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1、I NTE R NATI ONAL STANDARD ISOIIEC 12087-3 First edition AMENDMENT 1 1995-02-1 5 1996-1 2-1 5 Information technology - Computer graphics and image processing - Image Processing and Interchange (IPI) - Functional specification - Part 3: Image Interchange Facility (IIF) AMENDMENT I : Type definition,
2、scoping, and logical views for image interchange facility Technologies de linformation - Infographie et traitement de limage - Traitement et change de limage (/Pl) - Spcification fonctionnelle - Partie 3: Accessoires pour lchange dimages (/IF) AMENDEMENT 7: Dfinition de type, domaine dapplication et
3、 vues logiques pour les accessoires pour lchange dimages (IIF) This material is reproduced from IS0 documents under International Organization for Standardization (ISO) Copyright License number IHSIICCI1996. Not for resale. No part of these IS0 documents may be reproduced in any form, electronic ret
4、rieval system or otherwise, except as allowed in the copyright law of the country of use, or with the prior written consent of IS0 (Case postale 56,1211 Geneva 20, Switzerland, Fax +41 22 734 10 79), IHS or the IS0 Licensors members. Reference number ISO/IEC 12087-3:1995/Am.l:1996(E) Copyright Inter
5、national Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/02/2007 21:41:13 MDTNo reproduction or networking permitted without license from IHS -,-,- - STD-IS0 32087-3-ENGL 3775 = 4853703 Ob7352Li 7bZ m ISO
6、DEC 12087-3: 1995lAmd.l: 1996(E) Foreword IS0 (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of Int
7、ernational Standards through technical committees established by the respective organization to deal with particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liais
8、on with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and IEC have established a joint technical committee, ISO/IEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an Int
9、ernational Standard requires approval by at least 75 % of the national bodies casting a vote. Amendment 1 to International Standard ISO/IEC 12087-3: 1995 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology, Sub- committee 24, Computer graphics and image processing. O ISO/
10、IEC 1996 All rights reserved. Unless otherwise specified, 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. Printed in Switzerland ISO/IEC Copyright
11、Office Case postale 5 6 CH-1211 Genve 20 Switzerland ii Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/02/2007 21:41:13 MDTNo reproduction or networking permitted without license
12、from IHS -,-,- STD*ISO 12087-3-ENGL 1795 l851703 Ob73525 bT8 O ISOAEC ISOAEC 12087-3:1995/Amd.l: 1996(E) Type definition, scoping, and logical views for image interchange facilty 5 The IIF data format (IIF-DF) . . . . . 5.1 Basic features of the IIF-DF . . . . . . . Add the following new subclause:
13、5.1.5 Segment Structure of IIF Data Stream The content of an IIF data stream consists of zero or more segments, hierarchically structuring the data in a tree like manner. Considering ASN.1 constructs as an alphabet, IPI Part3 (IIF) can be seen as a grammar which combines elements of this alphabet to
14、 build entities carrying image processing specific semantics as defined in IPI Part i and Part 2. In addition to the straightforward usage of these entities, an application may select one, two or more of them, group them together, and associate some additional or new semantics with such a set. Segme
15、nts provide the mechanisms to make that grouping persistent. Each IIF segment has three parts. The first part, called prolog (entity number 90i), serves as the definition space for attributes that apply to the second part, called body (entity number 010). The prolog provides also facilities to assoc
16、iate a segment with a unique name and user defined label. These can be used as handles while processing the IIF data stream. The prolog may also contain a reference to a segment type definition in order to constrain the structure of segment to conform that definition. The body of a segment contains
17、ail IPI-CAI data types required to interchange image and image related data as well as types necessary for the application specific structuring of these data. The third part of a segment, called epilog (entity 902), is provided for syntactical and processing reasons. It specifies a mark-up denoting
18、the boundary of a segment, and it may contain useful IIF profile dependent or application specific information to facilitate random access to an IIF data stream residing in the memory buffer or on a file. The main objectives which are addressed by the introduction of segmentation into IIF can be sum
19、marised as follows below. 5.1.5.1 Attribute Inheritance and Management Each segment may contain a collection of image related data (entity number 301), image attributes (entity number 401), image annotations (entity number 501) and basic data types (entity number 602) referred to as “segment attribu
20、tes“ (entity number 903). These attributes are inherited by the child segments i.e. by segments nested in the given segment. A child segment may in turn specify an attribute which has a higher precedence than the inherited one and so modify it. In this sense, every segment carries a set of attribute
21、s, which are either specified in that segment or inherited from the parent segment. These attributes are considered as default attributes of the given segment and apply to the content specified in the body of a segment, unless they are overwritten by newly specifying them immediate in the body of a
22、segment (refer to syntax entity No. 008, ContentsBoy) . 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/02/2007 21:41:13 MDTNo reproduction or networking permitted without licens
23、e from IHS -,-,- ISO/IEC 12087-3:1995/Amd.l:19%(E) O ISO/IEC The definition of an attribute allows to specify the type of an attribute and the value of an attribute. The type of an attribute is specified as a hierarchy of context sensitive ASN.1 tags referring to the grammar of IIF data stream. The
24、value of an attribute is specified according to definitions provided in IPI-CAI. Explicit management scheme for instantiation of attributes is outlined by the segment type definition facility (see clause below on constraints on topology and attributes of a segment). This scheme defines the rules of
25、presence and propagation for each attribute specified in the definition of a segment type (via construct SegmenrSrructure of SegmentTypeDefn entity number 910). The presence and propagation rule for an attribute is a combination of predicates which shall be applied to the concerned attribute by an a
26、pplication processing the content of a segment (Attributeccurrence entity number 912). 5.1.5.2 Constraints on Topology and Attributes of a Segment Any segment may be constrained to have a specific topology and a prescribed set of segment attributes associated with this topology. This is achieved by
