From ColourWiki

Revision as of 22:39, 20 Oct 2006; view current revision
←Older revision | Newer revision→

There are several standards connected with color management. Some technical standards are about color management should work. Other standards are more about the exchange of color data in daily practice. On some points, both groups of standards interfere.

Some standards are maintained by official international standard-organisations like ISO (, IEC ( or W3C ( Some standards are maintained by a consortium of vendors. At least there are de-facto standards of only one vendor, because he is the market dominator.

Table of contents

The ICC specifications

The ICC ( specifications are maintained by an industry-consortium and are now also an ISO standard.

The specifications contain a format for color profiles and a CMM for using the profiles on system-level or in applications.

The ICC-specifications are not embedded in workflow recommendations for the end-users. There are also no straight guidelines, how the OS, applications and printer drivers should interact and should be presented to the user for a transparent ICC color management workflow. As there are no such recommendations and guidelines, it is impossible to construct test data, if OS, applications and printer drivers are working like they should. As result, vendors of operating systems, applications and printer drivers implement ICC-based color management like they think it should work. Even for color management specialist, it is often not possible to predict, how OS, applications and printer drivers interact.

In the ICC-specifications, gamut mapping is standardized for colorimetric matches. Perceptual mapping is actual not standardized. The reference medium gamut and relative colorimetric matching with blackpoint compensation are first steps for a standardized perceptual gamut mapping, if profiles from different vendors interact.



Very good site! Thanks! <A href="url">keyword</A> [URL=url]keyword[/URL]<a href="">garage storage cabinet</a> <a href="">natural colon cleanser</a> <a href="">airsoft bb gun</a> <a href="">body jeep part</a> <a href="">massage parlor</a> <a href="">omron blood pressure monitor</a> <a href="">owe s home improvement</a> <a href="">toyota truck part</a> <a href="">portable air compressor</a> <a href="">tempurpedic mattress pad</a>

Formats for exchange of files or documents

There are several formats for the exchange of files or documents. If the data is used for consumer imaging, office-documents, webdesign, graphic arts or high-end digital photography, it is common to say, that RGB-files with no embedded ICC-profile are referring to sRGB. Other files should have embedded ICC-profiles. For CMYK-files with no embedded profile, it is common to refer to the colorspace for offset printing on coated paper.

Standard Printing conditions

Standard Printing conditions makes color management for the graphics arts easy. From the point of the developer, they are the standard-settings for the CMYK colorspace in graphic arts applications. From the point of the user, they have following functions:

  • clear communication of color between graphic designer and printing-house
  • target colorspace for separation of RGB-images
  • source colorspace for simulation offset printing on monitor (softproof)
  • source colorspace for simulation offset printing on inkjet (contract proof)
  • descriptive colorspace for CMYK PDF/X-data (output intent)
  • descriptive colorspace for contract proofs (printed control slug)
  • target for judging the color of contract proofs (colorimetric quality control)

The most often used standard printing conditions are SWOP in the US and ISO coated in Europe.

Colour measurements / swatches

Single colours are used to communicate palettes / swatches. An other purpose is to measure how a single device colour maps to an reference colour space. Such a reference can be the CIE*XYZ/L*a*b* colour spaces or spectral data. Beside measurement errors, this makes the colour repeatable, which is a fundamental in colour management.

The ICC standard includes an profile format for swatches. It is called NamedColor2. This, as usual, binary ICC format can be used to exchange palettes.

CGATS is the text based standard for profiling applications. Free implementations exist in Argyll and littleCMS. More versatile is the CxF – Color Exchange Format ( from GretagMacbeth. It is based on XML. For WCS is an XML measurement based profile format planned, which shall replace the ICC format. Specifications for this format are not published yet.

Some graphic applications utilise own text files and specify simply RGB values there. See here ( Others use undocumented, proprietary formats, which makes exchanging limited or impossible.