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

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

   Date: Tue, 2 May 2000 23:46:00 +0000
   From: Jean-Marc Verbavatz <ver...@if...>

   My name is Jean-Marc Verbavatz. I have joined the developers of
   gimp-print a few days ago and would like to introduce myself.

Welcome!

   { 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?

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.

Could someone test these on a 740 and a 900 (standard_dither_ranges
and dot_sizes also needs to be fixed the same way)?

   On my STP870, my values yield absolutely identical densities for each of the
   inks/levels. The color balance still needs to be improved.

What's wrong?  Maybe I can make some suggestions.

   I see that these have already been modified in print-escp2.c v 1.134 in the
   meantime and in the same direction except for dark level 2. In particular we
   went from 5 to 6 levels (light 3 was not being used).
   If I understand well, this should therefore apply as well to print-escp2.c:

   1217,1218c1217,1218
   <         dither_set_c_ranges(dither, 5, variable_dither_ranges, v->density);
   <         dither_set_m_ranges(dither, 5, variable_dither_ranges, v->density);
   ---
   >         dither_set_c_ranges(dither, 6, variable_dither_ranges, v->density);
   >         dither_set_m_ranges(dither, 6, variable_dither_ranges, v->density);

Indeed it should.

   Finally as of the version before today's black was too dark.

Let us know how the version as of this morning works, since that was
one of the key improvements.  Maybe we can also try lower black
thresholds (particularly k_lower) with the variable dot sizes.

-- 
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