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Question

Working Space overrides Embedded Profile, sometimes

Forum|Forum|4 years ago
March 15, 2022
3 replies
981 views

My understanding is that the Working Space functions as the default color space and should only used when a document lacks an embedded profile.

I've encountered some scenarios where this does not happen. As an example, I'm comparing the regular sRGB IEC61966-2.1 with these profiles from Elle Stone:

https://github.com/ellelstone/elles_icc_profiles/blob/master/profiles/sRGB-elle-V2-g22.icc

https://github.com/ellelstone/elles_icc_profiles/blob/master/profiles/sRGB-elle-V2-g18.icc

The aim is to embed an untagged image with sRGB 2.2 Gamma, to match the monitor it was created on.

Comparing with unmanaged appearence:

Scenario A: Working Space: sRGB, Embedded Profile: sRGB-elle-V2-g22 – darks are lighter, indicating sRGB TRC

Scenario B: Working Space: sRGB, Embedded Profile: sRGB – image looks identical to Scenario A.

Scenario C: Working Space: sRGB-elle-V2-g22, Embedded Profile: sRGB – image looks good with proper blacks, as expected. Looks the same as unmanaged, as this color space matches the monitor characteristics.

Scenario D: Working Space: sRGB, Embedded Profile: sRGB-elle-V2-g22 – image shows up too bright, brighter than sRGB TRC.

In cases A and B, the Working Space takes precedence, which is the opposite of what I would expect to happen. I would have expected B and C to be identical, instead of A and B. For some reason the Working Space is only overridden in Scenario D.

I can fix this on my personal computer by picking my desired profile (sRGB-elle-V2-g22) as my Working Space, but then this image won't show up correctly for somebody else, assuming they have a calibrated monitor but has set their Working Space to the default sRGB.

I can't make heads or tails of this - is it a bug, or did I make a mistake?

Photoshop 23.1.1

Windows 11/10 (tested on 2 computers)

Windows

This topic has been closed for replies.

HybelkaninAuthor

Participating Frequently

I've managed to find a workaround for this bug:

When creating the sRGB 2.2 Gamma profile for Embedding, adjust one of the primaries a miniscule amount that is not noticable. As long as the primaries don't exactly match sRGB, the profile will work as intended and override the Standard sRGB Working Space.

This is consistent with my hypothesis that Photoshop discards the profile because it believes they are identical. I've tested this using the Custom RGB tool in Photoshop so far.

D Fosse

Community Expert

Here's what it all boils down to: all of these should display correctly and hence identically. It shouldn't matter what the embedded profile is as long as there is one (aside from any gamut clipping, but that's obvoiously not a concern here). And it definitely shouldn't matter what the working space is.

My immediate suspicion is that this "elle" profile isn't written to correct icc specification.

There's also very little point to the whole exercise. Chances are sRGB IEC61966-2.1 is a better match to an average monitor's TRC than a straight gamma 2.2. Very few monitors have a perfect 2.2 gamma response. That's what the monitor profile is there for.

In short, this seems like a solution in search of a problem.

HybelkaninAuthor

Participating Frequently

Hi,

Thanks for the response.

If you take a document without an embedded profile, and you assign a new profile, the appearence of the image is dependent on which profile you assign, no? Or maybe I'm misunderstanding what you're saying.

I don't actually have any hard data on which monitors are most common, but my general impression from reading reviews (where they analyze and calibrate the monitors), my very limited experience with different monitors, and from what people say on various forums, is that modern LCD monitors are closer to g2.2 than sRGB TRC. That's my general impression, though - if you have a good source on this, it would be really helpful.

I'll try to explain my specific issues more clearly:

I work on creating art for video games where the end output is not color managed. My goal is twofold:

a) make sure all the artists see the same thing when working on the documents - hence embedding a profile

b) make the best possible guess about what will look good on the average uncalibrated monitor. My working assumption is that sRGB gamut with 2.2 Gamma serves that purpose.

The bug (?) I've described makes it so that my images will not show up correctly, when tagged with a sRGB 2.2 profile if the aritst has Photoshop set to default settings which is a sRGB Working Space.

Secondly, most artists unfortunately don't work in calibrated environments. If I download a digital painting from the net and import it into Photoshop, the default assumption of sRGB is likely to be wrong if the monitor originally used was closer to 2.2 than sRGB TRC (again, if this is a bad assumption, please correct me).

I welcome any alternative perpsectives on this issue.

HybelkaninAuthor

Participating Frequently

What characterizes LCD monitors generally, is a dip in the shadows. This is a deviation from a regular gamma curve. It's accounted for in the monitor profile, so what you see in a color managed application is a correct representation. But without color management, deep shadows will usually appear too dark.

Very high-end monitors (Eizo, NEC) may be corrected for this from the factory, but I've never bothered to check, since it doesn't matter in a color managed environment.

Right - I'm not sure which part you're responding to, but it sounds like we agree. A perfect sRGB monitor would have brighter shadows, as opposed to the typical LCD monitor you are describing.

Besides, calibrating to 2.2 seems to be most common, and is the default setting for most calibration tools. Meaning even in non-managed apps, such as a game, content would look best if encoded as 2.2 instead of sRGB due to the VCGT calibration.

And who knows if this is the only scenario affected by this bug - it just happens to be my specific use case. I really hope it can be fixed.

NB, colourmanagement

Community Expert

"My understanding is that the Working Space functions as the default color space and should only used when a document lacks an embedded profile."

yep, that’s how it should work

Photoshop reads the embedded profile and if it's present, ignores the default workingspace.

I wonder if there's something strange about those sRGB variants.

"The aim is to embed an untagged image with sRGB 2.2 Gamma, to match the monitor it was created on."

Why?

I feel that there is literally no point in doing things to an image specifically related to the display it was created upon.

I see you are comparing images with different embedded profiles, are you simply assigning the alternative profile to your test document? Or converting between the mentioned colour spaces?

I hope this helps
neil barstow, colourmanagement net :: adobe forum volunteer:: co-author: 'getting colour right'
google me "neil barstow colourmanagement" for lots of free articles on colour management

HybelkaninAuthor

Participating Frequently

Hi,

Thanks for the response.

I wonder if there's something strange about those sRGB variants.

Maybe - but the same thing happens if I create the synthetic profile using Custom RGB in Photoshop, or using the synthetic profile creator in DisplayCal. I haven't been able to create a profile where Photoshop doesn't show this issue.

I feel that there is literally no point in doing things to an image specifically related to the display it was created upon.

A lot of images I work with were created in uncalibrated environments, and will be viewed on uncalibrated monitors. Most monitors follow a 2.2 Gamma curve closer than the sRGB curve. So this is a best guess for what will look best for the greatest amount of people, and a best guess of what the image is supposed to look like, if I open somebody else's untagged document.

If an app (such as Photoshop) assumes sRGB by default, the image will have washed out blacks.

Does that make sense?

I see you are comparing images with different embedded profiles, are you simply assigning the alternative profile to your test document? Or converting between the mentioned colour spaces?

I'm assigning the profiles, not converting.

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