SIST EN ISO 11664-5:2016

Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u', v' uniform chromaticity scale diagram (ISO/CIE 11664-5:2016)

This 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 perceived 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 system 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 displays, 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 primary 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.

Farbmetrik - Teil 5: CIE 1976 L*u*v* Farbenraum und gleichabständige u', v' Farbtafel (ISO/CIE 11664-5:2016)

Dieser Teil der ISO/CIE 11664 legt das Verfahren zum Berechnen der Koordinaten des L*u*v* Farbenraums CIE 1976 fest, Zuordnungen für Helligkeit, Buntheit, Sättigung und Buntton eingeschlossen. Er enthält zwei Verfahren zum Berechnen euklidischer Abstände in diesem Farbenraum, um die relative empfindungs¬gemäße Größe von Farbabständen darzustellen. Außerdem legt sie das Verfahren zum Berechnen der Koordinaten der gleichabständigen u‘, v‘ Farbtafel fest.
Dieser Teil der ISO/CIE 11664 ist auf Farbwerte anwendbar, die nach den Spektralwertfunktionen des Normvalenzsystems CIE 1931 oder des Normvalenzsystems CIE 1964 berechnet wurden. Dieser Teil der ISO/CIE 11664 darf für die Festlegung von Farbreizen angewendet werden, die als zu einem reflektierenden oder transmittierenden Objekt zugehörig empfunden werden, wenn ein dreidimensionaler Farbenraum erforderlich ist, der gleichabständiger ist als der Farbenraum der Farbwerte. Dies schließt selbstleuchtende Displays, wie Kathodenstrahlröhren ein, wenn sie dazu verwendet werden, reflektierende oder transmittierende Objekte zu simulieren, und wenn die Farbreize in geeigneter Weise normiert sind. Dieser Teil der ISO/CIE 11664 als Ganzes ist nicht auf Farbreize anwendbar, die als zu einer Fläche zugehörig empfunden werden, die Licht als eine primäre Lichtquelle zu emittieren oder solches Licht gerichtet zu reflektieren scheint. Nur die in 4.1 definierte gleichabständige u‘, v‘ Farbtafel und die in 4.3 definierten Zuordnungen von Buntton und Sättigung gelten für solche Farbreize.

Colorimétrie - Partie 5: Espace chromatique L*u*v* et diagramme de chromaticité uniforme u', v' CIE 1976 (ISO/CIE 11664-5:2016)

ISO/CIE 11664-5:2016 fixe la méthode de calcul des coordonnées de l'espace chromatique L*u*v* CIE 1976 ainsi que des correspondants de clarté, de chroma, de saturation et de teinte. Elle comprend deux méthodes de calcul de la distance euclidienne dans cet espace, représentant la valeur perçue des différences de couleur. Elle spécifie également la méthode de calcul des coordonnées u′,v′ du diagramme de chromaticité uniforme.
ISO/CIE 11664-5:2016 est applicable aux composantes trichromatiques calculées en utilisant les fonctions colorimétriques du système colorimétrique normalisé CIE 1931 ou du système colorimétrique normalisé CIE 1964. La présente partie de l'ISO/CIE 11664 peut être utilisée pour la spécification de stimulus de couleur se rapportant à des objets qui réfléchissent ou qui transmettent la lumière, pour lesquels un espace chromatique tridimensionnel plus uniforme que le système trichromatique est nécessaire. Ceci comprend les afficheurs auto-lumineux, tels que les tubes cathodiques, quand ils sont utilisés pour simuler des objets qui réfléchissent ou transmettent la lumière, si les stimulus sont convenablement normalisés. La présente partie de l'ISO/CIE 11664, dans son ensemble, ne s'applique pas à des stimulus de couleur se rapportant à des surfaces qui paraissent émettre de la lumière comme le font les sources primaires de lumière ou qui apparaissent réfléchir spéculairement de telles lumières. Seuls s'appliquent à de tels stimulus le diagramme de chromaticité uniforme u′,v′ défini en 4.1 et les correspondants de teinte et de saturation définis en 4.3.

