ISO 12653-2:2000

INTERNATIONAL ISO
STANDARD 12653-2
First edition
2000-12-15
Electronic imaging — Test target for the
black-and-white scanning of office
documents —
Part 2:
Method of use
Imagerie électronique — Cible d'essai pour le scanning en noir et blanc
des documents de bureau —
Partie 2: Méthodes d'utilisation
Reference number
ISO 12653-2:2000(E)
©
ISO 2000

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ISO 12653-2:2000(E)
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ISO 12653-2:2000(E)
Contents
Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .1
4 Method .2
4.1 General.2
4.2 Quality.2
5 Procedures .3
5.1 Initial system set-up .3
5.2 Use of image enhancement and compression .3
5.3 Test target scanning.3
5.4 Internal test systems .5
5.5 Frequency.5
6 Evaluation of the results .5
7 Method .5
7.1 Test elements.5
7.2 Test procedures.7
8 Additional targets .20
8.1 General.20
8.2 Continuous tone test target.20
8.3 Target 3: RIT Process Ink Gamut Chart.20
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ISO 12653-2:2000(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO
member bodies). The work of preparing International Standards is normally carried out through ISO technical
committees. Each member body interested in a subject for which a technical committee has been established has
the right to be represented on that committee. International organizations, governmental and non-governmental, in
liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical
Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this part of ISO 12653 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 12653-2 was prepared by Technical Committee ISO/TC 171, Document imaging
applications, Subcommittee SC 1, Quality.
ISO 12653 consists of the following parts, under the general title Electronic imaging — Test target for the black-
and-white scanning of office documents:
� Part 1: Characteristics
� Part 2: Method of use
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ISO 12653-2:2000(E)
Introduction
This part of ISO 12653 describes procedures for evaluating the output quality of a black-and-white scanning system
for office documents, using the test target specified in ISO 12653-1.
Test charts and targets already exist for micrographics and facsimile transmission, but they are specific to these
said fields and do not meet the needs of the users of document scanning systems.
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INTERNATIONAL STANDARD ISO 12653-2:2000(E)
Electronic imaging — Test target for the black-and-white scanning
of office documents —
Part 2:
Method of use
1 Scope
This part of ISO 12653 specifies test methods for evaluating the consistency of the output quality over time from
the black-and-white reflection scanning of office documents using the test target specified in ISO 12653-1 and
other targets.
It is applicable to assessing the output quality of black-and-white scanners used for black-and-white or colour office
documents, with or without half-tone or colour.
It does not apply to colour scanners or scanners used for the scanning of transparent or translucent documents.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 12653. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 12653 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
ISO 446:1991, Micrographics — ISO character and ISO test chart No. 1 — Description and use.
ISO 3334:1989, Micrographics — ISO resolution test chart No. 2 — Description and use.
ISO 12651:1999, Electronic imaging — Vocabulary.
Recommendation ITU T.22, Standardized test charts for document facsimile transmissions.
3 Terms and definitions
For the purposes of this part of ISO 12653, the terms and definitions given in ISO 12651 and the following apply.
3.1
test element
pattern represented on a target
EXAMPLES Millimetre scale, grey scale, circle.
3.2
continuous tone
tonal variation in a document represented by areas of different density
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ISO 12653-2:2000(E)
4 Method
4.1 General
The method for assessing the output quality of black-and-white scanners may be used in the following cases:
� initially to set up the system to yield satisfactory images;
� to check for consistent quality;
� to check that equivalent performance is being obtained from another system.
If the whole system is checked, from input to output, the results obtained may vary depending on the different items
of equipment used. For example, one visual display unit screen may be poorly set up, giving worse quality than a
well set up screen. It is thus important to establish the parts of the system on which to perform the tests. If tests are
required of other parts of the system, then the tests should be repeated as appropriate.
The regular use of these procedures should enable a given level of quality to be maintained.
The method is intended to:
� enable the operator to check that the scanner is correctly set up;
� inform the operator of the capabilities and limits of the scanner;
� enable the user to monitor image quality over a period of time;
� enable the user to draw up quality assessment procedures.
4.2 Quality
Factors which affect the quality achieved by a document scanning system are:
� physical scanning irregularities;
� uniformity of exposure;
� chromatic sensitivity of the photosensing unit;
� contrast;
� threshold setting;
� reproduction of half-tones;
� resolution;
� scale.
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ISO 12653-2:2000(E)
5 Procedures
5.1 Initial system set-up
Tests shall be run under normal operational conditions. Any required warm-up period shall be allowed before these
tests are carried out. Where appropriate, initial calibration routines shall be performed, in accordance with the
manufacturer's instructions, before these tests are carried out.
5.2 Use of image enhancement and compression
The quality of output of a scanning system can be modified by the use of image enhancement and compression
techniques. For these tests, the system shall be operating under normal conditions, with scanner settings as used
for normal documents. It may be an advantage during the initial testing to establish the best settings for these
controls. Software changes may introduce different enhancement or compression techniques. New initial tests may
be needed for validation after such changes.
5.3 Test target scanning
When a test target is scanned, it shall be positioned correctly in the scanner. If the scanner incorrectly moves the
target, the resultant image shall be rejected if any major quality problems are evident. For example, if the target
alignment is substantially incorrect due to a problem with the paper path, the target shall be re-scanned.
Scan the test target (see Figure 1), and either view or print the image.
)
1
NOTE Figure 1 is for information only. It is a reduced reproduction and should not be used as a test target .
1� Test targets can be obtained from AFNOR, Tour Europe, Cedex 7, 92049 Paris La Défense, France. Tel: 33 (1) 42 91 55 55.
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ISO 12653-2:2000(E)
Figure 1 — Sample layout of test target
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ISO 12653-2:2000(E)
5.4 Internal test systems
Many systems include test procedures in their software. These tests can be performed in conjunction with the test
targets defined in this part of ISO 12653.
5.5 Frequency
The frequency of testing of a system should be set by the user, taking advice from the system supplier. It is
preferable to test a system prior to the scanning of a batch of documents and, where necessary, at the end of the
batch. The tests shall also be performed after any maintenance operation or when any system component is
changed.
6 Evaluation of the results
A description of the test to be undertaken is given in 7.2, for each test element on the test target.
The results obtained should be checked on a screen or on hard-copy. The results obtained on a screen may not
agree with those obtained on hard-copy print out. In general, the legibility on screen is inferior t
...