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TELECOMMUNICATION (11/94)
STANDARDIZATION SECTOR
OF ITU
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)4542ECOMMENDATION4
(Previously “CCITT Recommendation”)
INTERNATIONAL TELECOMMUNICATION UNION
Foreword
ITU (International Telecommunication Union) is the United Nations Specialized Agency in the field of
telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU.
Some 179 member countries, 84 telecom operating entities, 145 scientific and industrial organizations and
38 international organizations participate in ITU-T which is the body which sets world telecommunications standards
(Recommendations).
The approval of Recommendations by the Members of ITU-T is covered by the procedure laid down in WTSC
Resolution No. 1 (Helsinki, 1993). In addition, the World Telecommunication Standardization Conference (WTSC),
which meets every four years, approves Recommendations submitted to it and establishes the study programme for the
following period.
In some areas of information technology which fall within ITU-T’s purview, the necessary standards are prepared on a
collaborative basis with ISO and IEC. The text of ITU-T Recommendation T.83 was approved on 11th of November
1994. The identical text is also published as ISO/IEC International Standard 10918-2.
___________________
NOTE
In this Recommendation, the expression “Administration” is used for conciseness to indicate both a telecommunication
administration and a recognized operating agency.
ITU 1995
All rights reserved. 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 ITU.
ITU-T Rec. T.83 (1994 E) i
CONTENTS
Page
Summary.................................................................................................................................................................... ii
Introduction ............................................................................................................................................................... ii
1 Scope.............................................................................................................................................................. 1
2 Normative references ..................................................................................................................................... 1
3 Definitions, abbreviations, symbols, and conventions ................................................................................... 1
4 General........................................................................................................................................................... 4
5 Compressed data format compliance testing.................................................................................................. 6
6 Encoder compliance tests............................................................................................................................... 19
7 Decoder compliance tests............................................................................................................................... 20
Annex A – Procedures for determining generic encoder and decoder compliance................................................... 25
Annex B – Quantization tables for generic compliance testing of DCT-based processes......................................... 28
Annex C – Compressed test data stream structure for generic decoder compliance tests......................................... 30
Annex D – Construction of application-specific compliance tests............................................................................ 51
Annex E – Compliance test data for testing of greater computational accuracy....................................................... 53
Annex F – Specification of supported parameter ranges........................................................................................... 55
Annex H – Examples and guidelines......................................................................................................................... 58
ii ITU-T Rec. T.83 (1994 E)
Summary
This Recommendation | International Standard, Digital Compression and Coding of Continuous-tone Still Images, is
published as two parts:
ITU-T Rec. T.81 | ISO/IEC 10918-1 “Requirements and guidelines” sets out requirements and implementation
guidelines for continuous-tone still image encoding and decoding processes, and for the coded representation of
compressed image data. These processes and representations are intended to be generic, that is, to be applicable to a
broad range of applications for colour and grayscale still images within communications and computer systems.
This part, ITU-T Rec. T.83 | ISO/IEC 10918-2 “Compliance testing” sets out tests for determining whether
implementations comply with the requirements for the various encoding and decoding processes specified in ITU-T
Rec. T.81 | ISO/IEC 10918-1. ITU-T Rec. T.83 | ISO/IEC 10918-2 also specifies tests for determining whether any
specific instance of compressed data complies with the ITU-T Rec. T.81 | ISO/IEC 10918-1 specification for compressed
data format.
Introduction
This Recommendation | International Standard, Digital Compression and Coding of Continuous-tone Still Images, is
published as two parts:
– ITU-T Rec. T.81 | ISO/IEC 10918-1: Requirements and guidelines.
– ITU-T Rec. T.83 | ISO/IEC 10918-2: Compliance testing.
ITU-T Rec. T.81 | ISO/IEC 10918-1 sets out requirements and implementation guidelines for continuous-tone still image
encoding and decoding processes, and for the coded representation of compressed image data. These processes and
representations are intended to be generic, that is, to be applicable to a broad range of applications for colour and
grayscale still images within communications and computer systems.
