Very confused with color management and profiles

Processing
, ,
#1

Hi,

I am having a HARD time to get color management to work properly. I actually have two problems mixed: monitor color management and output ICC_Profile in exif. (Everything I use is set to relative colorimetric).

I use either RawTherapee or Darktable (depending on the image) to save them, or I send the image to GIMP and save it from there.

My problem is that the different software I use to view my images (GIMP, RawTherapee, Darktable, gqview, geeqie, firefox and chrome) on the same monitor do not render the saved images equally (I see this clearly). The ONLY way that I see a consistent output is when I tell DT,RT or GIMP NOT to use monitor profile and NOT to save color profile to the images (i.e., no ICC_Profile in EXIF). In this situation, everything looks the same. In this case, all programs choose sRGB that seems to be consistent.

I even have problems in GIMP itself: The image that I see in GIMP right before saving is not the same shown in firefox after saving (unless I go with the double NOT above). A good example of this, where stripping the exif renders the image differently in firefox: https://www.dpreview.com/forums/post/64787534

The really bad guys seems to be firefox/chrome. I think I can make the others consistent using color management. Is this a bug in firefox/chrome?

A bit of my settings:

Monitor profile: I use an old DELL 2209WA monitor that works pretty well. According to darktable-cmstest, the system has the correct monitor profile configured. If I set “Color-managed display” in Preferences > Color Management, GIMP shows me the DELL 2209WA profile.

Color space: I have GIMP configured to Convert Images to Built-in sRGB in Preferences > Image import/export.

What am I doing wrong? Which is the correct way of setting GIMP (and RawTherapee) to have a consistent output in firefox/chrome/gqview/other viewers?

I’m new to the forum, sorry if this is not the correct place for my question.

Thanks!

L.

2 Likes
#2

I would try picking one icc for your srbg and using it in all programs. There can be “flavour” differences that might show up. That might eliminate part of it but likely there are other nuances. I think a nice rgb profile is elle’s from https://github.com/ellelstone/elles_icc_profiles/tree/master/profiles If you are changing programs that much maybe just use that for your display profile as well to avoid that conversion…esp since your display is older ?? Just some random thoughts If you are in WINdows set it in the WIndows color management as well so everything uses that profile for sRGB.

#3

Can you confirm if you have done the following:

Firstly, told each program (darktable, rt, gimp, firefox, etc…) what your monitors profile is. Ie. Point it to the saved .icc file.

Secondly, in each image editor, ensure you aren’t soft proofing in a different profile. Soft proof should = monitor profile

Thirdly, saved the image with an embedded colour profile - the same profile in each program. Set this in export/output. For web use, this should be srgb.

Also, what OS are you using?

#4

Thanks Todd for your answer.

Sorry, I think I wasn’t clear enough. I am not really worried about MY software. I am worried that, if my Firefox doesn’t render images like my gimp, then probably YOUR Firefox doesn’t either. So I don’t have control on how the internet viewers see my images.

By using a special RGB profile, I feel the risk is even higher. The more “standard” the sRGB, the better.

Thanks again, 

     L.
#5

Hi Tim,

I’ve done the first and second stages.
The third also, but it is a bit more subtle (I want to save as sRGB since I post my pictures over the internet):

  • RawTherapee has one called RT4_sRGB, other RT2_sRGB, or not to save any profile (it says “No ICM: sRGB”, and saves no ICC_Profile tags in the EXIF)
  • Gimp has something called a “Gimp built in sRGB”
  • Darktable seems to have a standard sRGB.

The output is basically identical, so this is no problem, and we may assume I did the third step.

The problem is that, after you saved sRGB, the rendering in firefox and chrome has different darks from what you see in RT, DT or GIMP. The only way that I can force firefox to show the exact same image is if I don’t do monitor profiling, and if I don’t save any profile (or strip ICC_Profile or the whole exif) in the images.

And there is an additional problem: even if everything works perfectly for me, if the viewer does not use color managing in his browser (e.g., Firefox in Android), they will see the image VERY different from what I see (± 1 stop).

I use Linux Fedora 33 fully updated.

#6

From what I can see as you say you can set up chrome and firefox for yourself but that may not translate to users. I wonder if you need to experiment and see what srgb profile they will recognize. It sounds like to me that that if either browser is not configured and it doesn’t recognize the embedded profile then it defaults to display which will vary with each user. So I wonder if you need to use the OS srgb or something like that as your output profile. Or maybe google and see if there is a profile that firefox and chrome will recognize and so display properly??

