ISO/IEC TR 21565:2018
(Main)Information technology — Office equipment — Viewing environment guideline for office equipment
Information technology — Office equipment — Viewing environment guideline for office equipment
ISO/IEC TR 21565:2018 provides an overview of office viewing environment and colour characterization guidelines for use with office equipment, in particular colour printing devices that have digital imaging capabilities, including multi-function devices.
Technologies de l'information — Équipements de bureau — Visualisation de la directive d'environnement pour les équipements de bureau
General Information
Standards Content (Sample)
TECHNICAL ISO/IEC TR
REPORT 21565
First edition
2018-02
Information technology — Office
equipment — Viewing environment
guideline for office equipment
Technologies de l'information — Équipements de bureau —
Visualisation de la directive d'environnement pour les équipements
de bureau
Reference number
ISO/IEC TR 21565:2018(E)
©
ISO/IEC 2018
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ISO/IEC TR 21565:2018(E)
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ISO/IEC TR 21565:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Viewing conditions . 1
4.1 General . 1
4.2 Visual assessment . 1
4.2.1 General. 1
4.2.2 Lighting of indoor workplaces . 2
4.2.3 Graphic technology and photography . 2
4.2.4 Multimedia systems and equipment . 2
4.2.5 Displays for colour proofing . 3
4.3 Colorimetry . 3
4.3.1 General. 3
4.3.2 Basic colorimetry . 3
4.3.3 Graphic technology and photography . 4
4.3.4 Multimedia systems and equipment . 4
4.4 Office equipment . 4
4.4.1 General. 4
4.4.2 Office lighting for imaging . 4
4.4.3 Colour copying machines . 4
5 Guideline for office colour assessment . 5
5.1 General . 5
5.2 Visual assessment . 5
5.3 Colorimetry . 5
5.4 Recommendation . 5
Annex A (informative) International standards related to viewing conditions .6
Annex B (informative) Example of viewing conditions for image comparison between
hardcopy and display . 9
Annex C (informative) Actual office viewing environment .13
Annex D (informative) Recommendation for office viewing conditions .14
Bibliography .15
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ISO/IEC TR 21565:2018(E)
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for
the different types of document should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject
of patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent
rights. Details of any patent rights identified during the development of the document will be in the
Introduction and/or on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 28, Office equipment.
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ISO/IEC TR 21565:2018(E)
Introduction
Viewing conditions for imaging devices such as 2D and 3D printers/scanners, copiers, projectors, fax,
displays and systems are specified in the various international standards and technical reports and
can be categorized according to their objectives. Those objectives are colour assessment such as direct
visual assessment and corresponding colorimetric measurements, defining colour space and colour
comparison between display and print.
CIE 15 provides CIE recommendations for basic colorimetry which recommends CIE illuminant D65 used
whenever possible and when D65 cannot be used, it is recommended that one of the daylight illuminants
D50, D55 or D75 be used. ISO 13655 provides requirements for spectral measurements and colorimetric
computations for graphic arts images and specifies CIE illuminant D50, which is used throughout the
printing industry and provides a consistent and unambiguous framework for assessing colour.
ISO 3664 similarly provides requirements for the visual assessment of colour for graphic technology
and photography and specifies CIE illuminant D50 for the same reasons as ISO 13655. IEC 61966-2-1
provides Default RGB colour space – sRGB which specified CIE illuminant D50 by referring ISO 3664.
These and other international standards designed for graphic arts specify CIE illuminant D50 as the
viewing illuminant ensuring consistent colour evaluation conditions.
The colour temperature of viewing illuminant in international standards specifying office lighting
ranges from 5 000 K to 7 500 K. However, the colour temperature of the viewing illuminant where
the product will be finally seen is largely a matter of personal taste. The general preference is to use
cool colours for a business-like atmosphere (e.g. in offices, factories, shops) and warm colours for a
social atmosphere (e.g. in hotels and homes). In office environment, popular viewing illuminants are
F2 (4 230 K) and F6 (4 150 K) which are generally inexpensive and compromising business and social
atmosphere.
