Hopefully, this will clear some things up!
The controls in the Tools:Measure window are designed
to give you a simplified workflow for measuring the
QTR step wedges and saving the results into a text
format that's suitable for using with QTR. There are
two variations of this: a) Measuring and saving the
results so that they can be used directly in a QTR
ink definition file (think of this as the "first"
linearization), and b) Measuring and saving the
results so that they can be used with the CreateICC
tool, which creates a 2nd linearization (further
improvement for smoothness) and creates a specialized
ICC profile which can be used in Photoshop.
***
1. For the main linearization (to be used in QTR ink
definition files):
- Click on Export To: and choose the name of a
temporary file to save your measurements into. (This
file will be written into PFP's "Export" data folder)
- Select Density
- Check the QTR Format Override box. (This tells PFP
to write the density measurements into the file format
that's specifically needed to use with QTR, rather
than as simply a series of text lines containing
density values).
- Make sure the Linearization radio button, beneath
that checkbox, is selected.
- Measure your QTR step wedges. (Either by pressing
down on the spectro's nose as you move across them,
or using the Return/Enter key to take the measurements
while you move the spectro) When you're finished,
click Done. NOTE: You have to take -exactly- 21 wedge
step measurements here, so make sure that you're using
the QTR 21-step gray wedges and that you measure each
patch.
- Use PFP's File:Open Export command to open the
Export data folder. You should see your exported
file containing the QTR data there.
- Open it with any text editor, in you'll see the
LINEARIZE="..." line of text containing the
measured density values. (NOTE: With PrintFIX PRO
2.0 and 2.1, there was a bug, and this line would
contain LINEARIZATION instead of LINEARIZE. If you
used PFP 2.0 or 2.1 to create the file, change it
to LINEARIZE (manually). This bug was fixed in
Spyder3Print.) Then, copy and paste the entire line,
starting with "LINEARIZE", into the bottom of a QTR
ink definition file. Consult the QTR documentation
if you're not sure how to proceed with this.
2. For a file to be used with the CreateICC tool,
repeat the procedure for (1) above, but click Lab
rather than Density, and click the CreateICC radio
button, rather than the Linearization radio button,
below the QTR Format Override checkbox. You'll end
up with a text file that contains Lab values that
are formatted so that you can use them directly with
the CreateICC tool. (If you're not sure how to use
CreateICC, again, consult the QTR documentation).
David Miller
Senior Software Developer, Digital Color Solutions
Datacolor