IEC 62977-3-4:2023

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

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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

– 2 – IEC 62977-3-4:2023 © IEC 2023
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

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

– 4 – IEC 62977-3-4:2023 © IEC 2023
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

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.

– 6 – IEC 62977-3-4:2023 © IEC 2023
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.

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,
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.

___________
Numbers in square brackets refer to the Bibliography.

– 8 – IEC 62977-3-4:2023 © IEC 2023
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

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].
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
– 10 – IEC 62977-3-4:2023 © IEC 2023
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. For the purpose of controlled metrology, the test signal is used
with a single set of signal parameters that is unique compared to other signals described in display-referred (refer to
Chapter 20 in [1]) whose signal represents the intent of the content creator that includes defined parameters for the
non-linearity, min/max luminance, and the colour encoding of the signal container, whereby the encoded signal values
can be directly transformed to absolute CIE XYZ.
Note 2 to entry: For the definitions of HDR test signals such as display-referred, signal container, etc., and for
background information see Chapter 20 in IDMS ver.1.1:2021 [1].

3.1.15
Maximum Content Light Level
MaxCLL
metadata which indicates the maximum light level value of any single pixel of the entire playback
sequence
Note 1 to entry: For MaxCLL, the unit is equivalent to cd/m when the brightest pixel in the entire video stream has
the chromaticity of the white point of the encoding system used to represent the video stream. Since the value of
MaxCLL is computed with a max() mathematical operator, it is possible that the true CIE Y luminance value is less
than the MaxCLL value.
3.1.16
Maximum Frame-average Light Level
MaxFALL
metadata which indicates the maximum frame average value within a temporal sequence of
frames
Note 1 to entry: For MaxFALL, the unit is equivalent to cd/m when the maximum frame average of the entire stream
corresponds to a full-screen of pixels that has the chromaticity of the white point of the encoding system used to
represent the video stream. The frame-average computation used to compute the MaxFALL value is performed only
on the active image area of the image data.
3.1.17
ΔE
00,D50
colour difference calculated based on adaptation to D50 using CIE 1931 colour-matching
functions (CMFs)
Note 1 to entry: This colour difference is different from CIE ΔE .
3.2 Abbreviated terms
For the purposes of this document, the following abbreviated terms apply.
ABC auto brightness control
ACR ambient contrast ratio
ALC ambient light control
APL average picture level
BRCR bright room contrast ratio
CAT chromatic adaptation transform
CIELAB CIE 1976 (L*a*b*) colour space
CMF colour-matching function
DRCR darkroom contrast ratio
DUT device under test
EOTF electro-optical transfer function
HDR high dynamic range
OETF opto-electrical transfer function
OLED organic light emitting diode
OOTF optical-to-optical transfer function
PQ perceptual quantizer (PQ tone curve as defined in Recommendation ITU-R
BT.2100)
RGBCMY red, green, blue, cyan, magenta and yellow
SDR standard dynamic range
SLET stray light elimination tube

– 12 – IEC 62977-3-4:2023 © IEC 2023
4 Standard measuring equipment
4.1 Video signal generator
A digital video signal generator is used, and the HDR test signal is implemented as follows. All
code values of the test signal shall be PQ encoded with BT.2020 colorimetry and 10-bit
full-range. The DUT should support a 10-bit or greater signal and colour range signal input of
Recommendation ITU-R BT.2020. This shall be included as “Supported” or ”Not supported” in
the test report of Clause 7. It is important that for each measurement result, metadata conditions
are defined, checked and reported; otherwise, the results might not be reproducible. The static
HDR metadata format shall be reported as described in 7.1 (refer to Section 20.1.1 and Section
20.1.5 in IDMS ver.1.1:2021 [1], [12], [15]). The HDR test signal format is defined as:
SMPTE ST 2084 EOTF, 10-bit RGB full range, BT.2020 primary encoding,
SMPTE ST 2086 metadata: The default metadata is set to P3D65, 4 000 cd/m peak
MaxCLL no data, MaxFALL no data
If the DUT exceeds the default metadata settings, these can be modified
accordingly as long as they are clearly reported.
The input signal or input data, in this document, means the transferred code values by the OETF
of PQ HDR defined in Recommendation ITU-R BT.2100 and Report ITU-R BT.2390 [17].
4.2 Conditions of measuring equipment
Refer to IEC 62977-2-1:2021, 5.3.4.
Additional conditions of the measuring equipment shall comply with IEC 62977-2-1.
4.3 Measuring equipment block diagram
Refer to IEC 62977-2-1. An example of block diagram is shown in Figure 1. The optical axis of
the optical test equipment shall be centered on the screen and perpendicular to the display
surface.
Figure 1 – Measuring layout for non-contact measurement

