ISO 18620:2016

DRAFT INTERNATIONAL STANDARD
ISO/DIS 18620
ISO/TC 130 Secretariat: SAC
Voting begins on: Voting terminates on:
2015-09-14 2015-12-14
Graphic technology — Prepress data exchange — Tone
adjustment curves exchange
Titre manque
ICS: 37.100.01
THIS DOCUMENT IS A DRAFT CIRCULATED
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ISO/DIS 18620:2015(E)
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TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
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PROVIDE SUPPORTING DOCUMENTATION. ISO 2015

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ISO/DIS 18620:2015(E)

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ii © ISO 2015 – All rights reserved

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ISO/DIS 18620
Contents Page
Foreword . iv
Introduction . v
1  Scope . 1
2  Normative references . 1
3  Terms and definitions . 1
4  Symbols and abbreviated terms . 1
4.1  Text styles . 1
4.2  Data types . 2
5  Requirements . 2
5.1  XML Namespace . 2
5.2  File structure . 2
5.3  Interpretation of TransferCurve . 5
5.4  Examples . 5
Annex A (Informative) Schema . 8
Bibliography . 10

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ISO/DIS 18620
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 2.
The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 18620 was prepared by Technical Committee ISO/TC 130, Graphic technology.
iv © ISO 2015 – All rights reserved

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ISO/DIS 18620
Introduction
The aim of this standard is to define a simple format to exchange data of Tone Adjustment Curves (also called
transfer functions and plate curves) between applications including but not limited to colour management,
calibration and raster image processor systems.
In many cases it is useful to be able to provide calibration data for printing plates in a standard form to ensure
easy and accurate exchange of data. Graphic arts raster image processor vendors all provide support for
printing plate calibration and adjustment of tone curves for digital presses using essentially the same data,
however each uses a proprietary format. One consequence of this is that companies providing tools to support
print certification must provide support for many different file formats. Increasingly the importance of
calibration is being recognised by printers who wish to provide a single, often centralised, solution for
calibration and in this context it is becoming increasingly difficult to keep up with the many different formats in
use.
TC130 experts know of no commercial reason for each vendor to adopt a different standard and believe that if
there was an ISO standard format this would be likely to be adopted by the industry. This standard aims to
define the minimum set of data required by all of today's applications and provide a format that is easily
extensible so that additional metadata can be included when agreed on between the parties.
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DRAFT INTERNATIONAL STANDARD ISO/DIS 18620

Graphic technology — Prepress data exchange — Tone
adjustment curves exchange
1 Scope
This International Standard specifies a simple extensible format for the exchange of tone adjustment curves
between applications including but not limited to colour management, calibration and raster image processor
systems.
2 Normative references
The following referenced documents are indispensable for the application 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.
Namespaces in XML 1.0 (Third Edition), W3C Recommendation 8 December 2009, available from
http://www.w3.org/TR/REC-xml-names/.
XML Schema Part 2: Datatypes Second Edition, W3C Recommendation 28 October 2004, Produced by:
World Wide Web Consortium (W3C), Available at http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
transfer curve
a curve that defines the relationship between input code values and output values, imaged or printed
3.2
transfer curve set
a set of transfer curves
4 Symbols and abbreviated terms
4.1 Text styles
The following documentation conventions are used.
Names of XML elements are shown in bold type, for example TransferCurve.
Names of XML attributes are shown in italics, for example SpotColorName.
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ISO/DIS 18620
4.2 Data types
All datatypes used in this International Standard are as defined by XML Schema Part 2: Datatypes.
5 Requirements
5.1 XML Namespace
This International Standard relies on XML to ensure clear communication of metadata. It is very likely that
different systems will want to add elements and attributes whose intended use falls outside of this
specification.
Extension of this sort is well supported by XML and the following rules apply:
 All elements and attributes defined by this International Standard shall use the
namespace ’http://www.npes.org/schema/ISO18620/’.
 Vendor specific attributes and elements may be included and when included shall be defined in a vendor-
specific namespace as described in “Namespaces in XML 1.0”.
 Compliant reader applications may safely ignore vendor specific attributes and elements. These attributes
and elements may enable additional functionality in closed environments but shall not change the base
functionality as defined in elements and attributes defined in this standard.
Such proprietary elements and attributes are out of the scope of this International Standard.
5.2 File structure
5.2.1 General
The file is intended to contain a single transfer curve set comprising one or more transfer curves. A schema is
provided in Annex A for information.
The first line of the file shall be:

5.2.2 TransferCurveSet
A single TransferCurveSet element shall be included and shall be as shown in Table 1.
Table 1 — TransferCurveSet element
1
Name Cardinality Data Type Description
xmlns Required anyURI The namespace shall be declared in accordance
with Clause 3 of Namespaces in XML1.0 (Third
Edition) and shall be
‘http://www.npes.org/schema/ISO18620/’.
Creator Optional string Describes the creator of the document. This is
usually the name and version of the authoring
application used.
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ISO/DIS 18620
CreationDate Optional dateTime The date and time when the file was created.
OperatorName Optional string Describes the operator who created the file.
PressName Optional string The name used to describe the press for which
the data has been created.
MediaName Optional string The name used to describe the media for which
the data has been created
Side Optional enumeration The side of the sheet for which the data has been
created. One of Front or Back.
Note that this attribute should be omitted if the
data applies to both sides of the sheet.
MeasurementFile Optional anyURI URI providing the location of one or more
(more than one measurement file(s) from which the data has been
may be provided) derived.
Note that there is no convention specified for the
URI or for the content of the files.
TransferCurveSetID Optional NMTOKEN TransferCurveSet identifier.
The value selected for this ID should be agreed
between stakeholders.
FormPreparationDetails Optional element Provides details of any specific form preparation
configuration, for example the screening family,
gravure engraving parameters, flexo anilox lpi etc
to which the data relates.
This information is likely to be vendor-specific.
PrintingCondition Optional (unless element Metadata describing the printing condition that
match a standard this adjustment applies to.
printing condition)
This shall be
...