Good evening,
this really puzzles me:
in RawPedia it is said that “you will be able to select your monitor’s color profile in the combo-box under the preview”. On my system, the monitor is calibrated and the monitor profile is used by all applications handling color management.
So why do I have to specify the monitor profile again in RT to have it applied to the preview window??? Or do I mis-understand something here?
Hermann-Josef
Hey
Monitor profile handling is done on a per-application basis, it’s a question of how that is implemented. Some applications force you to use the monitor profile “installed” by the resident color management system, e.g. colord, which is dumb. Others, such as RawTherapee, don’t rely on a color management system daemon and instead let you choose one manually, or inherit the profile “installed” in some way if that way is supported, which depends on the operating system (you didn’t mention which OS you use). I don’t have time to check the code right now, but IIRC auto-detection only works on Windows, and the _ICC_PROFILE X11 atom is not checked.
Thanks for your reply, Morgan.
I am using Windows10.
Hermann-Josef
Many thanks for your reply. The latest Rawpedia shows the following under Preferences>Color Management tab>Printer (Soft-Proofing):
You can select here the color profile of your own printer or your print service in order to simulate the rendering of the printed image.
For this to work the printer profile must be copied to an appropriate folder in order to appear in the drop-down list. Can you tell me the proper location for Windows7? (presumably the directory selected at Preferences>Color Management). Rawpedia says: “the directory where ICC profiles can be found”.
I am guessing this does NOT mean the RT folder “iccprofiles>output”
I am using: C:\Windows\System32\spool\drivers\color and this seems to work OK.
It leaves unanswered the question: What profile should/must be specified at Tools>Color tab>Color Management>Output profile (please see my first post in this thread). As it is currently configured RT will not allow me to select my printer (.icc) profile as Output profile even if it is an RGB color space and has been copied to both “iccprofiles>output” and to the directory selected at Preferences>Color Management.
Please forgive me if I am being a bit overly fastidious.
@mikesan You’re not overly fastidious, I’m just long to answer. don’t have much time and I’m trying to understand that subject the best I can too :).
Yes, the path is C:\Windows\System32\spool\drivers\color for Windows7 and you’re right, you still can’t select the printer profile as output profile.
The output profile to select depends on your workflow, of course. If you want to make further edit in a pro software, you can use a wide gamut color profile (the biggest one is ACES I think) or if you want to prepare your images for printing, you’ll soon be able to select the printer profile (given that it has an RGB color space) if your print service told you so. You can still attach the AdobeRGB profile as output profile even to send you image to your print service, their system should make the transformation themselves from AdobRGB to their printer profile. However using their printer profile for soft-proofing only will let you approximately see the finale rendering (on paper). You won’t be able to see possible artifacts due to the gamma and bit depth problem (i.e. banding in shadows).
I’m pushing the change (which is a minor and safe change) to the dev branch, it’ll be part of RT5.1 once ready.
User that can build themselves can now use the printer profiles (RGB color space only) as output profile (dev branch).
@Morgan_Hardwood I’ve updated the documentation a bit too fast. It is correct for the dev branch but not for RT5.0.rev1. Should I revert the doc to the official version ?
Not directly a tool for examining ICC profiles but maybe still interesting for some: You can extract the profile from an image with ImageMagick: convert name-of-image.jpg name-of-profile.icc
Hombre,
Many thanks for your prompt reply.
It will be great when RT is modified so that I can select my printer profile as output when sending an image for printing. Meanwhile my immediate concern is simply using the soft-proofing capability of RT for final editing of the image. I am going to assume that, for that purpose, I can enter the printer profile at Preferences>Color Management and simply ignore the entry at Tools>Color tab>Color Management>Output profile
Please let me know if this assumption is correct.
@mikesan It is correct, but depending on the degree of artwork you’re doing with your image, you might have to chose a correct output profile, beyond the narrow sRGB. As said by Marty Maria, the gamut of a printer is generally smaller than sRGB, excepted for some colors like yellow. I think that using a large gamut output profile may be counterproductive because the print service will chose a rendering intent to fit the data into its colorspace. I’d chose AdobeRGB, but your print provider might tell you the best option (or perhaps @Elle ? 
).
