Returns the u' and v' chromaticity values calculated for a given spectral power distribution (power per unit area per unit wavelength) and a selected set of color matching functions. The colormatchuv function assumes that the units of wavelength for the spectral power distribution are nanometers, for example, W/(m 2 nm). The available color functions are the CIE 1931 and CIE 1964.
The u' and v' values are dimensionless and they are related to the X, Y and Z values by:
$$ u^{\prime}=\frac{4 X}{X+15 Y+3 Z}, v^{\prime}=\frac{9 Y}{X+15 Y+3 Z} $$
References:
https://en.wikipedia.org/wiki/CIE_1931_color_space
http://en.wikipedia.org/wiki/CIELUV
CIE Proceedings (1932), 1931. Cambridge: Cambridge University Press.
CIE Proceedings (1964) Vienna Session, 1963, Vol. B, pp. 209-220 (Committee Report E-1.4.1), Bureau Central de la CIE, Paris.
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Syntax |
Description |
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cmuv = colormatchuv(colormatch(spec, lam, "functions")); |
Returns u', v' for the spectrum spec evaluated at the wavelength values in lam (units of meters), using the selected color functions. If no functions are specified, the "CIE 1931" set is used. |
Example
This example shows how to calculate the u', v' values for a given spectral power distribution.
# create a dummy spectrum lambda = linspace(300e-9,700e-9,500); # note SI units (meters) spectrum = exp(-(lambda-450e-9)^2/(30e-9)^2); plot(lambda*1e9,spectrum,"wavelength(nm)","test spectrum"); ?cmuv64 = colormatchuv( colormatch(spectrum,lambda,"CIE 1964") ); result: 0.167023 0.158749 ?cmuv36 = colormatchuv( colormatch(spectrum,lambda) ); result: 0.191558 0.0979782
The following figure shows the plot of the test spectrum created by the example code.
See Also
List of commands , plot , colormatchfunction , colormatch , colormatchxy