IEC 63145-21-20:2022

Eyewear display - Part 21-20: Specific measurement methods for VR image quality - Screen door effect

IEC 63145-21-20:2022(E) specifies the standard measurement conditions and measurement methods for determining the screen door effect (SDE), which is one of the image quality aspects of eyewear displays of virtual reality (VR) type.

General Information

• Status: Published
• Publication Date: 26-Jul-2022
• ICS: 17.180.99 - Other standards related to optics and optical measurements
• ICS: 31.120 - Electronic display devices
• Technical Committee: TC 110 - Electronic displays
• Drafting Committee: WG 12 - TC 110/WG 12
• Current Stage: PPUB - Publication issued
• Start Date: 27-Jul-2022
• Completion Date: 26-Aug-2022

IEC 63145-21-20:2022 - Eyewear display (VR) - Screen door effect (SDE)

Overview

IEC 63145-21-20:2022 specifies standard measurement conditions and methods for quantifying the screen door effect (SDE) in virtual reality (VR) eyewear displays. SDE is defined as the visibility of inter-pixel areas caused by limited spatial resolution or insufficient pixel fill-factor/aperture ratio. This part of the IEC 63145 series provides reproducible procedures for lab testing of SDE using imaging light measuring devices and defined test patterns.

Key topics and technical requirements

• Scope and purpose: Standardizes how to measure SDE as an image-quality metric for VR eyewear displays.
• Measurement systems: Defines the use of a 2D imaging light measuring device (LMD) with a two-dimensional sensor (e.g., CCD). Key LMD recommendations:
  • Capture at least a ±2.5° measurement field; measurement field shall be less than 18°.
  • Entrance pupil between 2 mm and 5 mm.
  • Minimum performance example: 30 cycles per degree at 50% Michelson contrast at the entrance pupil.
• Standard conditions: Environmental, power, warm-up, and dark-room conditions follow IEC 63145-20-10 and IEC 63145-20-20.
• Test patterns: Prescribed patterns include:
  • Checkerboard pattern (e.g., 5×5) for alignment and basic SDE observation.
  • 4% colour window signal patterns (white, red, green, blue) for localized measurement.
• Measuring points: Centre (single-point) and multi-point (five- or nine-point) measurement layouts; positions can be specified in pixel coordinates or azimuth/elevation angles.
• Procedures and reporting: Includes preparations, measurement procedures, calculations (including Moving Window Average - MWA), and recommended reporting tables and figures. Informative annexes cover MWA algorithms, contrast modulation, visibility, and non-rectangular pixel layouts.

Practical applications and users

• Who uses it:
  • VR headset manufacturers and display designers
  • R&D and optical engineering teams optimizing pixel fill-factor and optics
  • Test laboratories and quality assurance teams performing objective image-quality assessments
  • Certification bodies and standards engineers comparing products or verifying compliance
• Why it’s useful:
  • Enables consistent, repeatable quantification of SDE across products and labs
  • Supports design decisions (pixel layout, optics, aperture) to reduce perceived SDE
  • Useful for benchmarking, quality control, and research into perceptual visibility of pixel structure

Related standards

• IEC 63145-1-2 - Eyewear display: Generic terminology
• IEC 63145-20-10:2019 - Fundamental measurement methods - Optical properties
• IEC 63145-20-20 - Fundamental measurement methods - Image quality

Keywords: IEC 63145-21-20:2022, eyewear display, VR, screen door effect, SDE measurement, 2D imaging LMD, checkerboard pattern, 4% window, pixel fill-factor, Moving Window Average.

Standards Content (Sample)

IEC 63145-21-20 ®
Edition 1.0 2022-07
INTERNATIONAL
STANDARD
colour
inside
Eyewear display –
Part 21-20: Specific measurement methods for VR image quality – Screen door
effect
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IEC 63145-21-20 ®
Edition 1.0 2022-07
INTERNATIONAL
STANDARD
colour
inside
Eyewear display –
Part 21-20: Specific measurement methods for VR image quality – Screen door

effect
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.180.99; 31.120 ISBN 978-2-8322-4253-7

– 2 – IEC 63145-21-20:2022 © IEC 2022
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms, definitions and abbreviated terms . 5
3.1 Terms and definitions . 5
3.2 Abbreviated terms . 6
4 Standard measurement conditions . 6
5 Measurement systems . 6
5.1 Standard coordinate system . 6
5.2 Measurement equipment . 6
5.2.1 2D imaging LMD . 6
5.2.2 Stage conditions . 6
5.2.3 Setup conditions . 6
5.3 Test patterns. 7
5.3.1 General . 7
5.3.2 Checkerboard pattern . 7
5.3.3 4 % colour window signal patterns . 7
5.4 Measuring points . 8
6 Measurement methods for screen door effect . 9
6.1 General . 9
6.2 Preparations . 9
6.3 Measurement procedures . 10
6.4 Calculation . 10
6.5 Report. 12
Annex A (informative) Moving window average (MWA) . 14
Annex B (informative) Contrast modulation and visibility . 18
Annex C (informative) Examples of non rectangular pixel layout . 19
Bibliography . 20