End users have various requirements but in all cases it is beneficial to agree a reference viewing
environment. A typical end user issue is where it is claimed that clouds and snows in original document
have become too reddish in printed copy. Without having an agreed reference viewing illuminant the
cause of such problems is hard to find and may be due, for example, to an incorrect assumption for the
intended viewing environment.
For office equipment, reference viewing conditions are not specified or explained with relevant
background information in any international standards. It is desirable to provide a guideline for
selecting viewing conditions for office equipment colour assessment. This document provides an
overview of an office viewing environment for the purpose of colour assessment, colorimetry and
colour evaluation. It also provides a colour characterization guideline for use with office equipment. The
objective of this document is to avoid misunderstanding of various viewing conditions recommended
by many international standards and to help office equipment manufacturers selecting proper viewing
conditions, so that they can provide products with suitable colour reproduction performance to satisfy
user needs in various viewing environments.
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TECHNICAL REPORT ISO/IEC TR 21565:2018(E)
Information technology — Office equipment — Viewing
environment guideline for office equipment
1 Scope
This document provides an overview of office viewing environment and colour characterization
guidelines for use with office equipment, in particular colour printing devices that have digital imaging
capabilities, including multi-function devices.
2 Normative references
There are no normative references in this document.
3 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 http:// www .electropedia .org/
— ISO Online browsing platform: available at http:// www .iso .org/ obp
3.1
viewing environment
environment in which something is viewed
3.2
viewing conditions
description of the surrounding environmental conditions during the process of viewing
[SOURCE: ISO/TS 18173:2005, 2.28]
4 Viewing conditions
4.1 General
Information relating to viewing conditions are reviewed in this clause, including international
standards, technical reports and web-based articles (as shown in Annex A). In general, colour
assessment related standards specified viewing conditions. Colour assessment can be done basically
in two ways. One is to use the human eyeball as a detector and the human brain to compute colour as a
psychometric feeling – so called visual assessment. The other is to use an artificial sensor as a detector
and a computer chip to compute colour coordinates – so called colorimetry. In multimedia systems and
equipment, viewing conditions are specified for defining colour space. In graphic technology, viewing
conditions are specified for proofing which involves colour comparison of the display and the printer.
4.2 Visual assessment
4.2.1 General
Viewing conditions for the visual assessment of colour are specified in several international standards.
ISO 8995 applies to the lighting of indoor workplaces. ISO 3664 applies to viewing conditions for graphic
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ISO/IEC TR 21565:2018(E)
technology and photography. IEC 61966-2-1 applies to default colour space for multimedia systems and
equipment. ISO 12646 applies to characteristics for displays for colour proofing.
4.2.2 Lighting of indoor workplaces
ISO 8995 specifies lighting requirements for indoor workplaces for people to perform visual tasks
efficiently, in comfort and safety throughout the whole work period. Illuminance, glare limitation and
colour quality are specified for various interiors (areas), tasks and activities. As described in ISO 8995,
the “colour appearance” of a lamp refers to the apparent colour (lamp chromaticity) of the light it emits.
It may be described by its correlated colour temperature. Lamps are usually divided into three groups
according to their correlated colour temperature, such as warm, intermediate and cool. Correlated
colour temperatures are below 3 300 K, 3 300 K to 5 300 K and above 5 300 K respectively. There are
260 different types of interior, task or activity and the distribution of number of types of interior, task
or activity in terms of colour temperatures are:
— 13 belong to colour temperature of at least 4 000 K;
— one belongs to 5 000 K, which is for colour inspection in multi-coloured printing;
— two belong to 5 000 K or more, which are for operating cavity and colour inspection (laboratories);
— one belongs to more than 5 000 K, which is for art rooms in art schools;
— one belongs to 6 000 K or more, which is for white teeth matching;
— one belongs to 6 500 K or more, which is for colour inspection in the chemicals, plastics and rubber
industries; and
— the other 241 belong to ‘not specified’. More than 90 % have no colour temperature given.
