CIE 1960 color space

CIE 1960 color space

The CIE 1960 color space ("CIE 1960 UCS", variously expanded "Uniform Color Space", "Uniform Color Scale", "Uniform Chromaticity Scale", "Uniform Chromaticity Space") is another name for the (u,v) chromaticity space devised by David MacAdam. [cite journal|authorlink=David MacAdam|first=David Lewis|last=MacAdam|title=Projective transformations of I.C.I. color specifications| journal=JOSA|volume=27|issue=8|month=August|year=1937|pages=294–299| url=http://www.opticsinfobase.org/abstract.cfm?URI=josa-27-8-294]

The CIE 1960 UCS does not define a luminance or lightness component, but the Y tristimulus value of the XYZ color space or a lightness index similar to W* of the CIE 1964 color space are sometimes used. [cite book|title=Digital Pictures: Representation, Compression, and Standards|publisher=Springer|isbn=030642195X|author=Arun N. Netravali, Barry G. Haskell|authorlink=Arun Netravali|edition=2E|page=288| url=http://books.google.com/books?id=-TXYfZrCBuQC&pg=PA288&vq=1960+CIE-UCS+coordinate+system&dq=Riemannian+munsell&source=gbs_search_s&sig=ep8zmQbO7sFBfjJbmOnYiA9mmmI]

Today, the CIE 1960 UCS is mostly used to calculate correlated color temperature, where the isothermal lines are perpendicular to the Planckian locus. As a uniform chromaticity space, it has been superseded by the CIE 1976 UCS.

Background

Judd determined that a more uniform color space could be found by a simple projective transformation of the CIEXYZ tristimulus values: [cite journal|title=A Maxwell Triangle Yielding Uniform Chromaticity Scales|journal=JOSA|first=Deane B.|last=Judd|volume=25|issue=1|year=1935|month=January|pages=24–35| url=http://www.opticsinfobase.org/abstract.cfm?URI=josa-25-1-24| quote=An important application of this coordinate system is its use in finding from any series of colors the one most resembling a neighboring color of the same brilliance, for example, the finding of the nearest color temperature for a neighboring non-Planckian stimulus. The method is to draw the shortest line from the point representing the non-Planckian stimulus to the Planckian locus.]

egin{pmatrix} R \ G \ B end{pmatrix} = egin{pmatrix} 3.1956 & 2.4478 & -0.1434 \ -2.5455 & 7.0492 & 0.9963 \ 0.0000 & 0.0000 & 1.0000 end{pmatrix} egin{pmatrix} X \ Y \ Z end{pmatrix}

Judd was the first to employ this type of transformation, and many others were to follow. Converting this RGB space to chromaticities one finds [cite journal|journal=JOSA|title=Quantitative data and methods for colorimetry|volume=34|issue=11|month=November|year=1944|author=OSA Committee on Colorimetry| pages=633–688|url=http://www.opticsinfobase.org/abstract.cfm?URI=josa-34-11-633 (recommended reading)]

u=frac{0.4661x+0.1593y}{y-0.15735x+0.2424}

v=frac{0.6581y}{y-0.15735x+0.2424}

or equivalently (for comparative purposes with the equations to follow):

u=frac{5.5932x+1.9116y}{12y-1.882x+2.9088}

v=frac{7.8972y}{12y-1.882x+2.9088}

MacAdam simplified Judd's UCS for computational purposes:

u = 4x / (12y - 2x + 3)

v = 6y / (12y - 2x + 3)

