[Problem] ROMM RGB ICC-profile turns image grey when converting to PDF

[STL]

Hi there, 
I hope someone can help me with this as I admittedly do not have a lot of experience with ICC-profiles and color management. 

I am in the processing of preparing my pictures to be uploaded to a print on demand site.
The site requires that the pictures have a ISO 22028-2 ROMM RGB profile and are in PDF.

While converting the image in GIMP 3.0.1-1 to the ISO 22028-2 ROMM RGB profile goes well enough, when I export my image to PDF, the image becomes quite greyed out / looses saturation. 

I do not know whether this is a GIMP, export settings, or ICC issue, and if anyone can recommend a solution, workaround or use of another programme to succeed, I would appreciate it greatly. 


Thank you in advance  

[rich2005]

(06-22-2025, 12:29 PM)STL Wrote: Hi there, 
I hope someone can help me with this as I admittedly do not have a lot of experience with ICC-profiles and color management.

It is worth mentioning Krita which has more colour tools, for example comparing the gimp.icc with the ROMM icc which has a wider profile. This will account for a colour change, as they get stretched into the envelope.

   

Quote:I am in the processing of preparing my pictures to be uploaded to a print on demand site.

Quote:The site requires that the pictures have a ISO 22028-2 ROMM RGB profile and are in PDF.

That is a bit strange, usually the printing company asks for a  RGB image or a CMYK PDF (not both) You can embed a RGB image in  a CMYK PDF using Scribus but that is not your requirement.

You can export your image as a PDF and no real way of knowing if the ROMM icc is used.  

Quote:While converting the image in GIMP 3.0.1-1 to the ISO 22028-2 ROMM RGB profile goes well enough, when I export my image to PDF, the image becomes quite greyed out / looses saturation. 

I do not know whether this is a GIMP, export settings, or ICC issue, and if anyone can recommend a solution, workaround or use of another programme to succeed, I would appreciate it greatly.

It is a function of the icc and colour management. Nothing you can tweekn (except change the colours) , generally a print loses some of the brighter colours compared with a non-calibrated computer display.  That ROMM profile is not the worst by any means.

As an experiment, open your image with the ROMM profile and go into View -> Color Management -> Color Manage This View  Toggle that on/off and look for changes. One screen display and other is print display.

   

[rich2005]

Quote:...I do not know whether this is a GIMP, export settings, or ICC issue, and if anyone can recommend a solution, workaround or use of another programme to succeed, I would appreciate it greatly.

Another day, another look at what might work.

You can use Gimp to export your image with the romm icc profile and check using ImageMagick  https://imagemagick.org command line as:  

   

Adobe says that PDF/X-4 keeps the RGB image profile even though the "rest" is cmyk
The best freeware tool for PDF publishing is Scribus https://www.scribus.net/  and a RGB image looks like this.

   

When it comes to export PDF/X-4 for printing, all the options are greyed out (that is usual) You set up profiles etc in preferences, but the RGB image profile shows.

   

So far I have not found a utility that confirms that the PDF does use that specific icc profile.

[STL]

Hi rich2005,

Thank you so much for your detailed replies and all the info on ICCs in general 

Good to hear that I am not the only one who finds the site's requirements quite weird. I have also tried reaching out to them to get some more details on this, but am still waiting for answers.

Also, it is good for me to be certain that it is indeed the ICC that causes the issue. 

Here is a screenshot of Color Manage This view where the left one is with a tick in the box (on?) and right one is without (off?):
   

The picture on the right is what it looks like in the PDF. But doesn't this mean that the loss of saturation is due to converting the file to the ROMM RGB profile? 
If I do this to my unconverted original file, there is no drastic change in colors.