IEC 62341-6-1:2025

IEC 62341-6-1 ®
Edition 4.0 2025-05
INTERNATIONAL
STANDARD
Organic light emitting diode (OLED) displays –
Part 6-1: Measuring methods of optical and electro-optical parameters
ICS 31.260  ISBN 978-2-8327-0395-3

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CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 9
4 Structure of measuring equipment . 9
5 Standard measuring conditions . 9
5.1 Standard measuring environmental conditions . 9
5.2 Standard measuring dark room conditions . 10
5.3 Standard setup conditions . 10
5.3.1 General . 10
5.3.2 Adjustment of OLED displays . 10
5.3.3 Starting conditions of measurements . 10
5.3.4 Measuring equipment requirements . 10
5.4 Standard locations of measurement field. 12
5.5 Standard test patterns . 13
6 Measuring methods for optical parameters . 17
6.1 Primary luminance, colour, and uniformity of full-colour high-resolution
displays . 17
6.1.1 Purpose . 17
6.1.2 Measuring conditions . 18
6.1.3 Measuring methods for high-resolution full colours . 18
6.1.4 Maximum luminance of white and RGB primaries . 19
6.1.5 Average colour of maximum white and RGB primaries . 19
6.1.6 Luminance uniformity of white and RGB primaries . 20
6.1.7 Chromaticity non-uniformity of maximum white and RGB primaries . 21
6.1.8 Colour additivity of maximum white and RGB primaries . 21
6.1.9 White correlated colour temperature . 21
6.2 Primary luminance, chromaticity and uniformity of low-resolution displays . 22
6.2.1 Purpose . 22
6.2.2 Measuring conditions . 22
6.2.3 Measuring methods for low-resolution displays and segmented displays . 22
6.3 Signal loading . 23
6.3.1 Purpose . 23
6.3.2 Measuring conditions . 23
6.3.3 Measuring methods . 23
6.4 Dark room contrast ratio . 24
6.4.1 Purpose . 24
6.4.2 Measuring conditions . 24
6.4.3 Measuring method . 24
6.5 Chromaticity gamut area . 25
6.5.1 Purpose . 25
6.5.2 Measuring conditions . 25
6.5.3 Measuring methods . 25
6.5.4 Chromaticity gamut area in CIE 1931 chromaticity diagram . 25
6.6 Colour gamut volume . 26

6.6.1 Purpose . 26
6.6.2 Measuring conditions . 27
6.6.3 Measuring methods . 27
7 Measuring methods for power consumption . 30
7.1 Purpose . 30
7.2 Measuring conditions . 30
7.3 Measuring methods . 30
7.3.1 Measuring the power consumption relevant to luminance of the OLED
display module without signal decoding process . 30
7.3.2 Measuring the power consumption of the OLED display module’s
embedded video connection terminal with a signal decoding process . 31
Annex A (normative) Response time of passive matrix display panels . 34
A.1 Purpose . 34
A.2 Measuring conditions . 34
A.3 Measuring methods . 34
Annex B (normative) Luminance current efficiency . 36
B.1 Purpose . 36
B.2 Measuring conditions . 36
B.3 Measuring methods . 36
Annex C (informative) Veiling glare frustum . 38
Annex D (informative) Methods to obtain the correlated colour temperature (CCT) from

chromaticity coordinates . 39
D.1 Method 1: Use of McCamy’s approximate formula . 39
D.2 Method 2: Use of Javier Hernandez-Andres’s approximate formula . 39
D.3 Method 3: Graphical determination of correlated colour temperature . 40
Annex E (informative) Measuring performance of modern colour-managed displays
and panels . 43
E.1 Legacy displays . 43
E.2 Modern displays . 43
E.3 Results . 45
E.4 Conclusion . 48
Annex F (informative) Simple window luminance and colour measurements . 49
F.1 Background. 49
F.2 Measuring conditions . 49
F.3 Maximum full screen luminance . 49
F.4 4 % window luminance . 49
F.5 Sampled luminance non-uniformity . 50
F.6 4 % window centre colour . 50
F.7 Sampled colour non-uniformity . 51
Bibliography . 52

