Encyclopedia of Color Science and Technology

Living Edition
| Editors: Ronnier Luo

Demichel Equations

Living reference work entry
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DOI: https://doi.org/10.1007/978-3-642-27851-8_21-1
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Synonyms

Halftone layer superposition equations

Definition

In color halftoning, the Demichel equations define the relationships between the surface coverages of the printed ink dots and the surface coverages of the Neugebauer primaries, i.e., the surface coverages of the colorants populating the color image. These equations are valid for the independently laid out ink layers that occur in stochastic screening, in error diffusion halftoning, and in mutually rotated clustered dot or line screens. The Demichel equations are used in connection with spectral models predicting the reflectances of color prints in function of the deposited amount of inks [1, 2].

Overview

Professional as well as desktop printers are either able to print with a limited number of pixel dot sizes or with a single pixel dot size. For example, in modern ink-jet printers, several droplets may be printed at the same pixel location, leading to a limited number of pixel dot sizes. In classical offset prints, a pixel...

Keywords

Surface Coverage Colorant Surface Pixel Location Error Diffusion Colorant Cyan 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
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References

  1. 1.
    Wyble, D.R., Berns, R.S.: A critical review of spectral models applied to binary color printing. Color Res. Appl. 25, 4–19 (2000)CrossRefGoogle Scholar
  2. 2.
    Hébert, M., Hersch, R.D.: Review of spectral reflectance models for halftone prints: principles, calibration, and prediction accuracy. Color Res. Appl. 40(4), 383–397 (2015)CrossRefGoogle Scholar
  3. 3.
    Demichel, M.E.: Procédé 26(3), 17–21 (1924)Google Scholar
  4. 4.
    Neugebauer, HEJ: “Die theoretischen Grundlagen des Mehrfarbendrucks”, Zeitschrift fuer wissenschaftliche Photographie 36, 36–73, (1937), translated by Wyble, D. and Kraushaar A, in “The theoretical basis of multicolor letterpress printing,” Color Res. Appl. 30, 323–331 (2005)Google Scholar
  5. 5.
    Amidror, I., Hersch, R.D.: Neugebauer and Demichel: dependence and independence in n-screen superpositions for colour printing. Color Res. Appl. 25, 267–277 (2000)CrossRefGoogle Scholar

Copyright information

© École Polytechnique Fédérale de Lausanne (EPFL) 2015

Authors and Affiliations

  1. 1.Ecole Polytechnique Fédérale de Lausanne (EPFL)LausanneSwitzerland