This part, ITU-T Rec. T.83 | ISO/IEC 10918-2, sets out tests for determining whether implementations comply with the
requirements for the various encoding and decoding processes specified in ITU-T Rec. T.81 | ISO/IEC 10918-1. ITU-T
Rec. T.83 | ISO/IEC 10918-2 also specifies tests for determining whether any specific instance of compressed data
complies with the ITU-T Rec. T.81 | ISO/IEC 10918-1 specification for compressed data format.
The committee which has prepared this Specification is the ISO/IEC JTC1/SC29/WG1 Sub Group on JPEG, also known
as the Joint Photographic Experts Group (JPEG). Both the committee and the two parts of this Specification continue to
be known informally by the name JPEG.
The “joint” in JPEG refers to the committee’s collaboration with the ITU-T SG8 Rapporteur’s Group on
Recommendation Q.16. In this collaboration, WG1 has performed the work of selecting, developing, documenting, and
testing the generic compression processes.
ITU-T SG8 has provided the requirements which these processes must satisfy to be useful for specific image
communications applications such as facsimile, videotex, and audiographic conferencing.
This Specification is presented in accordance with the rules of ITU-T and ISO/IEC JTC1 established by “Rules for
presentation of ITU-T | ISO/IEC common text”.
Annexes A, B, C, and D form an integral part of this Specification. Annexes E, F, G, and H are for information only.
ISO/IEC 10918-2 : 1995 (E)
ITU-T Rec. T.83 (1994 E) 1
INTERNATIONAL STANDARD
ISO/IEC 10918-2 : 1995 (E)
ITU-T Rec. T.83 (1994 E)
ITU-T RECOMMENDATION
INFORMATION TECHNOLOGY – DIGITAL COMPRESSION AND CODING OF
CONTINUOUS-TONE STILL IMAGES: COMPLIANCE TESTING
1 Scope
This Recommendation | International Standard is concerned with compliance tests for the continuous-tone still image
encoding processes, decoding processes, and compressed data formats specified in ITU-T Rec. T.81 | ISO/IEC 10918-1.
This Specification:
– specifies compliance tests for the ITU-T Rec. T.81 | ISO/IEC 10918-1 compressed data formats;
– specifies compliance tests for the ITU-T Rec. T.81 | ISO/IEC 10918-1 encoding processes;
– specifies compliance tests for the ITU-T Rec. T.81 | ISO/IEC 10918-1 decoding processes;
– specifies a method for constructing application-specific compliance tests;
– gives guidance and examples on how to implement these tests in practice.
This Specification specifies normative generic compliance tests for the ITU-T Rec. T.81 | ISO/IEC 10918-1 encoding
and decoding processes. These compliance tests are applicable to “stand-alone” generic implementations of one or more
of the encoding and decoding processes specified in ITU-T Rec. T.81 | ISO/IEC 10918-1. Among the purposes of these
tests is to ensure that generic encoder (and decoder) implementations compute the discrete cosine transform (DCT) and
quantization functions with sufficient accuracy.
2 Normative references
The following ITU-T Recommendations and International Standards contain provisions which, through reference in this
text, constitute provisions of this Recommendation | International Standard. At the time of publication, the editions
indicated were valid. All Recommendations and Standards are subject to revision, and parties to agreements based on
this Recommendation | International Standard are encouraged to investigate the possibility of applying the most recent
editions of the Recommendations and Standards indicated below. Members of IEC and ISO maintain registers of
currently valid International Standards. The Telecommunication Standardization Bureau of the ITU-T maintains a list of
the currently valid ITU-T Recommendations.
2.1 Additional references
– ISO 5807:1985, Information processing – Documentation symbols and conventions for data, program
and system flowcharts, program network charts and system resources charts.
3 Definitions, abbreviations, symbols, and conventions
3.1 Definitions
For the purposes of this Specification, the following definitions apply.
3.1.1 (coding) process 1: Coding process with baseline sequential DCT, 8-bit sample precision.
3.1.2 (coding) process 2: Coding process with extended sequential DCT, Huffman coding, 8-bit sample precision.
3.1.3 (coding) process 3: Coding process with extended sequential DCT, arithmetic coding, 8-bit sample precision.
3.1.4 (coding) process 4: Coding process with extended sequential DCT, Huffman coding, 12-bit sample precision.
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