PS: reading your comment again, I think I misunderstood it …
Actually not a problem for me. I send my images to Costco for printing. Their system is perfectly happy to accept images converted to the color space of their printer profile. So for now I can output such images with P’shop and when RT is changed to allow using their printer profile as Output Profile, I will be in good shape.
Don’t know what comment you may have misunderstood. No matter 
Thank you for the changes @Hombre. I will revise RawPedia later today, please do not revert. It’s fine to describe how things are in dev not in the latest release, because the alternative is not feasible.
Use RT_Medium_gsRGB and let your printer know that you’re using the AdobeRGB colorspace.
http://rawpedia.rawtherapee.com/Color_Management#Output_Profile
Thanks! I didn’t know ImageMagick could do that.
Here are two more ways to retrieve an ICC profile that’s embedded in an image file:
Using a recent version GIMP 2.9, open the image and do “Image/Color Management/Save Color Profile to File” - this can handle V2 and V4 profiles and works with any file format that GIMP can open (which is to say, a lot of different file formats).
Using ArgyllCMS “extracticc” (http://argyllcms.com/doc/extracticc.html) from the command line:
extracticc name-of-image-file name-you-want-to-give-to-extracted-icc-profile.icc
This requires either a jpeg or a tiff, and probably only works with V2 profiles.
How many printable colors exceed the sRGB color gamut depends on the printer and the paper (and no doubt on the number and quality of the inks, state of calibration of the printer, and so forth).
Here are some 3D gamut comparisons between sRGB and four photographic printer profiles using various papers:
http://ninedegreesbelow.com/files/srgb-vs-printer-profiles/sRGB-vs-Frontier-Glossy.x3d.html
http://ninedegreesbelow.com/files/srgb-vs-printer-profiles/sRGB-vs-Chromira-Matte.gam.x3d.html
http://ninedegreesbelow.com/files/srgb-vs-printer-profiles/sRGB-vs-Silver_Rag_Epson_9890.x3d.html
http://ninedegreesbelow.com/files/srgb-vs-printer-profiles/sRGB-vs-SilverRag_Epson_4900.x3d.html
What do you think? Are there any significant printable colors that exceed the sRGB color space?
The 3D gamut comparisons (made using ArgyllCMS) require a browser that supports X3DOM: » Browser support - x3dom.org
I forgot to say, the gamut views can be rotated so you can see the differences in color gamut coverage from all angles. The color gamuts are in the LAB color space. The white wire frame is the sRGB color gamut. The color areas are the comparison printer profile color gamut.
If you aren’t familiar with LAB, here’s a brief introduction:
Pictures of Color Spaces Inside CIELAB
I summarized the various ways of extracting and examining ICC profiles here:
http://rawpedia.rawtherapee.com/How_to_extract_and_examine_ICC_profiles
Feel free to copypasta.
Thanks @Elle ! So which output profile would you recommend ? The printer one or a large standard color profile ?
You didn’t ask me, but I will put in my $0.02.
It depends on how you will print the image.
If you are sending it to a commercial printer who provides a profile for their printer AND who will accept the image already converted to that profile’s color space, then using the printer profile for soft-proofing AND for output is the preferred method. Of course that option is not currently available in RT. Regarding this method, I strongly recommend reading this thread , particularly the posts by"digitaldog". Note what he has to say about commercial printers who provide a printer profile for soft-proofing, but insist that the image you send be in sRGB space.
If you are printing at home the choice of output profile will depend on what software you use to print. Can’t offer any advice there.
@mikesan summarizes the situation pretty well. The post he refers to is well worth reading. The best answer is “it depends” on the printer and the color gamut of the image, and also (as discussed in the luminous landscape forum) on what the place you send your image to be printed actually does with the file you send them.
If you take the time to look at the color gamut comparisons I put together showing various printer profile color gamuts compared to the sRGB color gamut (and really you should if you are interested in making prints), you’ll see that:
Even the lowly Frontier printer can print blue-greens, greens, yellow-greens, yellows, and oranges that fall outside the sRGB color gamut.
Compared to the Frontier printer, the Chromira printer can print a somewhat larger volume of colors in the same range.
The Epson printers with Silver rag paper can print hugely more colors in the same range, plus they can print some reds and magentas that fall outside the sRGB color space.