Kolorimetrija - 5. del: Barvni prostor L*u*v* in diagram enakomerne barvnosti u', v' po CIE 1976 (ISO/CIE 11664-5:2016)

Ta del standarda ISO/CIE 11664 določa metodo za izračun koordinat CIE 1976 L*u*v*, vključno s korelacijo svetlobe, barv, saturacije in odtenka. Vključuje dve metodi za izračun evklidskih razdalj v tem prostoru za predstavo relativne magnitude teh barvnih razlik. Določa tudi metodo za izračun koordinat diagrama kromatskega merila za u′,v′.
Ta del standarda ISO/CIE 11664 se uporablja za tristimulusne vrednosti, izračunane z uporabo barvno skladnih funkcij kolorimetričnega sistema v skladu s standardom CIE 1931 ali kolorimetričnega sistema v skladu s standardom CIE 1964. Ta del standarda ISO/CIE 11664 se lahko uporablja za specifikacijo barvnih stimulov, dojetih kot refleksni ali oddajni predmeti, kjer je zahtevan tridimenzionalni prostor, enotnejši od tristimulusnega prostora. To vključuje samosvetilne zaslone, kot so katodne cevi, če se uporabljajo za simulacijo predmeta, ki odbija ali oddaja svetlobo, in če so dražljaji ustrezno normalizirani. Ta del standarda ISO/CIE 11664 se v celoti ne uporablja za barvne dražljaje, zaznane, da pripadajo območjem, za katere je videti, da oddajajo svetlobo kot primarni svetlobni viri ali da sijajno odsevajo takšno svetlobo. Za takšne barvne vrednosti se uporabljajo samo diagram enotnega kromatskega merila u′,v′, določen v točki 4.1, in korelacije odtenkov in saturacije, določene v točki 4.3.

General Information

• Status: Published
• Public Enquiry End Date: 02-Jun-2016
• Publication Date: 06-Nov-2016
• ICS: 17.180.20 - Colours and measurement of light
• Technical Committee: IBLP - Paints and varnishes
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 26-Oct-2016
• Due Date: 31-Dec-2016
• Completion Date: 07-Nov-2016
• Ref Project: EN ISO 11664-5:2016 - Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u', v' uniform chromaticity scale diagram (ISO/CIE 11664-5:2016)

Relations

• Replaces: SIST EN ISO 11664-5:2011 - Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u', v' uniform chromaticity scale diagram (ISO 11664-5:2009)
• Effective Date: 01-Dec-2016
• Revised: oSIST prEN ISO/CIE 11664-5:2023 - Colorimetry - Part 5: CIE 1976 L*u*v* colour space and u', v' uniform chromaticity scale diagram (ISO/CIE DIS 11664-5:2023)
• Effective Date: 01-May-2023

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 11664-5:2016
01-december-2016
1DGRPHãþD
SIST EN ISO 11664-5:2011
Kolorimetrija - 5. del: Barvni prostor L*u*v* in diagram enakomerne barvnosti u', v'
po CIE 1976 (ISO/CIE 11664-5:2016)
Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u', v' uniform chromaticity scale
diagram (ISO/CIE 11664-5:2016)
Farbmetrik - Teil 5: CIE 1976 L*u*v* Farbenraum und gleichabständige u', v' Farbtafel
(ISO/CIE 11664-5:2016)
Colorimétrie - Partie 5: Espace chromatique L*u*v* et diagramme de chromaticité
uniforme u', v' CIE 1976 (ISO/CIE 11664-5:2016)
Ta slovenski standard je istoveten z: EN ISO 11664-5:2016
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
SIST EN ISO 11664-5:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 11664-5:2016

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SIST EN ISO 11664-5:2016


EN ISO 11664-5
EUROPEAN STANDARD

NORME EUROPÉENNE

September 2016
EUROPÄISCHE NORM
ICS 17.180.20 Supersedes EN ISO 11664-5:2011
English Version

Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u',
v' uniform chromaticity scale diagram (ISO/CIE 11664-
5:2016)
Colorimétrie - Partie 5: Espace chromatique L*u*v* et Farbmetrik - Teil 5: CIE 1976 L*u*v* Farbenraum und
diagramme de chromaticité uniforme u', v' CIE 1976 gleichabständige u', v' Farbtafel (ISO/CIE 11664-
(ISO/CIE 11664-5:2016) 5:2016)
This European Standard was approved by CEN on 1 July 2016.

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
concerning 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 into 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 11664-5:2016 E
worldwide for CEN national Members.

