IEC 61966-2-4:2006
(Main)Multimedia systems and equipment - Colour measurement and management - Part 2-4: Colour management - Extended-gamut YCC colour space for video applications - xvYCC
Multimedia systems and equipment - Colour measurement and management - Part 2-4: Colour management - Extended-gamut YCC colour space for video applications - xvYCC
IEC 61966-2-4:2006 is applicable to the encoding and communication of YCC colours used in video systems and similar applications by defining encoding transformations for use in defined reference capturing conditions. If actual conditions differ from the reference conditions, additional rendering transformations may be required. Such additional rendering transformations are beyond the scope of this standard. This bilingual version (2013-02) corresponds to the monolingual English version, published in 2006-01.
Systèmes et appareils multimédia - Mesure et gestion de la couleur - Part 2-4: Gestion de la couleur - Extension de gamme de l'espace chromatique YCC pour applications vidéo - xvYCC
La CEI 61966-2-4:2006 est applicable au codage et à la communication des couleurs YCC utilisées dans des systèmes vidéo et applications analogues en définissant les transformations de codage utilisées dans des conditions de capture définies. Si les conditions réelles diffèrent des conditions de référence, les transformations de rendu complémentaires peuvent être nécessaires. De telles transformations de rendu complémentaires se situent au delà du domaine d'application de cette norme. La présente version bilingue (2013-02) correspond à la version anglaise monolingue publiée en 2006-01.
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IEC 61966-2-4
Edition 1.0 2006-01
INTERNATIONAL
STANDARD
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
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IEC 61966-2-4
Edition 1.0 2006-01
INTERNATIONAL
STANDARD
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
R
ICS 33.160.40 ISBN 2-8318-8426-8
– 2 – 61966-2-4 IEC:2006(E)
CONTENTS
FOREWORD.3
INTRODUCTION.5
1 Scope.6
2 Normative references .6
3 Terms and definitions.6
4 Colorimetric parameters and related characteristics .7
4.1 Primary colours and reference white.7
4.2 Opto-electronic transfer characteristics .7
4.3 YCC (luma-chroma-chroma) encoding methods.8
4.4 Digital quantization methods .8
5 Encoding transformations .9
5.1 Introduction .9
5.2 Transformation from xvYCC values to CIE 1931 XYZ values .9
5.3 Transformation from CIE 1931 XYZ values to xvYCC values .11
Annex A (informative) Compression of specular components of Y’ signals .13
Annex B (informative) Default transformation from 16-bit scRGB values to xvYCC values.14
Annex C (informative) xvYCC/ITU-R BT.709 and sYCC/sRGB compatibility .16
Bibliography.18
Figure A.1 – Example of the specular compression method .13
Figure C.1 – Relationship between ITU-R BT.709 and sRGB .16
Figure C.2 – Relationship between xvYCC and sYCC .17
Table 1 – CIE chromaticities for reference primary colours and reference white.7
.
61966-2-4 IEC:2006(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 2-4: Colour management –
Extended-gamut YCC colour space
for video applications – xvYCC
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61966-2-4 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
CDV Report on voting
100/967/CDV 100/1026/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
– 4 – 61966-2-4 © IEC:2006(E)
IEC 61966 consists of the following parts, under the general title Multimedia systems and
equipment – Colour measurement and management:
Part 2-1: Colour management – Default RGB colour space – sRGB
Part 2-2: Colour management – Extended RGB colour space – scRGB
Part 2-4: Colour management – Extended-gamut YCC colour space for video applications –
xvYCC
Part 2-5: Colour management – Optional RGB colour space – opRGB (under consideration)
Part 3: Equipment using cathode ray tubes
Part 4: Equipment using liquid crystal display panels
Part 5: Equipment using plasma display panels
Part 6: Front projection displays
Part 7-1: Colour printers – Reflective prints – RGB inputs
Part 7-2: Colour printers – Reflective prints – CMYK inputs (proposed work item)
Part 8: Multimedia colour scanners
Part 9: Digital cameras
Part 10: Quality assessment (proposed work item)
Part 11: Quality assessment – Impaired video in network systems (proposed work item)
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.
The contents of the corrigendum of November 2006 have been included in this copy.
61966-2-4 IEC:2006(E) – 5 –
INTRODUCTION
After the publication of IEC 61966-2-1, Amendment 1, the sYCC colour encoding was used to
capture, store and print extended colour gamut for still image applications. Users received
pleasant benefit by exchanging and reproducing wide-gamut colour images.
