Colorimetry - Part 3: CIE tristimulus values (ISO/CIE 11664-3:2019)

This document specifies methods of calculating the tristimulus values of colour stimuli for which
the spectral distributions are provided. These colour stimuli can be produced by self-luminous light
sources or by reflecting or transmitting objects.
This document requires that the colour stimulus function be tabulated at measurement intervals of
5 nm or less in a wavelength range of at least 380 nm to 780 nm. Extrapolation methods are suggested
for cases where the measured wavelength range is less than 380 nm to 780 nm.
The standard method is defined as summation at 1 nm intervals over the wavelength range from 360 nm
to 830 nm. Alternative abridged methods are defined for larger intervals (up to 5 nm) and shorter
ranges (down to 380 nm to 780 nm). The alternative methods are to be used only when appropriate and
when the user has reviewed the impact on the final results.
This document can be used in conjunction with the CIE 1931 standard colorimetric observer or the
CIE 1964 standard colorimetric observer.

Farbmetrik - Teil 3: CIE-Farbwerte (ISO/CIE 11664-3:2019)

Dieses Dokument legt Verfahren zur Berechnung von Farbwerten aus Farbreizen, für die die Spektralverteilungen gegeben sind, fest. Diese Farbreize können von selbstleuchtenden Lichtquellen oder durch reflektierende oder transmittierende Objekte erzeugt werden.
Dieses Dokument erfordert, dass die Farbreizfunktion in Messintervallen von 5 nm oder weniger in einem Wellenlängenbereich von mindestens 380 nm bis 780 nm tabelliert wird. Für Fälle, bei denen der gemessene Wellenlängenbereich kleiner als 380 nm bis 780 nm ist, werden Extrapolationsverfahren vorgeschlagen.
Das Normverfahren wird als Summierung bei Intervallen von 1 nm über den Wellenlängenbereich von 360 nm bis 830 nm definiert. Für größere Intervalle (bis zu 5 nm) und kleinere Bereiche (bis auf 380 nm bis 780 nm) werden Kurzverfahren definiert. Die alternativen Verfahren sind nur dann anzuwenden, wenn sie geeignet sind und der Anwender die Auswirkung auf die Endergebnisse überprüft hat.
Dieses Dokument kann zusammen mit dem farbmetrischen Normalbeobachter CIE 1931 oder dem farbmetrischen Normalbeobachter CIE 1964 angewendet werden.

Colorimétrie - Partie 3: Composantes trichromatiques CIE (ISO/CIE 11664-3:2019)

Le présent document spécifie les méthodes de calcul des composantes trichromatiques des stimulus de couleur dont les répartitions spectrales sont disponibles. Ces stimulus de couleur peuvent être produits par des sources primaires de lumière ou par des objets qui réfléchissent ou qui transmettent la lumière.
Le présent document impose que la fonction de répartition spectrale du stimulus étudié soit donnée à des intervalles de mesure de 5 nm, ou à des intervalles plus faibles, dans un domaine de longueurs d'onde s'étendant au moins de 380 nm à 780 nm. Des méthodes d'extrapolation sont suggérées dans les cas où le domaine de longueurs d'onde mesuré est moindre que de 380 nm à 780 nm.
La méthode normalisée est définie comme une sommation à des intervalles de 1 nm sur un domaine de longueurs d'onde compris entre 360 nm et 830 nm. Des méthodes alternatives simplifiées sont définies pour des intervalles plus grands (jusqu'à 5 nm) et des domaines plus réduits (limités de 380 nm à 780 nm). Ces méthodes alternatives ne sont à utiliser que si leur emploi le nécessite et si l'utilisateur a évalué leur impact sur les résultats définitifs.
Le présent document peut être utilisé en liaison soit avec l'observateur CIE 1931 de référence pour la colorimétrie, soit avec l'observateur CIE 1964 de référence pour la colorimétrie.

