SIST EN 61966-8:2003
(Main)Multimedia systems and equipment - Colour measurement and management -- Part 8: Multimedia colour scanners
Multimedia systems and equipment - Colour measurement and management -- Part 8: Multimedia colour scanners
Applies to the characterization and assessment of multimedia colour scanners used in computer systems, multimedia and similar applications. Defines measurement conditions, methods of measurement and characterization to facilitate colour management.
Multimediasysteme und -geräte - Farbmessung und Farbmanagement -- Teil 8: Multimedia-Farbscanner
Systèmes et appareils multimédia - Mesure et gestion de la couleur -- Partie 8: Numériseurs couleur
La CEI 61966-8:2001 est applicable à la caractérisation et l'évaluation des scanners couleur utilisés dans les systèmes informatiques et les applications multimédia et similaires. Elle est conçue pour permettre la caractérisation et l'évaluation de la performance objective des scanners couleur multimédia qui peuvent saisir des images couleur et des informations couleur de sortie, telles que les données rouge, verte et bleue à partir des originaux à réflexion. Les résultats mesurés sont destinés à être utilisés pour les besoins de la gestion de la couleur dans les systèmes multimédia. Les conditions de mesure, les méthodes possibles de mesure et la caractérisation sont définies pour permettre la gestion de la couleur. La présente version bilingue (2013-03) correspond à la version anglaise monolingue publiée en 2001-02.
Multimedia systems and equipment - Colour measurement and management - Part 8: Multimedia colour scanners (IEC 61966-8:2001)
General Information
Standards Content (Sample)
SLOVENSKI SIST EN 61966-8:2003
STANDARD
december 2003
Multimedia systems and equipment - Colour measurement and management - Part
8: Multimedia colour scanners (IEC 61966-8:2001)
ICS 17.180.20; 33.160.60 Referenčna številka
SIST EN 61966-8:2003(en)
© Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno
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EUROPEAN STANDARD EN 61966-8
NORME EUROPÉENNE
EUROPÄISCHE NORM May 2001
ICS 33.160.60; 35.180
English version
Multimedia systems and equipment -
Colour measurement and management
Part 8: Multimedia colour scanners
(IEC 61966-8:2001)
Systèmes et appareils multimédia - Multimediasysteme und -geräte -
Mesure et gestion de la couleur Farbmessung und Farbmanagement
Partie 8: Numériseurs couleur Teil 8: Multimedia-Farbscanner
(CEI 61966-8:2001) (IEC 61966-8:2001)
This European Standard was approved by CENELEC on 2001-04-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway,
Portugal, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2001 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61966-8:2001 E
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EN 61966-8:2001 - 2 -
Foreword
The text of document 100/192/FDIS, future edition 1 of IEC 61966-8, prepared by IEC TC 100, Audio,
video and multimedia systems and equipment, was submitted to the IEC-CENELEC parallel vote and
was approved by CENELEC as EN 61966-8 on 2001-04-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (don) 2002-01-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2004-04-01
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexes A, B and ZA are normative and annex C is informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61966-8:2001 was approved by CENELEC as a European
Standard without any modification.
