The CIE (Commission Internationale de l'Eclairage, which is French for International Commission on Illumination) is an organization that's dedicated to exploring, describing and consolidating information about light, lighting, color, vision, photobiology and image technology.
The CIE is responsible for the creation of the CIE color space, which dates back to 1931, and which have influenced the study of human color vision ever since. A color space is a mathematical model for how to represent color. The CIE discovered, based on a set of experiments conducted in the 1920s by William David Right and John Guild, that color is essentially composed of red, green and blue. Further, they found that humans see green best, red somewhat, and a little bit of blue. This information is all captured in the chart.
Additionally the CIE is responsible for incorporating the idea of luminance - how bright objects are.
Today the CIE continues its studies using six active divisions:
- Division 1: Vision and Color
- Division 2: Physical Measurement of Light and Radiation
- Division 3: Interior Environment and Lighting Design
- Division 4: Transportation and Exterior Applications
- Division 6: Photobiology and Photochemistry
- Division 8: Image Technology
Division 5: Exterior Lighting and Other Applications and Division 7: General Aspects of Lighting are not active at this time.
The CIE's major contribution is the 1931 color space chromacity diagram discussed above, as well as more recent details about color matching and the creation of two additional color spaces in 1976, called CIELAB and CIELUV.