27、declaring the segment to be of a given “segment type“. The constraints on topology of a segment structure are defined in terms of a nested combination of orderings (sequence, set, choice) and occurrences (one or more required or optional items). A set of attributes can be associated, in the way prov
28、ided in this specification, with every item of the segments structure. Thus, the segment type is defined by the specification of constrains on its topology and by the specification of its attributes. A segment which is constrained to be of a given type must possess the topology and attributes as pre
29、scribed in the definition of that type. Note however, that for the attributes specified in a definition of segment type, the value of an attribute, and any part of the definition of an attribute type can remain undefined. See in that context data-required construct in several entities, e.g. IndexND
30、(entity number 308), CompoundDataType (entity number 603) etc. An undefined type and value specification can be completed, without the violation of a segment type, by an application using the segment of a such type. Therefore, in an IIF data stream the segments adhering to the same type can have not
31、 only different content, different values of attributes, but also their attributes can differ in some parts of its type definition. Such segments may constitute thereby hierarchy of classes of segment types. Note also that an application can associate with given segment type, or with given class of
32、segment types, specific methods how to process the content of such segments (see the construct user-label in SegmentProlog entity number 901, and similar construct in SegmentTypeDefn entity number 910). 5.1.5.3 Symbolic References Each segment may contain a collection of definitions, each of which i
33、s associated with an identifier. The constructs which can be defined in such a way (with help of the Numedltems entity, entity number 904) are image related data, image attributes, image annotations, basic data types, image structures and segment types. In contrast to segment attributes, these const
34、ructs do not apply to the content specified in the body of a segment, and are not directly inherited by the child segments. Instead, they are used as targets for references in other segments which may need the same constructs: such segments will rather make a symbolic reference to an appropriate def
35、inition than duplicate the same definitions in their headers or bodies. Reference mechanism is implemented within the name and address space associated with the segments. This space consists of segment identifiers unique in given context. By definition, such a context can be for example a specific I
36、IF data stream, or a referenced external data repository. Note that by merging together IIF data streams, or different external data repositories, the uniqueness of identifiers must be preserved. The technique recommended to achieve this goal is to use the addressing scheme as specified in ISOAEC 10
37、031, Distributed Office Application Model (DOAM), Part 2: Distinguished Object Reference (DOR) to generate segment identifiers. 2 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 04/02
38、/2007 21:41:13 MDTNo reproduction or networking permitted without license from IHS -,-,- STD-IS0 12087-3-ENGL 1775 4851903 Ob73527 470 O ISOAEC ISOAEC 12087-3: 1995/Amd.l:19%(E) 5.1.5.4 Logical Views of Image Data Instead of physically supplying the image data in its content, a segment may use there
39、 symbolic references into the image structure describing some physical data set. Since the image structure fully corresponds to the image data, such references into image structure are equivalent to (i.e. can be resolved to result in) references into image data. A logical view of a remote data set i
40、s a segment which has symbolic references into parts of image data supplied elsewhere. The referencing mechanism is implemented through the naming of image structures within the name and address space as described above in clause on symbolic references. See also in this context the definition of the
41、 IIF syntax entity, Referencellnit (entity number 201 ). As long as the reference path is a-cyclic, the targets of references may themselves be symbolic references, resulting in a mechanism for logical reordering of physical image data. It is obvious that the logical views required by the applicatio
42、n can not go beyond the granularity implied by the physical data set, Le., the atomic elements a logical view consists of can not be smaller than referable elements of the referenced structure. This implies, that some application may need to restructure the physical data set collected by another app
43、lication in order to offer a more detailed granularity required by its own semantics. 5.1.5.5 Information Integration Support An IIF data stream may need to integrate other data. These could be modelled as another IIF data stream, as a flat or structured stream of ASN.1 tokens following rules of a g
44、rammar other then IIF, as an arbitrary octet string, or as any other stream of bits. Structuring facilities and mechanisms associated with these facilities allow to differentiate precisely between all three cases providing well defined rules how to access the data in the best way. External reference
45、 mechanism allows that a repository of information can reside outside the IIF data stream. The ASN. object identification scheme is used to provide necessary information about the syntax of referenced data. The so called EntityHandle (entity number 917) offers a flexible mechanism to choose between
46、different kind of pointers to the data structured according to IIF grammar and to the data encoded according to any ASN. i or even non-ASN. grammar. The syntax of this pointer has well defined semantics within IIF grammar but it is also flexible enough to point into other repositories (e.g. Common O
47、bject Request Broker specified by WOpen and Object Management Group). The possibility to type segments introduced by SegmentTypeDefn entity provides a facility to bind given application specific processing methods to required parts of the IIF data stream. 5.1.5.6 Access Support While stored in a fil
48、e or buffered in the memory of a computer, an IIF data stream usually represents large amount of sequential organised data. Therefore random access to an arbitrary chosen part of these data is, somehow, not trivial problem in terms of time and consumed resources. It can be, however, significantly fa
49、cilitated by the “a priori“ knowledge of generic logical structure for given IIF data stream. Such a generic structure will consist of a hierarchy of segment types definitions, and it can be provided as a type guide in ContentsHeader entity, or as an explicit profile definition in Profile entity. Based on possible unique application specific semantics which can be associated with the element