[Gimp-print-devel] Halftoning algorithms

[Raph L. <arc...@db...>]

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Hi gimp print people,

   I've done quite a bit of work over the years on
screening algorithms. I'm trying to push some of
them for commercial licensing, see
http://www.artofcode.com/eventone/ for details.

   To this end, I've been building a testbed that
includes RGB->CMYK conversion and actual device
driving. Thus, this work duplicates driver work in
both GhostScript and gimp-print. So far, I have
drivers for Epson Stylus Color Pro and Stylus
Color 600. The code pushes both of these printers
to the limit, achieving full 1440 x 720 resolution
in the latter case.

   Not to overstate things, but the quality is
incredible. It is dramatically better than the gs
and gimp-print drivers, and, while I haven't done
serious comparison yet with the bundled windows
drivers, my guess is that it's comparable or
slightly better.

   I want to do the right thing in terms of
releasing this code as open source, but I'm moving
cautiously on that right now. There are a number
of companies who have stated that they're working
on improving print quality (the VA - HP alliance
and Corel come to mind), and I'd like to see if
they can fund the project.

   In the meantime, I want to keep you guys in the
loop. I am happy to give you guys the code to play
around with, with the understanding that it is not
yet free software, but will be at some date in the
not too distant future. I talked to Peter Deutsch
a few days ago, so he's up to speed as well.

   I've learned a lot by reading the gimp-print
code. I think you might enjoy reading through my
code. Among other things, I have _much_ simpler
code for microweaving. At the moment, the code is
specialized for the stc600 and needs to be
parameterized a bit, but the entire Epson driver
is 236 lines of code.

Raph


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