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<h1>File formats that Argyll uses</h1>
<br>
Argyll uses a number of file formats for its operation, some that
are
external standards, and some that are unique to Argyll.<br>
<br>
<a href="#.ti1">.ti1</a><br>
<a href="#.ti2">.ti2</a><br>
<a href="#.ti3">.ti3</a><br>
<a href="#.cal">.cal</a><br>
<a href="#.cht">.cht</a>
<br>
<a href="#.gam">.gam</a>
<br>
<a href="#.sp">.sp</a><br>
<a href="#CGATS">CGATS</a><br>
<a href="#ICC">ICC</a><br>
<a href="#MPP">MPP</a><br>
<a href="#TIFF">TIFF</a><br>
<a href="#VRML">VRML</a><br>
<br>
<h2><a name=".ti1"></a>.ti1</h2>
Target Information 1 data. This is an ASCII text, <a href="#CGATS">CGATS</a>,
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 <a href="targen.html">
targen</a>
tool.<br>
<br>
<h2><a name=".ti2"></a>.ti2</h2>
Target Information 2 data. This is an ASCII text, <a href="#CGATS">CGATS</a>,
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 <a
href="printtarg.html">printtarg</a> or <a href="filmtarg.html">
filmtarg</a>
tools.<br>
<br>
<h2><a name=".ti3"></a>.ti3</h2>
Target Information 3 data. This is an ASCII text, <a href="#CGATS">CGATS</a>,
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 <a href="chartread.html">chartread</a>, <a
href="dispread.html"> dispread</a>,
<a href="filmread.html">filmread</a>, <a href="scanin.html"> scanin</a>,
<a href="fakeread.html"> fakeread</a> or one of the conversion
tools
such as <a href="cb2ti3.html">cb2ti3</a>, <a href="kodak2ti3.html">kodak2ti3</a>,
<a href="txt2ti3.html">txt2ti3</a>. See <a
href="ti3_format.html">TI3
file
format</a> for more detail.
<h2><a name=".cal"></a>.cal</h2>
Device calibration information. This is ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, Argyll specific format,
used
to hold a description of device setup information that brings it to
a
desired calibration state. Created by <a href="dispcal.html">dispcal</a>,
<a href="printcal.html">printcal</a>, <a href="synthcal.html">synthcal</a>.
See
<a href="cal_format.html">CAL file format</a> for more
detail.
<h2><a name=".cht"></a>.cht</h2>
Test chart recognition file. This is ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, 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 <a href="scanin.html">
scanin</a>
tool. <span style="font-weight: bold;">.cht</span> files are
created manually (usually in combination with <a href="scanin.html">
scanin</a> creating a boilerplate file containing
the recognition parameters, but not the patch location information),
or
by the <a href="printtarg.html"> printtarg</a> tool, when creating
a test print chart that will be scanned in, rather than read by an
instrument.
See <a href="cht_format.html">CHT file format</a> for more
detail.<br>
<h2><a name=".gam"></a>.gam</h2>
Gamut surface description. This is an ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, Argyll specific format,
used
to hold a 3 Dimensional surface description of a color gamut.
Typical
this is created using the <a href="iccgamut.html">iccgamut</a>, <a
href="tiffgamut.html">tiffgamut</a>, or <a href="mpplu.html">mpplu</a>
tools. The resulting file is typically viewed using the <a
href="viewgam.html">viewgam</a> tool to convert one or more gamuts
into a <a href="#VRML">VRML</a> file, or as input to <a
href="collink.html">collink</a>, to describe a source colorspace
gamut.<br>
<h2><a name=".sp"></a>.sp</h2>
Spectral illuminant description. This is an ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, 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.<br>
<h2><a name=".ccmx"></a>.ccmx</h2>
Colorimeter Correction Matrix. This is an ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, Argyll specific format,
used
to hold a 3x3 correction matrix. The matrix is for a specific
display
and Colorimeter, and is used to transform the instruments XYZ values
to
make them better match a reference spectrometers measurements for
that
display. The file contains a description of the display, Colorimeter
and reference Spectrometer. See <a href="ccxxmake.html">ccxxmake</a>
for more information.<br>
<h2><a name=".ccss"></a>.ccss</h2>
Colorimeter Calibration Spectral Set. This is an ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, Argyll specific format,
used
to hold a set of display spectral samples. For Colorimeters that
have
known sensor spectral sensitivity information (such as the i1d3),
this
allows a calibration
to be created that is tuned for a particular display. The file
contains
a description of the display, the display technology type, the type
of
spectrometer used for taking the readings. See <a
href="i1d3ccss.html">i1d3ccss</a>
and <a href="ccxxmake.html">ccxxmake</a>
for more information.<br>
<h3><a name="CGATS"></a>CGATS</h3>
CGATS.5 Data Exchange Format, from the Annex J, of the ANSI
CGATS.5-1993 standard.<br>
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.<br>
<h3><a name="ICC"></a>ICC</h3>
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 <a href="http://www.color.org">http://www.color.org</a>,
and
the
profile
specification.
Argyll currently supports profiles that
meet the V3.4 specification. These files are commonly named with a <b>.icm</b>
extension on the Windows platform, <b>.pr</b> or <b>.icc</b> 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 <a href="colprof.html">colprof</a>
or <a href="collink.html"> collink</a> tools. 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.<br>
<h3><a name="MPP"></a>MPP</h3>
Model based device profile format. This is an ASCII text, <a
href="File_Formats.html#CGATS">CGATS</a>, 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 <a href="mppprof.html">mppprof</a>
tool.<br>
<h3><a name="TIFF"></a>TIFF</h3>
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 <a
href="http://en.wikipedia.org/wiki/TIFF">http://en.wikipedia.org/wiki/TIFF/</a>.
Argyll
makes
use
of
this as a default raster
format.<br>
<h3><a name="JPEG"></a>JPEG</h3>
Joint Photographic Experts Group, (JPEG), a widely used format
within the graphic
arts and photographic industries for storing image data. It handles
various forms of
compression, and various colorspaces, including RGB and CMYK. See <a
href="http://en.wikipedia.org/wiki/JPEG/">http://en.wikipedia.org/wiki/JPEG/</a>.
Argyll
makes
use
of
this as an alternate raster
format for some tools.<br>
<h3><a name="VRML"></a>VRML</h3>
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 <a href="http://www.vrml.org/">http://www.vrml.org/</a>
for more information.<br>
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