DIN EN ISO 11664-4-2012 Colorimetry - Part 4 CIE 1976 L a b Colour space (ISO 11664-4 2008) German version EN ISO 11664-4 2011《比色法 第4部分 CIE 1976 L a b 颜色空间》.pdf

1、June 2012 Translation by DIN-Sprachendienst.English price group 9No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 17

2、.180.20!$|ZG“1895536www.din.deDDIN EN ISO 11664-4Colorimetry Part 4: CIE 1976 L*a*b* Colour space (ISO 11664-4:2008)English translation of DIN EN ISO 11664-4:2012-06Farbmetrik Teil 4: CIE 1976 L*a*b* Farbenraum (ISO 11664-4:2008)Englische bersetzung von DIN EN ISO 11664-4:2012-06Colorimtrie Partie 4

3、: Espace chromatique L*a*b* CIE 1976 (ISO 11664-4:2008)Traduction anglaise de DIN EN ISO 11664-4:2012-06SupersedesDIN EN ISO 11664-4:2011-07www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1205.12 2 A comma is used as the decimal ma

4、rker. National foreword This standard has been prepared by Technical Committee CIE “International Commission on Illumination” in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Norme

5、nausschuss Farbe (Colour Standards Committee), Joint Working Committee NA 025-00-02 GA Gemeinschaftsarbeitsausschuss FNF/FNL: Farbmetrik. DIN EN ISO 11664 consists of the following parts, under the general title Colorimetry: Part 1: CIE standard colorimetric observers Part 2: CIE standard illuminant

6、s Part 4: CIE 1976 L*a*b* Colour space Part 5: CIE 1976 L*u*v* Colour space and u, v uniform chromaticity scale diagram Amendments This standard differs from DIN 6174:2007-10 and DIN 5033-3:1992-07 as follows: a) the colorimetric evaluation of colour coordinates and colour differences according to t

7、he approximately uniform CIELAB colour space is now covered by the present standard. Thus, DIN 6174:2007-10 will be withdrawn; b) the content of DIN 5033-3 will be covered by the present standard, DIN EN ISO 11664-3 (in preparation) and DIN EN ISO 11664-5. DIN 5033-3 will be withdrawn upon publicati

8、on of DIN EN ISO 11664-3. Compared with DIN EN ISO 11664-4:2011-07 the following correction has been made: a) the scope has been corrected. Previous editions DIN 5033: 1935-11, 1944-05 DIN 5033-3: 1954x-04, 1972-04, 1980-01, 1992-07 DIN 6174: 2007-10 DIN EN ISO 11664-4: 2011-07 DIN EN ISO 11664-4:20

9、12-06 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 11664-4 April 2011 ICS 17.180.20 English Version Colorimetry - Part 4: CIE 1976 L*a*b* Colour space Colorimtrie - Partie 4: Espace chromatique L*a*b* CIE 1976 (ISO 11664-4:2008) Farbmetrik - Teil 4: CIE 1976 L*a*b* Farbenraum This Europe

10、an Standard was approved by CEN on 17 March 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references conce

11、rning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member int

12、o its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Irela

13、nd, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17

14、, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 11664-4:2011: E(ISO 11664-4:2008) (ISO 11664-4:2008) Contents Page DIN EN ISO 11664-4:2012-06 EN ISO 11664-4:2011 (E) 2 Foreword 3 Introduction .4 1 Scope 4

15、 2 Normative references 4 3 Definitions, symbols and abbreviations 4 4 Calculation 4.1 Basic coordinates 5 4.2 Correlates of lightness, chroma and hue 6 4.3 Colour differences .7 Annex (informative) Reverse transformation .9 Bibliography 10 method .5Foreword The text of ISO 11664-4:2008 has been pre

16、pared by Technical Committee CIE “International Commission on Illumination” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 11664-4:2011 by Technical Committee CEN/TC 139 “Paints and varnishes” the secretariat of which is held by DIN. This European Stand

17、ard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2011, and conflicting national standards shall be withdrawn at the latest by October 2011. Attention is drawn to the possibility that some of the elements of t

18、his document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European St

19、andard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the Unit

20、ed Kingdom. Endorsement notice The text of ISO 11664-4:2008 has been approved by CEN as a EN ISO 11664-4:2011 without any modification. DIN EN ISO 11664-4:2012-06 EN ISO 11664-4:2011 (E) 3 COLORIMETRY - PART 4: CIE 1976 L*a*b* COLOUR SPACE INTRODUCTION The three-dimensional colour space produced by

