Digital BW, The Print

Sorry....I posted this on the QTR forum, but it is a little slow over 
there.  Please excuse the 'cross post'.

*************************************

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 increasing. 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 in the L* 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 data pastes 
fine looks fine to me.  It is listed L* units in descending order as 
in other profiles I have built successfully.  

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

I "think" I figured out the problem, but I'd love some confirmation 
from more experienced QTR curve builders.

I believe I had the ink limit set too high, which bunched the deep 
shadow values a little to close together.  There was 'some' 
difference between shadow values, and they always did increase (no 
reversals), but it appears that wasn't enough.  I am guessing the 
curve creation module looks for a minimum difference between patches 
before it will accept the linearization data.  

I lowered the ink limit, bumped up the black boost, and this gave me 
the same Dmax but much more spacing between shadow values.  When I 
did that, it seemed to work.

Does this sound about right?

Thanks, Lou

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Louis Dina" 
<lou@...> wrote:
>
> Sorry....I posted this on the QTR forum, but it is a little slow 
over 
> there.  Please excuse the 'cross post'.
> 
> *************************************
> 
> 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 increasing. 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 in the L* 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 data pastes 
> fine looks fine to me.  It is listed L* units in descending order 
as 
> in other profiles I have built successfully.  
> 
> 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
>

Lou,

I think your analysis is right. I have experienced a similar 
situation earlier. QTR gives this message also of L-values are too 
close to one another, of in in other words: if the L-curve is too 
flat, even if there are strictly no reversals in the curve.

Joost

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Louis Dina" 
<lou@...> wrote:
>
> I "think" I figured out the problem, but I'd love some confirmation 
> from more experienced QTR curve builders.
> 
> I believe I had the ink limit set too high, which bunched the deep 
> shadow values a little to close together.  There was 'some' 
> difference between shadow values, and they always did increase (no 
> reversals), but it appears that wasn't enough.  I am guessing the 
> curve creation module looks for a minimum difference between 
patches 
> before it will accept the linearization data.  
> 
> I lowered the ink limit, bumped up the black boost, and this gave 
me 
> the same Dmax but much more spacing between shadow values.  When I 
> did that, it seemed to work.
> 
> Does this sound about right?
> 
> Thanks, Lou
> 
> --- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Louis Dina" 
> <lou@> wrote:
> >
> > Sorry....I posted this on the QTR forum, but it is a little slow 
> over 
> > there.  Please excuse the 'cross post'.
> > 
> > *************************************
> > 
> > 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 increasing. 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 in the L* 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 data 
pastes 
> > fine looks fine to me.  It is listed L* units in descending order 
> as 
> > in other profiles I have built successfully.  
> > 
> > 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
> >
>