[Openicc] New options on the mainline

[Robert Krawitz]

   Date: Sun, 20 Jan 2008 21:24:33 +0100 (CET)
   From: Kai-Uwe Behrmann <ku.b at gmx.de>
   MIME-Version: 1.0
   Cc: OpenICC Liste <openicc at lists.freedesktop.org>
   Content-Type: text/plain; charset="us-ascii"

   Am 20.01.08, 11:28 -0800 schrieb Hal V. Engel:

   > On Sunday 20 January 2008 10:58:15 Robert Krawitz wrote:
   > >    Date: Sun, 20 Jan 2008 19:30:00 +0100 (CET)
   > >    From: Kai-Uwe Behrmann <ku.b at gmx.de>
   > >
   > >    About exporting the current calibrations: from the previous post
   > >    I'd guess most parts are already somehow available through a
   > >    interface. How much work would it be to make a small tool to export
   > >    the Uncorrected curves to something readable? I could help on
   > >    transforming say integer or double arrays to the above mentioned DL
   > >    profiles inside such a tool. With the tool, I'd guess, the
   > >    Uncorrected mode is not that much desired to keep stable across
   > >    releases. Uncorrected still remains as a good starting calibration.
   > >    The created DL profiles would not at all know about device
   > >    states. So this part remains open. I would later connect this as
   > >    well, i.e. make the DL knowing about the Gutenprint options.
   > >
   > > Right now there's no straightforward way to extract those curves --
   > > they're not generated until very late in the initialization process,
   > > and the GCR curves are computed in a different module from the other

   GCR involves already Rgb to Cmyk conversion. I thought more of 
   linearisations, i.e. one curve per colour channel.

   > > color curves.  But it would be worthwhile to figure out how to do
   > > this.

   In which file is the struct described?

   > > The format I would dump them out in would be either the Gutenprint XML
   > > curve format, or as a dump of the internal lookup table structure
   > > (probably just the curves), which itself would contain a collection of
   > > curves.  But I'm open to other suggestions.

   Internal lookup table structures (curves) are probably more convenient. So 
   I'd not need to reparse xml.

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.

-- 
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."
--Eric Crampton