Digital BW, The Print

Ah.  I now see what you mean! I thought you were still feeding evenly spaced
data but just noting for this conversation observations that weren't. Duh.
I was too rushed.

This is the risk I mentioned earlier when Carl noted that QTR Create ICC
could operate without the Gray reference column.  I don't think QTR Create
ICC should make any assumptions about to what stimulus the output
corresponded to.  Hence the minimum input file should also have the GRAY
column (as in the version I sent you Paul) and QTR Create ICC should make
use (if it is at all possible from a programming perspective) of this
column.

From my earlier post in response to Carl:

"I guess QTR Create ICC can simply assume the
steps are evenly spaced...If so anyone using less than 100 would need to
make sure their steps are.  Personally I think this is a risk and if this is
one way Roy is making the data input file more flexible I would ask him to
reverse it. One might want to do say 60 steps and have more data points at
the dark end.  Having the input co-ordinate and not assuming it makes sense
to me."


> From: Paul Roark <paul.roark@...>
> Reply-To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Date: Wed, 19 Oct 2005 14:54:40 -0700
> To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
> Subject: RE: [Digital BW] ICC v. Transfer Function in Epson driver
> 
> Carl,
> 
> Here it is.  I'll have more time to get to this later.  I don't know if it's
> the uneven steps, PC or what that is crushing the shadows.  For manual
> input, however, an uneven entry really helps.  The shadows are almost always
> were the action is.  I'll post the actual Lab L readings later.
> 
> 
> File: C:\Documents and Settings\Paul Roark\Desktop\C86_G2_Con-10-out.txt
> Step Dens Lab A B 
> 0.00 0.034 97.00 0 0 -                             b
> L +
> 10.00 0.148 87.52 0 0 -                             b
> L       +
> 20.00 0.233 81.03 0 0 -                             b
> L           +
> 30.00 0.338 73.52 0 0 -                             b
> L               +
> 40.00 0.465 65.16 0 0 -                             b
> L                    +
> 50.00 0.599 57.24 0 0 -                             b   L
> +
> 60.00 0.783 47.62 0 0 -                           L b
> +
> 70.00 1.012 37.36 0 0 -                     L       b
> +
> 80.00 1.229 29.17 0 0 -                L            b
> +
> 85.00 1.340 25.49 0 0 -              L              b
> +
> 90.00 1.429 22.74 0 0 -            L                b
> +
> 95.00 1.519 20.15 0 0 -           L                 b
> +
> 96.00 1.534 19.74 0 0 -          L                  b
> +
> 97.00 1.542 19.51 0 0 -          L                  b
> +
> 98.00 1.572 18.71 0 0 -          L                  b
> +
> 99.00 1.574 18.66 0 0 -          L                  b
> +
> 100.00 1.607 17.80 0 0 -         L                   b
> +
> 
> Created ICC file C:\Documents and Settings\Paul
> Roark\Desktop\C86_G2_Con-10.icc
> 
> Paul
> www.PaulRoark.com
> 
> _______________________________
> 
>> -----Original Message-----
>> From: DigitalBlackandWhiteThePrint@yahoogroups.com
>> [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of Carl
>> Schofield
>> Sent: Wednesday, October 19, 2005 11:54 AM
>> To: DigitalBlackandWhiteThePrint@yahoogroups.com
>> Subject: Re: [Digital BW] ICC v. Transfer Function in Epson driver
>> 
>> Paul,
>> 
>> I thought the steps had to be evenly spaced, but maybe not if you
>> were able to generate an icc profile.  Can you post the text file
>> that was generated when you made the icc profile?  I'm just wondering
>> how Create-icc  treated the uneven steps.  My experience has been
>> that the icc profiles improve shadow separation in 2400 ABW prints,
>> rather than compress the data.
>> 
>> Carl
>> 
>> On Oct 19, 2005, at 10:37 AM, Paul Roark wrote:
>> 
>>> Steve,
>>> 
>>> I thought maybe my, in my view too-compressed, low values might
>>> just be an
>>> artifact of a bad un-adjusted distribution and too few points.  So,
>>> I tried
>>> the Create ICC and Print with Preview workflow with a printing
>>> setup that
>>> had a reasonably smooth low end.  I took readings at every 1% point
>>> between
>>> 100% and 95%, then at 5% to 80%, and then at 10% intervals.  I was
>>> also
>>> curious if the program needed even distributions of input data.
>>> 
>>> The results were not much different than my previous attempts.
>>> Whereas the
>>> un-adjusted printing setup separated all the 95% - 100% points
>>> reasonably,
>>> the output adjusted with the Create ICC compressed the dark tones and
>>> posterized the 95% - 100% range.
>>> 
>>> I don't know what caused this, but it's not, in my view, an output
>>> that
>>> efficiently utilizes the grayscale file information.
>>> 
>>> Paul
>>> www.PaulRoark.com
>>