IEC 61966-2-4:2006/AMD2:2021

Amendment 2 - Multimedia systems and equipment - Colour measurement and management - Part 2-4: Colour management - Extended-gamut YCC colour space for video applications - xvYCC

General Information

• Status: Published
• Publication Date: 12-Jul-2021
• ICS: 33.160.40 - Video systems
• Technical Committee: TA 2 - Colour measurement and management
• Drafting Committee: MT 61966-2-4 - TC 100/TA 2/MT 61966-2-4
• Current Stage: PPUB - Publication issued
• Start Date: 13-Jul-2021
• Completion Date: 29-Jul-2021

Relations

• Amends: IEC 61966-2-4:2006 - Multimedia systems and equipment - Colour measurement and management - Part 2-4: Colour management - Extended-gamut YCC colour space for video applications - xvYCC
• Effective Date: 05-Sep-2023

Overview

The IEC 61966-2-4:2006/AMD2:2021 is an important amendment to the international standard that focuses on multimedia systems and equipment related to colour measurement and management. Specifically, this amendment extends Part 2-4 of the IEC 61966 standard, which deals with the Extended-gamut YCC colour space (xvYCC) for video applications. Introduced by the International Electrotechnical Commission (IEC), this update broadens the capability of xvYCC to encode wider color gamut and higher luminance signals, addressing modern display technology challenges such as high dynamic range (HDR) and wide color gamut (WCG) video content.

Key Topics

• Extended-gamut YCC colour space (xvYCC): An advanced color space designed to allow video signals to represent colors beyond the standard RGB gamut safely encoded in YCbCr video signals.

• High luminance signal encoding (xvYCCext): This amendment introduces xvYCCext, a method for encoding extended luminance signals that enables accurate representation of specular highlights and fluorescence effects in video content.

• Opto-Electronic Transfer Function (OETF) extension: The amendment defines new encoding formulas to manage signals exceeding the traditional standard dynamic range, allowing luminance encoding up to twice the reference white of SDR (Standard Dynamic Range).

• Electro-Optical Transfer Characteristics (EOTF): Extended decoding functions are specified for rendering extended luminance in compliance with new standards, providing smooth transitions between SDR and HDR luminance ranges.

• Digital quantization: Highlights the need for digital depth greater than 10 bits for accurate encoding of the extended luminance range offered by xvYCCext.

• Image processing guidance: Recommends that complex image processing involving extended luminance signals be performed in linear or uniform color spaces like RGB, CIELAB, or ITU-R BT.2100 HLG to prevent color hue shifts due to signal compression.

Applications

• Video Broadcasting and Production: Enables broadcasters and production houses to encode video signals with extended color gamut and luminance, crucial for HDR content delivery.

• Consumer Electronics Display Devices: Supports manufacturers in developing displays capable of reproducing wider color gamuts and higher dynamic ranges, improving viewer experience with richer and more vibrant images.

• Video Codec and Signal Processing: Assists codec developers to implement encoding/decoding algorithms that preserve high luminance and color fidelity, essential for UHDTV and HDR video systems.

• Color Management Systems: Helps in accurate color transformation and management in multimedia workflows integrating various devices and standards.

• Standardization and Compliance Testing: Provides a reference for conformity assessments and interoperability testing of devices and systems implementing extended color gamut video standards.

Related Standards

• IEC 61966-2-4:2006: The original standard defining the xvYCC color space for video applications.

• ITU-R BT.709: Standard-definition television color space, predecessor to extended gamut color spaces.

• ITU-R BT.2020: A wide color gamut standard used in Ultra High Definition Television (UHDTV).

• ITU-R BT.2100: Defines HDR video parameters including transfer functions such as PQ and HLG.

• IEC 61966-12-1 and IEC 61966-12-2: Metadata specifications important for encoding and decoding color management data, applicable to extended luminance coding.

• SMPTE ST 2084: HDR Electro-Optical Transfer Function (EOTF) standard defining mastering display characteristics.

• EBU Tech 3320: User requirements for video monitors in television production, detailing performance expectations suited to HDR and wide gamut displays.

Practical Value and SEO Keywords

This amendment to IEC 61966-2-4 enhances the capability of video color management systems to handle wide color gamut and high dynamic range video encoding through xvYCCext. Technical professionals, device manufacturers, and multimedia content creators benefit from the extended luminance and color space features enabling superior visual quality. Integration with modern standards like ITU-R BT.2100, PQ-OETF, and xvYCC ensures future-proof implementation for UHDTV, HDR video, and advanced multimedia color management.

Keywords: IEC 61966-2-4 amendment, xvYCC color space, extended gamut YCC, video color management, high dynamic range video, HDR encoding, wide color gamut, extended luminance signal, multimedia color measurement, IEC color standards, advanced video color encoding, PQ-OETF, ITU-R BT.2100, HDR video applications, video display standards.

Standards Content (Sample)

IEC 61966-2-4 ®
Edition 1.0 2021-07
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 2
Multimedia systems and equipment – Colour measurement and management –
Part 2-4: Colour management – Extended-gamut YCC colour space for video
applications – xvYCC
IEC 61966-2-4:2006-01/AMD2:2021-07(en)

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IEC 61966-2-4 ®
Edition 1.0 2021-07
INTERNATIONAL
STANDARD
colour
inside
AMENDMENT 2
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 33.160.40 ISBN 978-2-8322-9952-4

– 2 – IEC 61966-2-4:2006/AMD 2:2021
© 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

AMENDMENT 2
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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Amendment 2 to IEC 61966-2-4:2006 has been prepared by technical area 2: Colour
measurement and management, of IEC technical committee 100: Multimedia systems and
equipment.
The text of this Amendment is based on the following documents:
Draft Report on voting
100/3535/CDV 100/3597/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Amendment is English.

IEC 61966-2-4:2006/AMD 2:2021 – 3 –
© IEC 2021
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
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specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The "colour inside" logo on the cover page of this document 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.

___________
– 4 – IEC 61966-2-4:2006/AMD 2:2021
© IEC 2021
Add, after Annex D, the following new Annex E:

Annex E
(informative)
xvYCCext – a method for encoding extended luminance signal
E.1 General
Recently, video standards for wide colour gamut and high dynamic range (HDR) colour space
encoding, such as ITU-R BT.2020 (UHDTV) and ITU-R BT.2100 (HDR), were established. In
contrast to the previous colour spaces, such as ITU-R BT.709 (high definition television) and
IEC 61966-2-4 (xvYCC), it is a very demanding challenge for the display industry to realize wide
colour gamut and/or high luminance displays. Therefore, recent mass produced displays for
consumer electronics covered only a certain range of wide colour gamuts an
...