Recently, various kinds of displays that are capable of producing a wider gamut of colour than
the conventional CRT-based displays are emerging. However, most of the current video
contents that are displayed on conventional displays, are rendered for the sRGB-gamut.
Users of wide-gamut displays could benefit from wide-gamut colour images by video colour
encoding that supports a larger colour gamut.
This standard defines the “extended-gamut YCC colour space for video applications”. It is
based on the current implementation of YCC colour encoding that is used in the video industry
(namely ITU-R BT.709-5) and extends its definition to the wider gamut of colour range.
– 6 – 61966-2-4 IEC:2006(E)
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 2-4: Colour management –
Extended-gamut YCC colour space
for video applications – xvYCC
1 Scope
This part of IEC 61966 is applicable to the encoding and communication of YCC colours used
in video systems and similar applications by defining encoding transformations for use in
defined reference capturing conditions. If actual conditions differ from the reference conditions,
additional rendering transformations may be required. Such additional rendering trans-
formations are beyond the scope of this standard.
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.
IEC 60050-845:1987, International Electrotechnical Vocabulary (IEV) – Part 845: Lighting
ITU-R Recommendation BT.601-5:1995, Studio encoding parameters of digital television for
standard 4:3 and wide-screen 16:9 aspect ratios
ITU-R Recommendation BT.709-5:2002, Parameter values for the HDTV standards for
production and international programme exchange
3 Terms and definitions
For the purposes of this document, the following terms and definitions, as well as those
concerning illuminance, luminance, tristimulus, and other related lighting terms given in
IEC 60050-845, apply.
3.1
scene-referred colour encoding
representation of estimated colour-space coordinates of the elements of an original scene,
where a scene is defined to be the relative spectral radiance
3.2
output-referred colour encoding
representation of estimated colour-space coordinates of image data that are appropriate for
specified output device and viewing conditions
3.3
extended gamut
colour gamut extending outside that of the standard sRGB CRT display defined in IEC 61966-
2-1
61966-2-4 IEC:2006(E) – 7 –
3.4
luma
luminance signal as defined by SMPTE/EG28:1993
NOTE 1 To avoid interdisciplinary confusion resulting from the two distinct definitions of luminance, it has been
proposed that the video documents use “luma” for “luminance, television” (i.e., the luminance signal).
NOTE 2 Video systems approximate the lightness response of vision by computing a luma component Y' as a
weighted sum of non-linear (or gamma-corrected) R'G'B' primary components. Luma is often carelessly referred to
as luminance.
4 Colorimetric parameters and related characteristics
This clause defines colorimetric parameters and the related characteristics of reference
capturing devices.
4.1 Primary colours and reference white
The CIE chromaticities for the reference red, green,
...
IEC 61966-2-4 ®
Edition 1.2 2021-07
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.
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3, rue de Varembé info@iec.ch
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Switzerland
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IEC 61966-2-4 ®
Edition 1.2 2021-07
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 00.000 ISBN 978-2-8322-5042-6
IEC 61966-2-4 ®
Edition 1.2 2021-07
CONSOLIDATED VERSION
REDLINE VERSION
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
– 2 – IEC 61966-2-4:2006+AMD1:2016
+AMD2:2021 CSV IEC 2021
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Colorimetric parameters and related characteristics . 7
4.1 Primary colours and reference white. 7
4.2 Opto-electronic transfer characteristics . 7
4.3 YCC (luma-chroma-chroma) encoding methods . 8
4.4 Digital quantization methods . 8
5 Encoding transformations . 9
5.1 Introduction . 9
5.2 Transformation from xvYCC values to CIE 1931 XYZ values . 9
5.3 Transformation from CIE 1931 XYZ values to xvYCC values . 10
Annex A (informative) Compression of specular components of Y’ signals . 13
Annex B (informative) Default transformation from 16-bit scRGB values to xvYCC
values . 14
B.1 Introduction . 14
B.2 Transformation from scRGB values to 8-bit xvYCC . 14
Annex C (informative) xvYCC/ITU-R BT.709 and sYCC/sRGB compatibility . 16
Annex D (informative) Recommended usage of IEC 61966-12-2 for this standard . 18
Annex E (informative) xvYCCext – a method for encoding extended luminance signal . 19
E.1 General . 19
E.2 Extended opto-electronic transfer characteristics . 19
E.3 Extended electro-optical transfer characteristics . 23
E.4 Digital quantization methods . 24
E.5 Image processing consideration . 24
Bibliography . 25
Figure C.1 – Relationship between ITU-R BT.709 and sRGB . 16
Figure C.2 – Relationship between xvYCC and sYCC . 17
Figure A.1 – Example of the specular compression method . 13
Figure E.1 – High luminance region of OETF for the variation of the reference white
2 2
luminance from 100 cd/m to 1 000 cd/m . 21
Figure E.2 – Approximation error of OETF . 22
Figure E.3 – Approximated gamma values in function of reference white luminance . 22
Figure E.4 – Encoderable luminance in multiples of SDR-white luminance . 23
Table 1 – CIE chromaticities for reference primary colours and reference white . 7
+AMD2:2021 CSV IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 2-4: Colour management –
Extended-gamut YCC colour space
for video applications – xvYCC
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendments has been
prepared for user convenience.