__________
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- 3 - EN 61966-8:2001
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-845 1987 International Electrotechnical --
Vocabulary (IEV)
Chapter 845: Lighting
IEC 61966-2-1 1999 Multimedia systems and equipment - EN 61966-2-1 2000
Colour measurement and management
Part 2-1: Colour management - Default
RGB colour space - sRGB
CIE 15.2 1986 Colorimetry - -
ISO 5-4 1995 Photography - Density measurements--
Part 4: Geometric conditions for
reflection density
ISO 9241-8 1997 Ergonomic requirements for office work EN ISO 9241-8 1997
with visual display terminals (VDTs)
Part 8: Requirements for displayed
colours
ISO 12641 1997 Graphic technology - Prepress digital--
data exchange - Colour targets for input
scanners calibration
ISO 13655 1996 Graphic technology - Spectral --
measurement and colorimetric
computation for graphic arts images
ISO/CIE 10527 1991 CIE standard colorimetric observers - -
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INTERNATIONAL IEC
STANDARD
61966-8
First edition
2001-02
Multimedia systems and equipment –
Colour measurement and management –
Part 8:
Multimedia colour scanners
IEC 2001 Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
W
International Electrotechnical Commission
For price, see current catalogue
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CONTENTS
Page
FOREWORD . 4
INTRODUCTION .6
1 Scope and object . 9
2 Normative references. 9
3 Terms and definitions. 10
4 Letters and symbols. 11
5 Conditions. 12
5.1 General conditions. 12
5.2 Output digital image data . 12
6 Measurement equipment and target of scan. 12
6.1 Spectrophotometer . 12
6.2 Spectroradiometer . 12
6.3 Specification of the target . 13
7 Spectral power distribution of the built-in light source . 15
7.1 Characteristics to be measured. 15
7.2 Measurement conditions . 15
7.3 Presentation of results . 15
8 Tone characteristics. 17
8.1 Characteristics to be measured. 17
8.2 Measurement conditions . 17
8.3 Method of measurement . 17
8.4 Calculation of results . 17
8.5 Presentation of results . 18
9 Inverse tone characteristics . 19
9.1 Characteristics to be calculated . 19
9.2 Method of calculation. 19
9.3 Presentation of results . 20
10 Spectral responsivity characteristics . 20
10.1 Characteristics to be measured. 20
10.2 Measurement conditions . 21
10.3 Method of measurement . 21
10.4 Presentation of results . 21
11 Spatial non-uniformity . 25
11.1 Characteristics to be measured. 25
11.2 Measurement conditions . 25
11.3 Method of measurement . 25
11.4 Presentation of results . 27
12 Mid-term instability. 28
12.1 Characteristics to be measured. 28
12.2 Measurement conditions . 28
12.3 Method of measurement . 29
12.4 Presentation of results . 29
13 Large area spatial crosstalk . 29
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61966-8 IEC:2001(E)
13.1 Characteristics to be measured. 29
13.2 Measurement conditions . 29
13.3 Method of measurement . 30
13.4 Presentation of results . 31
Annex A (normative) Estimation of multiband of wavelength sensitivities. 32
A.1 Quantities to be estimated . 32
A.2 Input to the algorithm. 32
A.3 Output to the algorithm . 33
A.4 Internal variables of the algorithm . 33
A.5 Estimation algorithm . 33
Annex B (normative) Scanner model output data from estimated multiband
sensitivities . 36
Annex C (informative) Examples for the application of the spectral characteristics . 37
C.1 Calculation of the ICC profiles . 37
C.2 Calculation of an optimized conversion for sRGB colour space . 37
Bibliography . 38
Figure 1 – Specification of the target for characterization of multimedia colour
scanners . 13
Figure 2 – Example of graphical representation of multiband spectral reflection of a
colour patch . 14
Figure 3 – Scanning area and the points of measurement . 15
Figure 4 – Example of the normalized spectral power distribution of the built-in light
source. 16
Figure 5 – Example of reporting form of tone characteristics, light flux Φ vs. output
data. 19
Figure 6 – An example of multiband spectral responsivity, s , s and s . 23
R G B
Figure 7 – Example of reporting form of the overall multiband spectral responsitivity,
S s , S s and S s . 25
n R n G n B
n n n
Figure 8 – Measurement points for spatial non-uniformity. 26
Figure 9 – Example of report of mid-term instability. 29
Figure 10 – Target for the measurement of spatial crosstalk. 30
Table 1 – Example of reporting form of a spectral table . 14
Table 2 – Example of multiband spectral characteristics of the light source . 16
Table 3 – Example of reporting form of the polynomial coefficients of the red, green
and blue channel. 18
Table 4 – Example of reporting form of the polynomial coefficients of the red, green
and blue channels . 20
Table 5 – Example of reporting form of the multiband responsitivity characteristics . 22
Table 6 – Reporting form for the measurement of spatial non-uniformity. 28
Table 7 – Reporting form for the measurement of spatial crosstalk. 31
Table 8 – Reporting form of average data and maximum crosstalk given by relative
maximum differences and relative standard deviations of data in red, green and blue
channels (8 bits per channel) . 31
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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MULTIMEDIA SYSTEMS AND EQUIPMENT –
COLOUR MEASUREMENT AND MANAGEMENT –
