QTR-Quadtone RIP

Joe,

The whole problem was having a few points on the curve, that while 
not showing reversal, were too close to each other, and then rejected 
by the linearization routine.

Roy created a droplet program that allows you to simply drop a text 
file with the scanned Lab readings on it, and the droplet puts it in 
sorted order.  All you need to do is highlight the raw sorted data, 
copy it, then paste it into QTR's linearization screen.  Works great.


Thanks for your thoughts, Lou.


--- In QuadtoneRIP@yahoogroups.com, "joemulligan_68" 
<joemulligan_68@...> wrote:
>
> I've had this problem before when trying to use the Create ICC 
program when trying to 
> create a proflle for an older printer that wasn't laying down the 
inks linearly.  However, 
> there was truly a reversal rather than just the small differences 
that you point out.
> 
> My other question is about your method of linearization.  I have 
never used the Linearize 
> Data exe file to linearize as you mention.  I read the densities 
through Gretag Measure tool  
> and simply type in the densities in the Curve Creation tab.  Once 
you save the curve 
> Linearization happens automatically.  I get the impression that you 
are taking Linearized 
> data and throwing it in curve creation tab and then saving this 
file.  You could be 
> linearizing twice.  Correct me if I didn't interpret you 
correctly.  
> 
> --- In QuadtoneRIP@yahoogroups.com, "Louis Dina" <lou@> wrote:
> >
> > I think I figured out what I was doing wrong and wanted to share 
it 
> > in case others are experiencing the same thing.  Not sure if it 
is 
> > the best solution, but it seemed to work and give me a better 
profile.
> > 
> > I had my default ink limit set fairly high initially, where the 
curve 
> > was getting very flat.  My Eye One showed very slight increases 
in 
> > density at this point, but by eye it looked black a few steps 
> > before.  The ink limit I chose loaded up the shadow areas with a 
lot 
> > of ink, and while there was 'a little separation' between tones, 
it 
> > wasn't much.  The 90, 95 and 100% tones were bunched up pretty 
> > close.  So, I lowered the ink limit (in this case from 65 to 45, 
then 
> > bumped the black boost up to about 70.  This changed the shape of 
the 
> > black curve substantially and gave me a lot more separation 
between 
> > shadow values (and a better Dmax).  The program accepted these 
values 
> > without any error messages.
> > 
> > So, even though there was a slight separation between tones, I am 
> > guessing the program has some default parameters for accepting or 
> > rejecting linearization data, and my points were just too close 
> > together to get a passing grade.  Just as well, since I am sure I 
> > ended up with a better profile.
> > 
> > If this seems like a convoluted approach, please feel free to set 
me 
> > straight.  
> > 
> > Thanks, Lou
> > 
> > --- In QuadtoneRIP@yahoogroups.com, "Louis Dina" <lou@> wrote:
> > >
> > > Thanks, Jim, but I don't think that is the problem.  I have 
other 
> > > files that linearized just fine, and they list the L* data in 
> > > descending order exactly as presented below.  
> > > 
> > > I did just upgrade to QTR 2.5.2.1, so maybe this is a bug?  
It's 
> > > probably something I am doing.  Perhaps the two or three 
darkest 
> > > patches are too close together.  I did notice that the QTR-
> > Linearize-
> > > Data version is 2.5.2.0.
> > > 
> > > Lou 
> > > 
> > > --- In QuadtoneRIP@yahoogroups.com, "Jim Thyer" <jimth@> wrote:
> > > >
> > > > Hi Diana,
> > > > 
> > > > Remembering when I did my linearization the numbers were in 
> > > ascending order, so try reversing them.
> > > > 
> > > > Jim Thyer
> > > > 
> > > >   ----- Original Message ----- 
> > > >   From: Louis Dina 
> > > >   To: QuadtoneRIP@yahoogroups.com 
> > > >   Sent: Saturday, October 13, 2007 3:37 PM
> > > >   Subject: [QuadtoneRIP] Invalid Linearize curve message
> > > > 
> > > > 
> > > >   I am using QTR 2.5.2.1 on a Windows XP machine. I keep 
getting 
> > an 
> > > >   error message when trying to linearize that reads:
> > > > 
> > > >   "Invalid linearize curve -- not constantly increaseing. 
Curve 
> > > >   Creation failed."
> > > > 
> > > >   I export data to a tab delimited text format and drag it 
onto 
> > the 
> > > QTR-
> > > >   Linearize-Data.exe file and I get a nice smooth ramp 
without 
> > any 
> > > >   reversals reversals in the density or luminance data. Then 
I 
> > copy 
> > > >   the "linearize" data line in the bottom of the generated 
text 
> > > file 
> > > >   and paste it into the Linearization window of the curve 
> > creation 
> > > >   module. The original data looks fine to me. 
> > > > 
> > > >   What the heck am I doing wrong? Below is the linearize data 
for 
> > > this 
> > > >   file:
> > > > 
> > > >   QTR-Linearize-Data version 2.5.2.0
> > > > 
> > > >   LINEARIZE="95.63 93.09 88.98 85.03 81.23 76.85 71.99 68.03 
> > 63.64 
> > > 58.9 
> > > >   53.9 49.73 44.41 39.95 34.64 28.78 22.71 15.46 10.57 6.85 
6.39"
> > > > 
> > > >   Thanks, Lou Dina
> > > > 
> > > > 
> > > > 
> > > >    
> > > > 
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> >
>