GNOME Bugzilla – Bug 689042
Unable to Assign and Embed Color Profile
Last modified: 2015-10-07 11:30:42 UTC
Here are the steps: 1. An existing JPG edited in GIMP exists on the file system that has no EXIF data, including an embedded color space (as seen when viewed using exiftool). 2. Photo lab (WHCC) requires the photo to be sRGB, but because there is no metadata to prove this, photos made in GIMP are rejected from printing. 3. Open the jpg/png/whatever in GIMP 4. Image>mode>assign sRGB 5. Export as jpg *Note that the EXIF export box is grayed out 6. Check for new color profile embedded in exported jpg using exiftool. None exists, although if working, it should have been there. 7. Documentation (http://gimp.open-source-solution.org/manual/gimp-imaging-color-management.html) says that "you can manually assign it to that image." The method described above doesn't do this, and documentation does not expound on the proper method for this to happen either.
I should also note that going to Image > properties shows that an sRGB profile exists, but this is not reflected in the image when saved.
Their FAQ claims: "All files not tagged with an embedded profile are assumed to be in sRGB." Did they tell you why they still reject the files?
"In looking at the files for printing I noticed they are missing an assigned color profile. This may result in color shifting, creating color discrepancies between your monitor and your prints as our photographic printers default is sRGB and files receive this profile when missing one. Our test prints main purpose is so you can check your color calibrated monitor to the print’s color. For this reason and for you to receive accurate test prints I will resend the email link back to you so you can resubmit the test files with a color profile embedded."
It looks like this shop (or its printer) cares only about the color space declared in the Exif metadata, not about any embedded ICC profiles. Note that Exif does not include any color profiles and supports only two values for its color space tag : sRGB and Uncalibrated (other values are reserved). However, the DCF standard and the current practice of some programs extend Exif by specifying some heuristics for recognizing the AdobeRGB color space as well, based on the combined values of other Exif tags. This is something that should probably be fixed in the lcms plug-in. *** This bug has been marked as a duplicate of bug 575744 ***
(In reply to Raphaël Quinet from comment #4) > It looks like this shop (or its printer) cares only about the color space > declared in the Exif metadata, not about any embedded ICC profiles. I'm not sure on what basis you make this claim. I checked their website (https://www.whcc.com/resources/color). They seem to care very much that the image have an actual embedded ICC profile. According to the quote in Comment 3 above, the reason the image was rejected is precisely because it didn't contain an embedded ICC profile. > > *** This bug has been marked as a duplicate of bug 575744 *** This bug is not a duplicate of bug 575744. Rather it's a duplicate of bug 627594 and bug 512485. The problem is that GIMP doesn't embed the GIMP built-in sRGB profile upon exporting an image. The only way to persuade GIMP to embed an sRGB ICC profile is to assign such a profile from disk. In which case the user is left to figure out sRGB profile to assign, as almost certainly the user already has a whole bunch of sRGB profiles floating around their system (http://ninedegreesbelow.com/photography/srgb-profile-comparison.html).