Kolorimetrija - 3. del: Barvne vrednosti CIE (ISO/CIE 11664-3:2019)

Ta dokument določa metode za izračun barvnih vrednosti barvnih dražljajev, za katere je podana spektralna porazdelitev. Te barvne dražljaje lahko povzročijo samosvetilni svetlobni viri ali odbojni predmeti ali oddajniki.
Ta dokument zahteva, da se funkcija barvnih dražljajev tabelira v intervalih merjenja največ 5 nm v razponu valovnih dolžin od najmanj 380 nm do 780 nm. Metode ekstrapoliranja so priporočene v primerih, kjer so merjeni razponi valovnih dolžin manjši od 380 nm do 780 nm.
Standardna metoda je določena kot vsota intervalov 1 nm v razponu valovnih dolžin od 360 nm do 830 nm. Alternativne skrajšane metode so določene za večje intervale (več kot 5 nm) in za krajše razpone valovnih dolžin (krajše od 380 nm do 780 nm). Alternativne metode se uporabljajo samo, kadar je to ustrezno in kadar je uporabnik pregledal vpliv na končne rezultate.
Ta dokument se lahko uporablja v povezavi s standardiziranim barvnometričnim opazovalcem CIE 1931 ali CIE 1964.

General Information

Status
Published
Public Enquiry End Date
03-Apr-2019
Publication Date
18-Aug-2019
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
24-Jul-2019
Due Date
28-Sep-2019
Completion Date
19-Aug-2019

Relations

Buy Standard

Standard
EN ISO/CIE 11664-3:2019
English language
17 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day
Draft
prEN ISO/CIE 11664-3:2019
English language
14 pages
sale 10% off
Preview
sale 10% off
Preview
e-Library read for
1 day

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO/CIE 11664-3:2019
01-september-2019
Nadomešča:
SIST EN ISO 11664-3:2013
Kolorimetrija - 3. del: Barvne vrednosti CIE (ISO/CIE 11664-3:2019)
Colorimetry - Part 3: CIE tristimulus values (ISO/CIE 11664-3:2019)
Farbmetrik - Teil 3: CIE-Farbwerte (ISO/CIE 11664-3:2019)
Colorimétrie - Partie 3: Composantes trichromatiques CIE (ISO/CIE 11664-3:2019)
Ta slovenski standard je istoveten z: EN ISO/CIE 11664-3:2019
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
SIST EN ISO/CIE 11664-3:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST EN ISO/CIE 11664-3:2019

---------------------- Page: 2 ----------------------

SIST EN ISO/CIE 11664-3:2019


EN ISO/CIE 11664-3
EUROPEAN STANDARD

NORME EUROPÉENNE

July 2019
EUROPÄISCHE NORM
ICS 17.180.20 Supersedes EN ISO 11664-3:2013
English Version

Colorimetry - Part 3: CIE tristimulus values (ISO/CIE
11664-3:2019)
Colorimétrie - Partie 3: Composantes trichromatiques Farbmetrik - Teil 3: CIE-Farbwerte (ISO/CIE 11664-
CIE (ISO/CIE 11664-3:2019) 3:2019)
This European Standard was approved by CEN on 24 May 2019.

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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO/CIE 11664-3:2019 E
worldwide for CEN national Members.

---------------------- Page: 3 ----------------------

SIST EN ISO/CIE 11664-3:2019
EN ISO/CIE 11664-3:2019 (E)
Contents Page
European foreword . 3

2

---------------------- Page: 4 ----------------------

SIST EN ISO/CIE 11664-3:2019
EN ISO/CIE 11664-3:2019 (E)
European foreword
This document (EN ISO/CIE 11664-3:2019) has been prepared by Technical Committee CEI
"International Commission on Illumination" 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 January 2020, and conflicting national standards shall
be withdrawn at the latest by January 2020.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 11664-3:2013.
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, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO/CIE 11664-3:2019 has been approved by CEN as EN ISO/CIE 11664-3:2019 without any
modification.