4.2.3 Graphic technology and photography
For graphic technology and photography, the viewing conditions are specified in ISO 3664. The viewing
illuminant is specified as CIE illuminant D50. Differences in illumination and viewing conditions can
cause corresponding differences in the colour appearance of substrates, reproductions and artwork. The
objective of specifying the viewing illuminant in ISO 3664 is to reduce errors and misunderstandings
caused by such deficiencies and inconsistencies. But, viewing conditions in ISO 3664 for print are not
common in the general office environment. As a result, sometimes the colour of print in a general office
does not match the colour of print based on ISO 3664 viewing conditions.
Reference ambient illuminance level when comparing an image on reflective print and a colour monitor
is specified as CIE illuminant D50 in ISO 3664 such as "Recommended ambient illumination for colour
monitors: ≤32 lx." and "Required ambient illumination for colour monitors: ≤64 lx". But, it is difficult
to set ambient illumination in an office to be the same as the one specified in ISO 3664 because that is
too dark to see print in general working usage. As a result, the colour of prints do not match between
ISO 3664 and the general office.
4.2.4 Multimedia systems and equipment
IEC 61966-2-1 adopted the viewing conditions specified in ISO 3664 as follows.
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ISO/IEC TR 21565:2018(E)
Specifications for the reference viewing environments are derived from ISO 3664 and shall be as
follows:
a) reference background for the background as part of the display screen, the background is 20 %
of the reference display luminance level (16 cd/m2); the chromaticity should average to x =
0,312 7, y = 0,329 0 (D65);
b) reference surround 20 % reflectance of the reference ambient illuminance level (12,8 lx); the
chromaticity should average to x = 0,345 7, y = 358 5 (D50) illuminance level;
2
c) reference proximal field 20 % of the reference display luminance level (16 cd/m ); the
chromaticity should average to x = 0,312 7, y = 0,329 0 (D65);
d) reference ambient illuminance level 64 lx;
e) reference ambient white point x = 0,345 7, y = 0,358 5 (D50);
f) reference veiling glare 1,0 %.
Furthermore, as described in IEC 61966-2-1:1999, Annex D, the typical ambient illuminance level in a
typical office is 350 lx.
4.2.5 Displays for colour proofing
Comparison of monitor and hard copy images are specified in ISO 12646. At the centre of the white
image defined in ISO 12646:2015, 5.3, the chromaticity of the display should be set to that of D50;
namely u′ = 0,209 2, v′ = 0,488 1 (as specified in CIE Publication 15). The chromaticity obtained for the
white point chosen by the software application vendor is within a circle of radius 0,005 from this point.
The luminance of the monitor should be as high as necessary to visually match an unprinted sheet of
white paper located close to the monitor having an illuminance of 500 lx, as specified in ISO 3664 for
2
viewing condition P2. If that is not possible, the luminance should be at least 80 cd/m but preferably
2
160 cd/m . The conditions within the viewing booth conform to viewing condition P2 of ISO 3664. An
example of viewing conditions for image comparison between hardcopy and display is introduced in
Annex B.
4.3 Colorimetry
4.3.1 General
Viewing conditions for colorimetry (the physical measurement of colour) are specified in several
international standards and technical reports. CIE 15 is the recommendation of the CIE concerning
basic colorimetry. The IEC 61966 series relates to colour characterization of multimedia systems and
equipment. ISO 13655 is the colorimetry standard for graphic technology and photography.
4.3.2 Basic colorimetry
In CIE 15 it is recommended that the following illuminants, defined by relative spectral power
1)
distributions given ISO/CIE 10526:1999, Table 1, be used for general colorimetry.
