1、National Standard of CanadaCAN/CSA-ISO/IEC 12089-01(ISO/IEC 12089:1997)International Standard ISO/IEC 12089:1997 (first edition, 1997-12-15), has been adopted withoutmodification as CSA Standard CAN/CSA-ISO/IEC 12089-01, which has been approved as a NationalStandard of Canada by the Standards Counci
2、l of Canada.ISBN 1-55324-321-8 February 2001The Canadian Standards Association, which The Standards Council of Canada is theoperates under the name CSA International coordinating body of the National Standards system, (CSA), under whose auspices this National Standard a federation of independent, au
3、tonomoushas been produced, was chartered in 1919 and organizations working towards the furtheraccredited by the Standards Council of Canada to the development and improvement of voluntaryNational Standards system in 1973. It is a not-for-profit, standardization in the national interest.nonstatutory,
4、 voluntary membership association The principal objects of the Council are to foster engaged in standards development and certification and promote voluntary standardization as a means activities. of advancing the national economy, benefiting theCSA standards reflect a national consensus of health,
5、safety, and welfare of the public, assisting producers and users including manufacturers, and protecting the consumer, facilitating domestic consumers, retailers, unions and professional and international trade, and furthering internationalorganizations, and governmental agencies. The cooperation in
6、 the field of standards.standards are used widely by industry and commerce A National Standard of Canada is a standard whichand often adopted by municipal, provincial, and federal has been approved by the Standards Council ofgovernments in their regulations, particularly in the Canada and one which
7、reflects a reasonablefields of health, safety, building and construction, and agreement among the views of a number of capablethe environment. individuals whose collective interests provide to theIndividuals, companies, and associations across greatest practicable extent a balance ofCanada indicate
8、their support for CSAs standards representation of producers, users, consumers, anddevelopment by volunteering their time and skills to others with relevant interests, as may be appropriateCSA Committee work and supporting the Associations to the subject in hand. It normally is a standardobjectives
9、through sustaining memberships. The more which is capable of making a significant and timelythan 7000 committee volunteers and the 2000 contribution to the national interest.sustaining memberships together form CSAs total Approval of a standard as a National Standard ofmembership from which its Dire
10、ctors are chosen. Canada indicates that a standard conforms to theSustaining memberships represent a major source of criteria and procedures established by the Standardsincome for CSAs standards development activities. Council of Canada. Approval does not refer to theThe Association offers certifica
11、tion and testing services technical content of the standard; this remains thein support of and as an extension to its standards continuing responsibility of the accrediteddevelopment activities. To ensure the integrity of its standards-development organization.certification process, the Association
12、regularly and Those who have a need to apply standards arecontinually audits and inspects products that bear the encouraged to use National Standards of CanadaCSA Mark. whenever practicable. These standards are subject In addition to its head office and laboratory complex to periodic review; therefo
13、re, users are cautioned in Toronto, CSA has regional branch offices in major to obtain the latest edition from the organizationcentres across Canada and inspection and testing preparing the standard.agencies in eight countries. Since 1919, the Association The responsibility for approving National St
14、andards has developed the necessary expertise to meet its of Canada rests with thecorporate mission: CSA is an independent service Standards Council of Canadaorganization whose mission is to provide an open and 270 Albert Street, Suite 200effective forum for activities facilitating the exchange of O
15、ttawa, Ontario, K1P 6N7goods and services through the use of standards, Canadacertification and related services to meet national andinternational needs.For further information on CSA services, write toCSA International178 Rexdale BoulevardToronto, Ontario, M9W 1R3CanadaAlthough the intended primary
16、 application of this Standard is stated in its Scope, it is importantto note that it remains the responsibility of the users to judge its suitability for their particular purpose.Registered trade-mark of Canadian Standards AssociationInformation technology Computer graphics and imageCAN/CSA-ISO/IEC
