Kartographie 8

-clarification of main message (e.g. land vs water)

-to highlight information (e.g. deep water vs shallow water)

-to emphasize information (e.g. important features stand out)

-to show variation in data (e.g. changing relief, changing temperatures)

-> color is a strong visual variable, but difficult to control

color is a result of the brain operating on received information from the world

3 elements of color perception:

-physical characteristics of a light source

-physical characteristics of surface

-characteristic of human color perseption and sensation

Electromagnetic radiation (EMR): range of human eye: 0.4 - 0.7 micrometers

Measurement of color throug a spectrophotometer (white as standard)

-> measured color reflectance signatures relative to white standard

-color hues (Töne): different signatures ampiltude (shape) -> sharper peaks = purer hue

-color stauration/ value: different signature shapes -> height as an indicator of color luminosity (higher peak = darker blue, sharper and higher peak = higher chroma (saturation)

process colors: RGM, CMYK

others: Munsell, CIE, PANTONE ...

- color wheel: visible part of EMR in a circle, useful to find certain properties of color

- substractive (paint) color model (user: painting industry) CMYK

primary colors: cian, magenta, yellow

secondary colors:blue(cyan+mangenta),red(mangenta+yellow),green(yellow+cyan)

black: inK, background white: no color

- Munsel color model is based on CMYK, but specially adapted to human perception to color-> excellent model for mapping

- additive (digital) color model (for TV;CRT; projector industry) RGB-System

primary colors: red, green, blue

secondary colors: yellow(red+green), cyan(green+blue), mangenta(blue+red)

white: red+green+blue black: no light (dark room)

In cube shape, RGB-diamont

- CIE color model (commission international d' eclairage) is based on RGB model and perceptually sound an dpsycho-physically tested

perception of color occurs in the eyes (cones: color hue: red, blue, green; rods: brightness/darkness) and in the brain

- interaction effects (center.surround contrasts)

-individual difference in perception

-group difference in perception(color blindness; correction through i.e. daltonisation)

-environmental effects (lightning context causes color shift)

-spatial effects (warm hues advancing and cod hues rereating in the visual field)

-harmony effects (based on properties in color wheel; adjactent (benachbarte) colors: harmonious, calm opposite colors: tension, contrast ; coupling with semantics)

pleasant: pure colors, clear contrasts, background: light or dark, but nor between, objects stand out from background, hues: green to blue without gray, vivid colors combined with grayish colors

unpleasant: yellow or yellowish-green

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the lion sleeps tonight