Colour management

The goal of colour management is to ensure that a document captured using any input device can be reproduced as closely as possible on any output device.

A high degree of similarity between the input and output images is known as colour fidelity. Colour management systems (CMS) are used in order to achieve colour fidelity; however, no system can ever deliver 100% accuracy.

Colour management systems use:

  • Device-specific colour descriptions (colour profiles)
  • Device-independent colour spaces known as profile connection spaces (PCS)

The task of a colour management system is to convert between the device-specific colour descriptions (the input and output devices) with the help of the device-independent profile connection space. The result is that every device within a colour management system displays colours in very similar ways.

A simple example involves printing colour documents which look almost identical on both a monitor and on paper  thanks to a colour management system:

  • ICC profiles are generally used as device profiles
  • The usual colour models are the RGB colour model (for digital cameras and monitors) and the CMYK colour model (for printers).
  • In this case, the device-independent CIELab colour space serves as the link between the other two colour spaces.

As well as the L*a*b* colour space on which current CM systems are based, there are other medium-independent colour spaces such as L*u*v, which unlike L*a*b is more often used to measure light colour. XYZ and xyY are other similar physical colour spaces which are together able to display all colours that can be perceived by the human eye – in other words, all colours of visible light.

Colourmanagement is often used in industries such as printing, photography and advertising. Demand for colour management solutions is constantly rising, not just among professionals but also among hobbyist photographers and ambitious amateurs.