17、12089-01 processing Encoding for the Image Interchange Facility (IIF)February 2001 CSA/1CAN/CSA-ISO/IEC 12089-01Information technology Computergraphics and image processing Encoding for the Image InterchangeFacility (IIF)CSA PrefaceStandards development within the Information Technology sector is ha
18、rmonized with internationalstandards development. Through the CSA Technical Committee on Information Technology (TCIT),Canadians serve as the Canadian Advisory Committee (CAC) on ISO/IEC Joint Technical Committee 1 onInformation Technology (ISO/IEC JTC1) for the Standards Council of Canada (SCC), th
19、e ISO memberbody for Canada and sponsor of the Canadian National Committee of the IEC. Also, as a member of theInternational Telecommunication Union (ITU), Canada participates in the International Telegraph andTelephone Consultative Committee (ITU-T).This International Standard was reviewed by the C
20、SA TCIT under the jurisdiction of the StrategicSteering Committee on Information Technology and deemed acceptable for use in Canada. (Acommittee membership list is available on request from the CSA Project Manager.) From time to time,ISO/IEC may publish addenda, corrigenda, etc. The CSA TCIT will re
21、view these documents for approvaland publication. For a listing, refer to the CSA Information Products catalogue or CSA Info Update orcontact a CSA Sales representative. This Standard has been formally approved, without modification, bythese Committees and has been approved as a National Standard of
22、 Canada by the Standards Council ofCanada.February 2001 CSA International 2001All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission ofthe publisher. ISO/IEC material is reprinted with permission. Inquiries regarding this National Stand
23、ard of Canada shouldbe addressed to CSA International, 178 Rexdale Boulevard, Toronto, Ontario, M9W 1R3.” INTERNATIONAL STANDARD lSO/IEC 12089 First edition 1997-12-15 Information technology - Computer graphics and image processing - Encoding for the Image Interchange Facility (W Technologies de Iin
24、forma tion - Infographie et traitement de Iimage - Codage pour /es accessoires pour khange de Iimage (IIF) Reference number ISO/1 EC 12089: 1997(E) ISO/IEC 12089: 1997(E) Foreword ISO (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form
25、the specialized System for worldwide standardization. National bodies that are members of ISO or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with particular fields of technical activity. ISO and IEC tec
26、hnical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the work. In the field of information technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
27、Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. International Standard ISO/IEC 12089 was prepared by Joint Technical
28、 Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 24, Computer graphics and image processing. 0 ISO/IEC 1997 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronie or mechamcal, including phot
29、ocopying and micro- film, without permission in writing from the publisher. 56 l CH-121 1 ISO/IEC Copyright Office l Case postale Geneve 20 l Switzerland INTERNATIONAL STANDARD 0 ISO/IEC ISO/IEC 12089:1997(E) Information processing (IIF) 1 Scope technology - Computer graphics and image - Encoding fo
30、r the Image Interchange Facility This International Standard defines the encoding rules which shall apply to the representation of IPI-IIF image data. The IPI-IIF data format is defined in ISOLEC 12087-3, called ,Image Interchange Facility (IIF)“. It is Part 3 of the Image Processing and Interchange
31、 International Standard, defined in ISO/IEC 12087. The IPI-IIF facilitates the interchange of digital images. It consists of two major Parts: (1) the IPI-IIF data format (IIF-DF) definition, whose Syntax is described using ASN. 1; (2) the IPI-IIF gateway definition, whose functionality is described
32、by an application programmers interface. The IPI-IIF is based on the definition described in Part 1, Common Architecture for Zmaging (CAI) of the ISO/IEC 12087. Due to the fact that the Syntax of the IIF-DF is expressed using the Abstract Syntax Notation One (ASN.l), defined by ISO/IEC 8824, this St
33、andard makes use of the Basic Encoding RuZes (BER) for ASN. 1, by referring to ISO/IEC 8825 for the definition of encoding rules. NOTE - A rationale for the introduction of new encoding rules in addition to those defined by the BER is given in clause 4. Reference shall be made to this International
34、Standard, and its definitions shall be employed, whenever images are interchanged, according to the IIF-DF, defined in ISO/IEC 12087-3. ISO/IEC 12089: 1997(E) 0 ISO/IEC 2 Normative references The following Standards contain provisions which, through reference in this text, constitute provisions of t
