[Openicc] [Gimp-print-devel] Looking ahead to 5.3

[Robert Krawitz]

   Date: Mon, 20 Oct 2008 00:30:01 +0200
   From: "edmund ronald" <edmundronald at gmail.com>

   I don't think Gutenprint itself should offer ANY embedded color management.

I always like doing less work :-)

   However, I believe Gutenprint should offer a good RGB photographer's
   CM toolkit for using a spectro to
   1. Help one linearize a printer for a given medium in order to get the
   best gamut out of it.
   2. Help one re-linearize a printer  the printer sample in line with a
   known ideal sample that has been profiled.
   3 Help one determine the ink curves
   4 Provide a tool for printing profiling charts easily with no
   sharpening or interpolation artefacts.
   5 Provide standard one-click setting for printing color-managed images
   in a profiled workflow, with the profile already applied.

   Of course the members of these lists doubtless have better suggestions.

Maybe, but that's a nice comprehensive set of high level suggestions
to get started from.  Some questions/comments:

1) What kind of assistance do you envision us providing?  I presume
   you mean that we should provide some kind of tool that would
   produce the necessary linearization data, preferably in a way that
   could be automatically applied to the printing system.

   Note that linearization would have to also refer to a particular
   resolution (or at least quality preset) and in some cases dither
   algorithm.  The dither algorithm we can default.  The resolution we
   can't default because it depends upon the user's desired tradeoff
   between quality and printing time.

2) Can you explain #2 more specifically (in particular, how it differs
   from #1)?

3) In what way do the ink curves differ from the linearization?

4) Gutenprint (at least the core library) never applies any sharpening
   or interpolation.  It resamples if necessary by either skipping or
   repeating input raster pixels, but it doesn't play games with the
   input.

5) Would PhotoPrint qualify in this way?

6) What do you believe should be done with >4 color printers (either
   with light inks or with extra colors, such as the Epson Stylus
   Photo R800)?  Should higher levels do the RGB->DeviceN conversion,
   or should Gutenprint?

   On Sun, Oct 19, 2008 at 9:37 PM, Hal V. Engel <hvengel at astound.net> wrote:
   > On Sunday 19 October 2008 07:50:03 Till Kamppeter wrote:
   >> Robert Krawitz wrote:
   >> >    From: "Hal V. Engel" <hvengel at astound.net>
   >> >    Date: Sat, 18 Oct 2008 09:28:34 -0700
   >> >
   > snip
   >
   >> >    Also work is underway to add CM to the print work flow in a way
   >> >    that makes it driver independent.  It will take a while for this to
   >> >    appear and then more time for it to mature but it will eventually
   >> >    be part of the new PDF based printing work flow.  Once that is in
   >> >    place CM printing will become available to all applications running
   >> >    on *nix platforms.
   >> >
   >> > I think it's time we determine exactly what role Gutenprint (or the
   >> > driver, in general) should take in the overall color processing
   >> > workflow -- what our responsibilities should be and what features we
   >> > should offer.