<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>Argyll File Formats</title> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> <meta name="author" content="Graeme Gill"> </head> <body> <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> utility.<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> utilities.<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 utilities such as <a href="cb2cgats.html">cb2cgats</a>, <a href="kodak2cgats.html">kodak2cgats</a>, <a href="logo2cgats.html">logo2cgats</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. Currently only display output curves are defined. Created by <a href="dispcal.html">dispcal</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> utility. <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> utility, 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> utilities. The resulting file is typically viewed using the <a href="viewgam.html">viewgam</a> utility to convert one or more gamuts into a <a href="#VRML">VRML</a> file, or as input to <a href="icclink.html">icclink</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> <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="profile.html">profile</a> or <a href="icclink.html"> icclink</a> 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.<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="mpprof.html">mpprof</a> utility.<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://www.remotesensing.org/libtiff/">http://www.remotesensing.org/libtiff/</a>. Argyll makes use of this as a default raster format.<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> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> </body> </html>