#7

Might be something to play with here…
http://www.gballard.net/psd/go_live_page_profile/embeddedJPEGprofiles.html#

#8

And we don’t even speak about the different screens configuration from one user to another like TVs, monitors, phones, tablets… and even between devices from the same user.

#9

A few thoughts,
Was black point compensation ticked in export?

What version firefox are you using? Firefox 77 had a bug which disabled color management for certain images. Firefox 78 fixed that, but can show some color distortion on images with v4 profiles. Here’s some steps to ensure Firefox color management is set up correctly: https://cameratico.com/color-management/firefox/

Can’t help what others are doing. Can only ensure things are optimal at your end, but srgb v2 profiles should display correctly on most monitors.

Does this use Wayland or Xorg? Wayland has some color management issues that may or may not apply here: Wayland color management

#10

[quote=“priort, post:6, topic:23099, full:true”]
https://www.benq.com/en-us/knowledge-center/knowledge/web-browsers-color-management.html[/quote]

I followed the instructions here, and that is kind of the core problem. It says I should change a couple of Firefox defaults (to force it to use my monitor profile). But then another user will certainly see the image different than me since he certainly did not change the defaults. Right? This is exactly what I want to avoid…

Almost. I cannot make firefox look exactly as GIMP, unless I don’t use monitor profile and I don’t save any ICC_Profile data in the exif (or if I delete the exif). If not, if I do everything as I am supposed to do, I see the images in firefox with slightly different contrast.

L.

#11

Ok, that is exactly my experience. The text says:

While all this is pretty cool and exciting stuff for color theorists like me — I still do not recommend embedding ICC profiles in Web graphics/photos because it is not reliable — unless your are using Firefox, Value1 and have a "calibrated’ monitor — you may only be fooling yourself about what other people are seeing.

So, for web usage, better user sRGB but do not embed any profiles?

#12

Yes, both in Gimp and RawTherapee (did not find anything at export time, but at color management). Could not find this in Darktable.

I use Firefox 84, Chrome 88.
But then, if I change my configs, other users will not have changed theirs…

Sorry, maybe I was not clear enough. I know how to make all my software look exactly the same for me, but I need to ensure that others see as close as I see. That’s my ONLY problem.

XOrg.

Thanks,
L.

#13

I was a bit confused as well but it seemed as though he said at some point that the most common is if no profile it will assume srgb and then convert to the users display which was the best approach?? I needed to give it another read….

#14

I cannot say that this is my problem, but it describes it pretty well.
Look at what it says in this article from 2015.:

Firefox then and now, or the difference black point compensation makes
…
As of 2015 and version 31, Firefox still doesn’t support black point compensation, which means that if . . .

  • you have properly calibrated and profiled your monitor, and your monitor has a reasonable black black point
  • you have your color managed image editor set to use relative colorimetric intent with black point compensation for display to the monitor
  • you produce a finished image ready for display on the web
  • you view the finished image in Firefox

. . . then as displayed by Firefox the shadows in your image will be more or less crushed compared to how the same image is displayed in your color managed image editor.

Black point compensation “compensates” for the fact that monitors can’t display “no light”. Without black point compensation, all shadows darker than the darkest dark your monitor can actually display are simply crushed to solid black. In a high key image image or an image that has few important shadows, you might not notice any difference. In an image that’s supposed to have rich dark shadows, the difference can ruin your appreciation of the image as all the shadow detail turns to muck.

2 Likes
#15

Then this is the problem with no solution. What are you going to do? Go around to every house in the world with a monitor calibrator to ensure their screen displays accurate colours? Find the browser with best colour management and install it on every single screen worldwide? Impossible. That’s why I said you can’t help what others are doing. That’s up to the screen makers and browser devs. It’s the unfortunate reality of showcasing your work on the web - it might display different to the viewer than it did the creator.

EDIT: Ok, I understand this thread now basically boils down to, should one publish images to web with embedded srgb profile or not?

Also keep in mind this, from the same article:

So it depends on your target audience.

Also keep in mind, that information is about 8 years old. Web colour management may have improved since then.

I always embed profiles, but no doubt others know more about this than I do.

