CIE 11664-5-2016 Colorimetry - Part 5 CIE 1976 L u v colour space and u v uniform chromaticity scale diagram (First Edition).pdf

1、Colorimetry Part 5: CIE 1976 L*u*v* colour space and u, v uniform chromaticity scale diagramColorimtrie Partie 5: Espace chromatique L*u*v* et diagramme de chromaticit uniforme u, v CIE 1976INTERNATIONAL STANDARDISO/CIE11664-5Reference numberISO/CIE 11664-5:2016(E)First edition2016-09-01 ISO/CIE 201

2、6ii ISO/CIE 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO/CIE 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, o

3、r posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright office CIE Central BureauCh. de Blandonnet 8 CP 401 Babenbergerstrae 9/9ACH-1214 Vernier, Gen

4、eva, Switzerland A-1010 Vienna, AustriaTel. +41 22 749 01 11 Tel. +43 1 714 3187Fax +41 22 749 09 47 copyrightiso.org ciecbcie.co.atwww.iso.org www.cie.co.atISO/CIE 11664-5:2016(E)ISO/CIE 11664-5:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms, definitions, symbols and abb

5、reviated terms . 13.1 Terms and definitions . 13.2 Symbols and abbreviated terms. 24 Calculation method 24.1 Uniform chromaticity scale diagram (UCS diagram) . 24.2 Uniform colour space 34.3 Correlates of lightness, saturation, chroma and hue 44.4 Colour differences 5Annex A (informative) Reverse tr

6、ansformation . 7Bibliography 8 ISO/CIE 2016 All rights reserved iiiContents PageISO/CIE 11664-5:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normall

7、y carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the

8、work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the di

9、fferent approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this document

10、may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/pat

11、ents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade

12、 Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html.The committee responsible for this document is ISO/TC 274, Light and lighting.This first edition of ISO/CIE 11664-5 cancels and replaces ISO 11664-5:2009, of which it constitu

13、tes a minor revision. (ISO 11664-5:2009 was prepared by CIE Technical Committee TC 1-57 of Division 1.)ISO 11664 consists of the following parts, under the general title Colorimetry: Part 1: CIE standard colorimetric observers Part 2: CIE standard illuminants Part 3: CIE tristimulus values Part 4: C

14、IE 1976 L*a*b* Colour spaceISO/CIE 11664 consists of the following parts, under the general title Colorimetry: Part 5: CIE 1976 L*u*v* colour space and u, v uniform chromaticity scale diagram Part 6: CIEDE2000 Colour-difference formulaiv ISO/CIE 2016 All rights reservedISO/CIE 11664-5:2016(E)Introdu

15、ctionThe three-dimensional colour space produced by 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 and diagrams do not represent equally percep

16、tible differences between colour stimuli. For this reason, in 1976, 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 uni

17、form colour spaces and associated colour difference formulae.28Both these more-nearly uniform colour spaces have become well accepted and widely used. Numerical values representing approximately the relative magnitude of colour differences can be described by simple Euclidean distances in the spaces

18、 or by more sophisticated formulae that improve the correlation with the relative perceived size of differences. The purpose of this part of ISO/CIE 11664 is to define procedures for calculating the coordinates of the CIE 1976 L*u*v* (CIELUV) colour space and the Euclidean colour difference values b

19、ased on these coordinates. This part of ISO/CIE 11664 also defines a related chromaticity diagram that is a projection of the CIE x,y chromaticity diagram maintaining straight lines of dominant and complementary wavelengths. This part of ISO/CIE 11664 does not cover the alternative uniform colour sp

20、ace, CIELAB,5nor does it cover more sophisticated colour difference formulae based on CIELAB, such as the CMC formula,3the CIE 94 formula,1the DIN 99 formula,4and the CIEDE2000 formula.6 ISO/CIE 2016 All rights reserved vColorimetry Part 5: CIE 1976 L*u*v* colour space and u, v uniform chromaticity