— CIE standard illuminant A, CIE standard illuminant D65, illuminant B, illuminant C.
— It is recommended that, in the interest of standardization, D65 be used whenever possible.
— When D65 cannot be used, it is recommended that one of the daylight illuminants D50, D55, or D75
defined in ISO/CIE 10526:1999, Table 1 be used.
1) Withdrawn in 2007. Also published as CIE S005/E-1998. CIE standard illuminants for colorimetry, 1998.
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ISO/IEC TR 21565:2018(E)
4.3.3 Graphic technology and photography
For graphic arts images the viewing illuminant is specified in ISO 13655, for example, the spectral
power distribution of the light flux incident on the specimen surface for the measurement should match
CIE illuminant D50. To obtain consistency of instrumental measurement data and visual assessment
data using viewing booths, it is desirable to adopt the same viewing illuminant, such as D50, for both
instrumental measurement and visual assessment.
4.3.4 Multimedia systems and equipment
For colour printers the viewing illuminant is specified in IEC 61966-7-1, for example, default illuminants
and colorimetric observers to derive Tristimulus values and CIELAB colour space is D50. IEC 61966-7-1
also specified D65, F11 and illuminant A as optional viewing illuminants.
4.4 Office equipment
4.4.1 General
As described in ISO 8995-1:2002, 4.6.1, the choice of colour appearance is a matter of psychology,
aesthetics and of what is considered to be natural. The choice depends on illuminance, the colours of the
room and furniture, the surrounding climate and the application. In warm climates a cooler light colour
appearance is generally preferred, and in cold climates a warmer light colour appearance is preferred.
Current office environments contain many different use cases, from high-end graphic arts to low-end
consumer products. Even though there is no standard which specifies how to choose suitable viewing
conditions, end users have various requirements so there are several different viewing condition
assumptions that are desirable in order to resolve each end user issue. If an end user issue, for example,
claimed the clouds and snows in an original document became too reddish in the output copy, it
can be assumed that the viewing illuminant selection of designing colour-matching functions of the
corresponding colour copier was at too high a colour temperature, such as D65.
4.4.2 Office lighting for imaging
The colour temperature of viewing illuminant at which the product will be finally seen is largely a
matter of personal taste. The general preference is to use cool colours for a business-like atmosphere
(e.g. in offices, factories, shops) and warm colours for a social atmosphere (e.g. in hotels and homes).
However there is considerable differences among countries in terms of the most popular light colour
of fluorescent lamp which is commonly used in offices. The favourable colour temperature in both
continental Europe and North America is 4 000 K Neutral White which strikes a balance between
creating a professional atmosphere while providing a feeling of warmth for a friendly working
environment. In the office environment, popular viewing illuminants are F2 (4 230 K) and F6 (4 150 K).
According to ISO 8995-1, as described in 4.2.2, there are 260 different types of interior, task or activity
and no colour temperature is specified for 90 % of those workplaces. F2 (4 230 K) and F6 (4 150 K) are
generally inexpensive among other colour temperatures, and that is one of the biggest reasons these
are popular light sources.
CIE Division 8 conducted worldwide data acquisition of spectral distribution of office lighting for
imaging and distribution of the colour temperatures of office lighting. The data showed that the colour
temperature range is 4 000 K – 5 000 K which is different from the colour temperatures specified in the
above international standards, such as 5 000 K – 7 500 K.
CIE Division 8 data includes reference ambient illuminance level. The data showed that the average
ambient illuminance level is approximately 350 lx, which is about 500 lx divided by square root of two.
This value is 5,5 times the maximum limit of display (see 4.2.4).
4.4.3 Colour copying machines
ISO/IEC 15775 specifies D65 for colour copying machines for colour reproduction evaluation.