Figure 1 – Layout diagram of measurement setup . 11
Figure 2 – Standard measurement positions in the display active area . 12
Figure 3 – Test pattern scaling used to define the area size of the coloured rectangles
in the active area of the display . 13
Figure 4 – Medium APL loading series of red, green, blue, and white test patterns used
for basic luminance, colour, and uniformity measurements. 14
Figure 5 – Low and high APL loading versions of CTR pattern . 15

– 4 – IEC 62341-6-1:2025 © IEC 2025
Figure 6 – Standard medium APL RGBCMY test pattern used for centre luminance and
colour measurements with 25 % APL . 16
Figure 7 – Examples of variable signal loading RGBCMY test patterns used for centre

luminance and colour measurements . 17
Figure 8 – Sequence for measuring luminance and colour at the nine standard display
positions for all coloured tile patterns . 18
Figure 9 – Chromaticity of blackbody source at various temperatures as represented
on the CIE 1931 chromaticity diagram . 22
Figure 10 – Example representation of the primary colours in the CIE 1931

chromaticity diagram . 26
Figure 11 – Example of range in colours produced by an sRGB display as represented
by the CIELAB colour space and by visualization using gamut rings . 29
Figure 12 – Example of measurement setup of power consumption . 31
Figure 13 – Example of measurement setup of power consumption with embedded
video terminal . 32
Figure A.1 – Relationship between driving signal and optical response times . 35
Figure B.1 – Example of a measurement configuration for measuring luminance current

efficiency . 37
Figure C.1 – Pattern for veiling glare frustum . 38
Figure D.1 – CIE 1931 XYZ chromaticity diagram . 41
Figure D.2 – Blackbody locus (Planckian locus) and isotemperature lines in CIE 1931
chromaticity diagram . 42
Figure E.1 – Legacy model where the independent drive electronics provide a direct
correlation between the input RGB signals and the display’s colour primaries . 43
Figure E.2 – Examples of modern drive models using multi-dimensional LUTs for RGB

(top) and multi-chromatic (bottom) displays . 44
Figure E.3 – Example of signal loading behaviour for an RGBW display (top) and RGB
(bottom) OLED display . 46
Figure E.4 – Low APL loading test pattern with small box size (1/9 of the screen size
dimensions) . 47
Figure E.5 – Signal loading profiles for several input colours measured at the centre of

the test pattern using Figure 8 . 48
Figure F.1 – Example of simple 4 % white window pattern at the centre of the screen . 50

Table 1 –Standard digital-equivalent input signals for rendering the white, primary and
secondary colours in test patterns . 17
Table 2 – Example of luminance measured for the same colour patch at the standard
nine screen positions and the resulting luminance non-uniformity . 19
Table 3 – Example of the chromaticity measured for the same colour patch at the nine

standard screen positions and the resulting chromaticity non-uniformity . 19
Table 4 – Scaling the size of the colour boxes in the APL loading pattern relative to the
screen dimensions . 24
Table 5 – Example of report format for CIELAB gamut volume . 30
Table 6 – Example of a module power consumption measurements summary sheet . 31
Table 7 – Example of module power consumption measurements with contents. 33
Table 8 – Example of module power consumption measurements with images . 33
Table D.1 – x , y , A and t for Formula (D.3) and Formula (D.4) . 40
e e i i
Table E.1 – Example of luminance data for an RGB display and an RGBW OLED
display . 45

– 6 – IEC 62341-6-1:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-1: Measuring methods of optical and electro-optical parameters

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
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the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 62341-6-1 has been prepared by IEC technical committee 110: Electronic displays. It is an
International Standard.
This fourth edition cancels and replaces the third edition published in 2022. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The standard average picture level (APL) RGBCMY test pattern is modified, and the variable
signal loading RGBCMY test pattern is added.
b) Chromaticity gamut area and colour gamut volume are modified.

