point coordinates, ([x.sub.0]; [Y.sub.0]; [Z.sub.0]), depend on the illuminating source used to capture the image.
CIELAB color space used a non-linear transformation of the tristimulus
space to simplify the original ANLAB formula developed by Adams in 1942, which was widely used in the colorant industry.
where [R.sub.b] and [R.sub.w] are the reflection coefficients of the paint film measured on, respectively, black and white substrates, [y.sub.10] is the tristimulus
function and [D.sub.65] is the illuminant.
The [L.sup.*], [a.sup.*] and [b.sup.*] coordinates can be calculated from the tristimulus
values X, Yand Z normalized to the white by equations (1)-(3):
Spectral data is reported every 10nm and tristimulus
color calculations are performed from 360 to 780nm as recommended by the CIE.
Suitable for classroom use, this technical text defines the tristimulus
specification, presents the principles of color matching and metamerism in vector-matrix form, and explains the least-square minimization technique for color transformation and several sophisticated methods for spectrum reconstruction.
Noodle sheet color was measured in Commission Internationale de l'Eclairage (CIE) tristimulus
color space ([L.sup.*], [a.sup.*], [b.sup.*]) with a Minolta CM-2002 spectrophotometer (Minolta Camera, Chuo-Ku, Osaka, Japan) with a 50-mm measurement aperture.
The color of material is generally defined by the tristimulus
value in the range of human vision (i.e.; 400 to 800 nm or 25,000 to 12,500 [cm.sup.-1]).
Current innovativa products include a complete line of spectrophotometers, tristimulus
colorimeters, quality control and color formulation software.
The method proposed for standardization specifies measurement of the tristimulus
values at three angles: near specular, far from specular and one more angle in between.