Part 8: Multimedia colour scanners
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the
two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this international standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61966-8 has been prepared by IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/192/FDIS 100/218/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
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61966-8 IEC:2001(E)
IEC 61966 consists of the following parts, under the general title: Multimedia systems and
equipment – Colour measurement and management:
1
• Part 1: General
1
• Part 2-0: Colour management in multimedia systems
• Part 2-1: Colour management – Default RGB colour space – sRGB
1
• Part 2-2: Colour management – Extended RGB colour space – sRGB64
1
• Part 2-3: Colour management – Default YCC colour space – sYCC
• Part 3: Equipment using cathode ray tubes
• Part 4: Equipment using liquid crystal display panels
1
• Part 5: Equipment using plasma display panels
1
• Part 6: Equipment used for digital image projection
1
• Part 7-1: Colour printers – Reflective prints – RGB inputs
1
• Part 7-2: Colour printers – Reflective prints – CMYK input
1
•
Part 7-3: Colour printers – Transparent prints
1
• Part 8: Multimedia colour scanners
• Part 9: Digital cameras
1
• Part 10: Quality assessment – Colour image in network systems
1
• Part 11: Quality assessment – Impaired video in network systems
Annexes A and B form integral parts of this standard.
Annex C is for information only.
The committee has decided that the contents of this publication will remain unchanged until
2003. At this date, the publication will be
reconfirmed;
withdrawn;
replaced by a revised edition, or
amended.
A bilingual version of this standard may be issued at a later date.
———————
1
To be published.
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INTRODUCTION
This introduction is intended to distinguish the field of application of ISO 12641 and
IEC 61966-8.
In order to standardize the calibration procedure for input scanners used in the printing and
prepress industry, ISO 12641 was published in 1997. This part of IEC 61966 targets colour
scanners for multimedia applications by providing characterization data necessary for colour
management in open multimedia systems. It characterizes any multimedia colour scanners for
consumer use, typically being connected to personal computers so as to capture colour
images and display the colour information, either locally or distributed worldwide.
In such applications, colour management is important. Any red – green – blue data should
have their colorimetric attributes clearly specified. The characterization data reported from
this part of IEC 61966 will be used for the calculation of equipment specific colorimetric
characterization so that colour management in open systems can be conducted.
The capture of colour information in a prepress input scanner usually assumes that the source
is a positive film (transparent) original. The second most common type of original is positive
photographic printing paper (reflective). Recently, prepress input scanners can support
various types of reflective originals in addition to printing paper and can also capture an
image directly from a negative film, although this is not yet very common. Due to these
circumstances, ISO 12641 was established for prepress digital data exchange corresponding
to transparent and reflective originals. However, a standard colour target for transparent film
negative originals has not yet been established.
Spectral sensitivity characteristics of prepress scanners are not derived from the calculation
based on a special colour system or the spectral distribution of printing ink; but are base
signals relatively close to the three primary colours (red, green, blue) acquired for calibration
purposes. The characteristics of the prepress input scanners are guaranteed by the
experience of the operator or the sophistication of the colour processing application so that
subtle variations among the colours appear in the printed result. In fact, printing and prepress
scanners have many settings that are made available to professional users, and the operator
can control the input scanner characteristics in a non-linear fashion to suit their objectives. In
older input scanners, these controls were part of the stand-alone scanner system itself. For
the scanners of the printing industry, these controls are typically part of the colour processing
application software which processes the signals after capture and transfers them to the
general purpose computer (workstation or server). In other words, a highly experienced and
skilled operator can adjust the settings to freely change scanner characteristics such as tone
and colour separation as he desires. Furthermore, scanner characteristics can be changed to
correct and compensate for the characteristics of the original image target, such as colour
fogging, as well as absorb them, and the operator can even change scanner colour separation
conditions (typically cyan, yellow, magenta and black) in anticipation of the later printing
process so as to obtain the most feasible printed result. As such, on the site of the prepress
scanner, good colour separation (reproduction) is and has been dependent on the skill of the
operator.