The text of this International Standard is based on the following documents:
Draft Report on voting
110/1690/CDV 110/1735/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 International Standard is English.
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 the parts in the IEC 62341 series, under the general title Organic light emitting diode
(OLED) 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, or
• revised.
– 8 – IEC 62341-6-1:2025 © IEC 2025
ORGANIC LIGHT EMITTING DIODE (OLED) DISPLAYS –

Part 6-1: Measuring methods of optical and electro-optical parameters

1 Scope
This part of IEC 62341 specifies the standard measurement conditions and measuring methods
for determining the optical and electro-optical parameters of organic light emitting diode (OLED)
displays. Except for the power consumption method, all methods are intended for unbounded
input signals measured in the flat regions of the display in a dark room.
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 60050-845, International Electrotechnical Vocabulary – Part 845: Lighting
IEC 62341-1-2, Organic light emitting diode (OLED) displays – Part 1-2: Terminology and letter
symbols
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-845,
IEC 62341-1-2 and the following apply.
ISO and IEC maintain terminology 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
signal pixel
smallest encoded picture element in the input image
Note 1 to entry: Signal pixel is defined as the unit of signal resolution.
3.1.2
pre-gamma average picture level
average input level of all signal pixels relative to an equivalent white pixel driven by a digital
RGB input
Note 1 to entry: The pre-gamma average picture level (APL) will simply be referred to as average picture level in
this document, unless otherwise stated.
Note 2 to entry: The APL will normally be expressed as a percentage, where a full white screen at maximum drive
level would be 100 % APL.
Note 3 to entry: The pre-gamma APL is also called the gamma-corrected APL in IEC 62087-2 [1]. It is noted that
the tone rendering curve may not have a power law function with a well-defined exponent (gamma).

3.1.3
average light level
ALL
average light of the input signal on all pixels
Note 1 to entry: ALL, which is calculated by averaging of post-EOTF signal pixels, is also called as the post-EOTF
APL.
3.1.4
unbounded input signal
input signal for which there is neither any host-side colour management nor any handshaking
taking place between the host and the DUT
3.2 Abbreviated terms
APL average picture level
CCT correlated colour temperature
CIE Commission Internationale de L’Eclairage (International Commission on
Illumination)
CIELAB CIE 1976 (L*a*b*) colour space
CMY cyan, magenta, and yellow
DRCR dark room contrast ratio
DUT device under test
eDP embedded display port
LMD light measuring device
LUT look-up table
MIPI mobile industry processor interface
PMOLED passive matrix organic light-emitting diode
RGB red, green, and blue
RGBCMY red, green, blue, cyan, magenta, and yellow
SPD spectral power distribution
sRGB standard RGB colour space as defined in IEC 61966-2-1
TCON timing controller
UCS uniform chromaticity scale
WRGB white, red, green, and blue
4 Structure of measuring equipment
Either the system diagrams or operating conditions of the measuring equipment, or both shall
comply with the structure specified in each item.
5 Standard measuring conditions
5.1 Standard measuring environmental conditions
Measurements shall be carried out under the standard environmental conditions as follows:
– temperature: 25 °C ± 3 °C
– relative humidity: 25 % RH to 85 % RH
– atmospheric pressure: 86 kPa to 106 kPa
When different environmental conditions are used, they shall be noted in the report.