IEC 61966-2-4 edition 1.2 contains the first edition (2006-01) [documents 100/967/CDV
and 100/1026/RVC] and its corrigendum 1 (2006-11), its amendment 1 (2016-04)
[documents 100/2457A/CDV and 100/2601/RVC] and its amendment 2 (2021-07)
[documents 100/3535/CDV and 100/3597/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendments 1 and 2. Additions and deletions are displayed in red, with
deletions being struck through. A separate Final version with all changes accepted is
available in this publication.
– 4 – IEC 61966-2-4:2006+AMD1:2016
+AMD2:2021 CSV IEC 2021
International Standard IEC 61966-2-4 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61966 consists of the following parts, under the general title Multimedia systems and
equipment – Colour measurement and management:
Part 2-1: Colour management – Default RGB colour space – sRGB
Part 2-2: Colour management – Extended RGB colour space – scRGB
Part 2-4: Colour management – Extended-gamut YCC colour space for video applications –
xvYCC
Part 2-5: Colour management – Optional RGB colour space – opRGB (under consideration)
Part 3: Equipment using cathode ray tubes
Part 4: Equipment using liquid crystal display panels
Part 5: Equipment using plasma display panels
Part 6: Front projection displays
Part 7-1: Colour printers – Reflective prints – RGB inputs
Part 7-2: Colour printers – Reflective prints – CMYK inputs (proposed work item)
Part 8: Multimedia colour scanners
Part 9: Digital cameras
Part 10: Quality assessment (proposed work item)
Part 11: Quality assessment – Impaired video in network systems (proposed work item)
Part 12-1: Metadata for identification of colour gamut (Gamut ID)
Part 12-2: Simple Metadata format for identification of colour gamut
The committee has decided that the contents of the base publication and its amendments will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
+AMD2:2021 CSV IEC 2021
INTRODUCTION
After the publication of IEC 61966-2-1, Amendment 1, the sYCC colour encoding was used to
capture, store and print extended colour gamut for still image applications. Users received
pleasant benefit by exchanging and reproducing wide-gamut colour images.
Recently, various kinds of displays that are capable of producing a wider gamut of colo
...
IEC 61966-2-4 ®
Edition 1.0 2006-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 2-4: Gestion de la couleur – Extension de gamme de l'espace chromatique
YCC pour applications vidéo – xvYCC
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester.
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.
About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
Useful links:
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withdrawn publications. Electrotechnical Vocabulary (IEV) on-line.
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IEC 61966-2-4 ®
Edition 1.0 2006-01
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 2-4: Gestion de la couleur – Extension de gamme de l'espace chromatique
YCC pour applications vidéo – xvYCC
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX R
ICS 33.160.40 ISBN 978-2-83220-610-2
– 2 – 61966-2-4 IEC:2006
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions. 6
4 Colorimetric parameters and related characteristics . 7
4.1 Primary colours and reference white. 7
4.2 Opto-electronic transfer characteristics . 7
4.3 YCC (luma-chroma-chroma) encoding methods . 8
4.4 Digital quantization methods . 8
5 Encoding transformations . 9
5.1 Introduction . 9
5.2 Transformation from xvYCC values to CIE 1931 XYZ values . 9
5.3 Transformation from CIE 1931 XYZ values to xvYCC values . 11
Annex A (informative) Compression of specular components of Y’ signals . 13
Annex B (informative) Default transformation from 16-bit scRGB values to xvYCC values . 14
Annex C (informative) xvYCC/ITU-R BT.709 and sYCC/sRGB compatibility . 16
Bibliography . 18
Figure A.1 – Example of the specular compression method . 13
Figure C.1 – Relationship between ITU-R BT.709 and sRGB . 16
Figure C.2 – Relationship between xvYCC and sYCC . 17
Table 1 – CIE chromaticities for reference primary colours and reference white . 7
61966-2-4 IEC:2006 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 2-4: Colour management –
Extended-gamut YCC colour space
for video applications – xvYCC
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61966-2-4 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
This bilingual version (2013-03) corresponds to the monolingual English version, published in
2006-01.
