1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 18381:2013Space data and informationtransfer systems Losslessmultispectral and hyperspectralimage compressionBS ISO 18381:2013 BRITISH STANDARDNational forewordThis Britis
2、h Standard is the UK implementation of ISO 18381:2013.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/68/-/7, Space systems and operations - Space dataand information transfer systems.A list of organizations represented on this committee can beobtained on request to i
3、ts secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 79731 6ICS 49.140Compliance with a British Standard cann
4、ot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 June 2013.Amendments issued since publicationDate Text affectedBS ISO 18381:2013Reference numberISO 18381:2013(E)ISO 2013INTERNATIONAL STANDARD ISO1838
5、1First edition2013-06-01Space data and information transfer systems Lossless multispectral and hyperspectral image compression Systmes de transfert des informations et donnes spatiales Compression dimages multispectrales et hyperspectrales sans perte BS ISO 18381:2013ISO 18381:2013(E) COPYRIGHT PROT
6、ECTED DOCUMENT ISO 2013 All rights reserved. Unless otherwise specified, 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. Per
7、mission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2013 All righ
8、ts reservedBS ISO 18381:2013ISO 18381:2013(E) ISO 2013 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through IS
9、O technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates c
10、losely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. 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 criter
11、ia needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
12、 rights. ISO 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. www.iso.org/patents Any trade name used in this
13、 document is information given for the convenience of users and does not constitute an endorsement. ISO 18381 was prepared by the Consultative Committee for Space Data Systems (CCSDS) (as CCSDS 123-0-B-1, May 2012) and was adopted (without modifications except those stated in Clause 2 of this Intern
14、ational Standard) by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 13, Space data and information transfer systems. BS ISO 18381:2013BS ISO 18381:2013INTERNATIONAL STANDARD ISO 18381:2013(E) ISO 2013 All rights reserved 1Space data and information transfer systems Lossl
15、ess multispectral and hyperspectral image compression 1 Scope This International Standard establishes a data compression algorithm applied to digital three-dimensional image data from payload instruments, such as multispectral and hyperspectral imagers, and specifies the compressed data format. Data
16、 compression is used to reduce the volume of digital data to achieve benefits in areas including, but not limited to: a) reduction of transmission channel bandwidth; b) reduction of the buffering and storage requirement; c) reduction of data-transmission time at a given rate. The characteristics of
17、instrument data are specified only to the extent necessary to ensure multi-mission support capabilities. This International Standard does not attempt to quantify the relative bandwidth reduction, the merits of the approaches discussed, or the design requirements for encoders and associated decoders.
18、 This International Standard addresses only lossless compression of three-dimensional data, where the requirement is for a data-rate reduction constrained to allow no distortion to be added in the data compression/decompression process. The scope and field of application are furthermore detailed in
19、subclause 1.3 of the enclosed CCSDS publication. 2 Requirements Requirements are the technical recommendations made in the following publication (reproduced on the following pages), which is adopted as an International Standard: CCSDS 123.0-B-1, May 2012, Lossless multispectral and hyperspectral ima
20、ge compression. For the purposes of international standardization, the modifications outlined below shall apply to the specific clauses and paragraphs of publication CCSDS 123.0-B-1. Pages i to vi This part is information which is relevant to the CCSDS publication only. Page 1-4 Add the following in
21、formation to the reference indicated: 1 Document CCSDS 121.0-B-2, May 2012, is equivalent to ISO 15887:2013. BS ISO 18381:2013ISO 18381:2013(E) 2 ISO 2013 All rights reservedPage C-1 Add the following information to the reference indicated: C2 Document CCSDS 133.0-B-1, September 2003, is equivalent
22、to ISO 22646:2005. C3 Document CCSDS 727-0-B-4, January 2007, is equivalent to ISO 17355:2007. C4 Document CCSDS 732.0-B-2, July 2006, is equivalent to ISO 22666:2006. 3 Revision of publication CCSDS 123.0-B-1 It has been agreed with the Consultative Committee for Space Data Systems that Subcommitte
23、e ISO/TC 20/SC 13 will be consulted in the event of any revision or amendment of publication CCSDS 123.0-B-1. To this end, NASA will act as a liaison body between CCSDS and ISO. BS ISO 18381:2013Recommendation for Space Data System Standards LOSSLESS MULTISPECTRAL (2) be changed to reflect the impac
24、t of new technologies, new requirements, or new directions; or (3) be retired or canceled. In those instances when a new version of a Recommended Standard is issued, existing CCSDS-related member standards and implementations are not negated or deemed to be non-CCSDS compatible. It is the responsibi
25、lity of each member to determine when such standards or implementations are to be modified. Each member is, however, strongly encouraged to direct planning for its new standards and implementations towards the later version of the Recommended Standard. ISO 18381:2013(E)6 ISO 2013 All rights reserved
26、BS ISO 18381:2013CCSDS RECOMMENDED STANDARD FOR LOSSLESS MULTISPECTRAL b) reduction of the buffering and storage requirement; c) reduction of data-transmission time at a given rate. 1.2 SCOPE The characteristics of instrument data are specified only to the extent necessary to ensure multi-mission su
27、pport capabilities. The specification does not attempt to quantify the relative bandwidth reduction, the merits of the approaches discussed, or the design requirements for encoders and associated decoders. Some performance information is included in reference C1. This Recommended Standard addresses