– 10 – IEC 62341-6-1:2025 © IEC 2025
5.2 Standard measuring dark room conditions
The luminance contribution from unwanted background illumination reflected off the test display
shall be less than 1/20 of the display’s black state luminance. If these conditions are not
satisfied, then background subtraction is required, and it shall be noted in the test report. In
addition, if the sensitivity of the light measuring device (LMD) is inadequate to measure 1/20 of
the black level, then the lower limit of the LMD shall be noted in the test report.
5.3 Standard setup conditions
5.3.1 General
Standard setup conditions are given below in 5.3.2, 5.3.3 and 5.3.4. Any deviations from these
conditions shall be reported.
5.3.2 Adjustment of OLED displays
The display shall be measured at its factory default settings. If other settings are used, they
shall be noted in the test report. These settings shall be held constant for all measurements,
unless stated in the report. The adjustments shall be kept constant, but also that the resulting
physical quantities remain constant during the measurement. This is not automatically the case
because of, for example, warm-up effects.
5.3.3 Starting conditions of measurements
Measurements shall be started after the OLED displays and measuring instruments achieve
stability. It is recommended that, when the display is first turned on, it be operated for at least
30 min with a loop of colour patterns rendered on the screen, such as the medium average
picture level (APL) pattern in Figure 4 with the colours rotating their positions every few seconds.
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 method for a given display
image.
5.3.4 Measuring equipment requirements
5.3.4.1 General conditions
Light measurements shall generally be made in terms of photometric or colorimetric units for a
. Luminance can be
CIE 1931 standard colorimetric observer as defined in CIE S 014-1 [2]
measured by a photometer, and CIE tristimulus values (X, Y, Z) or CIE chromaticity coordinates
by a colorimeter. A spectroradiometer can also obtain photometric and colorimetric values
through a numerical conversion of the measured spectral radiance data (see for example [3]).
A telescopic LMD, where the LMD is not in direct contact with the screen, shall be used without
an illumination source. The following requirements are given for these instruments.
a) The LMD shall be a luminance meter, colorimeter, or a spectroradiometer. The
spectroradiometer shall be capable of measuring spectral radiance over at least the 380 nm
to 780 nm wavelength range, with a maximum bandwidth of 10 nm for smooth broadband
spectra. For OLED primaries with a bandwidth ≤ 25 nm, the maximum bandwidth shall
be ≤ 5 nm. The spectral bandwidth of the spectroradiometer shall be an integer multiple of
the sampling interval. For example, a 5 nm sampling interval can be used for a 5 nm or
10 nm bandwidth.
Ensure that the LMD has enough sensitivity and dynamic range to perform the required task.
The measured LMD signal shall be at least ten times greater than the dark level (noise floor)
of the LMD, and no greater than 85 % of the saturation level.
___________
Numbers in square brackets refer to the Bibliography.

b) The LMD shall be focused on the image plane of the display and generally aligned
perpendicularly to the display surface at the centre of the measurement field, unless stated
in the report.
c) The relative uncertainty and repeatability of all the measuring devices shall be maintained
by following the instrument supplier’s recommended calibration schedule.
d) The LMD integration time shall be an integer number of frame periods, synchronized to the
frame rate, or the integration time shall be greater than one hundred frame periods.
e) If LMD measurements are taken for displays with impulse driving or duty driving, the high
peak luminance of these displays can cause detector saturation errors. The accuracy of
these measurements can be checked by attenuating the light with a neutral-density filter. If
the change in signal amplitude of the detector is proportional to the transmittance of the
neutral-density filter, then there are no detector saturation errors. This method is for
measuring the maximum time-averaged full-screen luminance.
When using LMDs, stray light within the LMD (e.g. lens flare, veiling glare), and non-uniformities
of sensitivity across detector area should be considered. Also, when measuring black regions,
stray light from adjacent bright regions of the displays can introduce significant errors. The stray
light can be significantly reduced by using a frustum (see Annex C).
In addition to LMDs that form an average value for the measured quantity over the measurement
field under consideration (i.e. spot photometers, see Figure 1), there are imaging LMDs which
give a value (or an array of values, e.g. R, G and B) for each individual area-element on the
device under test (DUT). Such LMDs can replace a sequential mechanical scan of the surface
of a display by an image of the entire active area of the DUT, and a subsequent evaluation of
the data.
When imaging LMDs are used, a flat-field correction shall be applied to the LMD at the
measuring distance.
Figure 1 – Layout diagram of measurement setup
5.3.4.2 High pixel count matrix displays (≥ 320 pixels × 240 pixels)
The following applies for high pixel count matrix displays.
a) When measuring matrix displays, the light measuring devices should be set to a
measurement field that includes more than 500 pixels. For LMDs with a circular
measurement field, this would be equivalent to a disk with a diameter greater than 25 display
pixels. If smaller measurement areas are necessary, photometric and colorimetric
equivalence to 500 pixels shall be confirmed and noted in the test report.

