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
 -k            Add markers for prim. & sec. "cusp" points
 -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% (estimate by default)
 -L klimit     set black ink limit, 0 - 100% (estimate by default)
 -c viewcond   set viewing conditions for CIECAM02,
               either an enumerated choice, or a series of parameters:value changes
            pp - Practical Reflection Print
            pe - Print evaluation environment
            mt - Monitor in typical work environment
            mb - Monitor in bright work environment
            md - Monitor in darkened work environment
            jm - Projector in dim environment
            jd - Projector in dark environment
           pcd - Photo CD - original scene outdoors
            ob - Original scene - Bright Outdoors
            cx - Cut Sheet 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 flag 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 flag causes a VRML file to be produced, as well as a gamut file.

The -n flag suppresses the L*a*b* axes being created in the VRML.

The -k flag adds markers for each of the primary and secondary "cusp" points (Red, Yellow, Green, Cyan, Blue & Magenta). No markers will be displayed if the cusps cannot be determined.

The -f parameter 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 parameter allows choosing the table being used by its intent. Anything other than colorimetric may not represent the native capabilities of the device. A  parameter value of j 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 parameter 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. tables. By default, a total ink limit will be estimated from the profile tables.

The -L parameter 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. By default, a black ink limit will be estimated from the profile tables.

The -c parameter 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.