1、INTERNATIONAL STANDARD ISOIIEC 109184 First edition 1994-02-15 Information technology - Digital compression and coding of continuous-tone still images: Requirements and guidelines Technologies de /information - Compression numdrique et codage des images fixes de nature photographique: Prescriptions
2、et lignes directrices Reference number ISOAEC 10918-1:1994(E) Processed and adopted by ASC NCITS and approved by ANSI as an American National Standard.Date of ANSI Approval: 1/11/99Published by American National Standards Institute,11 West 42nd Street, New York, New York 10036Copyright 1999 by Infor
3、mation Technology Industry Council (ITI).All rights reserved.These materials are subject to copyright claims of International Standardization Organization (ISO),International Electrotechnical Commission (IEC), American National Standards Institute (ANSI), andInformation Technology Industry Council (
4、ITI). Not for resale. No part of this publication may be reproducedin any form, including an electronic retrieval system, without the prior written permission of ITI. All requestspertaining to this standard should be submitted to ITI, 1250 Eye Street NW, Washington, DC 20005.Printed in the United St
5、ates of AmericaAdopted by INCITS (InterNational Committee for Information Technology Standards) as an American National Standard.Date of ANSI Approval: 1/11/99Published by American National Standards Institute,25 West 43rd Street, New York, New York 10036Copyright 2002 by Information Technology Indu
6、stry Council (ITI).All rights reserved.These materials are subject to copyright claims of International Standardization Organization (ISO), InternationalElectrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council(ITI). Not for resale.
7、No part of this publication may be reproduced in any form, including an electronic retrieval system, withoutthe 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 AmericaISO/IEC
8、10918-1:1994(E) Contents Page 1 scope 1 2 Normative references 1 3 Definitions, abbreviations and symbols . 1 4 General . 12 5 Interchange format requirements . 23 6 Encoder requirements . 23 7 Decoder requirements . 23 Annexes A Mathematical definitions 24 B Compressed data formats 3 1 C Huffman ta
9、ble specification 50 D Arithmetic coding ; 54 E Encoder and decoder control procedures . 77 F Sequential DCT-based mode operation . 87 G Progressive DCT-based mode of operation . 119 H Lossless mode of operation . 132 J Hierarchical mode of operation . 137 K Examples and guidelines . 143 L Patents 1
10、79 M Bibliography . 181 63 ISO/IEC 1994 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. ISO/IEC Co
11、pyright Office l Case postale 56 l CH-1211 Genke 20 l Switzerland Printed in Switzerland ISO/IEC 10918-1:1994(E) Foreword IS0 (the International Organization for Standardization) and IEC (the Inter- national Electrotechnical Commission) form the specialized system for worldwide standardization. Nati
12、onal bodies that are members of IS0 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. IS0 and IEC technical committees collaborate in fields of mutual interest
13、. Other international organizations, governmental and non-governmental, in liaison 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/lEC JTC 1. Draft International Standards adopted by the joint technica
14、l 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/lEC 10918- 1 was prepared by Joint Technical Com- mittee ISO/lEC JTC 1, Informafion technology, Subco
15、mmittee SC 29, Coding of audio, picture, multimedia and hypermedia information, in collaboration with the CCITT. The identical text is published as CCITT Recommendation T.81. ISO/lEC 10918 consists of the following parts, under the general title Information technology - Digital compression and codin
16、g of continuous-tone still images: - Part I : Requirements and guidelines - Part 2: Compliance testing Annexes A, B, C, D, E, F, G, H and J form an integral part of this part of ISO/lEC 10918. Annexes K, L and M are for information only. Patents During the preparation of this part of ISO/IEC 10918,
17、information was gathered on patents upon which application of the standard might depend. Relevant patents were identified as belonging to the patent holders listed in annex L. However, ISO/lEC cannot give authoritative or comprehensive information about evidence, validity or scope of patent and like
18、 rights. The patent holders have stated that licences will be granted under reasonable terms. Communications on this subject should be addressed to the patent holders (see annex L). . . . 111 ISOllEC 10918-1:1994(E) Introduction This part of ISO/IEC 10918 was prepared by CCIlT Study Group VIII and t
