spectro/fakeread
Summary
Simulate the measurement of a devices response, using an existing
device profile, or measured test point data set. The device profile can
be either
an ICC or MPP profile, or the data set can be a
.ti3 file. A device link
separation or color space conversion can be applied before the
print/measure simulation.
Usage
fakeread [-v] [-s] profile.[icm|mpp|ti3] outfile
-v
Verbose mode
-s
Lookup MPP spectral values
-p
Use separation profile
-l
Output Lab rather than XYZ
-0
pow
Apply power to input device chanel 0-9 (after sep.)
-r
level
Add total of <level> random to input device values 0.0 - 1.0
(after sep.)
-R
level
Add total of <level> random to output PCS values 0.0 - 100.0
[separation.icc]
Device link separation profile
profile.[icm|mpp|ti3] ICC, MPP
or .ti3
profile/file to use
outfile
Base name for
input[.ti1]/output[.ti3] file
Examples
fakeread profile.icm testvalues
fakeread -p convert.icm profile.icm testvalues
Comments
The -v flag does nothing at the moment.
The -s flag works only with MPP profiles that contain spectral model
information.
The -p flag enables a device to device value conversion before
converting to expected PCS values.
The -l flag causes the CIE output values to be L*a*b* rather than the
default XYZ values.
The -0, -1, -2 .. -9 parameters are a way of simulating changes in the
behaviour of the simulated printing system. The parameter supplied to
the flag will be used to modify the device values (after any separation
is applied) by raising them to the power of the parameter. This applies
a transfer curve to the simulated device response.
The -r parameter is a way of simulating instability in the behaviour of
the simulated
printing system. The parameter supplied to the flag will be used to
scale a random offset added to the device values (after any separation
is applied). The offset will be +/- 0.5 * <level>, added to the
device value that is in the range 0.0 - 1.0. A typically value supplied
might be 0.01 to simulate
+/- 0.5% randomness.
The -R parameter is a way of simulating instability in the behaviour of
the simulated
measuring system. The parameter supplied to the flag will be used to
scale a random offset added to the PCS values. The offset will be +/-
0.5 * <level>, added to the PCS value that is typically in the
range 0.0 - 100.0 for an XYZ PCS, and 0.0 - 100.0 and -128.0 - 127.0
for Lab. A typically value supplied might be 1.0 to simulate
+/- 0.5% randomness.
Fakeread is useful in creating artificial test value for testing profile, as well as providing one path for
turning an MPP profile into an ICC profile. If a .ti3 file is
specified instead of an ICC or MPP profile,
then the closest matching measured points in the ..ti3 are substituted
for the test values in the .ti1
file on
output. If the .ti1
file is a monochrome test file with a White device value, then an RGB ICC profile, MPP or .ti3 may be used, and the White
values will be translated to equal RGB values. If the .ti1
file is a monochrome test file with a Black device value, then a CMYK ICC profile, MPP or .ti3 may be used, and the Black
values will be translated to equal CMY = 0, K = grey values.
If a separation device profile is provided (e.g. from CMY -> CMYK,
or perhaps CMYK->CMYK, to simulate a color correction step before
"printing"), then this will be applied to the .ti1 device values,
before converting the the device values into .ti3 PCS values.