– 12 – IEC 62341-6-1:2025 © IEC 2025
b) For small displays, the recommended measuring distance is between 20 cm to 50 cm. For
larger displays, the measurement area shall contain at least 500 pixels. The measurement
area contains at least 500 pixels. The measuring distance shall be noted in the report.
c) The angular aperture shall be less than or equal to 5°, and the measurement field angle
shall be less than or equal to 2° (see Figure 1).
d) The display shall be operated at its design field frequency. When using separate driving
signal equipment to operate a panel, the drive conditions shall be noted in the report.
5.3.4.3 Low pixel count matrix displays (< 320 pixels × 240 pixels) and segmented
displays
The following applies for low pixel count matrix displays.
a) Low pixel count displays can contain less than 500 pixels. When the number of pixels in the
measurement field is less than 500, it shall be noted in the report. The angular aperture
shall be less than or equal to 5°, and the measurement field angle shall be less than or
equal to 2°. The measurement conditions used shall be recorded.
b) For segment displays, the angular aperture shall be less than or equal to 5°, and the
measurement field angle shall be less than or equal to 2°. All measurements shall be
performed at the centre of a segment with the measurement field completely contained
within the segment.
c) For small displays, the recommended measuring distance is between 20 cm to 50 cm. For
larger displays, follow the manufacturer’s recommended viewing distance. For larger
displays, the measurement area shall contain at least 500 pixels. The measuring distance
shall be noted in the report.
5.4 Standard locations of measurement field
Luminance, spectral distribution and tristimulus measurements should be taken at several
specified positions on the display surface. The standard measurement locations are identified
to P in the active area, as illustrated in Figure 2. The active screen area is
by positions P
1 9
divided into nine equal-sized boxes, with the measurement area centred within each box and
identified by the corresponding numbering shown in Figure 2. Each box is 1/3 of the width (W)
and height (H) of the active area. Centre screen measurements are taken at position P . The
display or detector shall be translated in the horizontal and vertical directions to perform
measurements at the desired display positions, with all measurements taken normal to the
screen. Any deviation from the standard positions above shall be recorded.

Figure 2 – Standard measurement positions in the display active area

5.5 Standard test patterns
The characterization of display luminance and colour can depend on the display test pattern.
Therefore, several standard test patterns are given to help make the measurements more
realistic to actual use cases (see Annex E). Additional test patterns may also be used (see
Annex F). The standard test patterns use the scaling illustrated in Figure 3. The display is
divided into a 3 × 3 array of rectangular areas, each of which has sides that are 1/3 of the
dimension of the height and width of the screen active area. Each of these nine rectangular
areas can then be further subdivided into smaller rectangles, as demonstrated in the upper left-
hand corner of Figure 3 . The smallest subdivision would yield a rectangular box that has
dimensions of 1/9 of those of the active area of each region of the 3 × 3 array.

Figure 3 – Test pattern scaling used to define the area size of
the coloured rectangles in the active area of the display
The standard test pattern for basic primary luminance and colour measurements shall use the
medium APL loading example of the colour tile test patterns illustrated in Figure 4. In this case,
coloured rectangular boxes, with 2/9 of the dimensions of the active area, are centred on the
nine standard active area locations on a black background. The red, green, and blue boxes are
driven at the maximum input signal levels for the primary channels. For example, the red box
is driven at the maximum input signal for the red channel, while the green and blue channels
are at their minimum signal level. The white boxes are driven at their maximum red, green, and
blue channel inputs. Each colour tile pattern is identified by the initials CT (colour tile) and the
colour of the centre box. The patterns in Figure 4 are identified as CTR, CTG, CTB, and CTW
starting at the upper left-hand pattern and moving clockwise.

