Couleur
L'approche artistique de la couleur produit des guides pour affiner la perception de la couleur et employer des pigments ; l'approche chimique étudie les colorants ; l'approche physique aborde la couleur par l'analyse spectrale ; l'approche physiologique relie la perception au système visuel ; l'approche psychophysique débouche sur la colorimétrie et sur la synthèse des couleurs. La philosophie tente, depuis l'Antiquité grecque, de relier les notions de la couleur. « Il est difficile de définir la couleur » — Sève 2009, p. 7 Selon les circonstances, la couleur peut désigner des caractères plus ou moins variés. Selon l'approche, la description de la couleur utilise des termes et des méthodes différentes. Approche artistique L'approche des artistes, essentiellement pratique, tire parti des approches physiologique et chimique, qu'elle a souvent inspirées. Approche chimique La couleur est une combinaison de substances, à l'origine de la perception colorée. Approche physique Approche physiologique
Primary color
The emission spectra of the three phosphors that define the additive primary colors of a CRT color video display. Unlike subtractive systems that use magenta, yellow, and cyan inks, additive systems such as computer displays mix red, green, and blue light to make all colors. Primary colors are sets of colors that can be combined to make a useful range of colors. For additive combination of colors, as in overlapping projected lights or in CRT displays, the primary colors normally used are red, green, and blue. The combination of any two primary colors creates a secondary color. The most commonly used additive color primaries are the secondary colors of the most commonly used subtractive color primaries, and vice versa. Biological basis[edit] It would be incorrect to assume that the world "looks tinted" to an animal (or human) with anything other than the human standard of three color receptors. Additive primaries[edit] CIE 1931 RGB color triangle with monochromatic primaries History[edit]
Portal:Color
From Wikipedia, the free encyclopedia Color or colour (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue and others. Color derives from the spectrum of light (distribution of light energy versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Color categories and physical specifications of color are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra. Because perception of color stems from the varying sensitivity of different types of cone cells in the retina to different parts of the spectrum, colors may be defined and quantified by the degree to which they stimulate these cells. A rainbow spans a continuous spectrum of colours; the discrete "bands" are an artifact of human color vision. A common depiction of a rainbow
Color balance
This article is about the process applied to still images. For the equivalent process applied to video, see Color grading. The left half shows the photo as it came from the digital camera. The right half shows the photo adjusted to make a gray surface neutral in the same light. In photography and image processing, color balance is the global adjustment of the intensities of the colors (typically red, green, and blue primary colors). An important goal of this adjustment is to render specific colors – particularly neutral colors – correctly; hence, the general method is sometimes called gray balance, neutral balance, or white balance. Image data acquired by sensors – either film or electronic image sensors – must be transformed from the acquired values to new values that are appropriate for color reproduction or display. Generalized color balance[edit] Illuminant estimation and adaptation[edit] A seascape photograph at Clifton Beach, South Arm, Tasmania, Australia. where , and so that:
Colorimetry
Colorimetry is "the science and technology used to quantify and describe physically the human color perception."[1] It is similar to spectrophotometry, but is distinguished by its interest in reducing spectra to the physical correlates of color perception, most often the CIE 1931 XYZ color space tristimulus values and related quantities.[2] §Instruments[edit] Colorimetric equipment is similar to that used in spectrophotometry. A tristimulus colorimeter measures the tristimulus values of a color.[3]A spectroradiometer measures the absolute spectral radiance (intensity) or irradiance of a light source.[4]A spectrophotometer measures the spectral reflectance, transmittance, or relative irradiance of a color sample.[4][5]A spectrocolorimeter is a spectrophotometer that can calculate tristimulus values.A densitometer measures the degree of light passing through or reflected by a subject.[3]A color temperature meter measures the color temperature of an incident illuminant. §See also[edit]
Color psychology
Color psychology is the study of color as a determinant of human behavior. Examples include quantification of individual color preferences[1] and investigating the relationship between shirt color and match outcome in English football.[2] However, the interface between color and environmental stimuli is a highly complex interface and one which is open to the influence of a large number of factors. In addition, there are a number of key reasons why the principle of caveat emptor should prevail in regard to color psychology, especially in regard to information about colour psychology found in mainstream media and popular culture (O'Connor, 2011).[3] Influence of colour on perception[edit] Perceptions not obviously related to colour, such as the palatability of food, may in fact be partially determined by colour. Placebo effect[edit] Blue public lighting[edit] Color preference and associations between color and mood[edit] Some studies find that color can affect mood. General model[edit]