35、his International Standard. At the time of publication, the editions indicated were valid. All Standards are subject to revision, and Parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the Standards indicat
36、ed below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO/IEC 8632:(all Parts), Information technology - Computer graphics - Metafile for the storage and transfer of picture description information. ISO/IEC 8824: 1990, Information technology - Open Systems I
37、nterconnection - Specification of Abstract Syntax Notation One (ASN. 1). ISO/IEC 8825: 1990, Information technology - Open Systems Interconnection - Specification of Basic Encoding Rules for Abstract Syntax Notation One (ASN. 1). ISOIIEC 8825-2: 1996, Information technology - ASN.1 encoding rules: S
38、pecification of Packed Encoding Rules (PER). ISO/IEC 12087- 1: 1995, Information technology - Computer graphics and image processing - Image Processing and Interchange (IPI) - Functional specification - Part 1: Common architecture for imaging. ISOIIEC 12087-2: 1994, Information technology - Computer
39、 graphics and image processing - Image Processing and Interchange (IPI) - Functional specification - Part 2: Programmers imaging kerne1 System application Programme integace. ISO/IEC 12087-3: 1995, Information technology - Computer graphics and image processing - Image Processing and Interchange (IP
40、I) - Functional specification - Part 3: Image Interchange Facility (IIFj. NOTE - Some ISO Standards are technically aligned with CCITT Recommendations, in particular the ASN. 1 Standard (ISO Standards 882418825 and CCITT Rets. X.208/X.209). The differentes between the International Standard definiti
41、ons and the CCITI definitions are quite small, and should not affect interoperability between implernentations written against either document. Within this part of ISO/IEC 12087, the ISO Standards are referenced whenever possible. 0 ISO/IEC ISO/IEC 12089: 1997(E) 3 Definitions and abbreviations ASN.
42、l Abstract Syntax Notation One BER frc Isb 1sB Basic Encoding Rules fraction least significant bit least significant Byte most significant bit most significant Byte msB S sign NOTE - For definitions and abbreviations concerning the Image Processing and Interchange Standard (IPI), refer also to claus
43、e 3 of ISO/IEC 12087-1, ISO/IEC 12087-2 and ISO/IEC 12087-3. ISO/IEC 12089: 1997(E) 0 ISOIIEC 4 Encoding rules for the IIF Syntax entities The encoding of Syntax entities shall conform to the Basic Encoding Rules (BER) for ASN.l - ISO/IEC 8825. NOTE - Using the BER encoding overheads may occur. In p
44、articular, the encoding of a large Pixel data field tan produce considerable space and processing time overhead, when every Pixel is represented as an elementary ASN. 1 data entity, consisting of a ,tag“ and a Jength“ field that proceeds the ,value“ field. For this reason this International Standard
45、 describes additional encoding methods that may be applied to Pixel fields. These methods may neither be regarded as extensions, nor as changes to the tag-length-value concept of the BER. Instead, they only describe how to interpret the data contained in the elementary ASN.l type OCTET STRING, when
46、this elementary type was used to encode an entire field of Pixel values (instead of just one value). Thus, these encoding rules may rather be regarded to lie ,on top of BER encoding/decoding tools. This International Standard defines additional encodings for space-efficient representation of Pixel f
47、ields. They are outlined in clause 5 in conjunction with additional IIF Syntax entities which describe the degree of freedom for the selection of an encoding method. 0 ISO/IEC ISO/XEC 12089: 1997(E) 5 IIF Syntax entities for the representation of Pixel fields The Syntax is expressed in ASN.1 (Abstra
48、ct Syntax Notation One), according to ISO/IEC Standard 8824, “Specification of Abstract Syntax Notation One (ASN.1)” ASN.l is a formal description language. It defines a set of primitive data types, such as INTEGER, ENUMERATED, and REAL and provides a facility to construct new elements with their ow
49、n typing inherent in the structure using the constructors SEQUENCE, SEQUENCE OF and CHOICE. This allows for new data types to be defined which are uniquely recognisable within an application. To make these definitions more readable, textual labels may be associated with the elements in a constructor type. In Order to distinguish different occurrences of the same type within one constructor, various types of tags are provided that may be associated with the constructors elements. Within the semantic description each element (which is either a primitive data type