21、plotting CIE tristimulus values (X,Y,Z) in rectangular coordinates is not visually uniform, nor is the (x,y,Y) space nor the two-dimensional CIE (x,y) chromaticity diagram. Equal distances in these spaces do not represent equally perceptible differences between colour stimuli. For this reason, in 19

22、76, the CIE introduced and recommended two new spaces (known as CIELAB and CIELUV) whose coordinates are non-linear functions of X, Y and Z. The recommendation was put forward in an attempt to unify the then very diverse practice in uniform colour spaces and associated colour difference formulae (Ro

23、bertson, 1990; CIE, 2004). Both these more-nearly uniform colour spaces have become well accepted and widely used. Numerical values representing approximately the magnitude of colour differences can be described by simple Euclidean distances in the spaces or by more sophisticated formulae that impro

24、ve the correlation with the perceived size of differences. The purpose of this CIE Standard is to define procedures for calculating the coordinates of the CIE 1976 L*a*b* (CIELAB) colour space and the Euclidean colour difference values based on these coordinates. The standard does not cover more sop

25、histicated colour difference formulae based on CIELAB, such as the CMC formula (Clarke et al., 1984), the CIE94 formula (CIE, 1995), the DIN99 formula (DIN, 2001), and the CIEDE2000 formula (CIE, 2001), nor does it cover the alternative uniform colour space, CIELUV. 1 SCOPE This CIE Standard specifi

26、es the method of calculating the coordinates of the CIE 1976 L*a*b* colour space including correlates of lightness, chroma and hue. It includes two methods for calculating Euclidean distances in this space to represent the perceived magnitude of colour differences. The Standard is applicable to tris

27、timulus values calculated using colour-matching functions of the CIE 1931 standard colorimetric system or the CIE 1964 standard colorimetric system. The Standard may be used for the specification of colour stimuli perceived as belonging to a reflecting or transmitting object, where a three-dimension

28、al space more uniform than tristimulus space is required. It does not apply to colour stimuli perceived as belonging to an area that appears to be emitting light as a primary light source, or that appears to be specularly reflecting such light. This Standard does apply to self-luminous displays, lik

29、e cathode ray tubes, if they are being used to simulate reflecting or transmitting objects and if the stimuli are appropriately normalized. 2 NORMATIVE REFERENCES The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited a

30、pplies. For undated references, the latest edition of the referenced document (including any amendments) applies. CIE 17.4-1987. International Lighting Vocabulary (Joint publication IEC/CIE). CIE S 014-1:2006. Colorimetry Part 1. CIE Standard Colorimetric Observers. ISO 11664-1:2007CIE S 014-2:2006.

31、 Colorimetry Part 2. CIE Standard Illuminants. ISO 11664-2:20073 DEFINITIONS, SYMBOLS AND ABBREVIATIONS For the purposes of this International Standard, the terms and definitions given in CIE 17.4-1987 (International Lighting Vocabulary), as amended by this standard and the following symbols and abb

32、reviations apply. X, Y, Z tristimulus values of test stimulus calculated using the colour-matching functions of the CIE 1931 standard colorimetric system (also known as the CIE 2 standard colorimetric system) DIN EN ISO 11664-4:2012-06 EN ISO 11664-4:2011 (E) 4 Xn, Yn, Zntristimulus values of a spec

33、ific white colour stimulus calculated using the colour-matching functions of the CIE 1931 standard colorimetric system L* CIELAB lightness a*, b* CIELAB a*, b* coordinates C*abCIELAB chroma habCIELAB hue angle L* CIELAB lightness difference a*,b* CIELAB a*, b* difference C*abCIELAB chroma difference

34、 habCIELAB hue angle difference H*abCIELAB hue difference E*abCIELAB colour difference If the character “ is not available, it may be replaced by the character “D“. The phrase “CIE 1976 L*a*b*“ and the term “CIELAB“ may be used interchangeably. Where tristimulus values are calculated using the colou

35、r-matching functions of the CIE 1964 standard colorimetric system (also known as the CIE 10 standard colorimetric system), a subscript 10 shall be added to all the above symbols. 4 CALCULATION METHOD 4.1 Basic coordinates The CIE 1976 L*a*b* colour space is a three-dimensional, approximately uniform