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SIST EN ISO 11664-5:2016
EN ISO 11664-5:2016 (E)
Contents Page
European foreword . 3

2

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SIST EN ISO 11664-5:2016
EN ISO 11664-5:2016 (E)
European foreword
This document (EN ISO 11664-5:2016) has been prepared by Technical Committee ISO/TC 274 "Light
and lighting" in collaboration with Technical Committee CEN/TC 139 “Paints and varnishes” the
secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by March 2017, and conflicting national standards shall
be withdrawn at the latest by March 2017.
Attention is drawn to the possibility that some of the elements of this 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.
This document supersedes EN ISO 11664-5:2011.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO/CIE 11664-5:2016 has been approved by CEN as EN ISO 11664-5:2016 without any
modification.

3

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SIST EN ISO 11664-5:2016

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SIST EN ISO 11664-5:2016
INTERNATIONAL ISO/CIE
STANDARD 11664-5
First edition
2016-09-01
Colorimetry —
Part 5:
CIE 1976 L*u*v* colour space and u’, v’
uniform chromaticity scale diagram
Colorimétrie —
Partie 5: Espace chromatique L*u*v* et diagramme de chromaticité
uniforme u’, v’ CIE 1976
Reference number
ISO/CIE 11664-5:2016(E)
©
ISO/CIE 2016

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SIST EN ISO 11664-5:2016
ISO/CIE 11664-5:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/CIE 2016, Published in Switzerland
All 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, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office CIE Central Bureau
Ch. de Blandonnet 8 • CP 401 Babenbergerstraße 9/9A
CH-1214 Vernier, Geneva, Switzerland A-1010 Vienna, Austria
Tel. [phone] Tel. [phone]
Fax [phone]
[e-mail] [e-mail]
www.iso.org www.cie.co.at
ii © ISO/CIE 2016 – All rights reserved

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SIST EN ISO 11664-5:2016
ISO/CIE 11664-5:2016(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Symbols and abbreviated terms. 2
4 Calculation method . 2
4.1 Uniform chromaticity scale diagram (UCS diagram) . 2
4.2 Uniform colour space . 3
4.3 Correlates of lightness, saturation, chroma and hue . 4
4.4 Colour differences . 5
Annex A (informative) Reverse transformation . 7
Bibliography . 8
© ISO/CIE 2016 – All rights reserved iii

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SIST EN ISO 11664-5:2016
ISO/CIE 11664-5:2016(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally 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 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 different 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 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/patents).
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 ISO’s adherence to the World Trade 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 constitutes 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: CIE 1976 L*a*b* Colour space
ISO/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 formula
iv © ISO/CIE 2016 – All rights reserved

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SIST EN ISO 11664-5:2016
ISO/CIE 11664-5:2016(E)

Introduction
The 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 perceptible 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 uniform
[2][8]
colour spaces and associated colour difference formulae. Both 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 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
based 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
[5]
space, CIELAB, nor does it cover more sophisticated colour difference formulae based on CIELAB,
[3] [1] [4] [6]
such as the CMC formula, the CIE 94 formula, the DIN 99 formula, and the CIEDE2000 formula.
© ISO/CIE 2016 – All rights reserved v

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SIST EN ISO 11664-5:2016

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SIST EN ISO 11664-5:2016
INTERNATIONAL STANDARD ISO/CIE 11664-5:2016(E)
Colorimetry —
Part 5:
CIE 1976 L*u*v* colour space and u’, v’ uniform
chromaticity scale diagram
1 Scope
This 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 perceived 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 system or the CIE 1964 standard colorimetric system.
This part of ISO/CIE 11664 may be used for the specification of colour stimuli
...

SLOVENSKI STANDARD
kSIST FprEN ISO 11664-5:2016
01-maj-2016
Kolorimetrija - 5. del: Barvni prostor L*u*v* in diagram enakomerne barvnosti u', v'
po CIE 1976 (ISO/FDIS 11664-5:2016)
Colorimetry - Part 5: CIE 1976 L*u*v* Colour space and u', v' uniform chromaticity scale
diagram (ISO/FDIS 11664-5:2016)
Farbmetrik - Teil 5: CIE 1976 L*u*v* Farbenraum und gleichabständige u', v' Farbtafel
(ISO/FDIS 11664-5:2016)
Colorimétrie - Partie 5: Espace chromatique L*u*v* et diagramme de chromaticité
uniforme u', v' CIE 1976 (ISO/FDIS 11664-5:2016)
Ta slovenski standard je istoveten z: FprEN ISO 11664-5
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
kSIST FprEN ISO 11664-5:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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kSIST FprEN ISO 11664-5:2016