3

---------------------- Page: 5 ----------------------

SIST EN ISO/CIE 11664-3:2019

---------------------- Page: 6 ----------------------

SIST EN ISO/CIE 11664-3:2019
INTERNATIONAL ISO/CIE
STANDARD 11664-3
First edition
2019-06
Colorimetry —
Part 3:
CIE tristimulus values
Colorimétrie —
Partie 3: Composantes trichromatiques CIE
Reference number
ISO/CIE 11664-3:2019(E)
©
ISO/CIE 2019

---------------------- Page: 7 ----------------------

SIST EN ISO/CIE 11664-3:2019
ISO/CIE 11664-3:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/CIE 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8 Babenbergerstraße 9/9A
CH-1214 Vernier, Geneva A-1010 Vienna, Austria
Phone: +41 22 749 01 11 Phone: +43 1 714 3187
Fax: +41 22 749 09 47 Fax: +41 22 749 09 47
Email: copyright@iso.org Email: ciecb@cie.co.at
Website: www.iso.org Website: www.cie.co.at
Published in Switzerland
ii © ISO/CIE 2019 – All rights reserved

---------------------- Page: 8 ----------------------

SIST EN ISO/CIE 11664-3:2019
ISO/CIE 11664-3:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviations . 2
5 Standard method . 3
5.1 General . 3
5.2 Calculation of tristimulus values . 3
5.3 Normalizing constant for self-luminous light sources . 4
5.4 Normalizing constant for reflecting or transmitting objects . 4
5.5 CIE 1964 standard colorimetric system . 5
6 Abridged methods. 5
6.1 General . 5
6.2 Abridged method for data at 5 nm intervals or less . 5
6.3 Abridged method for 10 nm or 20 nm data for reflecting or transmitting objects. 5
6.4 Abridged method for 10 nm or 20 nm data for self-luminous light sources . 6
7 Supplementary treatment of input data . 6
7.1 General . 6
7.2 Extrapolation . 7
7.3 Interpolation . 7
7.4 Bandwidth . 7
8 Chromaticity coordinates . 8
9 Numerical procedures . 8
10 Presentation of results . 8
Bibliography . 9
© ISO/CIE 2019 – All rights reserved iii

---------------------- Page: 9 ----------------------

SIST EN ISO/CIE 11664-3:2019
ISO/CIE 11664-3:2019(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 of the voluntary nature of standards, 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 www .iso
.org/iso/foreword .html.
This document was prepared by the International Commission on Illumination (CIE) in cooperation
with Technical Committee ISO/TC 274, Light and lighting.
This first edition of ISO/CIE 11664-3 cancels and replaces ISO 11664-3:2012 | CIE S 014-3:2011, of which
it constitutes a minor revision, incorporating minor editorial updates.
A list of all parts in the ISO 11664 and ISO/CIE 11664 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO/CIE 2019 – All rights reserved

---------------------- Page: 10 ----------------------

SIST EN ISO/CIE 11664-3:2019
ISO/CIE 11664-3:2019(E)

Introduction
Colour stimuli with different spectral distributions can look alike. An important function of colorimetry
is to determine which stimuli look alike to a given observer with a given set of colour-matching
functions. This is done by calculating a set of three tristimulus values for each stimulus. Equality
of tristimulus values indicates equality of colour appearance under equal irradiation and viewing
[1]
conditions. This document is based on long-standing CIE recommendations (see CIE 15 ) for the
calculation of tristimulus values.
© ISO/CIE 2019 – All rights reserved v

---------------------- Page: 11 ----------------------

SIST EN ISO/CIE 11664-3:2019

---------------------- Page: 12 ----------------------

SIST EN ISO/CIE 11664-3:2019
INTERNATIONAL STANDARD ISO/CIE 11664-3:2019(E)
Colorimetry —
Part 3:
CIE tristimulus values
1 Scope
This document specifies methods of calculating the tristimulus values of colour stimuli for which
the spectral distributions are provided. These colour stimuli can be produced by self-luminous light
sources or by reflecting or transmitting objects.
This document requires that the colour stimulus function be tabulated at measurement intervals of
5 nm or less in a wavelength range of at least 380 nm to 780 nm. Extrapolation methods are suggested
for cases where the measured wavelength range is less than 380 nm to 780 nm.
The standard method is defined as summation at 1 nm intervals over the wavelength range from 360 nm
to 830 nm. Alternative abridged methods are defined for larger intervals (up to 5 nm) and shorter
ranges (down to 380 nm to 780 nm). The alternative methods are to be used only when appropriate and
when the user has reviewed the impact on the final results.
This document can be used in conjunction with the CIE 1931 standard colorimetric observer or the
CIE 1964 standard colorimetric observer.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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/CIE 11664-1, Colorimetry — Part 1: CIE standard colorimetric observers
ISO 23539, Photometry — The CIE system of physical photometry
CIE S 017, ILV: International Lighting Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CIE S 017 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO/CIE 2019 – All rights reserved 1

