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Scribus => PDF Generation => Topic started by: forslund on April 18, 2020, 01:54:08 pm

Title: Generating pdf with specific CMYK color profile
Post by: forslund on April 18, 2020, 01:54:08 pm
Hi,

I'm prepping a cardgame for print and are trying to export pdf's including tiff images with a colorprofile. If I use a file with plain CMYK I get a pdf where the image is tagged as CMYK

Quote
$ pdfimages -list warlord-a.pdf
page   num  type   width height color comp bpc  enc interp  object ID x-ppi y-ppi size ratio
--------------------------------------------------------------------------------------------
   1     0 image    2728  3927  cmyk    4   8  image  no        12  0  1200  1200 7135K  17%
   1     1 smask    2728  3927  gray    1   8  image  no        12  0  1200  1200 13.6K 0.1%

But if I apply the recommended colorprofile to the tiff file in question (using imagemagick convert) the output is

Quote
$ pdfimages -list warlord-a.pdf
page   num  type   width height color comp bpc  enc interp  object ID x-ppi y-ppi size ratio
--------------------------------------------------------------------------------------------
   1     0 image    2728  3927  icc       4   8  image  no        12  0  1200  1200 7135K  17%
   1     1 smask    2728  3927  gray    1   8  image  no        12  0  1200  1200 13.6K 0.1%

What could be the issue of this? Can it be something like the color profile isn't found by the pdf-exporter?
Title: Re: Generating pdf with specific CMYK color profile
Post by: RodneyLee on April 18, 2020, 04:51:39 pm
I am a bit confused are you using scribus to save cmyk pdfs or imageconvert to make tiffs into cmyk
my guess is if the profile is in scribus and your export a pdf with proper setting you would get a cmyk with that profile as a pdf
Title: Re: Generating pdf with specific CMYK color profile
Post by: forslund on April 19, 2020, 12:04:26 am
I might be missunderstanding things but I'm doing the layout in scribus

In my layout I have some background artwork (Image frame referencing a tiff)

The tiff is based on a rgb source which I convert to CMYK. plain CMYK produce a pdf with a CMYK image, if I add a color profile when creating the tiff used in Scribus the exported PDF lists a icc (which is an rgb image as far as I can understand).

Can I in scribus import an rgb image and have the pdf export convert to CMYK with a profile? I thought the input raster image needed to be in the correct format along with the correct profile for the exported pdf have the correct settings?
Title: Re: Generating pdf with specific CMYK color profile
Post by: utnik on April 19, 2020, 12:30:03 am
hi forslund

…if I add a color profile when creating the tiff used in Scribus the exported PDF lists a icc (which is an rgb image as far as I can understand)

why do you think this is an rgb image? icc stands for 'international color consortium', the organisation wich defined the standards for our color profiles…

Quote
Can I in scribus import an rgb image and have the pdf export convert to CMYK with a profile?

yes, that's the usual way. but it doesn't work with .pdf/x-3 and .pdf/x-4. those standards don't require a color conversion for the .pdf creation. the other .pdf versions will be converted to the defined color profile if you chose the output intended for 'printer'.

utnik
Title: Re: Generating pdf with specific CMYK color profile
Post by: forslund on April 19, 2020, 11:28:35 am
Basically I would believe that because of my newness to this software (and industry in general) :)

Ok right, so the icc would still be cmyk but with a color profile?

I think I need the pdf/x-4 (or possibly 3) to get spot colors in the pdf.
Title: Re: Generating pdf with specific CMYK color profile
Post by: utnik on April 19, 2020, 07:08:50 pm
hi forslund

…so the icc would still be cmyk but with a color profile?

yes.

Quote
I think I need the pdf/x-4 (or possibly 3) to get spot colors in the pdf.

no, but the box 'convert spot colors to process colors' in the .pdf export dialog has to stay unchecked!

utnik
Title: Re: Generating pdf with specific CMYK color profile
Post by: forslund on April 20, 2020, 02:28:56 pm
Thanks for clearing that up for me. Must have completely misunderstood the wikipage about spot colors.

Now I will have to re-export all those documents one more time (hopefully for the last time now!).