Search results
Results from the WOW.Com Content Network
The Euclidean measure is known to work poorly on large color distances (i.e. more than 10 units in most systems). A hybrid approach where a taxicab distance is used between the lightness and the chroma plane, Δ E HyAB = ( a 2 − a 1 ) 2 + ( b 2 − b 1 ) 2 + | L 2 − L 1 | {\textstyle \Delta E_{\text{HyAB}}={\sqrt {(a_{2}-a_{1})^{2}+(b_{2}-b ...
This is by design; the XYZ color matching functions are normalized such that their integrals over the visible spectrum are the same. [1] Illuminant E is not a black body, so it does not have a color temperature, but it can be approximated by a D series illuminant with a CCT of 5455 K. (Of the canonical illuminants, D 55 is the closest.)
The CIE XYZ color space was deliberately designed so that the Y parameter is also a measure of the luminance of a color. The chromaticity is then specified by the two derived parameters x and y , two of the three normalized values being functions of all three tristimulus values X , Y , and Z : [ 14 ] [ further explanation needed ]
The CIELAB color space, also referred to as L*a*b*, is a color space defined by the International Commission on Illumination (abbreviated CIE) in 1976. [a] It expresses color as three values: L* for perceptual lightness and a* and b* for the four unique colors of human vision: red, green, blue and yellow.
Colorimetry is "the science and technology used to quantify and describe physically the human color perception". [1] 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 tristimulus values and related quantities.
The CRI is calculated by comparing the color rendering of the test source to that of a "perfect" source, which is a black body radiator for sources with correlated color temperatures under 5000 K, and a phase of daylight otherwise (e.g., D65). Chromatic adaptation should be performed so that like quantities are compared.
A colorimeter or a digital camera with a color filter array can, under certain conditions, be used as an alternative to a spectrophotometer. [7] [8] The illuminant and observer conditions should be specified when citing a measurement (e.g. D65/10°). [9] The quality of a colorimeter may be assessed using the means in CIE publication 179:2007. [10]
The CIE 1964 (U*, V*, W*) color space, also known as CIEUVW, ... where (u 0, v 0) is the white point and Y is the luminous tristimulus value of the object.