---------------------- Page: 13 ----------------------

SIST EN ISO/CIE 11664-3:2019
ISO/CIE 11664-3:2019(E)

4 Symbols and abbreviations
k, k normalizing constants
10
K maximum spectral luminous efficacy of radiation in the CIE standard
m
system of physical photometry
K maximum spectral luminous efficacy of radiation when the V (λ) func-
m,10 10
tion is used for photometry
R(λ) spectral reflectance factor
S(λ) relative spectral distribution of an illuminant
V(λ) spectral luminous efficiency function in the CIE standard system of
physical photometry
V (λ)
10
spectral luminous efficiency function when the y ()λ function is used
10
for photometry
W (λ), W (λ), W (λ) pre-calculated weighting functions for tristimulus integration using the
x y z
CIE 1931 standard colorimetric observer
W (λ), W (λ), W (λ) pre-calculated weighting functions for tristimulus integration using the
x,10 y,10 z,10
CIE 1964 standard colorimetric observer
x, y, z chromaticity coordinates calculated using the CIE 1931 standard colori-
metric observer
x , y , z chromaticity coordinates calculated using the CIE 1964 standard colori-
10 10 10
metric observer
colour-matching functions of the CIE 1931 standard colorimetric observ-
xy()λλ,( ),z()λ
er (also known as the CIE 2° standard colorimetric observer)
colour-matching functions of the CIE 1964 standard colorimetric observ-
xy()λλ,( ),z ()λ
10 10 10
er (also known as the CIE 10° standard colorimetric observer)
X, Y, Z tristimulus values calculated using the CIE 1931 standard colorimetric
observer
X , Y , Z tristimulus values calculated using the CIE 1964 standard colorimetric
10 10 10
observer
β(λ) spectral radiance factor
Δλ wavelength interval
φ (λ) colour stimulus function (description of a colour stimulus by the spec-
λ
tral concentration of a radiometric quantity, such as radiance or radiant
power, as a function of wavelength)
φ(λ) relative colour stimulus function (relative spectral distribution of the
colour stimulus function)
λ wavelength
ρ(λ) spectral reflectance
τ(λ) spectral transmittance
2 © ISO/CIE 2019 – All rights reserved

---------------------- Page: 14 -------
...

SLOVENSKI STANDARD
oSIST prEN ISO/CIE 11664-3:2019
01-marec-2019
Kolorimetrija - 3. del: Barvne vrednosti CIE (ISO/CIE/FDIS 11664-3:2019)
Colorimetry - Part 3: CIE tristimulus values (ISO/CIE/FDIS 11664-3:2019)
Farbmetrik - Teil 3: CIE-Farbwerte (ISO/CIE/FDIS 11664-3:2019)
Colorimétrie - Partie 3: Composantes trichromatiques CIE (ISO/CIE/FDIS 11664-3:2019)
Ta slovenski standard je istoveten z: prEN ISO/CIE 11664-3
ICS:
17.180.20 Barve in merjenje svetlobe Colours and measurement of
light
oSIST prEN ISO/CIE 11664-3:2019 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO/CIE 11664-3:2019

---------------------- Page: 2 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
FINAL
INTERNATIONAL ISO/CIE
DRAFT
STANDARD FDIS
11664-3
CIE
Colorimetry —
Secretariat: ISO secretariat
Voting begins on:
Part 3:
2019-01-29
CIE tristimulus values
Voting terminates on:
2019-04-23
Colorimétrie —
Partie 3: Composantes trichromatiques CIE
Member bodies are requested to consult relevant national interests in ISO/TC
274 before casting their ballot to the e-Balloting application.
ISO/CEN PARALLEL PROCESSING
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/CIE FDIS 11664-3:2019(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 2019

