Chromaticity

File:Chromaticity Diagram RGB.svg

File:Chromaticity Diagram RGB.svg

Chromaticity is a specification of the quality of a color regardless of its luminance. It is an objective measure of the hue and saturation of a color, which together define its chromaticity. Chromaticity is often represented in a two-dimensional space, where the coordinates are derived from the color's spectral properties.

Definition

Chromaticity is defined by two parameters:

• Hue: This is the aspect of color which is described by terms such as red, yellow, green, blue, etc. It is the dominant wavelength of the color.
• Saturation: This describes the intensity or purity of the color. A fully saturated color contains no white light.

Chromaticity is often represented in a chromaticity diagram, such as the CIE 1931 chromaticity diagram, which maps the chromaticity of colors in a two-dimensional space.

Chromaticity Diagrams

Chromaticity diagrams are graphical representations of the chromaticity of colors. The most well-known chromaticity diagram is the CIE 1931 chromaticity diagram, which uses the x and y coordinates to represent chromaticity.

CIE 1931 Chromaticity Diagram

The CIE 1931 chromaticity diagram is based on the CIE 1931 color space, which was the first mathematically defined color space. In this diagram, the chromaticity of a color is represented by its x and y coordinates, which are derived from the color's tristimulus values (X, Y, Z).

The diagram is a horseshoe-shaped plot, with the spectral colors (colors of a single wavelength) forming the curved boundary. The line connecting the ends of the horseshoe represents the purples, which are non-spectral colors.

Applications

Chromaticity is used in various fields, including:

• Colorimetry: The science of measuring colors and assigning them numerical values.
• Display technology: Ensuring accurate color reproduction in devices such as monitors and televisions.
• Lighting: Designing lighting systems with specific color characteristics.

Mathematical Representation

Chromaticity can be mathematically represented using different color spaces, such as the CIE 1931 color space, CIE 1976 (L*, a*, b*), and others. Each color space provides a different method for calculating chromaticity coordinates.

Also see

• Color space
• CIE 1931 color space
• Colorimetry
• Hue
• Saturation (color theory)