IEC 62977-3-4:2023

Electronic displays - Part 3-4: Evaluation of optical performances - High dynamic range displays

IEC 62977-3-4:2023 specifies the standard evaluation methods for determining the optical characteristics of HDR electronic display modules and systems. These methods apply to emissive and transmissive direct-view displays that render real 2D images on a flat panel or on a curved panel with a local radius of curvature larger than 1 500 mm. This document evaluates the optical characteristics of these displays under darkroom conditions. This document applies to the testing of display performance in response to HDR digital input signals that are absolute luminance encoded such as the HDR signal comprising RGB component values of Recommendation ITU-R BT.2020 colorimetry with SMPTE ST 2084 PQ luminance encoding and SMPTE ST 2086 metadata.

General Information

• Status: Published
• Publication Date: 27-Mar-2023
• ICS: 31.120 - Electronic display devices
• ICS: 31.260 - Optoelectronics. Laser equipment
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 13 - TC 110/WG 13
• Current Stage: PPUB - Publication issued
• Start Date: 28-Apr-2023
• Completion Date: 28-Mar-2023

Standards Content (Sample)

IEC 62977-3-4
®

Edition 1.0 2023-03
INTERNATIONAL
STANDARD

colour
inside


Electronic displays –
Part 3-4: Evaluation of optical performances – High dynamic range displays

IEC 62977-3-4:2023-03(en)

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IEC 62977-3-4

®


Edition 1.0 2023-03




INTERNATIONAL



STANDARD








colour

inside










Electronic displays –

Part 3-4: Evaluation of optical performances – High dynamic range displays


























INTERNATIONAL

ELECTROTECHNICAL


COMMISSION





ICS 31.120; 31.260 ISBN 978-2-8322-6701-1




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® Registered trademark of the International Electrotechnical Commission

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CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 11
4 Standard measuring equipment . 12
4.1 Video signal generator . 12
4.2 Conditions of measuring equipment . 12
4.3 Measuring equipment block diagram . 12
5 Standard measuring conditions . 13
5.1 Standard measuring environmental conditions . 13
5.2 Power supply . 13
5.3 Warm-up time . 13
5.4 Standard darkroom conditions . 13
5.5 Adjustment of HDR display . 13
6 Measuring methods of optical characteristics . 14
6.1 HDR peak luminance . 14
6.1.1 HDR peak luminance variation by black and white pattern . 14
6.1.2 APL by the window and background level . 15
6.1.3 Test pattern for HDR peak luminance . 16
6.1.4 Measuring method . 16
6.2 Black luminance and contrast ratio . 17
6.2.1 Test patterns for black luminance . 17
6.2.2 Contrast ratio . 18
6.2.3 Local contrast ratio . 19
6.2.4 Measuring method . 19
6.2.5 Contrast ratio with ambient illumination . 20
6.3 Luminance loading . 20
6.3.1 General . 20
6.3.2 Measuring method . 21
6.4 Transition times and duration of peak luminance . 21
6.4.1 Test pattern for transition time . 21
6.4.2 Measurement of rise and fall times . 21
6.4.3 Measuring method of duration time and interval . 22
6.5 Tone reproduction . 23
6.5.1 General . 23
6.5.2 Information on the evaluation of tone reproduction . 23
6.6 HDR tone mapping . 24
6.6.1 General . 24
6.6.2 Information on the evaluation of tone mapping . 24
6.7 Chromaticity gamut area and colour reproduction . 25
6.7.1 Chromaticity gamut area evaluation . 25
6.7.2 Information on the evaluation of colour reproduction . 26
7 Reporting. 27

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IEC 62977-3-4:2023 © IEC 2023 – 3 –
7.1 Reporting requirements . 27
7.2 Reporting of measurement results. 27
Annex A (informative) Example of tone reproduction measurement and evaluation . 29
A.1 General . 29
A.2 Test pattern for tone reproduction with constant APL . 29
A.3 Example inputs for tone reproduction measurement . 30
A.4 Measuring method of tone reproduction . 31
A.5 Grey scale tracking accuracy . 32
Annex B (informative) Example of tone mapping evaluation . 33
B.1 Inputs of tone mapping test patterns . 33
B.2 Evaluation method of tone mapping input value outside of the display
luminance range . 33
B.3 Supplemental measurement . 35
Annex C (informative) Example of colour reproduction measurement and evaluation . 36
C.1 General . 36
C.2 Test pattern for colour reproduction with constant APL . 36
C.3 Example inputs for colour reference pattern . 37
C.4 Measuring method of colour reproduction . 41
C.5 Colour reproduction accuracy . 42
Bibliography . 43

