On 11/10/2018 2:34 PM, Jan U. Hasecke wrote:
Am 09.11.18 um 17:20 schrieb luigi scarso:
I think you should use the best colorspace (<something>rgb )
and let the print shop do its job -- of course this means that you have
signed  their sample (hard proof) of your project.


I really tend to do this. I am currently exploring the color management
system of ConTeXt together with a friend you is working as a color
manager in print industry.

And my first try was a failure. The cmyk values in the resulting pdf
file (with color profile) differs from the values we calculated (using
the same color profile in Gimp).

But we have to investigate  a bit further, so don't panic. Maybe I the
fault was mine.

Is there a test case tex file we could use to test the color management?
there is no real 1-1 translation from rgb-cmyk .. in many programs that do that there is some additional magic (i remember that photoshop also applied the paper properties and that there was no roundtrip)

this is where color profiles come in

even viewers (like acrobat) can apply some magic so that the colors come out different from what you expect

try this on screen and in print:

\startMPpage

    path p ; p := fullcircle scaled 1cm ;

    fill p shifted (0cm,1cm) withcolor (1,1,0) ;
    fill p shifted (1cm,1cm) withcolor (0,0,1,0) ;
    fill p shifted (0cm,0cm) withcolor (1/2,1/2,0) ;
    fill p shifted (1cm,0cm) withcolor (0,0,1/2,0) ;

\stopMPpage


Hans


-----------------------------------------------------------------
                                          Hans Hagen | PRAGMA ADE
              Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
       tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl
-----------------------------------------------------------------
___________________________________________________________________________________
If your question is of interest to others as well, please add an entry to the 
Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
webpage  : http://www.pragma-ade.nl / http://context.aanhet.net
archive  : https://bitbucket.org/phg/context-mirror/commits/
wiki     : http://contextgarden.net
___________________________________________________________________________________

Reply via email to