1、INCITS/ISO/IEC 24754-2008 (ISO/IEC 24754:2008, IDT) Information technology Document description and processing languages Minimum requirements for specifying document rendering systemsINCITS/ISO/IEC 24754-2008(ISO/IEC 24754:2008, IDT)INCITS/ISO/IEC 24754-2008 ii ITIC 2008 All rights reserved PDF disc
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5、ITS (InterNational Committee for Information Technology Standards) as an American National Standard. Date of ANSI Approval: 12/18/2008 Published by American National Standards Institute, 25 West 43rd Street, New York, New York 10036 Copyright 2008 by Information Technology Industry Council (ITI). Al
6、l rights reserved. These materials are subject to copyright claims of International Standardization Organization (ISO), International Electrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council (ITI). Not for resale. No part of this pu
7、blication may be reproduced in any form, including an electronic retrieval system, without the prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW, Washington, DC 20005. Printed in the United States of America iiiForeword ISO (the
8、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 IECparticipate in the development of International Standards through technical committees estab
9、lished by therespective organization to deal with particular fields of technical activity. ISO and IEC technical committeescollaborate in fields of mutual interest. Other international organizations, governmental and non- governmental, inliaison with ISO and IEC, also take part in the work. In the f
10、ield of information technology, ISO and IEC haveestablished a joint technical committee, ISO/IEC JTC 1.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.The main task of the joint technical committee is to prepare International Standards. Draft
11、International Standardsadopted by the joint technical committee are circulated to national bodies for voting. Publication as an InternationalStandard requires approval by at least 75 % of the national bodies casting a vote.Attention is drawn to the possibility that some of the elements of this docum
12、ent may be the subject of patent rights.ISO and IEC shall not be held responsible for identifying any or all such patent rights.ISO/IEC 24754 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, SubcommitteeSC 34, Document description and processing languages.INCITS/ISO/I
13、EC 24754-2008 ITIC 2008 All rights reservedAMERICAN NATIONAL STANDARD INCITS/ISO/IEC 24754-20081 Information technology Document description and processinglanguages Minimum requirements for specifying documentrendering systems1 ScopeWhen a structured document is interchanged between an originator an
14、d a recipient, the recipient refers to the stylespecifications that the originator provides to reconstruct the presentation. However, when the recipient does nothave sufficient rendering functionality, it may fail to reconstruct the presentation output as the originator expected.In order to preserve
15、 presentation output in the course of interchange, the originator and recipient need to negotiateover functionalities referring to the specifications of document rendering systems. To satisfy this requirement, thisstandard provides the minimum requirements for specifying document rendering systems.
16、The documentspecification format shall have the same minimum requirements described here.This International Standard can apply to the document processing environment, where a document is given in alogically structured format which is expressed by a structure markup language, and the visual represent
17、ation of thedocument is described by means of the external style and layout specifications which a style and layoutspecifications language provides. The visual representation of the given document is generated when the style andlayout specifications are applied to the logical structure by a document
18、 rendering system.This International Standard provides an abstract list of the features that a rendering system for an authoreddocument may have. The list provides a frame of reference, against which the user and implementor can comparethe features of document rendering systems. However, this Intern
19、ational Standard does not specify a concreteinterchange syntax or direct how each document rendering system shall behave.This International Standard provides the minimum requirements to specify the features that a document renderingsystem which transforms formatting objects to rendering output. It m
20、ay be used as a frame of reference, againstwhich the user, implementer, or software agent may compare the features of a document rendering system.According to these requirements, the user may express what he or she expects of a document rendering system,the implementer may describe the functionality
21、 and capability of the document rendering system that he or sheimplements, and the software agent may negotiate a minimum set of functionality and capability that are sharedacross different document rendering system implementations.2 Terms and definitions2.1 document rendering systemsoftware agent w
22、hich takes in formatted document and generates rendered output2.2 renderingtransforming of a structured document from a certain set of constraints to another set of constraintsNOTE: In most cases, a rendered document has stronger constraints than a pre-rendering document does.2.3 featurecharacterist
23、ic which a document rendering system supports in order to process a document, particularly at timeswhen the document rendering system negotiate the rendering content with physical boundaries, e.g. line break orpage break, of the output media2.4 paged mediaform of media, which is divided into one or
24、more smaller repetitive areas, each of which has its ownindependent geometric attributes ITIC 2008 All rights reserved2 geometric part of a page that has static position and can appear at the same position on sequential pages2.6 areaarbitrary part on a page that may have a floating position or be ha
25、ndled as a flowed object2.7 headera set of objects that are positioned at the beginning of each page of a document, which may include such objectsas page number, title of document, etc.2.8 footerobjects that are positioned at the end of each page of a document, which may include such objects as page
26、number, title of document, etc.2.9 operatora person who interacts with a document or with the document rendering system in order to print or display thedocument3 Features of a document rendering system3.1 General description of a document rendering system3.1.1 Supported output deviceThe output devic
27、e(s) that the document rendering system supports are described. E.g. printing systems andbrowsers.3.1.2 Supported document formatsThe document formats, e.g. XML, RTF, which the document rendering system supports to express the logicalstructure of a given document are described.3.1.3 Supported style