---------------------- Page: 3 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/CIE 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, 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
CP 401 • Ch. de Blandonnet 8 Babenbergerstraße 9/9A
CH-1214 Vernier, Geneva A-1010 Vienna, Austria
Phone: +41 22 749 01 11 Phone: +43 1 714 3187
Fax: +41 22 749 09 47 Fax: +41 22 749 09 47
Email: copyright@iso.org Email: ciecb@cie.co.at
Website: www.iso.org Website: www.cie.co.at
Published in Switzerland
ii © ISO/CIE 2019 – All rights reserved

---------------------- Page: 4 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviations . 2
5 Standard method . 3
5.1 General . 3
5.2 Calculation of tristimulus values . 3
5.3 Normalizing constant for self-luminous light sources . 4
5.4 Normalizing constant for reflecting or transmitting objects . 4
5.5 CIE 1964 standard colorimetric system . 5
6 Abridged methods. 5
6.1 General . 5
6.2 Abridged method for 5 nm data . 5
6.3 Abridged method for 10 nm or 20 nm data for reflecting or transmitting objects. 5
6.4 Abridged method for 10 nm or 20 nm data for self-luminous light sources . 6
7 Supplementary treatment of input data . 6
7.1 General . 6
7.2 Extrapolation . 7
7.3 Interpolation . 7
7.4 Bandwidth . 7
8 Chromaticity coordinates . 8
9 Numerical procedures . 8
10 Presentation of results . 8
Bibliography . 9
© ISO/CIE 2019 – All rights reserved iii

---------------------- Page: 5 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(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 of the voluntary nature of standards, 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 www .iso
.org/iso/foreword .html.
This document was prepared by the International Commission on Illumination (CIE) in cooperation
with ISO/TC 274, Light and lighting.
This first edition of ISO/CIE 11664-3 cancels and replaces ISO 11664-3:2012/CIE S 014-3:2011, of which
it constitutes a minor revision, incorporating minor editorial updates.
A list of all parts in the ISO/CIE 11664 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the CIE Central Bureau or to the user’s
national standards body. A complete listing of these bodies can be found at www .iso .org/members .html.
iv © ISO/CIE 2019 – All rights reserved

---------------------- Page: 6 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(E)

Introduction
Colour stimuli with different spectral distributions can look alike. An important function of colorimetry
is to determine which stimuli look alike to a given observer with a given set of colour-matching
functions. This is done by calculating a set of three tristimulus values for each stimulus. Equality
of tristimulus values indicates equality of colour appearance under equal irradiation and viewing
[1]
conditions. This document is based on long-standing CIE recommendations (see CIE 15 ) for the
calculation of tristimulus values.
© ISO/CIE 2019 – All rights reserved v

---------------------- Page: 7 ----------------------
oSIST prEN ISO/CIE 11664-3:2019

---------------------- Page: 8 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
FINAL DRAFT INTERNATIONAL STANDARD ISO/CIE FDIS 11664-3:2019(E)
Colorimetry —
Part 3:
CIE tristimulus values
1 Scope
This document specifies methods of calculating the tristimulus values of colour stimuli for which
the spectral distributions are provided. These colour stimuli can be produced by self-luminous light
sources or by reflecting or transmitting objects.
This document requires that the colour stimulus function be tabulated at measurement intervals of
5 nm or less in a wavelength range of at least 380 nm to 780 nm. Extrapolation methods are suggested
for cases where the measured wavelength range is less than 380 nm to 780 nm.
The standard method is defined as summation at 1 nm intervals over the wavelength range from 360 nm
to 830 nm. Alternative abridged methods are defined for larger intervals (up to 5 nm) and shorter
ranges (down to 380 nm to 780 nm). The alternative methods are to be used only when appropriate and
when the user has reviewed the impact on the final results.
This document can be used in conjunction with the CIE 1931 standard colorimetric observer or the
CIE 1964 standard colorimetric observer.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
CIE S 017, ILV: International Lighting Vocabulary
ISO/CIE 11664-1, Colorimetry — Part 1. CIE Standard Colorimetric Observers
ISO 23539, Photometry — The CIE system of physical photometry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CIE S 017 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
© ISO/CIE 2019 – All rights reserved 1

