The subtractive color model explains the mixing of a limited set of dye, ink, paint pigment, or natural dye to create a wider range of colors, each partial or complete reduction (ie, absorbing) some wavelength light and not the other. The surface color depends on which part of the visible spectrum is not absorbed and therefore remains visible.
The subtractive color system begins with light, maybe white light. Colored inks, paints, or filters between the observer and the light source or reflective surface subtract the wavelength from the light, give the color. If the incident light is in addition to white, our visual mechanisms can compensate well, but are not perfect, often giving the impression of defects in "right" surface colors.
Instead, the additional color system begins with darkness. Various light sources of wavelengths are added in various proportions to produce various colors. Typically, three primary colors are combined to stimulate the human trichromatic color vision, which is felt by the three types of cone cells in the eye, giving a seemingly complete range.
Video Subtractive color
RYB
RYB (Red, Yellow, Blue) is a collection of previous subtractive primary colors used to mix pigments. It is used in art and art education, especially in the art of painting. It precedes the theory of modern scientific colors.
Red, yellow, and blue are the main colors of standard "wheels" colors. The secondary color, violet (or purple), orange, and green (VOG) form another triad, formed by mixing equal amounts of red and blue, red and yellow, and blue and yellow, respectively.
The primary colors of RYB form the basis of 18th century color vision theories when fundamental sensory qualities combine in the perception of all physical and equal colors in the physical mixture of pigments or dyes. These theories are enhanced by an 18th-century investigation of a variety of purely psychological color effects, in particular the contrast between "complementary" or the opposite color produced by color after image and in contrasting shadows in colored light. These ideas and many personal color observations are summarized in two founding documents in the theory of color: the Theory of Colors (1810) by German poets and government ministers Johann Wolfgang von Goethe, and The Law of Contrast Color Simultaneously (1839) by French industrial chemist Michel-EugÃÆ'¨ne Chevreul.
In the late nineteenth and early twentieth centuries of commercial printing, the use of traditional RYB terminology still prevailed even though the more versatile CMY (Cyan, Magenta, Kuning) was adopted, with cyan sometimes referred to as the "blue process" and magenta as a "red process".
Maps Subtractive color
CMY and CMYK printing process
In color printing, the usual primary colors are cyan, magenta and yellow (CMY). Cyan is a red complement, meaning cyan serves as a filter that absorbs the red color. The amount of cyan applied to a piece of white paper controls how much red in the white light will be reflected back from the paper. Ideally, cyan is completely transparent to green and blue light and has no effect on the parts of the spectrum. Magenta is a green complement, and a blue yellow complement. The combination of different amounts of the three can produce various colors with good saturation.
In inkjet color printing and mass production photomechanical printing process, K ink black component (Key) is included, resulting in CMYK color model. Black ink serves to cover unwanted tints in the dark areas of the printed image, resulting from ineffective commercial CMY ink transparencies; to improve the sharpness of the image, which tends to be degraded by the imperfect registration of the three color elements; and to reduce or eliminate the consumption of more expensive color inks where only black or gray is required.
The pure photographic color process almost never includes the K component, because in all the commonly used processes CMY dye is much more transparent, there is no registration error for camouflage, and replaces the black dye for a saturated CMY combination, the trivial cost benefit is best, technologically not practical in non-electronic analog photography.
See also
- Additional colors
- Mixing colors
- Color picture movie
- Color space
- Color theory
- Primary color
References
- Berns, Roy S. (2000). The Color Technology Principles of Billmeyer and Saltzman, 3rd ed. . Wiley, New York. ISBNÃ, 0-471-19459-X.
- Stroebel, Leslie, John Compton, Ira Current, and Richard Zakia (2000). Basic Photography Materials and Processes, 2nd edition . Focal Press, Boston. ISBN: 0-240-80405-8. CS1 maint: Many names: list of authors (links)
- Wyszecki, GÃÆ'¼nther & amp; W. S. Stiles (1982). Color Science: Concepts and Methods, Quantitative Data and Formulas . Wiley, New York. ISBN: 0-471-02106-7. Ã,
External links
- Stanford University CS 178 Interactive Flash demo that compares additive and subtractive color mixing.
Source of the article : Wikipedia
0 Comments