Whiteness
Encyclopedia
In colorimetry
, whiteness is the degree to which a surface is white. An example of its use might be to quantitatively compare two pieces of paper which appear white viewed individually, but not when juxtaposed.
The International Commission on Illumination
describes it in the following terms:
where
The numbers in the subscript indicate the observer: two for the CIE 1931 standard observer and ten for the CIE 1964 standard observer.
Colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception."It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space...
, whiteness is the degree to which a surface is white. An example of its use might be to quantitatively compare two pieces of paper which appear white viewed individually, but not when juxtaposed.
The International Commission on Illumination
International Commission on Illumination
The International Commission on Illumination is the international authority on light, illumination, color, and color spaces...
describes it in the following terms:
Calculation
where
- Y is the Y tristimulus value (relative luminance),
- (x,y) is the chromaticity coordinate in the CIE 1931 color spaceCIE 1931 color spaceIn the study of color perception, one of the first mathematically defined color spaces is the CIE 1931 XYZ color space, created by the International Commission on Illumination in 1931....
- (xn,yn) is the chromaticity coordinate of the perfect diffuser (reference white)
The numbers in the subscript indicate the observer: two for the CIE 1931 standard observer and ten for the CIE 1964 standard observer.
External links
- ISO 105-J02:1997 Textiles -- Tests for colour fastness -- Part J02: Instrumental assessment of relative whiteness
- ISO 11475:2004 Paper and board -- Determination of CIE whiteness, D65/10 degrees (outdoor daylight)
- ISO 11476:2000 Paper and board -- Determination of CIE-whiteness, C/2 degree (indoor illumination conditions)
- ISO/AWI 11476 Paper and board -- Determination of CIE-whiteness, C/2 degree (indoor illumination conditions)