Figure 1 – Measuring layout for non-contact measurement . 12
Figure 2 – Measuring layout for close-up type LMD . 14
Figure 3 – Example of white luminance curve as function of the white window area,
expressed by its APL (%) . 15
Figure 4 – General window pattern with A % area . 16
Figure 5 – A % APL pattern with A % area white . 16
Figure 6 – Input patterns for black luminance . 18
Figure 7 – Graphical example of rise time and fall time of peak luminance . 22
Figure 8 – OETF and EOTF curves . 23
Figure 9 – Example of tone mapping for PQ curve . 24
Figure 10 – BT.2020 and DCI-P3 chromaticity gamut in xy chromaticity diagram . 25
Figure A.1 – Multi-colour pattern for grey scale measurement . 30
Figure B.1 – Black-to-colour image for PQ HDR with saturation . 34
Figure B.2 – Black-to-colour image for PQ HDR with no saturation . 34
Figure B.3 – Colour-to-white image for PQ HDR with saturation . 35
Figure B.4 – Colour-to-white image for PQ HDR with no saturation . 35
Figure C.1 – Multi-colour pattern with centre reference colour for colour reproduction
measurement . 36

Table 1 – Primary colours of BT.2020 and DCI-P3 . 25
Table A.1 – Examples of measuring range for PQ grey scale measurement . 31
Table B.1 – Code values for tone mapping test patterns . 33
Table C.1 – Conversion matrix between XYZ and RGB for BT.2020 colorimetry . 37
Table C.2 – Conversion matrix between XYZ and RGB for DCI-P3@D65 colorimetry . 37

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Table C.3 – Example of the colour reference pattern target values . 38
Table C.4 – Example RGB inputs of colour reference pattern for BT.2020 colorimetry . 39
Table C.5 – Example RGB inputs of colour reference pattern for DCI-P3@D65
colorimetry . 40

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IEC 62977-3-4:2023 © IEC 2023 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

ELECTRONIC DISPLAYS –

Part 3-4: Evaluation of optical performances –
High dynamic range displays

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 62977-3-4 has been prepared by IEC technical committee 110: Electronic displays. It is an
International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
110/1493/FDIS 110/1509/RVD

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 International Standard is English.

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This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 62977 series, published under the general title Electronic displays,
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
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.

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IEC 62977-3-4:2023 © IEC 2023 – 7 –
INTRODUCTION
High dynamic range (HDR) systems enable more natural images that contain wider variations
in brightness. For the wider dynamic range, newly designed electro-optical transfer function
(EOTF) replaces the BT.1886 function of standard dynamic range (SDR) HDTV. High dynamic
range (HDR) systems utilize non-linear signal encoding that enables reproduction over a wider
range of light levels, from subtle grey differences at very low luminance levels up to very bright
highlights. This very wide range of light levels occurs in both natural as well as synthetic imagery.
In particular, in order to render the native image according to the intent of the content creator,
1
signal codewords of SMPTE ST 2084 [2] HDR EOTF, also known as the perceptual quantizer
(PQ), are mapped to absolute luminance values within the mastering peak luminance as
specified in metadata of the HDR content, versus an SDR signal level which indicates relative
brightness according to the display luminance. In this case, tone mapping would be necessary
when the display luminance cannot make the darker and the brighter luminance because HDR
content preserves details in the darkest and brightest areas of a picture that are lost when using
SDR standards (see 3.1.4) [20] such as Recommendation ITU-R BT.709 [12]. The tone mapping
curve can depend upon the display manufacturer.
This document intends to describe the measurement and evaluation of the optical performance
of HDR displays as a reference for forthcoming standards to make the work of the involved
experts more efficient and to avoid duplication of efforts.
There are unique requirements to evaluate HDR displays, and particular attention is given to
the measurements, so that they are done properly. For example,
1) very low luminance levels will be measured, with careful control of stray light from both the
display as well as ambient light sources;
2) to measure high light output levels, measurements timing and test pattern need to be
carefully controlled to correctly and accurately capture peak or high luminance levels since
HDR displays can have a peak luminance time limit, and many HDR displays have
luminance loading limits;
3) for HDR content, 10 bits or higher bit-depth should be used for sufficient luminance
quantization;
4) the HDR test signal has SMPTE ST 2086 [3] HDR static metadata assigned to fixed values.
Other metadata is not used in this document.
Proper source content is critical to evaluating HDR performance of the displays including the
driver (and interface). In SDR displays, it is possible to separate these issues from the
evaluation of “panels”, but for HDR displays it is not possible to separate these issues because
HDR displays include one or more internal blocks that process the HDR video signal, such as
EOTF and tone mapping, etc., in addition to essential driving stages for the display panel.


