Munsell color system

The three axes of the Munsell color system (chroma, hue, and value) [2]. 

Fig. 3-4. The cyliadrical coordinates of the Munsell color systems (left) and the hue notation (right). (Figure provided by Munsell, a division of GretagMacbeth, LLC.)...

The Judd formula given here is too difficult to use and it is the Glasser formula which came into general use to modify the Munsell Color System back towards the cylindrical form. Nevertheless, it is well to note that it was the subjective observation of the lack of correction for lumuiosify in the Munsell System that gave impetus to the original development of the CIE Color System, The major problem with the Munsell system was that... 

The Munsell color system is sometimes also shown graphically (Figure 14-7). The colors are then arranged anticlockwise in a circle, that is, in the direction Y-GY-G-BG-B-PB-P-RP-R-YR. The value is written along an axis from top to bottom which passes through the center of the circle. The chroma is given as the distance from the center of the circle. 

Munsell book of color n. A collection of color chips, which illustrate the Munsell Color System, manufactured by the Munsell Color Co. (MD, USA) in both matte and glossy finishes. It consists of pages of constant hue at 2.5 hue step intervals, with darkest colors (of lowest value at the bottom) increasing in value upwards to the top and colors of lowest chroma in the center fold increasing to highest chroma at the outside edge of the page. 

Color Systems. The human eye can discriminate thousands of colors. However, it is difficult for a person to tell another person what colors he/she sees. Two types of color systems are used one that uses color samples and one that identifies colors mathematically. The visual color system used in the United States is the Munsell Color System with color chips, classified in a three-dimensional system. The dimensions of the Munsell System are hue, value, and chroma. The color chips have equal visual differences between pairs of adjacent chips. The light source must be specified. Surface roughness affects color, and so comparisons have to be made at equal gloss levels. Two sets of Munsell chips are available one with high gloss and the other with low gloss. 

The Munsell color system is conceptually similar to the QELAB system, but with some significant differences. The Munsell system was conceived by the American painter Albert H. MunseU in 1905 with subsequent revisions and variations. The three variables used to describe colors in the system are hue, brightness (similar to lightness in QELAB), and saturation (similar to chroma also called value). As shown in Figure 11.14, the color space is cylindrical. The hue is divided into 100 equal spaces around the circle that forms the cross section of the cylinder, while the y direction is the brightness, scaled from 0 to 18. The x-axis is the saturation, scaled from 10 to 18. Munsell charts and collections are used in the forensic analysis of paints and soils. Because books and samples of color are used for color comparison, the Munsell color space is sometimes referred to as a catalog system. An example application is in soil analysis in which soil particles can be seived, sorted, and grouped by their Munsell color. 

Munsell Color System A color space based on a catalog of standard colors and a uniform 3D color space. 

The Munsell color system specifies colors based on three color dimensions ... 

Once this fact was rccdized, it was understood that an average of what each person saw would have to be made if a standard system weis to be formed and promulgated. This led to the concept of the "Standard Observer". Thus, the research required to define and measure color took a completely different path from the original methods such as the Munsell Color Tree. 

On a practical basis, if we wish to set up this system, we would assemble a set of "color-chips". Each color-chip would be specified by two factors, H = hue, and V/C, which is value (grayness) modified by chroma (saturation). The actual number of layers in the Munsell Color Tree was determined by "minimum perceptual difference". That is, the minimum change that produces a visual perceptible difference. This arrangement specifies all light colors as well cis the dark ones. To use such a system, one would choose the color-chip closest to the hue and saturation of the test color and thus obtain values for H and V/C. However, it was soon discovered that the system was not perfect. Reasons for this include the facts that the hues defined by Munsell are not those of the primaries of the human eye. Furthermore, Munsell was somewhat subjective in his definitions of hues. 

Three attributes characterize color hue, lighmess (or value), and saturation (or chroma) and they are graphically represented in color solids (e.g., Munsell solid. Hunter solid). The Munsell Color Notation is a rapid, portable, widespread, and economical system of color determination. However, as it depends on sensory evaluation by panels, many laboratories prefer when possible to replace human judgment by instrumental techniques that are easier to handle. The CIELAB established by the Commission International d Eclairage (CIE) has become widely used with the availability of reflectance spectrophotometric instrumentation. 

Thompson, T.E., Grauke, L.J., and Young, E., Pecan kernel color standards using the Munsell color notation system, J. Am. Soc. Hort. ScL, 121, 548, 1996. 

Note that the uniformity of a color space is of concern only if color is regarded as a (visual) quality. When using color as an analytical tool, the color system which differentiates the iron oxides most effectively would be the most favorable, no matter whether it is uniform or not. A discriminant analysis performed with a large number of iron oxide samples showed that CIE-Yxy, CIE-Lab, and the Munsell system performed equally well (Scheinost and Schwertmann, 1999). Therefore, the choice of a color system is not crucial. Furthermore, computer programs are available which transfer colors from one system into another. More details on color theory and color systems are given by Wyszecki and Styles (1982) and Hunter and Harold (1987). 

One of the first attempts to specify reflective colors, color mixing and saturation was accomplished by Munsell (1903). He devised a color system based on factors he called hue, chroma and value. Munsell set up a three-dimensional arrangement based upon mintmum perceptual color... 

In Munsell s system, hues are specified in a circular fashion with the same set of hues on the same level. As the value, i.e.- "lightness", changes, one Jumps to the next highest circle. The amount of color "deepness" is specified as chroma and becomes less as one approaches the edge of each color circle. 

What we should get is a circular spacing of the ten Munsell colors, if the Munsell system is truly accurate in regard to the luminosity factor. However, they are not. On the CIE diagram, the spacing is considerably distorted. Since we already know the CIE method to be corrected for the luminosity factor, the conclusion is obvious. In 1920, Priest showed that if the Munsell-Chips were viewed on a white-background, the "brightness", i.e.- lightness as viewed by the human eye, could be related to the Munsell system by ... 

The Munsell system arranges color samples according to a definite systematic process. The differences between the individual colors have been revised many times over the years the improved system is known as the Munsell Renotation System. Two different MR systems are used, one for glossy, the other for mat surfaces. 

Color order systems n. Systems used to describe an orderly three-dimensional arrangement of colors. Three bases can be used for ordering colors (1) an appearance basis, i.e., a psychological basis in terms of hue, saturation, and lightness - an example is the Munsell System (2) an orderly additive color mixture basis, i.e., a psychophysical basis - examples are the CIE System and the Ostwald System and (3) an orderly subtractive color mixture basis - an example is the Plochere Color System, based on an orderly mixture of inks. 

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