19、he Joint Photographic Experts Group (JPEG) of ISO/IEC JTC l/SC 29/WG 10. This Experts Group was formed in 1986 to establish a standard for the sequential progressive encoding of continuous-tone grayscale and colour images. This part of ISO/IEC 10918 sets out requirements and implementation guideline
20、s for continuous-tone still image encoding and decoding processes, and for the coded representation of compressed image data for interchange between applications. These processes and representations are intended to be generic, that is, to be applicable to a broad range of applications for colour and
21、 grayscale still images within communications and computer systems. ISO/IEC 10918-2 sets out tests for determining whether implementations comply with the requirements for the various encoding and decoding processes specified in this part of ISO/IFX 10918. The requirements which these processes must
22、 satisfy to be useful for specific image communications applications such as facsimile, Videotex and audiographic conferencing are defined in CCITT Recommendation T.80. The intent is that the generic processes of Recommendation T.80 will be incorporated into the various CCITT Recommendations for ter
23、minal equipment for these applications. In addition to the applications addressed by the CCITT and ISO/IEC, the JPEG committee has developed a compression standard to meet the needs of other applications as well, including desktop publishing, graphic arts, medical imaging and scientific imaging. Thi
24、s Specification aims to follow the guidelines of CCITT and ISO/IEC JTC 1 on Rules for presentation of CCllT 1 ISOIIEC common text. iv ISO/IEC 1091 - specifies processes for converting compressed image data to reconstructed image data: - gives guidance on how to implement these processes in practice;
25、 - specifies coded representations for compressed image data NOTE - This Specification does not specify a complete wded image representation. Such representations may include certain parameters, such as aspect ratio, component sample registration, and colour space designation, which are application-
26、 dependent. 2 Normative references The following CCITI Recommendations and International Standards contain provisions which, through reference in this text, constitute provisions of this CCITI Recommendation I International Standard. At the time of publication, the editions indicated were valid. All
27、 Recommendations and Standards are subject to revision, and parties to agreements based on this CCITT Recommendation I International Standard are encouraged to investigate the possibility of applying the most recent edition of the Recommendations and Standards listed below. Members of IEC and IS0 ma
28、intain registers of currently valid International Standards. The CCITT Secretariat maintains a list of currently valid CCITT Recommendations. - CCIlT Recommendation T-80 (1992), Common components for image compression and communication - Basic principles. 3 Definitions, abbreviations and symbois 3.1
29、 Definitions and abbreviations For the purposes of this Specification, the following definitions apply. 3.1.1 abbreviated format: A representation of compressed image data which is missing some or all of the table specifications required for decoding, or a representation of table-specification data
30、without frame headers, scan headers, and entropy-coded segments. 3.1.2 AC coefficient: Any DCT coeffkient for which the frequency is not zero in at least one dimension. 3.13 (adaptive) (binary) arithmetic decoding: An entropy decoding procedure which recovers the sequence of symbols from the sequenc
31、e of bits produced by the arithmetic encoder. 3.1.4 (adaptive) (binary) arithmetic encoding: An entropy encoding procedure which codes by means of a recursive subdivision of the probability of the sequence of symbols coded up to that point. 3.1.5 application environment: The standards for data repre
32、sentation, communication, or storage which have been established for a particular application. CCITT Rec. T.81(1992 E) 1 ISOAEC lo!W a sample in lossless processes. 2 CClTT Rec. T DCT: Either the forward discrete cosine transform or the inverse discrete cosine transform. 3.1.48 downsamplhg (filter):
33、 A procedure by which the spatial resolution of an image is reduced (in hierarchical mode coding). 3.1.49 encoder: An embodiient of an encoding process. 3.150 encoding process: A process which takes as its input a continuous-tone image and outputs compressed image data. 3.1.51 entropy-coded (data) s
34、egment: An independently de FDCIr A mathematical transformation using cosine basis functions which converts a block of samples into a corresponding block of original DCT coefficients. CClTI Rec. T IDCX A mathematical transformation using cosine basis functions which converts a block of dequantized D