Figure 1 – Example of 5 × 5 checkerboard pattern . 7
Figure 2 – Example of 4 % white window signal pattern . 7
Figure 3 – Example of measuring points for the centre and multi-point measurements . 8
Figure 4 – Example of measuring points in azimuth and elevation angles . 9
Figure A.1 – Example of pseudo code of MWA. 15
Figure A.2 – Example of MWA conversion of 2D luminance data (image) . 16
Figure A.3 – Example of the horizontal cross section . 17
Figure B.1 – Example of MWA image and contrast modulation . 18
Figure B.2 – Visibility under various spatial frequency and contrast . 18
Figure C.1 – Example of non rectangular pixel layout . 19

Table 1 – Example of report table . 13

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EYEWEAR DISPLAY –
Part 21-20: Specific measurement methods
for VR image quality – Screen door effect

FOREWORD
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IEC 63145-21-20 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
110/1433/FDIS 110/1444/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.

– 4 – IEC 63145-21-20:2022 © IEC 2022
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
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at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
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A list of all parts in the IEC 63145 series, published under the general title Eyewear display,
can be found on the IEC website.
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EYEWEAR DISPLAY –
Part 21-20: Specific measurement methods
for VR image quality – Screen door effect

1 Scope
This part of IEC 63145 specifies the standard measurement conditions and measurement
methods for determining the screen door effect (SDE), which is one of the image quality aspects
of eyewear displays of virtual reality (VR) type.
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 63145-1-2, Eyewear display – Part 1-2: Generic – Terminology
IEC 63145-20-10:2019, Eyewear display – Part 20-10: Fundamental measurement methods –
Optical properties
IEC 63145-20-20, Eyewear display – Part 20-20: Fundamental measurement methods – Image
quality
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 63145-1-2 and the
following 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 http://www.iso.org/obp
3.1.1
screen door effect
SDE
visibility of inter-pixel areas due to a spatial display resolution lower than that of the human
visual system or to an insufficient pixel fill-factor/aperture ratio

– 6 – IEC 63145-21-20:2022 © IEC 2022
3.2 Abbreviated terms
2D two dimensional
CCD charge-coupled device
DUT device under test
LMD light measuring device
MWA moving window average
VR virtual reality
4 Standard measurement conditions
Standard measurement conditions (standard environmental conditions, power supply, warm-up
time, dark room conditions) shall comply with IEC 63145-20-10 and IEC 63145-20-20.
5 Measurement systems
5.1 Standard coordinate system
The standard coordinate system shall comply with IEC 63145-20-10 and IEC 63145-20-20.
5.2 Measurement equipment
5.2.1 2D imaging LMD
The 2D imaging light measuring device (LMD) shall comply with IEC 63145-20-10 and
IEC 63145-20-20, if not described otherwise in the following paragraphs.
The 2D imaging LMD (using a two-dimensional sensor such as a CCD) is a kind of a filter-type
LMD. The performances of the 2D imaging LMD shall comply with the LMD specified in
IEC 63145-20-10 and IEC 63145-20-20. A 2D imaging LMD that can capture at least a ±2,5°
measurement field shall be used. The measurement field shall be less than 18°. The valid
measurement field angle of the 2D imaging LMD shall be confirmed and the peripheral image
of the 2D imaging LMD shall confirm the absence of vignetting. The 2D imaging LMD should
have a minimum performance of 30 cycles per degree with 50 % Michelson contrast at the
entrance pupil of 2 mm to 5 mm. The optical measurement capabilities of the LMD, such as
luminance and spectral radiance, should be traceable to national metrology standards under
the same conditions (for example entrance pupil size, measurement field angle and focus
distance in some structures).
NOTE 1 The measurement field of some 2D imaging LMDs is affected by the smaller entrance aperture. The 2D
imaging LMD will have an entrance pupil between 2 mm to 5 mm. (See [1] , [2] for the effect of aperture size.)
NOTE 2 Moiré effect might occur in the 2D imaging LMD due to factors such as pixel structure, rotational
misalignment, etc. If moiré occurs, the measurement cannot be performed. (See [3] for more information about moiré.)
NOTE 3 The peripheral 2D luminance data of the 2D imaging LMD can include vignetting. The valid measurement
field angle can include only 2D luminance data without such peripheral 2D luminance data.
5.2.2 Stage conditions
Stage conditions shall comply with IEC 63145-20-10 and IEC 63145-20-20.
5.2.3 Setup conditions
Setup conditions shall comply with IEC 63145-20-10 and IEC 63145-20-20.
____________
Numbers in square brackets refer to the Bibliography.

5.3 Test patterns
5.3.1 General
The following test patterns shall be specified, and the applied test pattern shall be noted in the
report. When other test patterns are applied, they shall be noted in the report.
5.3.2 Checkerboard pattern
The checkerboard pattern as shown in Figure 1 should be used to measure the applicable
properties and can be us
...