profile/invprofcheck
Summary
Check ICC forward against
reverse lookup.
Usage Summary
usage: invprofcheck [-options] profile.icm
-v [level]
Verbosity level (default 1), 2 to print each DE
-l
limit Set total
ink limit (estimate by default)
-L
klimit Set black channel ink
limit (estimate by default)
-h
High res test (27)
-u
Ultra
high res test (61)
-R
res
Specific grid resolution
-I
Do bwd to fwd check
-c
Show
CIE94 delta E values
-k
Show
CIEDE2000 delta E values
-w
Create
X3DOM visualisation (profile.x3d.html)
-x
Use
X3DOM axes
-e
Color
vectors acording to delta E
-Y
c:file.cal Provide or overide
calibration total ink curves
profile.icm Profile to check
Usage Details and Discussion
invprofcheck provides a way of checking how well an ICC profile inverse transform
inverts the forward transform. For devices with more than 4
channels, a total ink limit is assumed, and (if no -l parameter is given) a
reasonable number is deduced from the reverse table. A grid of
device values is created, and the transform from PCS->device, and
then device->PCS is computed in L*a*b* space. The average,
maximum and RMS error delta E values are computed and displayed in
the chosen delta E metric. A X3DOM
plot of the error vectors can be created. invprofcheck tries to only test in-gamut color
values. Note that because it scans a device grid, for a CMYK device,
the density of test points will be progressively higher in the dark
regions, and the average and RMS values will be distorted by the
denser sampling.
The -v flag prints out extra information during the
checking. A value greater than 1 will print the color values of each
test point.
The -l flag allows setting a total ink limit (TAC) for
printing devices. If a device has a total ink limit, and hasn't been
characterised with device values above this limit, then plotting the
gamut in these areas will almost certainly be misleading. The ink
limit will be in final raw device values if the profile includes
calibration information.
The -L flag allows setting a black channel ink limit for
printing devices. If a device has a black ink limit, and hasn't been
characterised with device values above this limit, then plotting the
gamut in these areas will almost certainly be misleading. The black
ink limit will be final raw device values if the profile includes
calibration information.
The default device grid is relativy low, and 11 (ie. 11 x 11 x 11
for an RGB device, 11 x 11 x 11 x 11 for a CMYK device etc.).
The -h flag selects a
higher device grid resolution of 27.
The -u flag selects an
extremely high device grid resolution of 61. This will probably take
a long time to run.
The -G res option allows a
specific grid resolution to be used.
If the -I option is used, then the grid is in L*a*b* space,
so out of gamut clipping behavior can be examined. Delta E's will be
high due to the clipping.
The -c option causes the error differences to be displayed
in CIE94 delta E, rather than plain L*a*b* delta E. CIE94 delta E
has a closer correspondence with perceived color differences than
the default CIE76 delta E values.
The -k option causes the error differences to be displayed
in CIEDE2000 delta E, rather than plain L*a*b* delta E. CIEDE2000
delta E has a closer correspondence with perceived color differences
than either CIE76 or CIE94 delta E values.
The -w creates a X3DOM
3D visualization of the differences between the test points and the
profiles prediction of the resulting colors.
The -x flag adds Lab axes to the X3DOM output.
The -e flag causes the
error vectors in the X3DOM output to be color coded according to
their lengths, from longest to shortest: yellow, red, magenta, blue,
cyan and green.
The -Y c:file.cal parameter adds
or overrides Calibration curves that will be used in the computation
of the total or black ink limit calculation. This allows the ink
limits to be computed in final raw device units.