___________
1
 Numbers in square brackets refer to the Bibliography.

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ELECTRONIC DISPLAYS –

Part 3-4: Evaluation of optical performances –
High dynamic range displays



1 Scope
This part of IEC 62977 specifies the standard evaluation methods for determining the optical
characteristics of HDR electronic display modules and systems. These methods apply to
emissive and transmissive direct-view displays that render real 2D images on a flat panel or on
a curved panel with a local radius of curvature larger than 1 500 mm. This document evaluates
the optical characteristics of these displays under darkroom conditions. This document applies
to the testing of display performance in response to HDR digital input signals that are absolute
luminance encoded such as the HDR signal comprising RGB component values of
Recommendation ITU-R BT.2020 colorimetry with SMPTE ST 2084 [2] PQ luminance encoding
and SMPTE ST 2086 [3] metadata.
NOTE A flat panel or flat panel display is a display with a planar surface that emits light from the surface. The
display can consist of light valves modulating a backlight or be self-luminous. Emissive/transmissive/reflective hybrid
displays can be non-planar panels or non-planar panel displays.
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.
IEC 62977-2-1:2021, Electronic displays – Part 2-1: Measurements of optical characteristics –
Fundamental measurements
IEC 62977-2-2:2020, Electronic displays – Part 2-2: Measurement of optical characteristics –
Ambient performance
CIE 015:2004, Colorimetry
Recommendation ITU-R BT.2020-2, Parameter values for ultra-high definition television
systems for production and international programme exchange
Recommendation ITU-R BT.2100-2, Image parameter values for high dynamic range television
for use in production and international programme exchange
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp

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IEC 62977-3-4:2023 © IEC 2023 – 9 –
3.1.1
HDR peak luminance
maximum stable white luminance of the display using the HDR test signal (see 3.1.14) under
the required measuring condition
3.1.2
dynamic range
range of the lowest to the highest luminance expressed by the ratio of the highest luminance to
the lowest luminance that the display can render by a non-zero signal value
Note 1 to entry: The unit of the dynamic range can be expressed in terms of the number of stops using the formula
Log [dynamic range].
2
3.1.3
high dynamic range
HDR
span of image luminance and contrast described in Recommendation ITU-R BT.2100
3.1.4
standard dynamic range
range of relative luminance with an unbounded input signal (generally exhibiting a power law
dependence with input signal to be displayed in accordance with the luminance range of the
display) that is normally possible for a conventional video display and content, whereby the
standard dynamic range signal for SDTV, HDTV and UHDTV is encoded with the format defined
in Recommendation ITU-R BT.601 [13], Recommendation ITU-R BT.709 [12] and
Recommendation ITU-R BT.2020, respectively
3.1.5
average picture level
APL
average input level of all signal pixels relative to the maximum signal setting expressed as a
percentage
Note 1 to entry: Post-EOTF APL is also called ALL (average light level), and calculated by averaging of post-EOTF
signal pixels (linear values).
3.1.6
code value
digital input value of an image signal component representing a signal pixel expressed in a
specified format such as RGB
3.1.7
opto-electrical transfer function
OETF
optical to signal transfer function which is used in image acquisition devices such as digital
cameras for mapping scene luminance to digital code values prior to encoding, transmission,
or compression
Note 1 to entry: If OETF and EOTF consist of or are close to a power function (such as generally used in SDR
systems), the function is called nonlinear encoding (gamma correction) and nonlinear decoding (inverse gamma
correction), respectively, where its exponent is called gamma or gamma value.
Note 2 to entry: In conventional non-constant luminance systems, the nonlinear decoding is done in the RGB
domain, whereas it is done in the YC C domain for constant luminance systems.
b r

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3.1.8
electro-optical transfer function
EOTF
mathematical function for the inverse OETF (and system gamma for power law functions),
usually used for display systems such as TVs and monitors, that maps digital code values to
displayed luminance
Note 1 to entry: Generally, EOTF is also called nonlinear decoding, which is the inverse of nonlinear encoding, but
custom decoding is also available in many display products.
3.1.9
optical-to-optical transfer function
OOTF
mathematical function that maps the captured luminance by a camera to the displayed
luminance by a display device according to the rendering intent or peak luminance of the display
3.1.10
white boosting
increase in the luminance of displayed white image elements beyond what is expected for
R + G + B primary colour additivity, and a corresponding decrease in colour saturation
Note 1 to entry: Luminance boosting such as white boosting can influence the tone curve according to colour
saturation that is deviated from the display gamma curve.
3.1.11
HDR display
display that can accommodate, properly process, and display the PQ-encoded HDR content
defined in Recommendation ITU-R BT.2100
Note 1 to entry: An HDR display can also display SDR content by changing the EOTF and its related functions such
as tone mapping and system gamma.
3.1.12
HDR content
image content mastering with OETF which is described in Recommendation ITU-R BT.2100
3.1.13
HDR tone mapping
mapping of the HDR test signal to the performance envelope of a display, whereby the display
system maps one set of tone ranges to another to approximate the appearance of the content,
when the content requires a wider dynamic range beyond the display’s capability to reproduce
the full range of light intensities ranging from the darkest to the highest target luminance levels
Note 1 to entry: HDR tone mapping can include dynamic range global or local clipping or roll-off while preserving
the chromaticity of the original image (see 6.6), perceptual colour rendering, or other forms of colour gamut mapping
which are dependent on the display mode.
Note 2 to entry: An HDR DUT can use different static and/or dynamic metadata as input to the tone mapping
algorithms.
3.1.14
HDR test signal
test signal referred to as an HDR10 implementation that has been adopted by the display
industry to describe an uncompressed signal that uses the PQ EOTF from Recommendation
ITU-R BT.2100 and HDR static metadata defined in SMPTE ST 2086 [3]
Note 1 to entry: An explanation can be found in 4.1. Fo
...