xicc/iccgamut
Create a gamut file or VRML file of the color gamut of an ICC
profile.
iccgamut allows creation of
gamut files from the forward or backwards
table of an ICC profile, in Lab or CIECAM02 Jab colorspace, and can
also
representing the gamut as a VRML file.
Usage
iccgamut [-options] profile
-v
Verbose
-d sres Surface
resolution details 1.0 - 50.0
-w
emit VRML .wrl file as well as CGATS .gam file
-n
Don't add VRML axes or white/black point
-f function f = forward*, b = backwards
-i intent p = perceptual, r
= relative colorimetric,
s = saturation, a = absolute*,
j = Appearance CIECAM02, d = default
-o order n = normal
(priority: lut > matrix > monochrome)
r = reverse (priority: monochrome > matrix >
lut)
-l tlimit set total
ink limit, 0 - 400% (default none)
-L klimit set black ink
limit, 0 - 100% (default none)
-c viewcond set viewing conditions for CIECAM02,
either an enumerated choice, or a series of
parameters:
0: Practical Reflection Print
1: Print evaluation environment
2: Monitor in typical work environment
3: Monitor in darkened work
environment
4: Projector in dim environment
5: Projector in dark environment
6: Original scene - Outdoors
7: Photo CD - original scene
8: Transparencies on a viewing box
s:surround a = average, m = dim, d = dark,
c = transparency (default average)
w:X:Y:Z Adapted white point
as XYZ (default media white)
w:x:y
Adapted white point as x, y
a:adaptation Adaptation luminance in cd.m^2 (default 50.0)
b:background
Background % of image luminance (default 20)
f:flare Flare
light % of image luminance (default 1)
f:X:Y:Z Flare color as
XYZ (default media white)
f:x:y
Flare color as x, y
profile
The name of the ICC
profile, as well as the basename of the gamut [.gam] and/or VRML [.wrl] file.
Comments
The parameters are all those that control which table in the ICC
profile to use, as well as what color space to convert it to.
The -v parameter dumps out the ICC profile header information.
The -d parameter controls the level of detail displayed in the
surface. The parameter roughly corresponds to a deltaE value, so
smaller
values give greater detail. The default value is around 10, and is a
good
place to start. Small values may take a lot of time to generate, and
will
produce big files.
The -w option causes a VRML file to be produced, as well as a
gamut file.
The -n parameter suppresses the L*a*b* axes being created in
the VRML.
The -f option allows choosing the ICC table to be used in
plotting the gamut. The backwards tables generally incorporate gamut
compression, and therefore don't reflect the native capabilities of the
device.
The -i flag allows choosing the table being used by its intent.
Anything other than colorimetric may not represent the native
capabilities of the device. The j parameter interprets the absolute
colorimetric table in terms of CIECAM02 appearance space Jab values.
An ICC profile is allowed to contain more than the minimum number of
elements or table needed to describe a certain transform, and may
contain redundant descriptions. By default, lut based table
information will be used first if present, followed by matrix/shaper
information, and only using
monochrome information if it is all that is present. The -o
flag,
reverses this order.
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 -L flag allows setting a black ink limit for printing
devices. If a device is to be used with a black ink limit, then it is
useful to evaluate
the gamut with the limit in place.
The -c option allows setting the CIECAM02 viewing conditions,
either by choosing a typical viewing environment, or controlling
particular viewing condition parameters.
Example
To create a view in L*a*b* of the absolute gamut of a CMYK file with an
ink limit of 260%, one might use:
iccgamut -w -ff
-ia -l260 profile.icm
and the resulting files will be profile.gam and profile.wrl.