5 Standard measuring conditions
5.1 Standard measuring environmental conditions
Refer to IEC 62977-2-1:2021, 5.1. The standard environmental conditions for performing the
measurements are defined as follows:
• temperature: 25 ºC ± 3 ºC,
• relative humidity: 25 % to 85 %,
• atmospheric pressure: 86 kPa to 106 kPa.
When different environmental conditions are used, they shall be noted in the report.
5.2 Power supply
The power supply for driving the DUT shall be adjusted to the rated voltage ±2 %. In addition,
the frequency of the power supply shall provide the rated frequency ±1 %.
5.3 Warm-up time
Measurements shall be started after the displays and measuring instruments achieve stability.
The DUT shall be turned on first and operated for at least 30 min prior to the measurement.
Some display technologies might require a loop of colour patterns rendered on the screen
during the warm-up period. Sufficient warm-up time has been achieved when the luminance of
the test feature to be measured varies by less than ±3 % over the entire measurement period
(e.g. uniformity measurements) for a given display image.
5.4 Standard darkroom conditions
The luminance contribution from the background illumination reflected from the test display
shall be below 0,000 5 cd/m . If the test pattern generates stray light, then stray light elimination
methods such as frustum or stray light elimination tubes should be used. The LMD shall have
a sufficient signal-to-noise ratio suitable to measure the low luminance of black. If there is
significant background illumination of more than 0,000 5 cd/m and of more than 10 % of the
measured black luminance, the off-state luminance by background illumination (also called
background black) should be subtracted from the measured black luminance of the on-state.
5.5 Adjustment of HDR display
The HDR display is a physical display that is receiving the HDR test signal. It is likely that the
HDR DUT is incapable of reproducing the entire display-referred HDR test signal which requires
absolute values with a definition of non-linearity, min/max luminance, and colour encoding of
the signal container [1]. The standard operating status of the display equipment shall be
adjusted by the following sequence.
a) Initialized status
The imaging setup configuration of the display equipment shall be returned to the factory
condition in the reference master mode. If the DUT does not have the reference master
mode, the image mode shall be adjusted to the HDR standard or corresponding mode. The
mode shall remain at that setting for all tests in this document. The selection of the mode
should be made once and only once in this document. Likewise, any other menu
configuration settings should be adjusted once and only once, and thereafter be left at the
same setting for all measurements. The mode and menu configuration used for all
measurements shall be recorded and reported.

– 14 – IEC 62977-3-4:2023 © IEC 2023
b) Adjustment of ambient light control
Turn off the ABC (or ALC) of the DUT. If it cannot be turned off, set the DUT under no less
than 300 lx lighting close-up or contacted with the light sensor for reasonable measurement
without dimming; this shall be reported. The lighting to disable the ambient light control shall
not influence the ambient illuminance for the darkroom and bright room condition. If the
lighting to disable ABC influences the results of the darkroom measurements, a close-up
type LMD as shown in Figure 2 could be used.

