Windows Color System

Windows Color System (WCS) is a platform for color management, first included with Windows Vista, that aims to achieve color consistency across various software and hardware, including cameras, monitors, printers and scanners. Different devices interpret the same colors differently, according to their software and hardware configurations. As a result, they must be properly calibrated to reproduce colors consistently across different devices. WCS aims to make this process of color calibration automatic and transparent, as an evolution of ICC profiles.

Windows Color System features a Color Infrastructure and Translation Engine (CITE) at its core. It is backed up by a color processing pipeline that supports bit-depths more than 32 bits per pixel, multiple color channels (more than three), alternative color spaces and high dynamic range coloring, using a technology named Kyuanos developed by Canon. The color processing pipeline allows device developers to add their own gamut mapping algorithm into the pipeline to customize the color response of the device. The new pipeline also supports floating point calculations to minimize round-off errors, which are inherent in integer processing. Once the color pipeline finishes processing the colors, the CITE engine applies a color translation according to a color profile, specific to a device to ensure the output color matches to what is expected.

Color model

A color model is an abstract mathematical model describing the way colors can be represented as tuples of numbers, typically as three or four values or color components. When this model is associated with a precise description of how the components are to be interpreted (viewing conditions, etc.), the resulting set of colors is called color space. This section describes ways in which human color vision can be modeled.

Tristimulus color space

One can picture this space as a region in three-dimensional Euclidean space if one identifies the x, y, and z axes with the stimuli for the long-wavelength (L), medium-wavelength (M), and short-wavelength (S) light receptors. The origin, (S,M,L) = (0,0,0), corresponds to black. White has no definite position in this diagram; rather it is defined according to the color temperature or white balance as desired or as available from ambient lighting. The human color space is a horse-shoe-shaped cone such as shown here (see also CIE chromaticity diagram below), extending from the origin to, in principle, infinity. In practice, the human color receptors will be saturated or even be damaged at extremely high light intensities, but such behavior is not part of the CIE color space and neither is the changing color perception at low light levels (see: Kruithof curve).