36、 colour space produced by plotting in rectangular coordinates, L*, a*, b*, quantities defined by the equations: ()16/116*n= YYfL (1) ()()nn/500* YYfXXfa = (2) ()()nn/200* ZZfYYfb = (3) where ()( )3/1nn/ XXXXf = if ( )3n)29/6(/ XX (4) () () 29/4/)108/841(/nn+= XXXXf if ( )3n)29/6(/ XX (5) and ()()3/1

37、nn/ YYYYf = if ( )3n)29/6(/ YY (6) () () 29/4/)108/841(/nn+= YYYYf if ( )3n)29/6(/ YY (7) and ()()3/1nn/ ZZZZf = if ( )3n)29/6(/ ZZ (8) () () 29/4/)108/841(/nn+= ZZZZf if ( )3n)29/6(/ ZZ (9) where X, Y, Z are the tristimulus values of the test colour stimulus based on the CIE 1931 standard colorimet

38、ric system defined in CIE S 014-1, and Xn, Yn, Znare the corresponding tristimulus values of a specified white stimulus. DIN EN ISO 11664-4:2012-06 EN ISO 11664-4:2011 (E) 5 In the case of simulated reflecting or transmitting objects produced on a self-luminous display, all the tristimulus values sh

39、all be first normalized by the same factor so that Y would be equal to 100 for an object with 100% reflectance or transmittance. If the angle subtended at the eye by the test stimulus is between about 1 and 4 the tristimulus values X, Y, Z calculated using the colour-matching functions of the CIE 19

40、31 standard colorimetric system should be used. If this angular subtense is greater than 4 the tristimulus values X10, Y10, Z10calculated using the colour-matching functions of the CIE 1964 standard colorimetric system should be used. The same colour-matching functions and the same specified white s

41、timulus shall be used for all stimuli to be compared with each other. When tristimulus values based on the CIE 1964 standard colorimetric system defined in CIE S 014-1 are used, a subscript 10 shall be added to all the symbols in equations (1) to (9). If the tristimulus values X, Y, Z are obtained b

42、y spectrophotometry, the tristimulus values Xn, Yn, Znof the specified white stimulus shall be calculated using the same method as used for the test stimulus (same colour-matching functions, same range and interval of wavelength, and same bandwidth). If the tristimulus values X, Y, Z are obtained by

43、 direct measurement using a tristimulus colorimeter, Xn, Yn, Znshall be measured using the same tristimulus colorimeter and a white reflectance standard calibrated relative to a perfect reflecting diffuser. NOTE 1 For real object colours, the specified white stimulus normally chosen for Xn, Yn, Znis

44、 light reflected from a perfect reflecting diffuser illuminated by the same light source as the test object. In this case, Xn, Yn, Znare the tristimulus values of the light source normalized by a common factor so that Ynis equal to 100. For simulated object colours, the specified white stimulus norm

45、ally chosen is one that has the appearance of a perfect reflecting diffuser, again normalized by a common factor so that Ynis equal to 100. NOTE 2 Examples of values of Xn, Ynand Znfor specific illuminants and specific calculation methods have been published (CIE, 2004). NOTE 3 Equations (5), (7) an

46、d (9) are based on a suggestion by Pauli (1976). NOTE 4 A value of 7,787 is approximately equal to the term (841/108) in equations (5), (7) and (9). The approximate value may be used in practice. NOTE 5 A value of 0,008856 is approximately equal to the term (6/29)3in equations (4), (5), (6), (7), (8

47、) and (9).The approximate value may be used in practice. NOTE 6 The fractions 6/29 and 4/29 in equations (4) through (9) are exactly equal to the fractions 24/116 and 16/116 appearing in CIE 15:2004. NOTE 7 The term (841/108) in equations (5), (7) and (9) is derived from and exactly equal to (1/3)(2

48、9/6)2. NOTE 8 Equation (1) reduces to L* 903,3(Y/Yn) when Y/Yn (6/29)3. When CIELAB values are reported, they should be accompanied by all relevant information relating to the measurement conditions and the procedures used to calculate the input tristimulus values. 4.2 Correlates of lightness, chroma and hue Approximate correlates of the perceived attributes lightness, chroma, and hue shall be calculated as follows: CIE 1976 lightness: L* as defined in section 4.1 CIE 1976 a,b chroma (CIELAB chroma) : ()()1/ 222ab