Where all the printer profiles fall short compared to sRGB is that sRGB holds brighter colors in the shadows and highlights, and this is especially true in the range of colors from red through magenta to violet-blue and blue. When using relative colorimetric intent, using black point compensation can sometimes help to bring the shadow colors into gamut. But bringing out of gamut highlights into gamut usually requires a bit of desaturation as well as lowering the image white point. And even with black point compensation, often you’ll need to desaturate the shadows to bring them fully into the printer’s color gamut.
One factor that hasn’t been addressed in this thread is the color gamut of the image itself, as compared to the color gamut of your chosen printer. If the image has colors that your chosen printer can print (and that you want to preserve in the final image to be printed), and these colors aren’t contained in the sRGB color space, then of course use a larger color space for editing. Otherwise those colors are clipped upon conversion to sRGB (assuming integer precision, unbounded floating point images changes this situation considerably).
As an example, this page has pictures in CIELAB space of clipped image colors upon conversion of a bright red flower from ProPhotoRGB to sRGB: Clipped colors from ICC profile conversions. I encourage you to make your own such CIELAB comparisons, so you have a better idea of what colors fit into which color spaces.
Another factor that the discussion in http://forum.luminous-landscape.com/index.php?topic=109714.0 touches upon is the color gamut of your monitor. Any color in your image that’s out of gamut with respect to your monitor will display as the nearest color your monitor can display. So soft proofing an image that has colors your monitor can’t display is problematic, though many people manage to still produce excellent prints under such circumstances.
The bottom of this page has pictures in CIELAB of several sample monitor profiles compared to sRGB: Your LCD monitor and the sRGB color gamut
I encourage you to make your own such comparisons using your own monitor profile, so you have a good idea of which colors your monitor can actually display, compared to whatever printer profile you might want to use, and whatever RGB working spaces you like to use.
In case anyone actually wants to make such color gamut comparisons, here are sample commands:
Make a “gam” file from a color profile such as sRGB or a printer profile or a monitor profile (iccgamut):
iccgamut -v -w -k -ir sRGB.icm
iccgamut -v -w -k -ir ClayRGB1998.icm
Make a “gam” file from an image file (tiffgamut - the image must be a tiff or a jpeg, and you have to tell tiffgamut what color space the image is in):
tiffgamut -v -k -ir ACES-elle-V2-labl.icc two-apples.tif
Compare two color gamuts (viewgam - can be color space to color space, color space to image, or image to image).
Here is a sample command for comparing the sRGB and ClayRGB1998 color gamuts, assuming you already have the “gam” files:
viewgam -i -cn -t0.5 -s ClayRGB1998.gam sRGB.gam -w sRGB-vs-ClayRGB1998
And here’s a link to the resulting 3D view of the two color gamuts:
http://ninedegreesbelow.com/files/srgb-vs-printer-profiles/sRGB-vs-ClayRGB1998.x3d.html
Here’s a sample command for comparing an image color gamut to a printer profile, assuming you already have the gam files:
viewgam -i two-apples.gam -cn -t0.4 MPL-Chromira-Matte.gam apples-chromira
Here’s a link to a 3D view of a sample image color gamut compared to a sample Chromira printer profile (the wire frame is the Chromira profile, the smaller solid color gamut is the image, which is a picture of two yellow apples sitting on a navy blue table cloth):
http://ninedegreesbelow.com/files/softproof-test/apples-chromira.x3d.html
As an important aside, there is no such thing as “the” Chromira or “the” Frontier or etc printer profile. As the Luminance Landscape discussion makes clear, these profiles are the result of actually profiling actual printers, and even “the same” printer will produce different results from profiling given things like age of the printer, it’s state of calibration, new ink lots, new paper lots, new profiling software, the operator’s knowledge level, and etc. I have verified this “not the same” by actually looking at some sample profiles, so this isn’t just theory.
Anyway, hope some of the above is helpful. But if you are looking for “do this to accomplish that”, then again, the answer is “it depends”. And so the best anyone can do is share insights into what actual commercial printing establishments actually do with your image files, which @mikesan has done, plus share some useful tools for exploring the relevant color gamuts so you can make an informed decision, which I have tried to do.