Re: [Openicc] colord 0.1.0 released!

[Robert Krawitz <rlk alum mit edu>]

On Mon, 17 Jan 2011 10:14:05 -0500, Leonard Rosenthol wrote:
>
> On Mon, Jan 17, 2011 at 9:56 AM, Robert Krawitz <rlk alum mit edu> wrote:
>
>> The real issue here is making sure that CUPS and its filter chain
>> don't modify color data on the way down unless they're told to, and
>> when they do so, it must be predictable.
>
> In this case, we're talking strictly about raster-based printers,
> correct?  Postscript, PCL, etc. based devices aren't part of this
> mix, since color management is handled in a completely different
> manner for such devices - yes?

Well, we drive PCL printers in raster mode.  For that matter, we even
have a PostScript output driver in Gutenprint, although we don't offer
that in the CUPS driver (there would be no point in it).  That's only
for other Gutenprint clients (such as GIMP and PhotoPrint) to be able
to print to printers not supported by Gutenprint.  But in general, yes.

>> That's the problem on OS X:
>> there doesn't seem to be any way to ensure that data from the
>> application reaches the printer (or driver) unmodified.  In other
>> words, if we send an RGB tuple (97, 38, 108) from an application, we
>> have no way to guarantee that Gutenprint sees that same RGB value.
>
> There are solutions for this for certain printer models, where the
> device vendor has provided their own private APIs to enable
> applications to bypass the OS.  Photoshop, for example, does this
> when it can (on both Mac OS X and Windows).  NOTE: I am still trying
> to get this info published, but it's not under our control and for
> reasons I have yet to fathom, they don't see the need for other apps
> to play too :(.

When I think about it, so do we -- the differences being that our API
is public (GPLv2+) and Gimp-Print/Gutenprint was originally developed
precisely as the original print plugin for GIMP and only later (but
not by much) were Ghostscript and CUPS drivers added using the same
API.

-- 
Robert Krawitz                                     <rlk alum mit edu>

Tall Clubs International  --  http://www.tall.org/ or 1-888-IM-TALL-2
Member of the League for Programming Freedom  --  http://ProgFree.org
Project lead for Gutenprint   --    http://gimp-print.sourceforge.net

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