---------------------- Page: 9 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(E)

4 Symbols and abbreviations
k, k normalizing constants
10
K maximum spectral luminous efficacy of radiation in the CIE standard
m
system of physical photometry
K maximum spectral luminous efficacy of radiation when the V (λ) func-
m,10 10
tion is used for photometry
R(λ) spectral reflectance factor
S(λ) relative spectral distribution of an illuminant
V(λ) spectral luminous efficiency function in the CIE standard system of
physical photometry
V (λ)
10
y ()λ
10
spectral luminous efficiency function when the function is used
for photometry
W (λ), W (λ), W (λ) pre-calculated weighting functions for tristimulus integration using the
x y z
CIE 1931 standard colorimetric observer
W (λ),W (λ), W (λ) pre-calculated weighting functions for tristimulus integration using the
x,10 y,10 z,10
CIE 1964 standard colorimetric observer
x, y, z chromaticity coordinates calculated using the CIE 1931 standard colori-
metric observer
x , y , z chromaticity coordinates calculated using the CIE 1964 standard colori-
10 10 10
metric observer
colour-matching functions of the CIE 1931 standard colorimetric observ-
xy()λλ,( ),z()λ
er (also known as the CIE 2° standard colorimetric observer)
colour-matching functions of the CIE 1964 standard colorimetric observ-
xy()λλ,( ),z ()λ
10 10 10
er (also known as the CIE 10° standard colorimetric observer)
X, Y, Z tristimulus values calculated using the CIE 1931 standard colorimetric
observer
X , Y , Z tristimulus values calculated using the CIE 1964 standard colorimetric
10 10 10
observer
β(λ) spectral radiance factor
Δλ wavelength interval
φ (λ) colour stimulus function (description of a colour stimulus by the spec-
λ
tral concentration of a radiometric quantity, such as radiance or radiant
power, as a function of wavelength)
φ(λ) relative colour stimulus function (relative spectral distribution of the
colour stimulus function)
λ wavelength
ρ(λ) spectral reflectance
τ(λ) spectral transmittance
2 © ISO/CIE 2019 – All rights reserved

---------------------- Page: 10 ----------------------
oSIST prEN ISO/CIE 11664-3:2019
ISO/CIE FDIS 11664-3:2019(E)

5 Standard method
5.1 General
This document may be used in conjunction with the CIE 1931 standard colorimetric observer or the
CIE 1964 standard colorimetric observer. If the angle subtended at the eye by the colour stimulus (or
fields to be matched in colour) is between about 1° and 4° the CIE 1931 standard colorimetric observer
shall be used. If this angular subtense is greater than 4° the CIE 1964 standard colorimetric observer shall
be used. The same colorimetric observer shall be used for all stimuli to be compared with each other.
5.2 Calculation of tristimulus values
In the CIE 1931 standard colorimetric system, tristimulus values X, Y and Z are defined as integrals over
the spectral range 360 nm to 830 nm according to Formulae (1) to (3):
Xk= ϕλ()x()λλd (1)
λ

λ
Yk= ϕλ()()y λλd (2)
λ

λ
Zk= ϕλ()z()λλd (3)
λ

λ
where
φ (λ) is the colour stimulus function to be evaluated;
λ
are the colour-matching functions of the CIE 1931 standard colorimetric observer;
xy()λλ,( ), z()λ
k is a normalizing constant defined in 5.3 and 5.4.
The standard method for evaluating these integrals is numerical summation from 360 nm to 830 nm at
wavelength intervals, Δλ, equal to 1 nm according to Formulae (4) to (6):
Xk= ϕλ()x()λλΔΔ (4)
∑ λ
λ
Yk= ϕλ()()y λλΔ (5)
∑ λ
λ
Zk= ϕλ()z()λλΔ (6)
∑ λ
λ
using colour-matching functions xy()λλ,( ),z()λ defined with seven significant figures in ISO/
CIE 11664-1 and a colour stimulus function, φ (λ), measured using a symmetrical triangular or
λ
trapezoidal
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.