Page 145 - ITU Journal, ICT Discoveries, Volume 3, No. 1, June 2020 Special issue: The future of video and immersive media

ITU Journal: ICT Discoveries, Vol. 3(1), June 2020

SOME LITTLE-KNOWN ASPECTS OF THE HISTORY OF THE JPEG STILL PICTURE-CODING
STANDARD, ITU-T T.81 | ISO/IEC 10918-1 (1986-1993)

István Sebestyén
Ecma International, Geneva, Switzerland

Abstract – The JPEG-1 standard of the Joint Photographic Experts Group (JPEG) whose specification was
submitted to and approved by the Consultative Committee for International Telephony and Telegraphy
(CCITT; now ITU-T) in 1992 and by ISO/IEC JTC1 in 1994 is still the most successful still-picture compression
standard on the market. Much has been written about the standard itself, how the image compression
functions, but less about the unique policies and processes of the JPEG, the origins of the requirements of the
JPEG-1 format, the common components principle, the fate of the targeted CCITT/ITU applications and the
nature of those applications that made JPEG one of the world’s most successful standards. It is also not
widely known that JPEG is one of the first standards to be followed and supported by an open source software
(OSS) project and code – developed and distributed by the Independent JPEG Group (IJG) – that has provided
a substantial drive towards market penetration and contributed to the wide acceptance of the JPEG
standard. This paper also presents an analysis of the JPEG-IJG co-operation and draws some conclusions
about its nature. Finally, the lessons learned are discussed.

INTRODUCTION

The JPEG Recommendation | International Standard (ITU-T T.81 | ISO/IEC 10918-1 [1]), first published in
1992, is still the most popular and most used picture-coding standard for photographic images. Much has been
written about the standard itself (e.g. [2]) and its history (e.g. [3][4]) focusing on:
• the technical design and characteristics of the standard, including the image compression capabilities of
the JPEG algorithm;
• the JPEG standardization selection procedure that resulted in a still picture standard based on the
discrete cosine transform (DCT).
However, standardization, which is to a certain extent an interdisciplinary exercise, is much broader than that.
Thus, this article presents and discusses some additional, perhaps little-known, although noteworthy, aspects
of JPEG standardization, with the aim of complementing the comprehensive picture of the history of the JPEG
format. These aspects include those relating to organization and process; what the original experts group JPEG
was; why the rules and working processes of that group were unique and could never be repeated in the
history of standardization; along with the roles of the “parent” organizations of JPEG, namely CCITT/ITU and
ISO/IEC. This article describes how the requirements for the JPEG standardization emerged; what the common
component concept was; which requirements became part of the standard and which were left to applications;
what the targeted applications in CCITT/ITU and ISO/IEC were; the eventual success of those applications;
and how unplanned applications, in the end, made JPEG one of the most successful standards worldwide.
Finally, the interaction between JPEG and the IJG group, who made a significant contribution to the early
market penetration of the standard with their Open Source Code, are described.

1. THE JPEG-1 PROJECT (ITU-T T.81 | ISO/IEC 10918-1) OF CCITT SGVIII AND
ISO/IEC JTC1 SC29 AND ITS WORKING RULES AND PROCEDURES

The JPEG-1 Recommendation | International Standard on still image compression was approved in 1992 by
ITU-T and in 1993 by ISO/IEC, and was among the first documents with a so-called joint-text adopted by both
ITU-T and ISO/IEC JTC1. ITU-T T.81 (1992) | ISO/IEC 10918-1:1993 [1] was also among the first to have
connections with the OSS community through the IJG.

Fig. 1 provides an overview of how the JPEG-1 Recommendation | International Standard was created.

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