’ display capabilities !)
It’s for this reason that I have Soft Proofing always enabled (to ensure WYSIWYG for sRGB output) … That’s my default (despite my monitor being Adobe RGB capable) … 'cos, otherwise, I’d be kidding/confusing myself when I see colours in PL’s main editing window that may not be the same as those achieved when exporting via/to a sRGB destination.