Chromaticity, coordinates diagram

The advantage of chromaticity coordinates is that we now have a set of normalized values which we can use to compare colors having different intensity values (and thus different energy values as well). Furthermore, we need only specify x and y since x + y + z = 1.00. TTiis allows us to specify monochromatic radiation in terms of our chromaticity coordinates. Since monochromatic radiation is a boundary of colormixing, then we can construct a CHROMATICITY COORDINATE DIAGRAM in terms of x and y, namely ... 

Ghromaticity Diagrams. The CIE 1931 chromaticity diagram uses the chromaticity coordinates ... 

They are represented as coordinates in a color plane. The chromaticity coordinates x and y are used to specify the saturation and hue of any color in the CIE chromaticity diagram. See Figure 4 a for illumination D 65. The CIE spectral tristimulus value y (2) corresponds to the lightness sensitivity curve of the human eye. Therefore, a third color variable is specified in addition to x and y, namely the CIE tristimulus value Y, which is a measure of lightness. 

QxQy coordinates are complementary xy chromaticity coordinates as shown in Fig. 3. These are analogues of the xy coordinates which are calculated from tristimulus XYZ values in order to plot color points in a two-dimensional diagram [11]. In this case, QxQy values are calculated by the same procedure adopted in the case of xy coordinates, but the transmission spectra T(X) are replaced with the absorption spectra A(X). The equations for QxQy are given as follows ... 

The emission color was analyzed with the help of CIE chromaticity coordinates. The coordinates of Na2Ca4Mg2Si4Oi5 Tb3+were found to fall in the yellowish green region of the CIE chromaticity diagram and with an decrease of Tb, the phosphor exhibited deeper green emission, as shown in Fig. 4. 

Chromaticity diagram n. CIK A two-dimensional graph of the chromaticity coordinates, x as the abscissa and y as the ordinate, which shows the spectrum locus (chromaticity coordinates of monochromatic light, 380-770 nm). It has many useful properties for comparing colors of both luminous and non-luminous materials. 

Chromaticity diagram n. General. Plane diagram formed by plotting one of the chromaticity coordinates against the other. 

Chromaticity difference diagrams n. Plane diagram formed by plotting the differences of one of the chromaticity coordinates against the differences of the other chromaticity coordinate, the differences being taken from the neutral point or, for a... 

Uniform chromaticity coordinates n. Chro-maticity coordinates yielding an approximately uniform chromaticity diagram for colors of equiluminosity. McDonald R (1997) Colour physics for industry, 2nd... 

The X and y chromaticity coordinates are typically plotted in a two-dimensional grid known as the CIE (x,y)-chromaticity diagram (Fig. 14.8). The curve is made of the pure spectral colours from the blue to the red, covering the entire visible... 

Figure 11.6 Chromatkity diagram or chart. Color as encoded in a VIS spectrum is described by plotting the chromaticity coordinates X and y points on the chart. The outer band contains spectral colors (ROYGBIV), and the connecting line consists of nonspectral colors, such as pink and purple. A colored version is found in the color insert. 

Figure 14.17 shows the elliptical regions of uncertainty for the fibers shown in Figure 14.18. The fiber here is a round polyamide type treated with different dispersive dyes. Figure 14.19 shows an example of an error or uncertainty ellipse in more detail. When a fiber is treated with a single colorant, the centr axis of the uncertainty ellipse generally points toward the coordinates of the undyed fiber. This observation is attributed to the depth of penetratiim of tiie dye varying from fiber to fiber. In other words, the fiber "starts" at the undyed position on the chromaticity diagram. The more of a single dye that is accepted by tile fiber, the deeper the color is and the farther the chromaticity coordinates shift away from e undyed fiber color. Taken to the extreme, this line would extend to coordinates of the pure dye. Because different individual fibers have different dye uptake characteristics, some fibers will take on more dye and some less, even when made of the same polymer in the same batch.

CIELAB A mathematical transform applied to chromaticity coordinates to address the asymmetry in a chromaticity diagram. 

K and appears to be bluish white. The CIE Standard Illuminant D65 (Figure 12.2b) is a commonly used standard illuminant that tries to portray standard illumination conditions in the open air in different parts of the world. It represents average daylight and has a CCT of approximately 6500 K (exactly 6504 K). The CIE 1931 color space chromaticity coordinates of D65 are x = 0.3128,3 = 0.3290, which is close to a white-point in the CIE diagram. 

Fig. 9 (a) Molecular structures of novel ESIPT dyes, 2,5,-bis[5-(4-t-butylphenyl)-[l,3,4]oxadia-zol-2-yl]-phenol (SOX), and 2,5-bis[5-(4-t-butylphenyl)-[l,3,4]oxadiazol-2-yl]-benzene-l,4,-diol (DOX). (b) Emission colors in the Commission Internationale de L Eclariage (CEE) chromaticity diagram. The inner oval and the filled circle at coordinate (x,y) of (0.33, 0.33) indicate the white region and the ideal color, respectively. Note that PS and PVK denote polystyrene and poly (N-vinylcarbazole) film (reprint from ref. [91], Copyright 2005 Wiley-VCH)... 

A chromaticity diagram can therefore be drawn presenting colors in terms of their andy coordinates, which are often termed hue and saturation, respectively. A diagram of this type is presented in Fig. 7. 

Fig. 7 Chromaticity diagram presented in terms of the x and y coordinates. (Data adapted from Ref. 39.)...

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