[Gimp-print-devel] Merge

[Jean-Marc V. <ver...@if...>]

As promised a while ago I have worked more on merging my work with the current
repository. Unfortunately I ran out of ink for several days, hence the delay.
Another reason it took that long is that I had overlooked recent dithering
progress, which is far too complex for me to understand easily.

This whole thing helped me improve my code a little. However, what was
bothering me most was fluffy rendering in some areas or other artefacts
depending on dither used. I found where this came from. If I understand well,
this is from the (now not so) new matrices unfortunately. i.e., either (in
print_color()):
default:
  vmatrix = DITHERPOINT(d, x, y, 6); (vs DITHERPOINT(d, x, y, 0))
or
else if (rangepoint >= DITHERPOINT(d, x, y, 5)) (vs DITHERPOINT(d, x, y, 3))
or both
produce this result.

I don't know what to think about this and I would like some advice. To me it
looks like these matrices semi-randomly spread out ink on a relatively large
surface area. To me again, that makes perfect sense for printers with few ink
levels. I'm not that convinced that it should be the case to the same extent
for 6 ink level printers such as the Epson 870. In my opinion these printers
have the ability to stick to colors more efficiently.
That's my little understanding and I may be completely wrong. The bottom line
is that these matrices yield strange light dot clusters on the Epson 870 in my
hands.

I've not posted a new version because I feel that I need to understand the
above for any successful merging of ideas.

What are your comments ?

-- 
--
Jean-Marc Verbavatz		<ver...@if...>
5, rue La Fontaine		"http://perso.cybercable.fr/verbavat"
F-75016 Paris