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ISO/IEC TR 21565:2018(E)
5 Guideline for office colour assessment
5.1 General
Graphic technology and photography adopted D50 for consistent data comparison. Office equipment
manufacturers accumulate their base data using the same viewing condition as graphic technology and
photography for designing their products for consistent data comparison. On the other hand, end users
are in various viewing environments, so that it is difficult to pick one light source to know every end
user’s degree of satisfaction. A better approach to gain end user satisfaction is to use more light sources
corresponding to each end user’s viewing environment.
5.2 Visual assessment
Assessment operation involving multiple light sources requires a high workload and cost in visual
assessment. An alternative approach is to pick an average light source for the office environment. If
there is a significant mismatch with D50, use a light source to reflect regional and ethnic preferences
appropriately. Annex C shows an actual office viewing environment.
5.3 Colorimetry
Once the spectral characteristics of object colour are available, it is easy to estimate colours of the same
object with multiple light sources so the viewing illuminant can be selected to match each objective.
Measurement data reporting requirements are available in ISO 13655, which includes required
information, recommended information and electronic data reporting.
5.4 Recommendation
Annex D shows the availability of viewing conditions for evaluation. Currently there is no conventional
visual assessment standard in an actual office user environment. In addition, LED light sources with
variable colour temperature, are commercialized and spreading around the world in recent years. So, it
is desirable to develop a viewing evaluation method for office equipment.
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ISO/IEC TR 21565:2018(E)
Annex A
(informative)
International standards related to viewing conditions
Table A.1 — International standards related to viewing conditions
Document reference Scope Typical Remarks Related standards/
number applications benefits
1 ISO 13655 Measurements and Offset lithogra- Definition: D50 ISO 5-2
colorimetrical phy, letterpress,
Most of office ISO 5-4
computations flexography,
users don’t use
gravure and ISO 3664
CIE illuminant
screen printing.
D50 as a viewing
ISO 11664-1
condition.
ISO 11664-2
ISO 11664-4
ISO 28178
2 ISO 3664 Comparison and Prints (both Definition: D50 ISO 5-2
appraisal images photographic
Most of office ISO 5-3
and photome-
users don’t use
chanical) and ISO 13655
CIE illuminant
transparencies,
D50 as a viewing
ISO 23603
Colour monitor condition.
CIE 13.3
projection.
CIE 15
CIE 69
3 ISO 22028-1 Photography and Digital Most of office ISO 11664-1
graphic technology photography users don’t use
CIE illuminant
Digital image
D50, D65.
storage, manip-
ulation and/or
interchange.
4 ISO 8995-1 Lighting require- People to ISO 3864
ments for indoor perform the
a
ISO 6309
workplaces visual tasks
efficiently, in ISO 6385
comfort and
ISO 9241
safety through-
out the whole CIE 13.3
work period.
CIE 16
CIE 17.4
CIE 19.2
a
Withdrawn in 2011.
b
Withdrawn in 2005.
c
Withdrawn in 2003.
d
Withdrawn in 2013.
e
Withdrawn in 2007. Also published as CIE S005/E-1998. CIE standard illuminants for colorimetry, 1998.
f
Withdrawn in 2007. Also published as CIE S002-1986. CIE standard colorimetric observers, 1986.
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ISO/IEC TR 21565:2018(E)
Table A.1 (continued)
Document reference Scope Typical Remarks Related standards/
number applications benefits
CIE 40
CIE 58
CIE S 008/E-2001
CIE 60
CIE 62
CIE 96
CIE 97
CIE 103/5
CIE 117
CIE 129
5 ISO/IEC 15775 Implementation Testing of Most of office ISO 216
and application reproduction users don’t use
ISO 536
of test charts for properties of CIE illuminant
colour copying colour copying D65.
ISO 554
machines machines.
ISO 2469
ISO 2471
ISO 2846-1
ISO 5627
b
ISO 5651
c
ISO 5737
d
ISO 7724-1
d
ISO 7724-3
ISO 8596
ISO 8597
ISO 12641
e
ISO/CIE 10526
f
I
...
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