Information technology — Lossy/lossless coding of bi-level images

This Recommendation | International Standard defines methods for coding bi-level images and sets of images (documents consisting of multiple pages). It is particularly suitable for bi-level images consisting of text and dithered (halftone) data. The methods defined permit lossless (bit-preserving) coding, lossy coding, and progressive coding. In progressive coding, the first image is lossy; subsequent images may be lossy or lossless. This Recommendation | International Standard also defines file formats to enclose the coded bi-level image data.

Technologies de l'information — Codage avec ou sans perte des images au trait

General Information

Publication Date
Current Stage
9060 - Close of review
Start Date
Ref Project


Buy Standard

ISO/IEC 14492:2019 - Information technology -- Lossy/lossless coding of bi-level images
English language
166 pages
sale 15% off
sale 15% off

Standards Content (Sample)

Second edition
Information technology — Lossy/
lossless coding of bi-level images
Technologies de l'information — Codage avec ou sans perte des
images au trait
Reference number
ISO/IEC 14492:2019(E)
ISO/IEC 2019

---------------------- Page: 1 ----------------------
ISO/IEC 14492:2019(E)

© ISO/IEC 2019
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Published in Switzerland
ii © ISO/IEC 2019 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/IEC 14492:2019 (E)
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form 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
technical 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.
The procedures used to develop this document and those intended for its further maintenance are described in
the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of
document should be noted (see
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights. Details of any
patent rights identified during the development of the document will be in the Introduction and/or on the ISO
list of patent declarations received (see or the IEC list of patent declarations received
Any trade name used in this document is information given for the convenience of users and does not constitute
an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
This document was prepared by ITU-T as ITU-T Rec. T.88 (2018) and drafted in accordance with its editorial
rules. It was adopted by Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee
SC 29, Coding of audio, picture, multimedia and hypermedia information.
This second edition cancels and replaces the first edition (ISO/IEC 14492:2001), which has been technically
revised. It also incorporates ISO/IEC 14492:2001/Amd.1:2004, ISO/IEC 14492:2001/Amd.2:2003 and
ISO/IEC 14492:2001/Amd.3:2012.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at
© ISO/IEC 2019 – All rights reserved ITU-T Rec. T.88 (2018 E) iii

---------------------- Page: 3 ----------------------
Information technology – Lossy/lossless coding of bi-level images

Rec. ITU-T T.88 | ISO/IEC 14492, commonly known as JBIG2, defines a coding method for bi-level images (e.g., black
and white printed matter). These are images consisting of a single rectangular bit plane, with each pixel taking on one of
just two possible colours. This Recommendation | International Standard has been explicitly prepared for a lossy,
lossless, and lossy-to-lossless image compression.

Edition Recommendation Approval Study Group Unique ID
1.0 ITU-T T.88 2000-02-10 8 11.1002/1000/4845
1.1 ITU-T T.88 (2000) Amd. 1 2003-06-29 16 11.1002/1000/6388
1.2 ITU-T T.88 (2000) Amd. 2 2003-06-29 16 11.1002/1000/6389
1.3 ITU-T T.88 (2000) Amd. 3 2011-05-14 16 11.1002/1000/11312
2.0 ITU-T T.88 2018-08-29 16 11.1002/1000/13688

Bi-level images; image compression; lossy image compression; lossless image compression; lossy-to-lossless image
compression; JBIG.

To access the Recommendation, type the URL in the address field of your web browser, followed b

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.