Denon S-5BD Owner's Manual

Also see for S-5BD: Product sheet Code List Service manual

Contents

Other documentation files in the distribution are:User documentation:install.doc How to configure and install the IJGsoftware.usage.doc Usage instructions for cjpeg, djpeg,jpegtran, rdjpgcom, and wrjpgcom.*.1 Unix-style man pages for programs(same info as usage.doc).wizard.doc Advanced usage instructions for JPEGwizards only.change.log Version-to-version change highlights.Programmer and internal documentation:libjpeg.doc How to use the JPEG library in your ownprograms.example.c Sample code for calling the JPEG library.structure.doc Overview of the JPEG library’s internalstructure.filelist.doc Road map of IJG files.coderules.doc Coding style rules --- please read if youcontribute code.Please read at least the files install.doc and usage.doc. Usefulinformation can also be found in the JPEG FAQ (Frequently AskedQuestions) article. See ARCHIVE LOCATIONS below to find outwhere to obtain the FAQ article.If you want to understand how the JPEG code works, we suggestreading one or more of the REFERENCES, then looking at thedocumentation files (in roughly the order listed) before diving intothe code.OVERVIEWThis package contains C software to implement JPEG imagecompression and decompression. JPEG (pronounced “jay-peg”)is a standardized compression method for full-color and gray-scaleimages. JPEG is intended for compressing “real-world” scenes; linedrawings, cartoons and other non-realistic images are not its strongsuit. JPEG is lossy, meaning that the output image is not exactlyidentical to the input image. Hence you must not use JPEG if youhave to have identical output bits. However, on typical photographicimages, very good compression levels can be obtained with novisible change, and remarkably high compression levels are possibleif you can tolerate a low-quality image. For more details, see thereferences, or just experiment with various compression settings.This software implements JPEG baseline, extended-sequential, andprogressivecompression processes. Provision is made for supporting all variantsof theseprocesses, although some uncommon parameter settings aren’timplemented yet.For legal reasons, we are not distributing code for the arithmetic-codingvariants of JPEG; see LEGAL ISSUES. We have made no provisionfor supportingthe hierarchical or lossless processes defined in the standard.We provide a set of library routines for reading and writing JPEGimage files, plus two sample applications “cjpeg” and “djpeg”, whichuse the library to perform conversion between JPEG and some otherpopular image file formats.The library is intended to be reused in other applications.In order to support file conversion and viewing software, we haveincluded considerable functionality beyond the bare JPEG coding/decoding capability; for example, the color quantization modulesare not strictly part of JPEG decoding, but they are essential foroutput to colormapped file formats or colormapped displays. Theseextra functions can be compiled out of the library if not required fora particular application. We have also included “jpegtran”, a utilityfor lossless transcoding between different JPEG processes, and“rdjpgcom” and “wrjpgcom”, two simple applications for insertingand extracting textual comments in JFIF files.The emphasis in designing this software has been on achievingportability and flexibility, while also making it fast enough to beuseful. In particular, the software is not intended to be read as atutorial on JPEG. (See the REFERENCES section for introductorymaterial.) Rather, it is intended to be reliable, portable, industrial-strength code. We do not claim to have achieved that goal in everyaspect of the software, but we strive for it.We welcome the use of this software as a component of commercialproducts.No royalty is required, but we do ask for an acknowledgement inproduct documentation, as described under LEGAL ISSUES.LEGAL ISSUESIn plain English:1. We don’t promise that this software works. (But if you find anybugs, please let us know!)2. You can use this software for whatever you want. You don’t haveto pay us.3. You may not pretend that you wrote this software. If you useit in a program, you must acknowledge somewhere in yourdocumentation that you’ve used the IJG code.In legalese:The authors make NO WARRANTY or representation, either expressor implied, with respect to this software, its quality, accuracy,merchantability, or fitness for a particular purpose. This software isprovided “AS IS”, and you, its user, assume the entire risk as to itsquality and accuracy.This software is copyright (C) 1991-1998, Thomas G. Lane.All Rights Reserved except as specified below.Permission is hereby granted to use, copy, modify, and distribute thissoftware (or portions thereof) for any purpose, without fee, subjectto these conditions:(1) If any part of the source code for this software is distributed,then this README file must be included, with this copyrightand no-warranty notice unaltered; and any additions, deletions,or changes to the original files must be clearly indicated inaccompanying documentation.