> Louis,
>
> I would do the same task with my EyeOne for QTR. If i could
transfer your informations to the QTR-Process i would like to get
your informations too if possible. May be i will try IJC/OPM later
too.
>
> Best Regards
>
> Rainer Taube
Rainer,
Here's a copy of the mail I sent to Bernd earlier.
Lou
*******************
I use my i1 with Gretag MeasureTool. If you don't have MeasureTool,
you can download it free from the Gretag MacBeth website. When you
open MeasureTool, first select Device/Port to configure your i1
(which must be plugged in before you start MT). Select "Reflective"
and uncheck the box that says "Spectral". Once the program
recognizes your i1, you can close the window.
Next, select the "Spot" measuring tool. MT will ask you to place
your i1 on the holder for calibration. When done, you can measure
your target. Set the color space to Lab and begin measuring.
IJC/OPM does not yet automate reading the targets, so you have to
write down the values for the 26 steps of the grayscale. All you
need are the L* readings (lightness values) for linearization. Once
you have recorded all the values on paper, open the IJC linearization
tab and hit the "clear" button to remove any old data. Then, enter
the values you wrote down directly into IJC with the lightest values
(eg, 98) near the top, and the darkest values at the bottom. The
vertical slider in IJC should be set to "0" when using L* values for
linearization. There is no advantage to converting these values to
density readings.
It is possible to convert L* to density values. There is a companding
calculator at http://www.brucelindbloom.com/ which does just that.
If you use density data, you will need to move the vertical gamma
slider in IJC so that step 13 has an "aim value" of between 0.63 and
0.70. This is because density is measure on a logarithmic scale,
unlike L* which is a linear scale. You will need to input the
density of step 1 and step 26 before you can set the slider
properly. I see no reason to use density instead of L* values. With
your i1, it is much easier, and just as accurate, to use L* values.
Joe Berndt (author of IJC.OPM) is working on automating the process
so that future releases of the program can load this data quickly and
easily. But at present, it is a manual process. You can try using a
scanner which is automated, but it won't be as accurate as using your
i1. The instructions are in the IJC/OPM user Manual.
Regards, Lou Dina
p.s. I wrote a tutorial for IJC which is posted in the Files section
of this website and also on the Bowhaus website. It has a lot of
information on how to do linearization in IJC.