All prepress input scanners show variation in colour sensitivity characteristics depending on
types, manufacturers, manufactured time and condition. Prepress input scanners tend to show
less variation than other general-purpose multimedia colour scanners because of their usage
in critical colour capturing in a closed system in comparison with the worldwide open system
such as the Internet. There has never been an attempt to standardize the colour character-
istics of prepress input scanners put on the market by different manufacturers.
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61966-8 IEC:2001(E)
However, it is demanded that the printing process should produce essentially the same
results from the same original regardless of the input scanner used. This demand has been
accomplished by the skill of the operator. For this reason, the process of scanning, including
colour processing for the raw data, should involve the human operator, and the total system
be considered as one system. In this human-machine interaction system, the characteristics
can be understood as unified or standardized.
Under these circumstances, and in consideration of the actual work process, ISO/TC 130
(Graphic technology) has established a method using a colour target as stipulated in
ISO 12641 for prepress input scanner calibration that includes functions capable of handling
colour changes accompanying local distortions in colour regions. These targets for both
positive reflective material (photographic printing paper) and positive transmission material
(photographic film) are implemented by the photographic manufacturers on their specific
materials of their particular products.
Multimedia colour scanners for general use which are much less expensive in comparison
with prepress input scanners, are available for small office/home office personal computers.
Targets for scanning are not specified as in prepress input scanners. Images of natural
objects such as the petals of violets, green plants or human skin will be most important. As
many of the users of multimedia colour scanners are not colour experts, it is preferable to
have an automatic system requiring minimal adjustment. The manufacturers of this type of
colour scanner do not provide colorimetric specifications of the red – green – blue data
obtained from their scanner on one hand. On the other hand, the data obtained from the
multimedia colour scanner are easily compressible and compatible to the World Wide Web
and anonymous users will use the colour information in colour reproduction without having
available the specific features of the original generator.
Prepress scanners have been used for many years in the printing and prepress industry and
an environment has already been created in which only prepress scanners meeting certain
critical criteria are selected. This being the case, there is no need for a new evaluation of pre-
press input scanner performance. In such an environment, however, the maintenance of input
scanner quality is important and it is necessary and sufficient to calibrate a scanner using the
appropriate target. The internationally standardized target in ISO 12641 exists for this
purpose.
However, open multimedia systems and composing equipment creates a new environment
different from the conventional printing industry, and the colour scanners used for multimedia
systems have not undergone a similar evaluation process in related industries. In the multi-
media environment, it is assumed that multimedia colour scanners will be used for a variety of
purposes. This means that the initially assumed environment will vary and the functions
required for individual multimedia colour scanners will also vary. In other words, the
multimedia colour scanners supplied to the market and bought by general users might be
designed for different purposes and will not all assure the same quality and characteristics.
This will not be the case if multimedia colour scanner specifications are unified in the future;
however, there is currently no movement in this direction.
Therefore, it would be a great advantage to the general user, if he could evaluate the
characteristics of the multimedia colour scanner he is about to buy and judge whether it suits
his purpose. In other words, knowing the colour reproduction characteristics of each scanner
before making a decision, would allow the user to select a multimedia colour scanner having
characteristics suited to his purpose.
While there is hope that scanners used in a multimedia environment will undergo critical
evaluation in the market over time, the ability to quantitatively evaluate the colour reproduc-
tion of such multimedia colour scanners would be of direct benefit to the critical issue of
colour management that we now face.
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The purpose of IEC 61966-8 is to provide a method for evaluating the colour reproduction of
multimedia colour scanners used in a multimedia environment and allows the specification of
their colour reproduction characteristics from spectral transmission functions, which can be
used for colour management. In an environment such as multimedia that has not yet matured
and is constantly developing, the most critical consideration is determining whether or not a
multimedia colour scanner is suited to the intended purpose. For this reason, IEC 61966-8
must be viewed separately from strict standards (such as ISO 12641) applicable to the
equipment once characteristics have reached a certain level. As such, IEC 61966-8 is
presented as a critical, though interim tool, during the undetermined period of evolution of
these types of scanners.
Colour control within the equipment is out of the scope of this part. This is because the output
data of a multimedia colour scanner depend on the spectral characteristics of the colour
pigments or colour inks of the original and a large variety of originals with different pigments
or inks has to be considered in office and m
...
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