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

[Hal V. Engel]

On Tuesday, May 17, 2011 02:14:22 PM Kai-Uwe Behrmann wrote:
> 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.

This part of the thread was asking about doing a printing work flow based on 
using the CMYK engine in GutenPrint driven by a CMYK profile and avoiding using 
the drivers internal RGB to CMYK conversion in the driver.  It has nothing to 
do with printing targets since a CMYK target would be submitted directly to 
the GutenPrint CMYK engine and there are currently no issues doing this.
 
> 
> So far I had no problems to print out Cmyk targets. One can use
> Scribus, CinePaint on openSUSE/Fedora or Photoprint for that. 

I have used both CinePaint and PhotoPrint to print CMYK targets. 

> 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.

But for many printers there will be an internal CMYK to DeviceN conversion in 
the drivers.

> 
> 
> kind regards
> Kai-Uwe Behrmann
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