File formats that Argyll uses
Argyll uses a number of file formats for its operation, some that are
external standards, and some that are unique to Argyll.
.ti1
.ti2
.ti3
.cal
.cht
.gam
.sp
CGATS
ICC
MPP
TIFF
VRML
.ti1
Target Information 1 data. This is an ASCII text, CGATS,
Argyll specific format, used to hold device value ready for creating a
profiling test chart, as well as the estimated CIE color values for
each value, used in laying out the test chart and reading
validation purposes. Additional information on possible spacer and
marking
values that may be needed in creating a rendered test chart is also
included.
This file is typically created using the targen
utility.
.ti2
Target Information 2 data. This is an ASCII text, CGATS,
Argyll specific format, used to hold device value that have been laid
out in a test chart, together with each test patches location, and
estimated CIE color values for each value used for reading validation
purposes. This file is typically created using the printtarg or
filmtarg
utilities.
.ti3
Target Information 3 data. This is an ASCII text, CGATS,
Argyll specific format, used to hold device value and CIE/Spectral
value pairs, the raw information needed to create device profiles. This
file is typically created using the chartread, dispread,
filmread, scanin,
fakeread or one of the conversion
utilities
such as cb2cgats, kodak2cgats,
logo2cgats. See TI3 file format for more detail.
.cal
Device calibration information. This is ASCII text, CGATS, Argyll specific format, used
to hold a description of device setup information that brings it to a
desired calibration state. Created by dispcal,
printcal, synthcal.
See CAL file format for more
detail.
.cht
Test chart recognition file. This is ASCII text, CGATS, Argyll specific format, used
to hold a description of a test chart, so that a raster image of the
chart
can be turned into device test values by the
scanin
utility. .cht files are
created manually (usually in combination with
scanin creating a boilerplate file containing
the recognition parameters, but not the patch location information), or
by the printtarg utility, when creating
a test print chart that will be scanned in, rather than read by an
instrument.
See CHT file format for more detail.
.gam
Gamut surface description. This is an ASCII text, CGATS, Argyll specific format, used
to hold a 3 Dimensional surface description of a color gamut. Typical
this is created using the iccgamut, tiffgamut, or mpplu
utilities. The resulting file is typically viewed using the viewgam utility to convert one or more gamuts
into a VRML file, or as input to collink, to describe a source colorspace gamut.
.sp
Spectral illuminant description. This is an ASCII text, CGATS, Argyll specific format, used
to hold a spectral description of an illuminant. Typically it is used
to
record a custom illuminant, for use in computing Fluorescent
Whitening
Agent compensation for reflective samples, as well as computing CIE
tristimulus
values from spectral samples.
CGATS
CGATS.5 Data Exchange Format, from the Annex J, of the ANSI
CGATS.5-1993 standard.
This is a general purpose ASCII file format suitable for representing
color data, and widely used to store color test values. Argyll uses
this as a base, human readable format, for a variety of purposes.
ICC
ICC files are files that conform to the International Color Consortium,
File Format for Color profiles. The ICC Profile Format attempts to
provide a cross platform device profile format, that can be used to
translate
color data created on one device into another device's native color
space.
For a fuller explanation of what the ICC Profile Format is all about,
please refer to http://www.color.org,
and the profile specification. Argyll currently supports profiles that
meet the V3.4 specification. These files are commonly named with a .icm
extension on the Windows platform, .pr or .icc on the
Macintosh
and other platforms. As well as device profiles, the ICC format can
also
store device link profiles, abstract profiles and named color profiles.
This file is typically created using the colprof
or collink utilities. A device link
profile
is also a way of specifying a custom ink separation from (say) CMYK to
the
6 or more colorants used by inkjet printers.
MPP
Model based device profile format. This is an ASCII text, CGATS, Argyll specific format, used
to hold the parameters to a general model based device profile. This is
a less precise and general format than and ICC profile, but is a
compact
way of representing a devices response when it has a large number of
color
channels, or when very few measured data points are available for its
construction.
This file is typically created using the mpprof
utility.
TIFF
Tag Image File Format (TIFF), a widely used format within the graphic
arts industries for storing image data. It handles various forms of
compression, and various colorspaces, including RGB, CMYK and
multi-channel files. See http://www.remotesensing.org/libtiff/.
Argyll makes use of this as a default raster
format.
VRML
Virtual Reality Modeling Language file. This is a portable way of
encoding 3 Dimensional objects (such as gamut surfaces). Typically
these can be viewed with a suitable standalone VRML viewer, or a plug
in for a web browser. VRML97 is International Standard ISO/IEC
14772-1:1997. See http://www.vrml.org/
for more information.