Colour management help, please

[davidc1815]

Please can someone give me a steer on why one usually gets an over saturated and red tinted image when looked at in a non colour managed space. I have a calibrated display (I1Display Pro on a UHR wide gamut dell laptop display), my working colour space is sRGB, and I am converting images to sRGB when I save them. My calibrated colour profile is loading in Windows 10.

I'm doing something stupid wrong. The problem has just started happening.  Don't know why.

Thanks.

David

[D Fosse]

Because the monitor profile - which describes the wide gamut - is ignored by those applications. It really is as simple as that.

In a color managed environment, the sRGB data are remapped into the wider color space, using the monitor profile. This preserves color appearance. Without color management, that doesn't happen, and the result is oversaturation.

Don't confuse calibration with monitor profile! Calibration is just a simple, linear correction. It can't do anything about gamut (or more precisely, the position of the primaries). The profile is something else, and it's only used by color managed software. The profile has much higher precision, and uses many more parameters.

People mix up calibration with profiling because they're usually performed in one go, just for practical reasons. But they are separate and unrelated processes. The profile is a detailed description of the monitor in its calibrated state, used in a standard profile conversion.

[davidc1815]

Thanks.  I guess the problem is that my wide gamut display is not correctly displaying for sRGB...it is displaying for its wider gamut. I thought I had achieved an sRGB colour profile (you can see the new profile kicking in a few seconds after every boot up) using the i1 Profiler software but maybe I haven't.  Maybe the desired sRGB profile has 'drifted' somehow.  Pictures which look 'correct' in Photoshop tend to look over saturated with hot reds in Fasttone Image viewer and in Word (within the text layout for a Photobook).

hmm...

[davescm]

Just a thought David.

You said over saturated and red tinted and that it just started happening.

The over saturated part is absolutely the wide gamut monitor with non color managed application trying to display an sRGB image.

However I did come across an issue on my system directly after the Windows 10 "Creator" update last week:

I have three monitors, each of which is calibrated and profiled. Windows normally takes the profiles and uploads the embedded calibration data for each to the video card on start.

Except that following the update it would not. The correct profiles were being used but the embedded calibration data was not being uploaded to the LUTs.

To get this to work I had to go into the Advanced tab on Windows Colour Management and check "Use Windows display calibration". I had to do this when I first moved to Windows 10 and had forgotten it since then (I don't think it was required back using Windows 7). Anyway - with that ticked, the correct calibration data for each monitor is now being uploaded and the profiles are being used on the calibrated monitors.

Dave

[D Fosse]

davescm  wrote

Anyway - with that ticked, the correct calibration data for each monitor is now being uploaded and the profiles are being used on the calibrated monitors.

Dave, it's important to use precise language here. It's not the profiles being used, it's the calibration tables that just happen to be stored in the profile, that are being used.

I can't emphasize this enough! Calibration and monitor profile are two different and unrelated things. Calibration plays no part in this.

[davescm]

Hi Dag - I know and agree.

That is why I was saying the "embedded calibration" data was not uploading. The result, before I resolved it, was three monitors with visibly incorrect white points.

The correct profiles were being used in color managed apps including Photoshop throughout.

Dave

[D Fosse]

davidc1815  wrote

you can see the new profile kicking in a few seconds after every boot up

That's what I said: that's not the profile. That's the calibration, which does nothing about the monitor's gamut. It can't.

Only the profile can account for the monitor gamut. The profile doesn't adjust anything, it doesn't do anything at all, it's just a description. The adjustments are then performed by the application's color management logic, based on that description.

The monitor profile is just a standard icc profile, like sRGB, Adobe RGB and so on - only not generic, but specific to your particular monitor. The application then converts, on the fly, from the document profile into your monitor profile, and those recalculated numbers are sent to the monitor.

Again - the calibration, which is what you see kick in after bootup, has nothing to do with this.

[davescm]

Sorry - I missed where you said you could see the calibration being uploaded. So it is not the same issue I had.

Dave

[D Fosse]

I know you know, Dave. But it's really, really important to use terms that keep the concepts perfectly clear.

All this would have been so much simpler if all software was color managed. Then calibration wouldn't be needed at all, except setting a white point and a black point. No further adjustments would be necessary on monitor level - it could all be handled by the profile conversion, which is a lot more accurate anyway.

This color balancing that happens in calibration is what confuses people. They think that's the point of it all. But it isn't. The color balancing is just done to make the monitor behave a little better without color management. In a color managed application it's not necessary at all.

But the way it is, these calibration data have to be stored somewhere, and it has to be associated with the monitor it's intended for. That's when a bright kid came up with a brilliant idea: let's put it in the profile! And it is brilliant, because it works, and it's reliable. The only problem is that it's so darn confusing...

[davescm]

Unfortunately we seem to be going in the opposite direction, with more and more devices and applications being used to view images and less and less ability to color manage. I was trying to find out how to use any form of color management on the mobile apps on Android. Bottom line is you can't.

Dave

[D Fosse]

davescm  wrote

Unfortunately we seem to be going in the opposite direction

Indeed we do. Since we talk about wide gamut displays, the hope was that they would force a wider implementation, since they rely on it. But no.

And again - I apologize for the stern look over the top of my glasses there ...but the devil is in the details, especially in this matter

[davidc1815]

I have read it two or three times and it is interesting without being easily helpful to me.  I thought I might end up in colour management hell and I have..

[davescm]

David

Just for clarity on your issue.

You are saying that within the color managed applications you have seen no change?

In non color managed applications you have recently seen a change both to saturation and to the overall "tint"? Have both changed or just the tint?

Dave

[davescm]

No problem Dag.

I will ask one question on something you said earlier though and that was where you seemed to  indicate that calibration was irrelevant to the profile. This puzzled me but it may  just be the way I read it.

My understanding is :

1. Calibration is bringing the monitor to a "behaviour " outside of color management.

2. You can profile without first calibrating - and color managed apps will work correctly with the resulting profile.

But:

3. If the characterisation (i.e. profiling) is done after calibration and with the calibration in place,  then it essential that that the calibration is retained for that profile to work correctly. Hence the usefulness of being able to embed both profile and calibration data  in a single file and have the OS color management system load both..

If I am wrong then I have been under that misapprehension for a while.

Calibration vs. Characterization

Dave

[D Fosse]

Yes, that's right, Dave. The two go hand in hand. I always sum it up like this: the profile has to describe the monitor's actual, current behavior.

But whether the monitor's behavior has been modified in the video card, or in the monitor's internal LUT, or not at all - all that is unimportant. As long as the monitor behaves in a certain way, that's all the profile needs to know.

[davescm]

Phew thanks

I asked David for clarity as I am at a bit of a loss to see why he would see a recent change to the way non color managed apps display but no change to the way his color managed apps display. That is the way I read his first post.

Dave

[davidc1815]

Yes, you have it - main difference is the red tint - the colour saturation is less noticeable. 

Here is an example:

...But...I have re run IProfiler and a normal service seems to have been restored. 

Thanks for your interest.

David

[davescm]

Hi David,

Glad your problem has gone.

Out of interest - did you get the big Windows Creator update at the time this started happening?

Dave

[davidc1815]

I have installed updates yesterday:

I don't know if these were Creator updates.  How do I find out?

[davescm]

Creator was the update to version 1703 so it was before those you show above. It may be in your update history under "Other updates". Mine was on 3/6/17 but it has been rolling for a while now.

Dave

[davidc1815]

Ah.  So my calibration must be wrong and needs to be done again?

David

[D Fosse]

No, david, it isn't wrong - it's irrelevant. It's not what this is about. Read again, carefully.