21、scale diagram1 ScopeThis part of ISO/CIE 11664 specifies the method of calculating the coordinates of the CIE 1976 L*u*v* colour space including correlates of lightness, chroma, saturation and hue. It includes two methods for calculating Euclidean distances in this space to represent the relative pe

22、rceived magnitude of colour differences. It also specifies the method of calculating the coordinates of the u,v uniform chromaticity scale diagram.This part of ISO/CIE 11664 is applicable to tristimulus values calculated using the colour-matching functions of the CIE 1931 standard colorimetric syste

23、m or the CIE 1964 standard colorimetric system. This part of ISO/CIE 11664 may be used for the specification of colour stimuli perceived as belonging to a reflecting or transmitting object, where a three-dimensional space more uniform than tristimulus space is required. This includes self-luminous d

24、isplays, like cathode ray tubes, if they are being used to simulate reflecting or transmitting objects and if the stimuli are appropriately normalized. This part of ISO/CIE 11664, as a whole, does not apply to colour stimuli perceived as belonging to an area that appears to be emitting light as a pr

25、imary light source or that appears to be specularly reflecting such light. Only the u,v uniform chromaticity scale diagram defined in 4.1 and the correlates of hue and saturation defined in 4.3 apply to such colour stimuli.2 Normative referencesThe following documents, in whole or in part, are norma

26、tively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 116641/CIE S 014-1, Colorimetry Part 1: CIE standard colori

27、metric observersISO 116642/CIE S 014-1, Colorimetry Part 2: CIE standard illuminantsCIE S 017, ILV: International Lighting Vocabulary3 Terms, definitions, symbols and abbreviated terms3.1 Terms and definitionsFor the purposes of this document, the terms and definitions given in CIE S 017 apply.INTER

28、NATIONAL STANDARD ISO/CIE 11664-5:2016(E) ISO/CIE 2016 All rights reserved 1ISO/CIE 11664-5:2016(E)3.2 Symbols and abbreviated termsX, Y, Z tristimulus values of a test stimulus calculated using the colour-matching functions of the CIE 1931 standard colorimetric system (also known as the CIE 2 stand

29、ard colorimet-ric system)Yntristimulus value, Y, of a specified white colour stimulus calculated using the colour-matching functions of the CIE 1931 standard colorimetric systemx, y chromaticity coordinates of a test stimulus calculated using the colour-matching functions of the CIE 1931 standard co

30、lorimetric systemL* CIELUV lightnessu*, v* CIELUV u*,v* coordinatesu, v CIE 1976 chromaticity coordinatesuvnn,CIE 1976 chromaticity coordinates of a specified white stimulussuvCIELUV saturationCuv*CIELUV chromahuvCIELUV hue angle(u,v) CIELUV chromaticity differenceL* CIELUV lightness differenceu*, v

31、* CIELUV u*,v* differencesCuv*CIELUV chroma differencehuvCIELUV hue angle differenceHuv*CIELUV hue differenceEuv*CIELUV colour differenceIf the character “” is not available, it may be replaced by the character “D”.The terms “CIE 1976 L*u*v*” and “CIELUV” may be used interchangeably.Where tristimulu

32、s values are calculated using the colour-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 method4.1 Uniform chromaticity scale diagram (UCS diagram)The CIE 197

33、6 uniform chromaticity scale diagram is a projective transformation of the CIE x,y chromaticity diagram yielding perceptually more uniform colour spacing. It is produced by plotting, as abscissa and ordinate, respectively, quantities defined by the following formulae:uXXYZ= +()4153 (1)2 ISO/CIE 2016

34、 All rights reservedISO/CIE 11664-5:2016(E)vYXYZ=9153+()(2)where X, Y, Z are the tristimulus values of the test colour stimulus based on the CIE 1931 standard colorimetric system defined in ISO 11664-1/CIE S 014-1.The same quantities may be obtained by the following formulae:uxxy= + +()4212 3 (3)vyx

