CIE 1931 color space

In 1931 the International Commission on Illumination (CIE) published the CIE 1931 color spaces which define the relationship between the visible spectrum and the visual sensation of specific colors by human color vision.^[1]^[2] The CIE color spaces are mathematical models that create a "standard observer", which attempts to predict the perception of unique hues of color. These color spaces are essential tools that provide the foundation for measuring color for industry, including inks, dyes, and paints, illumination, color imaging, etc. The CIE color spaces enabled the development of color television, instruments to assist in maintaining consistent color in the manufacturing process, and other methods of color management.

The initials CIE come from the french name "Commission Internationale de l'éclairage", which has maintained and developed many of the standards in use today relating to colorimetry. The CIE color spaces were created using data from a series of experiments, where human test subjects adjusted red, green, and blue primary colors to find a visual match to a second, pure color. The original experiments were conducted in the mid 1920s by William David Wright using ten observers^[3] and John Guild using seven observers.^[4] The experimental results were combined, creating the CIE RGB color space. The CIE XYZ color space was derived from CIE RGB in an effort to simplify the math.

The CIE 1931 XYZ color space is still widely used, even though it is not perceptually uniform in relation to human vision. In 1976 The CIE published the CIELUV and CIELAB color spaces, which are derived from XYZ, and are intended to provide more uniform predictions relative to human perception.

^ CIE (1932). Commission internationale de l'Eclairage proceedings, 1931. Cambridge: Cambridge University Press.
^ Smith, Thomas; Guild, John (1931–32). "The C.I.E. colorimetric standards and their use". Transactions of the Optical Society. 33 (3): 73–134. Bibcode:1931TrOS...33...73S. doi:10.1088/1475-4878/33/3/301.
^ Wright, William David (1928). "A re-determination of the trichromatic coefficients of the spectral colors". Transactions of the Optical Society. 30 (4): 141–164. doi:10.1088/1475-4878/30/4/301.
^ Guild, J. (1932). "The colorimetric properties of the spectrum". Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character. 230 (681–693): 149–187. Bibcode:1932RSPTA.230..149G. doi:10.1098/rsta.1932.0005. JSTOR 91229. The trichromatic coefficients for [Wright's] ten observers agreed so closely with those of the seven observers examined at the National Physical Laboratory as to indicate that both groups must give results approximating more closely to 'normal' than might have been expected from the size of either group

[cie1931-1] CIE (1932). Commission internationale de l'Eclairage proceedings, 1931. Cambridge: Cambridge University Press.

[2] Smith, Thomas; Guild, John (1931–32). "The C.I.E. colorimetric standards and their use". Transactions of the Optical Society. 33 (3): 73–134. Bibcode:1931TrOS...33...73S. doi:10.1088/1475-4878/33/3/301.

[wright-3] Wright, William David (1928). "A re-determination of the trichromatic coefficients of the spectral colors". Transactions of the Optical Society. 30 (4): 141–164. doi:10.1088/1475-4878/30/4/301.

[guild-4] Guild, J. (1932). "The colorimetric properties of the spectrum". Philosophical Transactions of the Royal Society of London. Series A, Containing Papers of a Mathematical or Physical Character. 230 (681–693): 149–187. Bibcode:1932RSPTA.230..149G. doi:10.1098/rsta.1932.0005. JSTOR 91229. The trichromatic coefficients for [Wright's] ten observers agreed so closely with those of the seven observers examined at the National Physical Laboratory as to indicate that both groups must give results approximating more closely to 'normal' than might have been expected from the size of either group

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