[Openicc] Introduction / Gutenprint

[Robert L Krawitz]

   Date: Sun, 10 Apr 2005 17:00:23 -0500 (CDT)
   From: Bob Friesenhahn <bfriesen at simple.dallas.tx.us>

   On Sun, 10 Apr 2005, Robert L Krawitz wrote:
   >
   >   From what I see, the role of application software stops at
   >   producing RGB or CMYK output, after which the image (or document)
   >   is passed to the printer driver for any additional processing.
   >
   > But what's the interpretation of the RGB or CMYK data?  Is it sRGB, or
   > some other color space?  If I tell you that my RGB values are
   > (101,176,82), what is the exact color that my eyes see?

   That is why there is a CMS profile associated with the data
   provided by the applications.  This makes the interpretation of the
   RGB or CMYK values concrete.

OK, I misunderstood what you meant by "stops at producing RGB or CMYK
output" -- of course, you meant "tagged RGB or CMYK".

   The complexity exposed by the printing system should be no more
   than is actually needed in order to achieve the quality and
   performance objectives.  Since this list is intended to discuss the
   system level implications and implementation of a color management
   system, we should be attempting to identify what the interface
   between the applications and the printing system must look like in
   order to meet requirements.  I expect that this interface will not
   require more than RGB or CMYK in order to satisfy requirements.

Then why is CMYK required?  I can understand RGB+K, where the K has a
different semantic meaning than ~RGB (it means "text black" or the
like), but CMYK is already a device-specific format.

My own take is "successive disclosure of complexity" -- the driver
should certainly offer simple RGB input -- but the other formats
should be provided for people who really know what they're doing.
However, I can certainly see how that's a distraction from the general
goal of an open color management system.

-- 
Robert Krawitz                                     <rlk at alum.mit.edu>

Tall Clubs International  --  http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom -- mail lpf at uunet.uu.net
Project lead for Gimp Print   --    http://gimp-print.sourceforge.net

"Linux doesn't dictate how I work, I dictate how Linux works."
--Eric Crampton