Re: [Gimp-print-devel] Stylus photo 870

[Robert L K. <rl...@al...>]

   Date: Wed, 3 May 2000 02:00:35 +0000
   From: Jean-Marc Verbavatz <ver...@if...>

   On May 2,  7:58pm, Robert L Krawitz wrote:

   >    { 0.152, 0x1, 0 },
   >    { 0.255, 0x2, 0 },
   >    { 0.38,  0x3, 0 },
   >    { 0.5,   0x1, 1 },
   >    { 0.67,  0x2, 1 },
   >    { 1.0,   0x3, 1 }
   >
   >    The last 3 values also go for K and Y (simple case).
   >
   > Well, this is easy to fix.  Thank you for doing this.  Would you like
   > to commit the fix?

   Sure if it's also applicable to other printers.

Might as well.  If different printers have different constants, we'll
fix those later.

I consider top quality from the Epson 870/1270 to be a key strategic
goal of this project (along with the Ghostscript driver).  I think we
should be prepared to accept some extra complexity to get this one
right.  The 870 is a recent, state of the art printer, and is widely
regarded to be one of the best, if not the best, inkjet out there (in
a reasonable price range).  This will go a long way toward making
Linux into a good desktop platform.  I'd like to support flagship
printers from other vendors too, but apparently they aren't being too
forthcoming with information.

(Is anyone from Epson reading this?  Does anyone smell opportunity for
hardware vendors?)

   > The balance between light and dark inks is very different from what I've
   > come up with; I came up with .25.  It might be that I'm using
   > different inks, or they might simply be reformulated.

   I just went back to what I had found for 3.1.2 and it was also between 0.35
   and 0.4. 0.25 is definitely too low for me; 0.33 already is (too low).

OK, probably the inks are different.  I should put an Epson cartridge
in my printer and see what happens.

   Primarily, red looks too yellow and blue too magenta to me. Gray is
   not quite gray either. This can probably be fixed by adjusting the
   respective densities but I haven't tried yet.

I've noticed that too.  Does your gray turn out slightly greenish?

   Wow, much better ! I can see color again :) The thresholds look excellent.
   Looks a bit grainy (Dither=2), but that's photo quality again.

Try adaptive random (dither=4).  I need to take a closer look at this
grain issue, since the stuff as of this morning seems to have
regressed a bit.

   By the way, I'm not using the gimp here, but ghostscript.

How many people are using this as a Gimp plugin, and how many as a
Ghostscript driver?

-- 
Robert Krawitz <rl...@al...>      http://www.tiac.net/users/rlk/

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

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