35、y= + +()9212 3 (4)where x and y are obtained by the following formulae:xXXYZ=+()(5)yYXYZ=+()(6)Euclidean distances in this diagram can be used to represent approximately the relative perceived magnitude of colour differences between colour stimuli of negligibly different luminances, of approximately

36、 the same size, and viewed in identical surroundings, by an observer photopically adapted to a field with the chromaticity of CIE standard illuminant D65 defined in ISO 11664-2/CIE S 014-2. The values given by this part of ISO/CIE 11664 may not correlate well with relative perceived colour differenc

37、es in other viewing conditions. The Euclidean distances are defined by the following formula:uv uv,()=()+()2212(7)whereuu u=10(8)vv v=10(9)and the subscripts 0 (usually the reference) and 1 (usually the test) indicate the two stimuli being compared.4.2 Uniform colour spaceThe CIE 1976 L*u*v* colour

38、space is a three-dimensional, approximately uniform colour space produced by plotting in rectangular coordinates, L*, u*, v*, quantities defined by the following formulae:LfYY* =()116 16n(10)uLuu*=( )13 n(11)vLvv*=( )13 n(12) ISO/CIE 2016 All rights reserved 3ISO/CIE 11664-5:2016(E)wherefYYY Ynn nif

39、 ()=() ()()13 3629 (13)fYYYYYYnn nif ()=()()+()()841 108 4296293(14)In these formulae, Y, u and v describe the test colour stimulus and Yn, unand vndescribe a specified white stimulus.In the case of simulated reflecting or transmitting objects produced on a self-luminous display, all the tristimulus

40、 values shall first be 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

41、 the CIE 1931 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 speci

42、fied white stimulus shall be used for all stimuli to be compared with each other.If the tristimulus values X, Y, Z are obtained by 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-

43、matching functions, same range and interval of wavelength, and same bandwidth). If the tristimulus values X, Y, Z are obtained by direct measurement using a tristimulus colorimeter, Xn, Yn, Znshall be measured using the same tristimulus colorimeter and a white reflectance standard calibrated relativ

44、e to a perfect reflecting diffuser.NOTE 1 For real object colours, the specified white stimulus normally chosen for Xn, Yn, Znis 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

45、 source normalized by a common factor so that Ynis equal to 100. For simulated object colours, the specified white stimulus normally 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,

46、Ynand Znfor specific illuminants and specific calculation methods have been published.2NOTE 3 Formula (14) is based on a suggestion by Reference 7.NOTE 4 A value of 7,787 is approximately equal to the term (841/108) in Formula (14). The approximate value may be used in practice.NOTE 5 A value of 0,0

47、08 856 is approximately equal to the term (6/29)3in Formula (13) and Formula (14). The approximate value may be used in practice.NOTE 6 The fractions 6/29 and 4/29 in Formula (13) and Formula (14) are exactly equal to the fractions 24/116 and 16/116 appearing in CIE 15:2004.NOTE 7 The term (841/108)

48、 in Formula (14) is derived from and exactly equal to (1/3)(29/6)2.NOTE 8 Formula (10) reduces to L* 903,3(Y/Yn) when Y/Yn (6/29)3.When CIELUV values are reported, they should be accompanied by all relevant information relating to the measurement conditions and the procedures used to calculate the i

49、nput tristimulus values.4.3 Correlates of lightness, saturation, chroma and hueApproximate correlates of the perceived attributes lightness, saturation, chroma, and hue shall be calculated as follows:4 ISO/CIE 2016 All rights reservedISO/CIE 11664-5:2016(E)CIE 1976 lightness: L* as defined in 4.2CIE 1976 u,v saturation (CIELUV saturation):suuvvuv nn=( )+( )132212 (15)CIE 1976 u,v chroma (CIELUV chroma):Cuvuv*=()+()2212(1