28、languagesThe style specification languages, DSSSL and other style specification languages, that the document renderingsystem supports are described.3.1.4 Rendering media dimensionThe dimension of the rendering media, whether it is paged media or non-paged media, is described here. If therendering me
29、dia is paged, supported page sizes are described, e.g. A4, Letter, Legal.3.1.5 Colour supportThe level of support for colour is described, referring to whether colour is supported by the document renderingsystem, and if colour is supported, what colour profiles are supported. Colour system, e.g. RGB
30、 and CMYK, anddepth of colour, e.g. 8-bit (256 colours) and 24-bit (16 million colours).3.1.6 Dynamic content generationThe support for dynamically-generated content, meaning content calculated by and supplied by the stylesheeteither as fixed value or conditionally-generated based on the presence or
31、 absence of data at rendering time.2.5 regionINCITS/ISO/IEC 24754-2008 ITIC 2008 All rights reserved3 Supported coded character standards and encoding schemes are described. E.g. UTF-8, SHIFT_JIS, KS-5601.3.1.8 Composition of combined charactersThe level of support for the composition of combined sy
32、llabic characters, whether the document rendering systemsupports the stacking of combined characters and environmental glyph alteration are supported, is described. E.g.Thai, Arabic.3.1.9 Directionality of textSupport for the inherent directions of the progression of text (from left to right, right
33、to left or top to bottom) andlines (from top to bottom, right to left or left to right) is described.3.1.10 Rendering of white-space charactersThe interpretation of white-space characters, e.g. tab, space, carriage return and line feed, is described. A string ofwhite-space characters may be collapse
34、d or may be interpreted literally. Additionally, white-space characters maybe removed before or after line breaks.3.1.11 Font substitutionSupport for font substitution mechanism, e.g. font substitution based on ISO/IEC 9541-1, is described.3.1.12 Font-resource portabilityCapability of embedding and
35、retrieving a font resource is described. If the document rendering system supportsfont-resource portability, it can extract an embedded font resource from the document and use it for rendering.3.1.13 Embedding of non-standard characters and glyphsSupport for the embedding of non-standard characters
36、and glyphs, e.g. glyphs registered by ISO/IEC 10036, isdescribed.3.2 Description of pagination and rendering of page layout3.2.1 Page geometry3.2.1.1 Simple page layoutThe attributes, e.g. page width and height, and margin and padding on top, bottom, left and right, of a page that thedocument render
37、ing system supports are described.3.2.1.2 Columnar paginationThe level of support for columnar pagination, i.e. whether columns are supported, and whether the column gap canbe specified, etc. is described.3.2.1.3 Region setting and positioningBasic attributes, e.g. width, height, margin and padding
38、on top, bottom, left and right, and positions in the page, ofthe regions that the document rendering system can specify are described.3.2.2 Page-geometry sequencingSupport for different types of page-geometry sequencing is described. Example types for page-geometrysequencing are single page ordering
39、, repeatable page ordering, and conditional page ordering. Example types forconditional page ordering are page parity and page position.3.1.7 Supported coded character sets and encoding schemesINCITS/ISO/IEC 24754-2008 ITIC 2008 All rights reserved4 3.2.3 Page flowSupport for static content, paginat
40、ed content and flow maps is described. E.g. document title, page header, pagefooter, sidebars and multiple flows.3.3 Layout independent formattingThis subsection provides a list of features that are independent from the layout of the document.3.3.1 Z-indexSupport for the specification of the z-index
41、 depth level of an area is described.3.3.2 Relatively-positioned areasSupport for relatively-positioned areas, or floats, for graphics and other objects is described. Treatments availablefor surrounding text are described. E.g. tight, box and arbitrary shape.3.3.3 Absolutely-positioned areasSupport
42、for absolutely-positioned areas for graphics and other objects is described. The available bases for theabsolute measurements are described. Treatments available for surrounding text are described. E.g. tight, box andarbitrary shape.3.3.4 AnnotationSupport for footnote, endnote and side note, the no
43、te body and the reference to the note is described.3.3.5 Cited contentSupport for references to cited content that will be replaced at rendering time is described.3.3.6 Dynamic content alterationSupport for content alteration that is triggered by the rendering environment, operator interaction or ot
44、her conditionsis specified.3.4 TablesThis subsection provides a list of features that relates to the rendering of tables.3.4.1 Table geometrySupported table geometry, e.g. width, height, padding and margin, is described.3.4.2 Table captionSupport for table captions is described.3.4.3 Table headerSup
45、port for the table header and its behaviour is described. Support for the orientation of headers and iteration ofheaders after the page break when the table spans across pages, is described.3.4.4 Table footerSupport for the table footer and its behaviour is described. Support for the orientation of
46、footers and iteration offooter before the page break when the table spans across pages, is described.INCITS/ISO/IEC 24754-2008 ITIC 2008 All rights reserved5 3.4.5 Table backgroundSupport for the types of background for a table, e.g. the placement of an image or the colour, is described.3.4.6 Comple
47、x table compositionsThe level of support for complex table compositions is described here, based on the structure set forth in ISO/IECTR 19758.3.5 ListsThis subsection provides a list of features that relates to the rendering of lists.3.5.1 List item dimensionsSupport for the geometry of the list, e
48、.g. widths, heights, paddings and margins of the list item label and the list itembody, is described here.3.5.2 List item identificationSupport for the identification of list items is described, including techniques such as enumeration and itemisation,and the types of symbols that can be supplied as
49、 list item labels.3.6 Block formattingThis subsection provides a list of features that relates to the rendering of blocks.3.6.1 Block geometrySupport for the geometry of a block of lines, e.g. width, height, margins, paddings, line leading and line-stackingstrategy, is described here.3.6.2 Wrapping of charactersSupport for the wrapping of characters is described, e.g. the wrapping of characters that often takes place forpunctuation characters in East Asian scripts, such as Chinese, Japanese and Korean. This is
