Munsell color system

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Munsell color system

The Munsell color system ( Munsell Color System or Munsell Color Order System ) goes back to the artist Albert Henry Munsell (1858-1918), who published the system from 1898 to 1905. Munsell's color atlas was measured and recalibrated by the Optical Society of America in 1929.

The Munsell system is one of the first complete, most widely used and still used color systems today . It is particularly widespread in the United States and Japan. Sectors in which it is frequently used there are architecture , mechanical engineering and consumer goods . In German-speaking countries, the Munsell system is used in heavy machinery construction ( shipbuilding ), in cosmetics and, above all, in soil science and archeology .

Emergence

At the end of the 19th century, there were various attempts to denote colors clearly and uniformly in order to enable communication about colors that went beyond the redundancy of color names .

Munsell developed a three-dimensional color space from a finite number of color samples that were presented in a color atlas. As a painter and teacher, it was his concern to present color samples in a way that corresponds to the sensation. The distances between neighboring samples should be perceived as being the same, the harmony of neighboring color samples should be right. He achieved this through psychovisual experiments, constant synchronization and re-mixing.

At the beginning of his research, Munsell, under the influence of Roods, used the color wheel as the basic level of his system. The system was later published for the standard illuminant C and the 2 ° normal observer. Because there are different degrees of chroma and brightness in the various hues, an irregular body was created.

Munsell color system

The system was first published in 1915 in the “Munsell Book of Colors”, in which the color dimensions of the “Munsell Book Notations” were defined. The Munsell Book of Colors consisted of two representations: 1277 color samples on matt and 1452 color samples on glossy material.

In 1943, in the Munsell Renotations of the American Optical Society, each color was defined by the CIE color dimensions x, y and Y and some samples were improved by the measurement methods that were now improved.

The Munsell system is uniform and independent of the lighting or the size of the color area considered.

System structure

The three principles of order are hue ( hue ), chroma ( saturation ) and value (value, brightness ). The primary criterion of this system is the color.

Munsell chose five main hues

  • Red (R)
  • Yellow (Y)
  • Green (G)
  • Blue (B)
  • Purple (P)

Intermediate hues further subdivide the perceptible color nuances

  • YR (yellow-red)
  • GY (green-yellow)
  • BG (blue-green)
  • PB (purple-blue)
  • RP (red-purple)

This arrangement results in a 10-part colored area . These ten color tones are again divided into ten gradations. Numbers (0 to 10) are added to the letter symbols to identify the hues: the hues ( Hue ) are designated with 1RP, 5P, 3Y or 7.5 GY, 2.5 PB, and similar.

On each line there are places of increasing saturation (chroma).

The value is added as the third dimension of the color body, the vertical central axis. This ranges from V = 10, the ideal white, to V = 0, the black that can be represented with colorants , resulting in a 10-part gray scale.

Each color sample in the Munsell system, that is, each displayed color, is given a name in the form of "HV / C", where H (hue) stands for hue, V (value) for lightness and C (chroma) for saturation.

As an example, the color 2.5 YR 5/10 is described, a yellow-red that tends towards red, has a medium brightness and appears maximally saturated.

The L * a * b * color space is a three-dimensional coordinate system in which each color is assigned a value in the three dimensions L, a, and b (similar to xy and z). In contrast, the Munsell system can be viewed as a mixture between vector representation and coordinate. A vector is defined by its direction (roughly expressed in degrees) and its length. Similarly, a Munsell color is defined by its hue (direction as a hue value) and its intensity (length as chroma), while the brightness is a coordinate component.

System properties

Due to the experimental and visual development of the system, the system is uniform and equidistant.

  • The system is uniform because changes to one parameter do not affect the other two parameters.
  • The system is equally spaced , as Munsell checked with both eyes and sensation to establish neighboring patterns. The color difference between all neighboring color samples is therefore perceived as the same by human viewers.
  • Hue: The rotation in the base plane by a fixed amount results in a perceived change in color tone (without a change in brightness or saturation).
  • Chroma: There are different numbers of saturation levels per hue. The distance from the center point to the color point (towards the edge) results in increasing saturation without changing the brightness. According to the (visual) construction, the color tone is retained and does not change. Since the intensity of the colors is different for different tones (as with yellow, high intensity is possible and only low intensity for blue), the number of color samples within the color tones (hue) is correspondingly different. The same also applies to different brightness values ​​(Value). Absolute white and black no longer have any chroma values ​​that can be perceived by the human eye in any Hue direction.
  • Value: The levels between white and black are on the axis through the center of the base plane. This is a (neutral) gray scale and represents the brightness (value). The saturation or hue of the patterns are not changed, the system was designed that way.

The colors of the Munsell color system cannot be converted into CIE color values. Only the value value can be determined as the CIE standard color value Y using a conversion formula. Tables are therefore used for conversions.

A color atlas can only display reflectance colors.

literature

  • TM Cleland: A Grammar of Color: Basic Treatise on the Color System of Albert H. Munsell . Van Nostrand Reinhold, New York 1969, ISBN 978-0-442-11343-8
  • SM Newhall, D. Nickerson, DBJudd: Final Report of OSA subcommitee on the spacing of the Munsell Colors . In: Journ. Opt. Soc. Americ. Vol. 33, Issue 7, pp. 385ff., O. O. 1943.