ISO_IEC_10918-7_2021-Character_PDF_documenten.pdf

Information technology Digital compression and coding of continuous-tone still images Part 7:Reference softwareTechnologies de linformation Compression numrique et codage des images fixes model continu Partie 7:Logiciel de rfrence ISO/IEC 2021INTERNATIONAL STANDARDISO/IEC10918-7Reference numberISO/IEC 10918-7:2021(E)Second edition2021-09 ISO/IEC 10918-7:2021(E)ii ISO/IEC 2021 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO/IEC 2021All 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 ISOs member body in the country of the requester.ISO copyright officeCP 401 Ch.de Blandonnet 8CH-1214 Vernier,GenevaPhone:+41 22 749 01 11Email:copyrightiso.orgWebsite:www.iso.orgPublished in SwitzerlandISO/IEC 10918-7:2021(E)ISO/IEC 2021 All rights reservediii Foreword 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 www.iso.org/directives or www.iec.ch/members_experts/refdocs).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 www.iso.org/patents)or the IEC list of patent declarations received(see patents.iec.ch).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 ISOs adherence to the World Trade Organization(WTO)principles in the Technical Barriers to Trade(TBT)see www.iso.org/iso/foreword.html.In the IEC,see www.iec.ch/understanding-standards.This document was prepared by ITU-T as Rec.ITU-T T.873(06/2021)and drafted in accordance with its editorial rules,in collaboration with 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 10918-7:2019),which has been technically revised.The main changes compared to the previous edition are as follows:the reference software implementations are updated to version 1.58 for reference software 1,and to version 2.0.5 for reference software 2.These versions do not include any new features,they correct implementation errors and improve the overall stability of the software.A list of all parts in the ISO/IEC 10918 series can be found on the ISO and IEC websites.Any feedback or questions on this document should be directed to the users national standards body.A complete listing of these bodies can be found at www.iso.org/members.html and www.iec.ch/national-committees.Rec.ITU-T T.873(06/2021)ivCONTENTS Page 1 Scope.1 2 Normative references.1 3 Definitions.1 4 Abbreviations.1 5 Conventions.2 6 Reference software.2 6.1 Purpose.2 6.2 Examples of use.2 6.3 General.2 Annex A Unpacking and compiling reference software A.4 Annex B Using reference software A.5 B.1General.5 B.2Encoder options defining the quality of the image.5 B.3Options controlling the colour space.5 B.4Options controlling the scan generation and entropy coding.5 B.5Options controlling the quantizer.6 B.6Options controlling the subsampling of components.6 B.7Miscellaneous options.6 B.8Decoder options.6 Annex C Unpacking and compiling reference software B.7 Annex D Using reference software B.9 D.1General.9 D.2Encoder options defining the quality of the base and full image.9 D.3Encoder options controlling the colour space.9 D.4Encoder options controlling the scan generation and entropy coding.9 D.5Encoder options controlling the DCT implementation.10 D.6Encoder options controlling the subsampling of components.10 D.7Miscellan