QTR-Quadtone RIP

Thanks Roy,

Since it's a Gimp based processing I'll try to get more info on the 
Gimps forum.

Could you possibly let me know the Gimp version used in QTR : there's 
been some questionning about it inb the past and I saw the latest QTR 
beta uses files dates July 5th 05 : have you updated the print engine 
or anything recently ?

Thanks again 

Olivier

--- In QuadtoneRIP@yahoogroups.com, "Roy Harrington" <roy@h...> wrote:
> 
> There's really only two dithering methods that I think are worth 
looking at.
> They are Ordered and Adaptive Hybrid.  From looking at the code 
both Floyd
> and Eventone just do Adaptive Hydrid.  Fast and Very Fast aren't 
that good as
> far as I can tell.  
> 
> The results from Ordered and Adaptive are pretty close -- they are 
different but
> overall give similar results.  On any given image there may be 
visible differences
> but I had a hard time conclusively saying one was clearly and 
always better than the other.
> Early on I remember seeing an occasional yet rare artifact in the 
Adaptive dither
> on specific test prints - not real photos.  That combined with the 
noticeably faster
> algorithm for Ordered, I always use Ordered.
> 
> Ordered dither is the only one that I can say I mostly understand.  
There seem to
> be some docs that imply that it doesn't do well with variable dot 
sizes.  I don't in
> general find that to be true but I have been experimenting with the 
handling of
> variable dot sizes.
> 
> Roy
> 
> 
> --- In QuadtoneRIP@yahoogroups.com, "Olivier" <odesmais@y...> wrote:
> > Based on this 3 links :
> > 
> > http://gimp-print.sourceforge.net/developer-html/gimpprint_26.html
> > http://man.digipedia.pl/man/man7/gimpprint-dithers.7.html
> > http://www.photo.net/bboard/q-and-a-fetch-msg?msg_id=00BR5g
> > 
> > it's very hard to find out the effects of each dithering methods 
> > (except "fast" and "very fast" are not adapted to fine BW prints).
> > 
> > The thread from photonet states that only ordered,fast and 
Adaptive 
> > Hybrid are implemented in QTR ?
> > 
> > The one from sourceforge seems to recommend Adaptive Hybrid since 
> > ordered is only preferable for 4colors none variable dot sized 
> > printers, A/H would use error diffusion in dark & halftones and 
ordered 
> > in light tones.
> > 
> > 
> > None of these papers is too explicite. Any additonal comments 
from 
> > better experimented people than me...
> > 
> > Olivier
> > 
> > 
> > --- In QuadtoneRIP@yahoogroups.com, "Olivier" <odesmais@y...> 
wrote:
> > > John, thanks for the below. In fact I'm looking for an 
explanation of 
> > > how the different dithering methods calculate the print and the 
> > > difference between each.
> > > 
> > > Olivier
> > > 
> > > --- In QuadtoneRIP@yahoogroups.com, "John Moody" 
<moodymz3@y...> 
> > wrote:
> > > > The reply has not changed, but I have been using eventone for 
matte 
> > > paper at
> > > > 1440 super, and ordered for luster at 2880 dpi with the R200 
> > printer.
> > > > 
> > > > Best regards,
> > > > John Moody
> > > >