Re: custom IT8 data files
Re: custom IT8 data files
- Subject: Re: custom IT8 data files
- From: "Bruce J. Lindbloom" <email@hidden>
- Date: Thu, 20 Sep 2001 11:17:36 -0500
Neil Snape wrote:
>
I would like to make a custom IT8 7/2 .txt data file (tdf). The white paper
>
on the Kodak tdf's it says that STD_DEV has to be in the file.
>
What exactly is needed to make a tdf for generating profiles?
>
I can input Lab data into X-Rite's Colorshop and get the equivalent XYZ data
>
but how do you get the chi squared delta E and mean deviations? If someone
>
would have an Excel sheet already prepared for making tdf's that'd help.
A "tdf" is a special form of a standard IT8 reference file that is used by
Kodak products. If you wish to make a custom IT8 reference file for use
with non-Kodak products (which I suspect is what you really want, judging
from your Subject line), it's pretty easy. A template is shown below.
First some comments on the template, though:
a) The types of measurements contained in the file are flexible, and you
indicate which are present by setting the "NUMBER_OF_FIELDS" value (in the
template below there are 9 fields: ID, X, Y, Z, L, a, b, C, H, but most of
these are not required). At a minimum, you should set this to 4 (for ID, X,
Y, Z).
b) The line between "BEGIN_DATA_FORMAT" and "END_DATA_FORMAT" should show
what your fields mean. The minimal case should read "SAMPLE_ID XYZ_X XYZ_Y
XYZ_Z".
c) The "NUMBER_OF_SETS" field should indicate the number of patches present,
which will be less than or equal to 288, depending on your target (Kodak
targets have a photo which reduces the number of patches).
d) The list of measurements follows. The minimal case will have lines like
"A1 3.75 3.10 2.16", showing the ID, X, Y and Z values.
e) Other fields like L, a, b, C, H, standard deviation, etc. are probably
not needed by any commercial profiling packages and may be omitted.
f) The first line must be "IT8.7/2" for reflective targets and "IT8.7/1" for
transparency targets.
g) Lines starting with "#" are comment lines.
IT8.7/2
ORIGINATOR "Your Name Here"
DESCRIPTOR "Q60R1, IT8.7/2 Data File, 5x7 inch Ektacolor"
CREATED "Tue Jun 9 14:47:59 1998"
MANUFACTURER "Eastman Kodak Company"
PROD_DATE "unknown"
SERIAL "whatever"
MATERIAL "Ektacolor Product Family"
NUMBER_OF_FIELDS 9
BEGIN_DATA_FORMAT
SAMPLE_ID XYZ_X XYZ_Y XYZ_Z LAB_L LAB_A LAB_B LAB_C LAB_H
END_DATA_FORMAT
NUMBER_OF_SETS 264
BEGIN_DATA
# X Y Z L a b C H
A1 3.75 3.10 2.16 20.42 12.39 3.38 12.84 15.25
A2 4.64 3.11 1.79 20.46 24.78 7.07 25.76 15.92
(etc.)
GS22 0.77 0.78 0.64 7.09 0.46 0.21 0.50 24.42
Dmax 0.32 0.30 0.30 2.70 1.28 -1.01 1.63 321.73
END_DATA
--
Bruce J. Lindbloom, Pictographics Intl. Corp.