Figure 2 – Measuring layout for close-up type LMD
c) Adjustment of aspect ratio
The aspect ratio of the DUT shall be adjusted in full screen mode without overscan.
d) Reference master mode of HDR display
The HDR DUT can provide different modes of operation. Some modes can perform
perceptual rendering, whereas the reference master mode can provide a colorimetric match
within its capability envelope. When measuring the DUT, it is not permitted to break out the
display device and the display system into separate optical functions. This is because some
optical functions such as tone mapping, white balance, frame rate conversion, dimming and
boosting, etc., cannot be turned off by users. In all measurements, the display shall meet
all the requirements of this specification without modifying the configuration settings.
6 Measuring methods of optical characteristics
6.1 HDR peak luminance
6.1.1 HDR peak luminance variation by black and white pattern
Due to the limitation of power consumption, the display luminance can be managed based on
the average luminance of the image. In this case, the APL to define white luminance would be
identical to the white window area with a black background. The white luminance curve
according to the white window area can be approximated by modeling as in the example given
in Formula (1), whereby the constants a, b and c should be calculated based on the design
concept of the luminance curve.
Figure 3 shows an example of an APL-dependent white luminance curve obtained at the centre
of the black and white test pattern as a function of the centre window area (A % area of the total
screen area). The A % white window area of the screen would make a pattern with A % APL.
Other displays not sensitive to the APL might show a more stable luminance curve up to 100 %
APL.
The curve can be modelled by the inverse of the white window area (%) corresponding to the
APL (%) as in the example given by Formula (1) which is expressed with coefficients to convert
the APL value to the white luminance in cd/m . The dashed line in Figure 3 demonstrates the
model estimation. A set of example coefficients was determined as 2, 11 000, and 55 for a, b,
and c, respectively. However, the coefficients vary with the optical characteristics and driving
scheme of the display system such as power management. The design of the luminance curve
might depend on the display device properties. The dimming and boosting in the luminance can
also be limited by electrical or material reliability issues, for example.
b

Lccd/m ≈+
(1)
white

Aa+
white
where
A is the white window area or APL in per cent;
white
a, b, c are constants to describe white luminance curve of a display module.

Figure 3 – Example of white luminance curve as function
of the white window area, expressed by its APL (%)
6.1.2 APL by the window and background level
An APL for a given A % area window pattern in Figure 4 would be determined by the luminance
levels of the window and its background as given in Formula (2). When it is an A % area window
with a window input (level X) and background input (level Y) in a 10-bit code word in Figure 4,
the APL is calculated by the sum of the APL between the centre window and its background.
APL ( %) = A × (X / 1 023) + (100 – A) × (Y / 1 023) (2)

where
X and Y are the 10-bit codes when the display has the full dynamic range specified by the
HDR content, while the luminance for the input can be variable according to the tone
mapping of the HDR system.
– 16 – IEC 62977-3-4:2023 © IEC 2023

Figure 4 – General window pattern with A % area
6.1.3 Test pattern for HDR peak luminance
The APL for the peak luminance could be defined by considering both the required luminance
and chromaticity of the HDR content. Some HDR system makers might have to design according
to the power consumption limitations or for other reasons related to specific technologies. In
such cases, the resultant peak white luminance level can vary as a function of APL, as shown
in Figure 3. If so, a suitably low APL shall be selected so that the peak luminance measurement
is not arbitrarily limited.
The peak luminance shall be measured at the A % area window (0,1 ≤ A ≤ 100) with black
background as shown in Figure 5 where H is the horizontal screen size, and V is the vertical
screen size. In case of white-only input, the A % area white shall be the A % APL to the display
which has the same APL between the pre-EOTF and the post-EOTF. The “A” value shall be
reported.
NOTE For a low APL with a small area window, the measurement field is set to contain at least 500 pixels.

Figure 5 – A % APL pattern with A % area white
6.1.4 Measuring method
The peak luminance L shall be measured as the highest luminance value for a white input
W
with a specific input APL during the stable luminance condition. The measuring methods might
differ according to the developer’s and user’s perspective because the A % for the HDR peak
luminance is usually unknown to users. The measuring method is as follows.
a) The measurement shall be performed in a darkroom using the test pattern of Figure 5.
b) Input the specified pattern for the measurement from the HDR video signal generator. All
mode and menu configuration settings shall remain as set according to 5.5.
c) If the A % value that provides the highest luminance is known, apply the pattern with this
A % white window area and measure the luminance at the centre of the pattern.

d) If the A % value that provides the peak luminance is not known, determine this APL value
for peak luminance by varying the A % white window area 0,1 %, 0,5 %, 1 %, 2 %, and from
4 % to 40 % APL by 2 % steps and 100 % to measure the luminance at the centre of the
screen. The peak luminance shall be determined at the A % APL value showing the highest
luminance.
e) By using the window pattern of Figure 5, measure the luminance at the centre of the A %
white window that might show the highest luminance.
f) If application of the peak luminance signal occurs at t = 0, that luminance data acquisition
should not begin before peak luminance has stabilized. Several frames can be required
before attempting to measure peak luminance, therefore it is recommended that luminance
reaches over 90 % of the threshold to begin acquir
...