35、CX coefficients into a corresponding block of samples. 3.1.78 Joint Photographic Experts Group; JPEG: The informal name of the committee which created this Specification. The “joint” comes from the CClTI and ISO/IEC collaboration. 3.1.79 latent OU: Output of the arithmetic encoder which is held, pen
36、ding resolution of carry-over (in arithmetic coding). 3.1.80 less probable symbol; LPS: For a binary decision, the decision value which has the smaller probability. 3.111 level shift: A procedure used by DCT-based encoders and decoders whereby each input sample is either converted from an unsigned r
37、epresentation to a twos complement representation or from a twos complement representation to an unsigned representation. 4 CClTT Rec. T.81(1992 E) ISOIIEC 10918-1:1994(E) 3.1.82 lossless: A descriptive term for encoding and decoding processes and procedures in which the output of the decoding proce
38、dure(s) is identical to tbe input to the encoding procedure(s). 3.1.83 iossless coding: The mode of operation which refers to any one of the coding processes defined in this Specification in which all of the procedures are lossless (see Annex H). 3.1J4 lossy: A descriptive term for encoding and deco
39、ding processes which are not lossless. 3.1.85 marker: A two-byte code in which the first byte is hexadecimal FF (XFF) and the second byte is a value between 1 and hexadecimal FE (XFE). 3.1.86 marker segment: A marker and associated set of parameters. 3.1.87 MC MCU: The smallest group of data units t
40、hat is coded. 3.1.89 modes (of operation): The four main categories of image coding processes defined in this Specification. 3.1.90 more probable symbol; MIS: For a binary decision, the decision value which has the larger probability. 3.1.91 non-differential frame: The fast frame for any components
41、in a hierarchical encoder or decoder. The components are encoded or decoded without subtraction from reference components. The term refers also to any frame in modes other than the hierarchical mode. 3.1.92 non-interleaved: The descriptive term applied to the data unit processing sequence when the s
42、can has only one component. 3.1.93 parameters: Fixed length integers 4, 8 or 16 bits in length, used in the compressed data formats. 3.1.94 point transform: Scaling of a sample or DCT coefficient. 3.1.95 precision: Number of bits allocated to a particular sample or DCT coefficient. 3.1.96 predictor:
43、 A linear combination of previously reconstructed values (in lossless mode coding). 3.1.97 probabiiity estimation state machine: An interlinked table of probability values and indices which is used to estimate the probability of the LPS (in arithmetic coding). 3.1.98 probability interval: The probab
44、ility of a particular sequence of binary decisions within the ordered set of all possible sequences (in arithmetic coding). 3.1.99 (probability) sub-interval: A portion of a probability interval allocated to either of the two possible binary decision values (in arithmetic coding). 3.1.100 procedure:
45、 A set of steps which accomplishes one of the tasks which comprise an encoding or decoding proC%TSS. 3.1.101 process: See coding process. 3.1.102 progressive (coding): One of the DCT-based processes defined in this Specification in which each scan typically improves the quality of the reconstructed
46、image. 3.1.103 progressive DCT-based: The mode of operation which refers to any one of the processes defined in Annex G. 3.1.104 quantization table: The set of 64 quantization values used to quantize the DCT coefficients. 3.1.105 quantization value: An integer value used in the quantization procedur
47、e. 3.1.106 quantize: The act of performing the quantization procedure for a DCT coefficient. 3.1.107 reference (reconstructed) component: Reconstructed component data which is used in a subsequent frame of a hierarchical encoder or decoder process (in hierarchical mode coding). CClTl Rec. T.81(1992
48、E) 5 ISOIIEC 10918-1:1994(E) 3.1.108 renormalization: The doubling of the probability interval and the code register value until the probability interval exceeds a fixed miniium value (m arithmetic coding). 3.1.109 restart interval: The integer number of MCUs processed as an independent sequence wit
49、hin a scan. 3.1.110 restart marker: The marker that separates two restart intervals in a scan. 3.1.111 run (length): Number of consecutive symbols of the same value. 3.1.112 sample: One element in the two-dimensional array which comprises a component. 3.1.113 sample-interleaved: The descriptive term applied to the repetitive multiplexing of small groups of samples from each component in a scan in a specific order. 3.1.114 scan: A single pass through the data for one or more of the components in an image. 3.1.115 scan header: A marker segment that contains a start-of-scan marke