– 14 – IEC 62341-6-1:2025 © IEC 2025

Figure 4 – Medium APL loading series of red, green, blue, and white test patterns used
for basic luminance, colour, and uniformity measurements
The area scaling of the coloured rectangles is adjusted to manipulate the APL loading on the
display. The amount of APL loading is input-referred, assuming it is an RGB digital input. The
percent APL is defined as:
N
PL
(1)
∑ i
i=1
APL % 100×
( )
N
where
the summation is over all pixels in the active area,
th
PL is the normalized signal pixel level of the i pixel relative to maximum white
i
level,
N is the total number of pixels.
A 100 % APL is represented by all pixels in the active area at maximum white level. This is
implemented by setting the levels for the red, green, and blue input channels to their maximum
values. A single primary colour (e.g. red) rendered on a full screen would have 1/3 of the APL
of a full white screen. If it is assumed that the red, green, and blue areas correspond to 1/3 of
the APL of the white areas, then the APL for each pattern in Figure 4 is (starting at the upper
left-hand corner and going clockwise) 21,4 %, 21,4 %, 21,4 %, and 24,7 %. The average APL
for the four patterns in Figure 4 is 22,2 %. An example calculation of the top left pattern in
Figure 4 is given by:
[(7 boxes of primary colours × 1/3 of white) + (2 white boxes × 3/3 of white)] ×

[(2/9) fractional area of boxes] = 21,4 % APL

=
Lower and higher loading versions of the colour tile pattern are illustrated in Figure 5. The
sequence of four-colour tile patterns at the low loading geometry would give an average APL
equivalent of 5,6 %, whereas the high loading pattern would give an average APL equivalent of
50 %.
a) Low APL loading version of CTR pattern

b) High APL loading version of CTR pattern
NOTE The corresponding CTG, CTB, and CTW patterns are of similar size but have green, blue, and white,
respectively, in the centre box.
Figure 5 – Low and high APL loading versions of CTR pattern

– 16 – IEC 62341-6-1:2025 © IEC 2025
In cases where more than the white and RGB input primary colours are necessary for luminance
and colour measurements, the medium APL loading RGBCMY box pattern illustrated in Figure 6
shall be used. This pattern is intended for centre luminance and colour measurements under
constant APL loading. Each of the large-coloured boxes in the test pattern is centred on the
nine standard active area locations (see Figure 2) on a black background, with height and width
corresponding to 2/9 of the dimensions of the active area. The centre rectangle is changed to
the desired colour to be measured. However, most of the colours in the surrounding eight
rectangular patterns shall remain constant at their maximum input-referred signal setting as
defined in Table 1. The small dark grey rectangles in the surrounding boxes are used to
compensate for the APL change in the pattern (if necessary) when the centre box colour is
changed. The intent is to maintain the APL at approximately 25 % for all the centre colour
measurements to eliminate any measurement influence due to APL loading. If the input RGB
signal code values of the centre colour are (r,g,b), then the colour of the small grey rectangles
in the surrounding boxes should be changed to (255 – r, 255 – g, 255 – b) when using 8-bit
encoding. For the example shown in Figure 6, when the centre colour is set to an 8-bit signal
value of (192, 192, 192), the small compensating rectangles are set to its complementary value
of (63, 63, 63). If the display active area is not rectangular, then the multi-colour test patterns
may be adjusted to fit the format. However, the APL level and uniform portion of colours shall
be maintained.
NOTE The small complementary rectangles will maintain the pre-gamma APL, but it is possible that it does not
maintain a constant luminance. The centre rectangle can be changed to any desired colour, while the surrounding
rectangles remain fixed except for the compensatory boxes.
Figure 6 – Standard medium APL RGBCMY test pattern used
for centre luminance and colour measurements with 25 % APL

Table 1 – Standard digital-equivalent input signals for rendering the white,
primary and secondary colours in test patterns
Colour Q Equivalent 8-bit digital signal level
Red channel Green channel Blue channel
K (black) 0 0 0
R (red) 255 0 0
G (green) 0 255 0
B (blue) 0 0 255
Y (yellow) 255 255 0
M (magenta) 255 0 255
C (cyan) 0 255 255
W (white) 255 255 255
a) Pattern with 10 % APL b) Pattern with 33 % APL

Figure 7 – Examples of variable signal loading RGBCMY test patterns used
for centre luminance and colour measurements
A more detailed evaluation of signal loading can be performed by starting with the low APL test
pattern, but the size of all boxes increases gradually until the entire screen is filled. Figure 7
shows examples of variable signal loading RGBCMY test pattern with 10 % and 33 % APLs.
The condition and locati
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