Digital BW, The Print

Making the change now... will let you know what happens. 

Is the dot size issue specific to that one resolution?
Or are there similar transition points for other resolutions?

-d



--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Roy 
Harrington" <roy@h...> wrote:
> 
> Hi David,
> 
> Glad to see things are getting better.  I've got a hunch about 
> the hitches in the gray ramp:  the 2200 printer has two dotsizes
> for 1440x720 resolution.  The gimp-print software has to transition
> from one dotsize to the next smoothly and it does this based on a 
weighting
> of the dotsizes.  I have a feeling that gimp-print hasn't had a 
very accurate
> way to measure this weighting, because they've changed it several 
times
> for the 2200.  Below is the code that has this weighting -- the 
0.661 is
> the important value.  The value should probably be lower, in GP 
I've seen
> it go to 0.56, then 0.50.  I've worked with Carl a bit trying to 
get a way to
> measure it accurately and on his machine 0.46 seemed best.  You can
> just edit the source file, recompile and install rastertoprinter-
quad.
> This will require a re-measurement for the profile.
> 
> Roy
> 
> 
> ---------file: RasterSrc/main/print-escp2-data.c ------------
> 
> /***************************************************************\
> *                                                               *
> *            ULTRACHROME (2100/2200, 7600, 9600)                *
> *                                                               *
> \***************************************************************/
> 
> static const stp_simple_dither_range_t 
standard_4pl_pigment_dither_ranges[] =
> {
>   { 0.661, 0x1, 0, 2 },
>   { 1.00,  0x2, 0, 3 }
> };
> 
> DECLARE_INK(standard_4pl_pigment, 1.0);
> 
> --------------------
> 
> 
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "David 
Wroblewski" 
> <dawroblewski@y...> wrote:
> > Hi all, 
> > 
> > First a quick update, then a question:
> > 
> > I've got Roy's QTR software up and cooking under redhat 9.
> > Thanks to Roger Sopher and Roy for help and preliminary
> > installation notes. Installation was almost painless--we 
> > discovered one idiosyncrasy with configuring the CUPS printing
> > system, which involved changing some processing rules; I've
> > created a file of additional CUPS MIME rules that resolve 
> > the issue for me, which Roy and Roger now have.
> > 
> > I'm driving an Epson 2200 loaded with standard UC inks.
> > 
> > To get started, I'm printing tif's from Linux using the
> > qtcups utility, and the output is lovely. So far, I've sunk
> > about a buck (3 blank CD's used to burn the RH9 ISO images)
> > and 30 hours of sweat equity into this project. Not a dongle
> > in sight, either. :-) I'm using a worthless old PII 333 MHz 
> > PC to run RH9. 128 MB memory, 6GB HD.
> > 
> > Now my question: 
> > 
> > When I print the 21Step image using the curve EEM_2200-cool I 
> > see two very distinct hitches in the continuous ramp, one above
> > the 60% patch and one above the 90% patch. After running my first
> > calibration series last night, I got the same thing in my own
> > profile, shifted to slightly different positions.
> > 
> > Except for the discontinuity at those two points, the ramp
> > looks great, cool and smooth with delicate highlights and a 
> > velvety black at 100%. 
> > 
> > Am I doing something wrong? Do others see this? The settings I 
> > used were:
> > 
> > Dither: Adaptive Hybrid
> > Image Type: Photograph
> > Ink Type: Seven Color Photo
> > Resolution 1440x720 Highest Quality. 
> > Blend Curves 1 and 2: 100-0
> > Quadtone Rip Curve 1: EEM_2200-cool
> > 
> > -David