xicc/tiffgamut

Summary

Create a gamut file or VRML file of the color gamut of the contents of a TIFF image.
tiffgamut allows creation of gamut files from the pixel values in a TIFF raster image, as defined by an ICC profile, in L*a*b* or CIECAM02 Jab colorspace, and can also represent the gamut as a VRML file. This can be used for visualizing and comparing the gamut of an image to the colorspace it is in, or a colorspace it might get transformed into, and can also be used to create an image source gamut for use with icclink.

For creating a gamut suitable for use with the icclink -g or -G flags, use the Jab appearance space intent and the same viewing conditions to be used in icclink using the -c flag, i.e. "tiffgamut -ij -c2 sRGB.icm image.tif"

Usage Summary

tiffgamut [-v level] profile.icm infile.tif
 -v                  Verbose
 -i intent          p = perceptual, r = relative colorimetric,
                      s = saturation, a = absolute, j = Appearance CIECAM02
 -o order          n = normal (priority: lut > matrix > monochrome)
                      r = reverse (priority: monochrome > matrix > lut)
 -c viewcond   set viewing conditions for CIECAM02,
               either an enumerated choice, or a parameter:
               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
 -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

Usage Details and Discussion

The -v parameter dumps out the ICC profile header information.

The -i flag allows choosing the ICC profile 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 -c option allows setting the CIECAM02 viewing conditions, either by choosing a typical viewing environment, or controlling particular viewing condition parameters.

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.