Shams-Nateri, "Estimation of CIE
tristimulus values under various illuminants," Color Research and Application, vol.
The
tristimulus values of CIE [L.sup.*][a.sup.*][b.sup.*] readings were calibrated against a standard white plate (Y = 84.8; x = 0.3199; y = 0.3377).
where R, G, and B are the red, green, and blue component of a pixel, X, Y, and Z are the CIE XYZ
tristimulus values (1), and L, A, and B ((2), (4), and (3)) are color lightness, chromaticity, and coordinates, respectively.
To determine the chromaticity of the dark state, [X.sub.bump], [Y.sub.bump], and [Z.sub.bump]
tristimulus values of the Commission International de 1'Eclairage (CIE) XYZ color space through the bump region can be written in the following form [14]:
Where, [X.sub.n], [Y.sub.n] and [Z.sub.n] are the CIE XYZ
tristimulus values from the brightest regions in the image.
For measurement and representation of a single quantized value, there are sets of
tristimulus values in space (CIEXYZ) indicating the percentages of red, green and blue, which describe it, however it has been shown that this space does not match for differences of color perceived by humans, because it is an extremely no uniform appreciation(10).
Instruments and software using ASTM tables would have agreement on the numerical integration of
tristimulus values to within or better than the measurement error of the instrument.
where the
tristimulus values are obtained by adding the product of the SPD of the light
[L.sub.*], [a.sub.*], and [b.sup.*] values correspond to CIE XYZ
tristimulus values X, Y, Z, by following equations:
and X, Y, Z are the tristimulus CIE color coordinates derived from RGB
tristimulus values by means of the following transformation matrix:
Both of the above concepts depend upon using more sophisticated color models, color appearance models, for metrics of illumination quality rather than the fundamental models of colorimetry (CIE XYZ
tristimulus values and chromaticity coordinates) and color difference metrics (CIELAB).
The
tristimulus values of the SSL while operating at temperatures of 120[degrees]C (original configuration) and 55[degrees]C (modified heat management scheme) have been acquired and the color-shift has been quantified in the CIELUV color-space.