ICC profile is a standard format for color management information. It may appear in a file by itself, or embedded in certain graphics file formats.
ICC stands for International Color Consortium, the organization responsible for the format. It was formerly (before about 1995) known as InterColor Consortium, and the format was known as InterColor Profile Format.
An ICC profile has a 128-byte header, followed by an index ("tag table") with a variable number of entries, followed by a data section containing items pointed to by the index.
acsp" appears at offset 36.
Many graphics-related formats can contain embedded ICC profiles. This is a partial list.
- In a TIFF file, tag 34675 is used for ICC profiles. See the ICC profile specification for details.
- In a JPEG file, an APP2 marker with an identifier of "ICC_PROFILE" is used for ICC profiles. See the ICC profile specification for details. Note that large ICC profiles must be split up, to accommodate JPEG's 64KB segment size limit.
- In a PNG file, chunk type iCCP contains an ICC profile. See the PNG specification for details.
- In a GIF file, an ICC profile uses application identifier "ICCRGBG1012".
- In the JPEG 2000 formats JP2, JPX and JPM, ICC profiles can be embedded in the "Colour Specification Box". The presence of an ICC profile is indicated by the value of the "METH" field of that box. The JP2 format imposes some restrictions on the use of ICC profiles; some of these restrictions were relaxed in a 2013 amendment to the format's specifications. More details on this can be found here.
- In Photoshop Image Resources metadata, an ICC profile uses Resource ID 0x040F.
In this family, the specification version is different from the profile version (a number stored in the ICC profile data).
- Version 3.0 (1994-06-10); profile version 2.0.0
- Version 3.01 (1995-05-08); profile version 2.0.0
- Version 3.2 (1995-11-20); profile version 2.0.0
- Version 3.3 (1996-11-11); profile version 2.1.0
- Version 3.4 (1997-08-15); profile version 2.1.0
- ICC.1:1998-09; profile version 2.2.0
- ICC.1A:1999-04: Addendum 2 to ICC.1:1998-09; profile version 2.2.0 or 2.3.0
- ICC.1:2001-04; profile version 2.4.0
- ICC.1:2001-12 (Version 4.0.0)
- ICC.1:2003-09 (Version 4.1.0)
- ICC.1:2004-10 (Version 18.104.22.168)
- ICC.1:2004-10 (Version 22.214.171.124) with errata incorporated, 2006-05-22
- ICC.1:2010-12 (Version 126.96.36.199)
Profile version 5 is named iccMAX. It is intended for situations where V4's features are insufficient, not as a replacement for V4.
- ICC.2:2019 (iccMAX); profile version 5.0.0