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kSIST FprEN ISO 11664-5:2016
FINAL
INTERNATIONAL ISO/CIE
DRAFT
STANDARD FDIS
11664-5
ISO/TC 274
Colorimetry —
Secretariat: DIN
Voting begins on:
Part 5:
2016-03-31
CIE 1976 L*u*v* Colour space and u’, v’
Voting terminates on:
uniform chromaticity scale diagram
2016-05-31
Colorimétrie —
Partie 5: Espace chromatique L*u*v* et diagramme de chromaticité
uniforme u’, v’ CIE 1976
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPORTING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/CIE FDIS 11664-5:2016(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO/CIE 2016

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kSIST FprEN ISO 11664-5:2016
ISO/CIE FDIS 11664-5:2016(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/CIE 2016, Published in Switzerland
All 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, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office CIE Central Bureau
Ch. de Blandonnet 8 • CP 401 Babenbergerstraße 9/9A • A-1010 Vienna
CH-1214 Vernier, Geneva, Switzerland
Tel. [phone] Tel. [phone]
Fax [phone] Fax [phone]
[e-mail] [e-mail]
www.iso.org www.cie.co.at
ii © ISO/CIE 2016 – All rights reserved

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kSIST FprEN ISO 11664-5:2016
ISO/CIE FDIS 11664-5:2016(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms, definitions, symbols and abbreviated terms . 1
3.1 Terms and definitions . 1
3.2 Symbols and abbreviated terms. 1
4 Calculation method . 2
4.1 Uniform chromaticity scale diagram (UCS diagram) . 2
4.2 Uniform colour space . 3
4.3 Correlates of lightness, saturation, chroma and hue . 4
4.4 Colour differences . 5
Annex A (informative) Reverse transformation . 7
Bibliography . 8
© ISO/CIE 2016 – All rights reserved iii

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kSIST FprEN ISO 11664-5:2016
ISO/CIE FDIS 11664-5:2016(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally 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 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 different 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 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/patents).
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 ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information.
The committee responsible for this document is ISO/TC 274, Light and lighting.
This second edition cancels and replaces the first edition (ISO 11664-5:2009), of which it constitutes a
minor revision.
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: CIE 1976 L*a*b* Colour space
— Part 5: CIE 1976 L*u*v* Colour space and u′, v′ uniform chromaticity scale diagram
— Part 6: CIE-DE2000 Colour-difference formula
iv © ISO/CIE 2016 – All rights reserved

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kSIST FprEN ISO 11664-5:2016
ISO/CIE FDIS 11664-5:2016(E)

Introduction
The 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 perceptible 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 uniform colour
[2][8]
spaces and associated colour difference formulae. Both 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 or by more
sophisticated formulae that improve the correlation with the relative perceived size of differences. The
purpose of this part of ISO 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 based on these coordinates.
This part of ISO 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
[5]
part of ISO 11664 does not cover the alternative uniform colour space, CIELAB, nor does it cover
[3]
more sophisticated colour difference formulae based on CIELAB, such as the CMC formula, the CIE 94
[1] [4] [6]
formula, the DIN 99 formula, and the CIEDE2000 formula.
© ISO/CIE 2016 – All rights reserved v

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kSIST FprEN ISO 11664-5:2016

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kSIST FprEN ISO 11664-5:2016
FINAL DRAFT INTERNATIONAL STANDARD ISO/CIE FDIS 11664-5:2016(E)
Colorimetry —
Part 5:
CIE 1976 L*u*v* Colour space and u’, v’ uniform
chromaticity scale diagram
1 Scope
This part of ISO 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 perceived 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 11664 is applicable to tristimulus values calculated using the colour-matching functions
of the CIE 1931 standard colorimetric system or the CIE 1964 standard colorimetric system. This part
of ISO 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 displays, 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 11664, as a
whole, 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. 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 references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 11664–1 (CIE S 014-1/E:2006), Colorimetry — Part 1: CIE standard colorimetric observers
ISO 11664–2 (CIE S 014-2/E:2006), Colorimetry — Part 2: CIE standard illuminants
CIE S 017/E. ILV: International Lighting Vocabulary
3 Terms, d efinitions , symbols and abbreviated terms
3.1 Terms and definiti ons
For the purposes of this document, the terms and definitions given in CIE S 017 apply.
3.2 Symbols and abbreviated terms
X, 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° standard colorimetric
system)
Y tristimulus value, Y, of a specified white colour stimulus calculated using the
n
colour-matching functions of the CIE 1931 standard colorimetric system
© ISO/CIE 2016 – All rights reserved 1

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