[Openicc] Printing targets: App or driver ? Profiling RGB or CMYK

[Kai-Uwe Behrmann]

Am 17.05.11, 10:55 -0700 schrieb Hal V. Engel:
> On Tuesday, May 17, 2011 08:38:11 AM Jan-Peter Homann wrote:
>> Hello Edmund and all,
>> I support, that profiling for Gutenprint should start based on the
>> avilable RGB Gutenprint setups.
>> May questions are about possibilities to allow an easier CMYK based
>> profiling for Gutenprint in future (no need to prioritize).
>
> I have been using ArgyllCMS generated CMYK profiles with my Epson R2400 for
> some time now.  These take more effort to create than RGB profiles but when done
> correctly give excellent results.  I use PhotoPrint for printing and it does
> the conversion from RGB images to the profiled CMYK printer color space and
> sends the CMYK data to CUPS/GutenPrint.

Maybe I have not understood you correctly.
Why do one want to convert a Rgb target to Cmyk for measurement and 
profiling? This is the work of the CMM conversion through ICC profiles 
after profiling.

So far I had no problems to print out Cmyk targets. One can use 
Scribus, CinePaint on openSUSE/Fedora or Photoprint for that. A
advantage is that Cmyk profiles impose no a bottlenck to the profiler by a 
fixed Rgb->Cmyk trasnform in the some part of the print chain.


kind regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org