Line of purples

The purple line, also called purple line, is the line that the two outermost points of the Spektralfarbenzugs so connects to the CIE Normvalenztafel that the projection of the color solid is closed. It thus lies between the short-wavelength violet and the long -wave red

Description

The purple line is a theoretical construction of the mathematical description of the human color perception, which is based on the three color receptors for the day marriages, which normalized to the standard observer. The purple line is that amount of a maximum of saturated color stimuli, which may be a normally sighted humans perceive and differentiate, but which do not belong to the set of spectral colors. The colors of the purple line are a result of color perception.

A thought experiment determine the cause

If visible radiation decomposed into the spectrum and this color stimuli successively viewed by long-wavelength ( from 780 nm) to short-wave ( 380 nm ), they react different receptors in the eye. First, the red-sensitive L cones are stimulated. In addition, the journals are also excited for the Green vision for the than Rotsehen. Successively arise corresponding valences and it will be seen yellow, orange, red and yellow, yellow shades. The M-cones for the green vision, and increasingly the Cyanreiz respond to the S-cones for the blue vision. Even shorter wavelength radiation ( higher-energy photons) (UV -A) do not trigger more color stimulus, since no receptors exist. UV radiation is absorbed by the lens, and the vitreous. The molecular vibrations lead with increasing energy (ie, the shorter the wavelength the light) to eye damage. To intense UV light can not be retained, leading to Verblitzungen and glare, with strong appeal to permanent damage. From the long-wave to short-wave light all three cone types are energized sequentially.

There is no ( single) spectral color, evokes the color stimulus in purple. But mixed colors, the wavelength- sensitive S and L cones stimulate both in the blue region as well as in the red. Such mixed colors and not actual colors of the spectrum are the everyday color stimuli of light colors and body colors. This purple tones have both long-and short-wave spectral components. There arise valences, which are perceived as red-violet or blue-violet mixed color. These mixed colors are reproduced on the purple line. Magenta, or the eponymous purple, and the modern Pink and Purple elderly are also included.

Representation across the color circle

An " educational " presentation of the purple line is evident in the color circle. Here both ends of the spectrum are brought together and the colors " blurred " to close the circle. This results in a closed line, in the simplest case a circle, in other color models are more complicated curves. The necessary to close the circle of colors are the colors of the purple line. The CIE diagram is therefore a more accurate representation of the color wheel. The particular form depends on the requirements to be met by the respective model. The basis of the color measurement, however, is so far the physical color stimulus of the spectrum, as a color perception so far can not be directly measured.