28、only lossless compression of three-dimensional data, where the requirement is for a data-rate reduction constrained to allow no distortion to be added in the data compression/decompression process. 1.3 APPLICABILITY This Recommended Standard applies to data compression applications of space missions
29、 anticipating packetized telemetry cross support. In addition, it serves as a guideline for the development of compatible CCSDS Agency standards in this field, based on good engineering practice. 1.4 RATIONALE The concept and rationale for the Image Data Compression algorithm described herein may be
30、 found in reference C1. ISO 18381:2013(E)13 ISO 2013 All rights reservedBS ISO 18381:2013CCSDS RECOMMENDED STANDARD FOR LOSSLESS MULTISPECTRAL b) the word should implies an optional, but desirable, specification; c) the word may implies an optional specification;d) the words is, are, and will imply
31、statements of fact.NOTE These conventions do not imply constraints on diction in text that is clearlyinformative in nature. (4)(5)(6)ISO 18381:2013(E)15 ISO 2013 All rights reservedBS ISO 18381:2013CCSDS RECOMMENDED STANDARD FOR LOSSLESS MULTISPECTRAL Background; Rationale; Discussion. 1.6.3 CONVENT
32、IONS In this document, the following convention is used to identify each bit in an N-bit word. The first bit in the word to be transmitted (i.e., the most left justified when drawing a figure) is defined to be bit 0, the following bit is defined to be bit 1, and so on up to bit N-1. When the word is
33、 used to express an unsigned binary value (such as a counter), the Most Significant Bit (MSB), bit 0, shall correspond to the highest power of two, i.e., 2N-1bit 0first transmitted bit = MSBbit 1 bit N-1. In accordance with modern data communications practice, spacecraft data words are often grouped
34、 into 8-bit words which conform to the above convention. Throughout this Recommended Standard, the following nomenclature is used to describe this grouping: 8-bit word = Byte 1.7 REFERENCE The following publication contains provisions which, through reference in this text, constitute provisions of t
35、his document. At the time of publication, the edition indicated was valid. All publications are subject to revision, and users of this document are encouraged to investigate the possibility of applying the most recent edition of the publication indicated below. The CCSDS Secretariat maintains a regi
36、ster of currently valid CCSDS publications. 1 Lossless Data Compression. Recommendation for Space Data System Standards, CCSDS 121.0-B-2. Blue Book. Issue 2. Washington, D.C.: CCSDS, May 2012. ISO 18381:2013(E)16 ISO 2013 All rights reservedBS ISO 18381:2013CCSDS RECOMMENDED STANDARD FOR LOSSLESS MU
37、LTISPECTRAL that theory is partially addressed in reference C1. The input to the compressor is an image, which is a three-dimensional array of integer sample values, as specified in section 3. The compressed image output from the compressor is an encoded bitstream from which the input image can be r
38、ecovered exactly. Because of variations in image content, the length of compressed images will vary from image to image. That is, the compressed image is variable-length. A user may choose to partition the output of an imaging instrument into smaller images that are separately compressed, e.g., to l
39、imit the impact of data loss or corruption on the communications channel, or to limit the maximum possible size of a compressed image. This Recommended Standard does not address such partitioning or the tradeoffs associated with selecting the size of images produced under such partitioning. Referenc
40、e C1 presents some examples. The compressor consists of two functional parts, depicted in figure 2-1: a predictor and an encoder. inputimagePredictormappedpredictionresidualscompressedimageEncoderFigure 2-1: Compressor Schematic The predictor, specified in section 4, uses an adaptive linear predicti
41、on method to predict the value of each image sample based on the values of nearby samples in a small three-dimensional neighborhood. Prediction is performed sequentially in a single pass. The prediction residual, i.e., the difference between the predicted and actual sample values, is then mapped to
42、an unsigned integer that can be represented using the same number of bits as the input data sample. These mapped prediction residuals make up the predictor output. The compressed image, specified in section 5, consists of a header that encodes image and compression parameters followed by a body, pro
43、duced by an entropy coder which losslessly encodes the mapped prediction residuals. Entropy coder parameters are adaptively adjusted during this process to adapt to changes in the statistics of the mapped prediction residuals. ISO 18381:2013(E)17 ISO 2013 All rights reservedBS ISO 18381:2013CCSDS RE
44、COMMENDED STANDARD FOR LOSSLESS MULTISPECTRAL it is assumed that the transport mechanism used for the delivery of the encoded bitstream will provide the ability to locate the header of the next image in the event of a bit error. In case the encoded bitstream is to be transmitted over a CCSDS space l
45、ink, several protocols can be used to transfer a compressed image, including: Space Packet Protocol (reference C2); CCSDS File Delivery Protocol (CFDP) (reference C3); packet service or bitstream service as provided by the AOS Space Data Link Protocol (reference C4). Limits on the maximum size data
46、unit that can be transmitted may be imposed by the protocol used or by other practical implementation considerations. The user is expected to take such limits into account when using this Recommended Standard. ISO 18381:2013(E)18 ISO 2013 All rights reservedBS ISO 18381:2013CCSDS RECOMMENDED STANDAR
47、D FOR LOSSLESS MULTISPECTRAL this neighborhood is suitably truncated when y = 0, x = 0, x = 1, or 0), the central local difference is defined as= 4 .4.5.2 DIRECTIONAL LOCAL DIFFERENCESWhen x and y are not both zero (i.e., when t 0), the three directional local differences are defined as(16)(17)(18)(19)ISO 18381:2013(E)24 ISO 2013 All rights reserved