The Colorimetry committee of the CIE considered MacAdam's proposal at its 14th Session in Brussels for use in situations where more perceptual uniformity was desired than the (x,y) chromaticity space, [cite journal| url=http://www.opticsinfobase.org/abstract.cfm?URI=josa-50-1-87| title=Brussels Session of the International Commission on Illumination|authorlink=International Commission on Illumination|journal=JOSA|volume=50|issue=1|month=January|year=1960|pages=89–90|author=CIE|quote=The use of the following chromaticity diagram is provisionally recommended whenever a diagram yielding color spacing perceptually more nearly uniform than the (xy) diagram is desired. The chromaticity diagram is produced by plotting 4X/(X+15Y+3Z) as abscissa and 6Y/(X+15Y+3Z) as ordinate, in which X, Y, Z are the tristimulus values corresponding to the 1931 CIE Standard Observer and Coordinate System.] and officially adopted it as the standard UCS the next year. [citation|location=Brussels|year=1960|author=CIE|authorlink=International Commission on Illumination|contribution=Official Recommendations|page=36|series=14th Session|title=Publication № 004: Proceedings of the CIE Session 1959 in Bruxelles|volume=A|url=http://cie.kee.hu/newcie/main/withdrawn.html]

Relation to CIEXYZ

:U=(2/3)X:V=Y:W=(-X+3Y+Z)/2:Z=(3U-3V+2W)/2

:u = 4X / (X + 15Y +3Z):v = 6Y / (X + 15Y + 3Z)

:u = 4x / (-2x + 12y + 3):v = 6y / (-2x + 12y + 3)

:x = 3u / (2u - 8v + 4):y = 2v / (2u - 8v + 4)

Relation to CIELUV

:u' = u:2v' = 3v

Reference

External links

* [http://www.efg2.com/Lab/Graphics/Colors/Chromaticity.htm Free Windows utility to generate chromaticity diagrams.] Delphi source included.


Wikimedia Foundation. 2010.

Поможем написать реферат

Look at other dictionaries:

  • CIE 1931 color space — In the study of color perception, one of the first mathematically defined color spaces is the CIE 1931 XYZ color space, created by the International Commission on Illumination (CIE) in 1931.[1][2] The CIE XYZ color space was derived from a series …   Wikipedia

  • CIE 1964 color space — The CIE 1964 color space, CIEUVW ( U^*V^*W^* ) is based on the CIE 1960 UCS: [cite book|title=Colorimetry: Understanding the CIE System|author=Janos Schanda|publisher=Wiley Interscience|year=2007|page=81] :U^*=13W^*(u u 0), quad V^*=13W^*(v v 0) …   Wikipedia

  • CIELUV color space — In colorimetry, the CIE 1976 ( L* , u* , v* ) color space, also known as the CIELUV color space, is a color space adopted by the International Commission on Illumination (CIE) in 1976, as a simple to compute transformation of the 1931 CIE XYZ… …   Wikipedia

  • Color rendering index — Emitted light spectrum determines the color rendering index of the lamp. Color render …   Wikipedia

  • Color temperature — The CIE 1931 x,y chromaticity space, also showing the chromaticities of black body light sources of various temperatures (Planckian locus), and lines of constant correlated color temperature. Color temperature is a characteristic of visible light …   Wikipedia

  • CIE 1964 — Traduction à relire CIE 1964 color space → …   Wikipédia en Français

  • RGB color model — RGB redirects here. For other uses, see RGB (disambiguation). A representation of additive color mixing. Projection of primary color lights on a screen shows secondary colors where two overlap; the combination of all three of red, green, and blue …   Wikipedia

  • Planckian locus — In color theory, the Planckian locus is generally the path or locus that the color of a black body would take ina particular color space as the blackbody temperature changes. Generally, a color space is a set of three numbers ( X , Y , and Z ,… …   Wikipedia

  • Colorimetry — This article is about measurement of color. For use in chemistry, see Colorimetry (chemical method). Not to be confused with Calorimetry. Colorimetry is the science and technology used to quantify and describe physically the human color… …   Wikipedia

  • Mired — Close up of the Planckian locus in the CIE 1960 color space, with the isotherms in mireds. Note the even spacing of the isotherms when using the reciprocal temperature scale. The even spacing of the isotherms on the locus implies that the mired… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”