The text of this standard is based on the following documents:
CDV Report on voting
100/967/CDV 100/1026/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
– 4 – 61966-2-4 IEC:2006
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
IEC 61966 consists of the following parts, under the general title Multimedia systems and
equipment – Colour measurement and management:
Part 2-1: Colour management – Default RGB colour space – sRGB
Part 2-2: Colour management – Extended RGB colour space – scRGB
Part 2-4: Colour management – Extended-gamut YCC colour space for video applications –
xvYCC
Part 2-5: Colour management – Optional RGB colour space – opRGB (under consideration)
Part 3: Equipment using cathode ray tubes
Part 4: Equipment using liquid crystal display panels
Part 5: Equipment using plasma display panels
Part 6: Front projection displays
Part 7-1: Colour printers – Reflective prints – RGB inputs
Part 7-2: Colour printers – Reflective prints – CMYK inputs (proposed work item)
Part 8: Multimedia colour scanners
Part 9: Digital cameras
Part 10: Quality assessment (proposed work item)
Part 11: Quality assessment – Impaired video in network systems (proposed work item)
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
The contents of the corrigendum of November 2006 have been included in this copy.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
61966-2-4 IEC:2006 – 5 –
INTRODUCTION
After the publication of IEC 61966-2-1, Amendment 1, the sYCC colour encoding was used to
capture, store and print extended colour gamut for still image applications. Users received
pleasant benefit by exchanging and reproducing wide-gamut colour images.
Recently, various kinds of displays that are capable of producing a wider gamut of colour than
the conventional CRT-based displays are emerging. However, most
...
IEC 61966-2-4 ®
Edition 1.1 2016-04
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 2-4: Gestion de la couleur – Extension de gamme de l'espace chromatique
YCC pour applications vidéo – xvYCC
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IEC 61966-2-4 ®
Edition 1.1 2016-04
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 2-4: Gestion de la couleur – Extension de gamme de l'espace
chromatique YCC pour applications vidéo – xvYCC
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.160.40 ISBN 978-2-8322-3369-6
IEC 61966-2-4 ®
Edition 1.1 2016-04
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
Systèmes et appareils multimédia – Mesure et gestion de la couleur –
Partie 2-4: Gestion de la couleur – Extension de gamme de l'espace chromatique
YCC pour applications vidéo – xvYCC
– 2 – IEC 61966-2-4:2006+AMD1:2016 CSV
IEC 2016
CONTENTS
FOREWORD. 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Colorimetric parameters and related characteristics . 7
4.1 Primary colours and reference white . 7
4.2 Opto-electronic transfer characteristics . 7
4.3 YCC (luma-chroma-chroma) encoding methods . 8
4.4 Digital quantization methods . 8
5 Encoding transformations . 9
5.1 Introduction . 9
5.2 Transformation from xvYCC values to CIE 1931 XYZ values . 9
5.3 Transformation from CIE 1931 XYZ values to xvYCC values . 10
Annex A (informative) Compression of specular components of Y’ signals . 13
Annex B (informative) Default transformation from 16-bit scRGB values to xvYCC
values . 14
Annex C (informative) xvYCC/ITU-R BT.709 and sYCC/sRGB compatibility . 16
Annex D (informative) Recommended usage of IEC 61966-12-2 for this standard . 18
Bibliography . 19
Figure A.1 – Example of the specular compression method . 13
Figure C.1 – Relationship between ITU-R BT.709 and sRGB . 16
Figure C.2 – Relationship between xvYCC and sYCC . 17
Table 1 – CIE chromaticities for reference primary colours and reference white . 7
© IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 2-4: Colour management –
Extended-gamut YCC colour space
for video applications – xvYCC
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 61966-2-4 edition 1.1 contains the first edition (2006-01) [documents 100/967/CDV
and 100/1026/RVC], its corrigendum 1 (November 2006) and its amendment 1 (2016-04)
[documents 100/2457A/CDV and 100/2601/RVC].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
– 4 – IEC 61966-2-4:2006+AMD1:2016 CSV
IEC 2016
International Standard IEC 61966-2-4 has been prepared by IEC technical committee
100: Audio, video and multimedia systems and equipment.
The French version of this standard has not been
...
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