| ICC profile | |
|---|---|
 ICC V4 certification logo | |
| Filename extension | .icc, .icm |
| Internet media type | application/vnd.iccprofile |
| Uniform Type Identifier (UTI) | com.apple.colorsync-profile |
| Magic number | 'acsp' |
| Developed by | International Color Consortium |
| Initial release | 1994; 31 years ago (1994) (ICCv2 "version 3.0") |
| Latest release | 4.4.0.0 May 2022; 3 years ago (2022-05) |
| Standards | ICC.1:2001-04 (v2), ICC.1:2010-12 (v4); ISO 15076-1 |
| Open format? | yes |
| Website | https://www.color.org/icc_specs2.xalter |
Incolor management, anICC profile is a set of data that characterizes a color input or output device, or acolor space, according to standards promulgated by theInternational Color Consortium (ICC). Profiles describe the color attributes of a particular device or viewing requirement by defining a mapping between the device source or targetcolor space and aprofile connection space (PCS). This PCS is eitherCIELAB (L*a*b*) orCIEXYZ. Mappings may be specified using tables, to whichinterpolation is applied, or through a series of parameters for transformations.
Every device that captures or displays color can be profiled. Some manufacturers provide profiles for their products, and there are several products that allow an end-user to generate their own color profiles, typically through the use of atristimulus colorimeter or aspectrophotometer (sometimes called a spectrocolorimeter).[1]
The ICC defines the format precisely but does not define algorithms or processing details. This means there is room for variation between different applications and systems that work with ICC profiles. Two main generations are used: the legacy ICCv2 and the December 2001 ICCv4. The current version of the format specification (ICC.1) is 4.4.[2]
ICC has also published a preliminary specification for iccMAX (ICC.2) or ICCv5, a next-generation color management architecture with significantly expanded functionality and a choice of colorimetric, spectral or material connection space.[3]
To see how this works in practice, suppose we have a particularRGB andCMYKcolor space, and want to convert from this RGB to that CMYK. The first step is to obtain the two ICC profiles concerned. To perform the conversion, each RGB triplet is first converted to the Profile connection space (PCS) using the RGB profile. If necessary the PCS is converted between CIELAB and CIEXYZ, a well defined transformation. Then the PCS is converted to the four values of C, M, Y, K required using the second profile.
So a profile is essentially a pair of mappings; one from a color space to the PCS and a second from the PCS to the color space. A mapping might be implemented using tables of color values to be interpolated or be implemented using a series of mathematical formulae.
A profile might define several mappings, according torendering intent. These mappings allow a choice between closest possible color matching, and remapping the entire color range to allow for differentgamuts.
The reference illuminant of the Profile connection space (PCS) is a 16-bit fractional approximation ofD50;[4] itswhite point is XYZ=(0.9642, 1.000, 0.8249). Different source/destination white points areadapted using theBradford transformation.[4]
Another kind of profile is thedevice link profile. Instead of mapping between a device color space and a PCS, it maps between two specific device spaces. While this is less flexible, it allows for a more accurate or purposeful conversion of color between devices. For example, a conversion between two CMYK devices could ensure that colors using only black ink convert to target colors using only black ink.
The ICC profile specification, currently being progressed as International Standard ISO 15076-1:2005,[5][6] is widely referred to in other standards. The following International andde facto standards are known to make reference to ICC profiles.
| CAM | |
|---|---|
| CIE | |
| RGB | |
| Y′UV | |
| Other | |
| Color systems and standards | |
For the vision capacities of organisms or machines, see  Color vision. | |