[Openicc] New options on the mainline

[Robert Krawitz]

   Date: Thu, 24 Jan 2008 18:43:21 +0100
   From: "Lars Tore Gustavsen" <lars.tore at mulebakken.net>

   >
   > I just checked in code (to the mainline) that lets you dump out the
   > LUT state, by means of the GIMP plugin or any other UI that lets you
   > specify file parameters (the GIMP plugin didn't yet have the generic
   > code for this, and more than half the code was just to make that
   > work).
   >
   > Anyway, if you want to try the latest CVS, there's a new parameter
   > called LUT Dump File.  If you specify this file, Gutenprint will
   > create a dump file containing all the data.
   >
   > This dump file format isn't documented per se, but you should be able
   > to figure it out (it's ASCII text).  This isn't production-ready by
   > any means, but it may give you something to play with if you like.


   Thanks for this improvement.
   When I printed from cinepaint with this new option I ended up with 7
   curves. The 3 first is called brightness correction, contrast
   correction and user color correction. All of them are linear.
   Then there is four channels named channel 0-3. I guess this is what
   I'm looking for, the individual cymk channels. What surprised me is
   that they are equal shaped.
   A plot is here.
   http://ltgustavsen.googlepages.com/lutdump.png

Looks like you were using CMYK input -- in this case, there will be no
GCR.  It shouldn't have printed that message (I fixed it).

The Ultrachrome ink set on the 2400 doesn't need different settings
for the individual CMYK channels.  For most printers, we use the same
gamma settings for all channels, and we use HSL-based correction in
the High Accuracy mode (which doesn't have anything to do with the
individual channel curves).  So I'm not surprised that all of the
curves are identical in the out of the box configuration.

-- 
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 Gutenprint   --    http://gimp-print.sourceforge.net

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