#16

As I wrote in the first post, I know how to make everything look the same for me. I want a setting that, for the majority of “normal” non technical users, they see my images as close as possible to mine.

Not just that:

  • Should I use monitor profile or not? (This is the main one)
  • Black compensation or not?
  • Is there any flavor of the standard (!!) sRGB better than others?

All questions pointing to the same: to make the majority of non technical users see my images as close as possible to mine. There is certainly a solution to this, not sure if someone knows it.

This is indeed interesting, and solves partially my problem.

This is also a valid point. 6 years is an eternity in these matters.

I am trying to learn something that I have no idea about!

Thanks for your patience,
L.

#17

Whether you use a monitor profile doesn’t seem relevant to the question, as you can’t embed a monitor profile in the image, and you have no control over what monitor profile your viewers will use. But in general, you should definitely calibrate your monitor, which will produce a profile, and you should then tell each application to use that profile. Calibration will give you greatest accuracy, and using it in every program will give a consistency. If all your programs, and web browser, are using the same profile, but the colours are different, then it is an issue with the colour management in program/browser, not the profile. Either the program/browser is not recognising the profile, or it is not colour managed properly.

Yes to black point compensation. You don’t want those blacks unnecessarily crushed. I don’t know if the issue you raised is still a problem in Firefox or not, but if you dont tick Black point compensation they will always get crushed to black. Whereas if you tick Black point compensation, they will only get crushed to black on browsers that don’t support it. At least that’s my understanding.

Someone above linked to elle stone’s website. She has an article or two on the different flavours of srgb. Where given the choice I use v2. V4 profiles are typically best for editing, but not every platform displays them correctly (or at least that was the case a few years ago), so v2 is safer for finished product.

#18

However, using a color managed (CM) display in all your software impacts how you process the image. Let’s say, if it looks lighter when activating CM display, you will compensate the exposure/curve to make it darker. To you, the end results of both workflows (with/without CM) should be (approximately) visually equal. But then the other user at other computer will see both visually different.

I guess that with CM the end result of what I see should be closer to what the other users see, right? Sorry if this is a silly question…

Yes. I learned this the hard way when I had a low quality LCD monitor and I ended up processing all my pictures with a magenta tint. I calibrated my mid range IPS monitor when I bought it, and basically did not have to change anything. After several years, each time I try to see if it is calibrated, it is spot on. (I don’t have special hardware for calibration, I check it with charts).

My problem could be here. I don’t know where is the black point compensation in Darktable (the only place in the manual where the expression “black point compensation” appears is for printing). In GIMP and RawTable it is clear.

Interesting. I always used V4 in RawTherapee. Maybe I should switch to V2.

Again, thanks a lot for your patience…

Cheers,

L.

#19

Wouldn’t I want to use sRGB for soft proofing since that’s what jpeg uses?

#20

Someone correct me if wrong, I’m quite sure we are viewing the image in output space when softproof is off. So if ouptut profile is set to srgb (as it should be if saving to web), then there is no need to softproof srgb, as you are already seeing it. However if output profile is set to something else (eg. rec 2020 or pro photo) and you want to see how it looks for web display, then softproofing in srgb makes sense. (Even then, a difference might not be noticeable, if a) all colours are in srgb gamut, or b) your monitor can’t display more than srgb - but I digress).

However contrary to what I said before, there is probably no need to soft proof according to monitor profile either, given we are already viewing on that device, so its a good thing you mentioned it. If I had a reason for soft proofing monitor profile, I can’t recall what it was!

If you do two edits of the same image image, 1) on calibrated display, properly colour managed, 2) uncalibrated display, not colour managed, then you will likely get two different results. Lets say you place edit 1 and edit 2 on different screens, side by side, and edit them so they look exactly the same - it doesn’t mean they really are exactly the same. In fact, they are different. Ie. If you were to display them on the same screen, they would both look different. So all we can really do as photographers is get things looking how we want on a calibrated display, with properly colour managed workflow. That way, what we see is correct. And what viewers with calibrated monitors see is correct. And those with uncalibrated monitors, we cross our fingers and pray its not too far off, but in some cases it will be.

I don’t know where black point compensation is in darktable either. I seem to recall Aurelien saying somewhere they didn’t use it in the pixel pipe, but I have no idea if they use it in export profiles.