IEVref:845-03-56ID:
Language:enStatus: Obsolete
Term: CIE 1976 <i>L</i>* <i>a</i>* <i>b</i>* colour space
Synonym1: CIELAB colour space
[Preferred]
Synonym2:
Synonym3:
Symbol:
Definition: three-dimensional, approximately uniform colour space produced by plotting in rectangular coordinates L* a* b* quantities defined by the equations

{     L ∗ =116 ( Y/ Y n ) 1/3 −16                                   Y/ Y n           a * =500[ ( X/ X n ) 1/3 − ( Y/ Y n ) 1/3 ]     X/ X n         b ∗ =200[ ( Y/ Y n ) 1/3 − ( Z/ Z n ) 1/3 ]       Z/ Z n    }>0,008 856 MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbbjxAHX garuavP1wzZbItLDhis9wBH5garmWu51MyVXgarqqtubsr4rNCHbGe aGqipG0dh9qqWrVepG0dbbL8F4rqqrVepeea0xe9LqFf0xc9q8qqaq Fn0lXdHiVcFbIOFHK8Feea0dXdar=Jb9hs0dXdHuk9fr=xfr=xfrpe WZqaaiqaciWacmGadaGadeaabaGaaqaaaOqaamaacmaaeaqabeaaca aMc8UaaGPaVlaaykW7caWGmbWaaWbaaSqabeaacqGHxiIkaaGccqGH 9aqpcaaIXaGaaGymaiaaiAdadaqadaqaamaalyaabaGaamywaaqaai aadMfadaWgaaWcbaGaaeOBaaqabaaaaaGccaGLOaGaayzkaaWaaWba aSqabeaacaaIXaGaai4laiaaiodaaaGccqGHsislcaaIXaGaaGOnai aaxMaacaWLjaWaaSGbaeaacaWLjaGaaGPaVlaaykW7caaMc8UaaGPa VlaaykW7caWGzbaabaGaamywamaaBaaaleaacaqGUbaabeaakiaayk W7caaMc8UaaGPaVlaaykW7aaaabaGaaGPaVlaaykW7caaMc8UacGPa VlaadggadaahaaWcbeqaaiaacQcaaaGccqGH9aqpcaaI1aGaaGimai aaicdadaWadaqaamaabmaabaWaaSGbaeaacaWGybaabaGaamiwamaa BaaaleaacaqGUbaabeaaaaaakiaawIcacaGLPaaadaahaaWcbeqaai aaigdacaGGVaGaaG4maaaakiabgkHiTmaabmaabaWaaSGbaeaacaWG zbaabaGaamywamaaBaaaleaacaqGUbaabeaaaaaakiaawIcacaGLPa aadaahaaWcbeqaaiaaigdacaGGVaGaaG4maaaaaOGaay5waiaaw2fa amaalyaabaGaaCzcaiaadIfaaeaacaWGybWaaSbaaSqaaiaab6gaae qaaOGaaGPaVlaaykW7aaaabaGaaGPaVlaaykW7caaMc8UaaGPaVlaa dkgadaahaaWcbeqaaiabgEHiQaaakiabg2da9iaaikdacaaIWaGaaG imamaadmaabaWaaeWaaeaadaWcgaqaaiaadMfaaeaacaWGzbWaaSba aSqaaiaab6gaaeqaaaaaaOGaayjkaiaawMcaamaaCaaaleqabaGaaG ymaiaac+cacaaIZaaaaOGaeyOeI0YaaeWaaeaacaWGAbGaai4laiaa dQfadaWgaaWcbaGaaeOBaaqabaaakiaawIcacaGLPaaadaahaaWcbe qaaiaaigdacaGGVaGaaG4maaaaaOGaay5waiaaw2faamaalyaabaGa aCzcaiaadQfaaeaacaWGAbWaaSbaaSqaaiaab6gaaeqaaOGaaGPaVl aaykW7aaaaaiaawUhacaGL9baacqGH+aGpcaqGWaGaaeilaiaabcda caqGWaGaaeioaiaaykW7caqG4aGaaeynaiaabAdaaaa@AB9D@

X, Y, Z describe the colour stimulus considered and Xn, Yn, Zn describe a specified white achromatic stimulus

NOTE – Approximate correlates of lightness, chroma and hue may be calculated as follows:

CIE 1976 lightness: L* = 116 (Y/Yn)1/3 − 16 where Y/Yn > 0,008 856

CIE 1976 a, b chroma: C*ab = (a*2 + b*2)1/2

CIE 1976 a, b hue-angle: hab = arctan (b */a *)


Publication date:1987
SourceCIE Publication CIE No. 15.2
Replaces:
Internal notes:2017-06-02: Cleanup - Remove Attached Image 845-03-56.gif
CO remarks:
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VT remarks:
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