(2) If only executable code is distributed, then the accompanyingdocumentation must state that “this software is based in part onthe work of the Independent JPEG Group”.(3) Permission for use of this software is granted only if the useraccepts full responsibility for any undesirable consequences; theauthors accept NO LIABILITY for damages of any kind.These conditions apply to any software derived from or based on theIJG code, not just to the unmodified library. If you use our work, youought to acknowledge us.Permission is NOT granted for the use of any IJG author’s name orcompany name in advertising or publicity relating to this software orproducts derived from it. This software may be referred to only as“the Independent JPEG Group’s software”.We specifically permit and encourage the use of this software as thebasis of commercial products, provided that all warranty or liabilityclaims are assumed by the product vendor.ansi2knr.c is included in this distribution by permission of L. PeterDeutsch, sole proprietor of its copyright holder, Aladdin Enterprisesof Menlo Park, CA.ansi2knr.c is NOT covered by the above copyright and conditions,but instead by the usual distribution terms of the Free SoftwareFoundation; principally, that you must include source code if youredistribute it. (See the file ansi2knr.c for full details.) However,since ansi2knr.c is not needed as part of any program generatedfrom the IJG code, this does not limit you more than the foregoingparagraphs do.The Unix configuration script “configure” was produced with GNUAutoconf.It is copyright by the Free Software Foundation but is freelydistributable.The same holds for its supporting scripts (config.guess, config.sub,ltconfig, ltmain.sh). Another support script, install-sh, is copyright byM.I.T. but is also freely distributable.It appears that the arithmetic coding option of the JPEG spec iscovered by patents owned by IBM, AT&T, and Mitsubishi. Hencearithmetic coding cannot legally be used without obtaining one ormore licenses. For this reason, support for arithmetic coding hasbeen removed from the free JPEG software.(Since arithmetic coding provides only a marginal gain overthe unpatented Huffman mode, it is unlikely that very manyimplementations will support it.)So far as we are aware, there are no patent restrictions on theremaining code.The IJG distribution formerly included code to read and write GIFfiles.To avoid entanglement with the Unisys LZW patent, GIF readingsupport has been removed altogether, and the GIF writer has beensimplified to produce “uncompressed GIFs”. This technique does notuse the LZW algorithm; the resulting GIF files are larger than usual,but are readable by all standard GIF decoders.We are required to state that“The Graphics Interchange Format(c) is the Copyright property ofCompuServe Incorporated. GIF(sm) is a Service Mark property ofCompuServe Incorporated.”REFERENCESWe highly recommend reading one or more of these referencesbefore trying to understand the innards of the JPEG software.The best short technical introduction to the JPEG compressionalgorithm isWallace, Gregory K. “The JPEG Still Picture CompressionStandard”, Communications of the ACM, April 1991 (vol. 34 no.4), pp. 30-44.(Adjacent articles in that issue discuss MPEG motion picturecompression, applications of JPEG, and related topics.) If you don’thave the CACM issue handy, a PostScript file containing a revisedversion of Wallace’s article is available at ftp://ftp.uu.net/graphics/jpeg/wallace.ps.gz. The file (actually a preprint for an article thatappeared in IEEE Trans. Consumer Electronics) omits the sampleimages that appeared in CACM, but it includes corrections and someadded material. Note: the Wallace article is copyright ACM and IEEE,and it may not be used for commercial purposes.A somewhat less technical, more leisurely introduction to JPEG canbe found in “The Data Compression Book” by Mark Nelson and Jean-loup Gailly, published by M&T Books (New York), 2nd ed. 1996, ISBN1-55851-434-1. This book provides good explanations and example Ccode for a multitude of compression methods including JPEG. It isan excellent source if you are comfortable reading C code but don’tknow much about data compression in general. The book’s JPEGsample code is far from industrial-strength, but when you are readyto look at a full implementation, you’ve got one here...The best full description of JPEG is the textbook “JPEG Still ImageData Compression Standard” by William B. Pennebaker and JoanL. Mitchell, published by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1. Price US$59.95, 638 pp.The book includes the complete text of the ISO JPEG standards (DIS10918-1 and draft DIS 10918-2).This is by far the most complete exposition of JPEG in existence, andwe highly recommend it.The JPEG standard itself is not available electronically; you mustorder a paper copy through ISO or ITU. (Unless you feel a need toown a certified official copy, we recommend buying the Pennebakerand Mitchell book instead; it’s much cheaper and includes a greatdeal of useful explanatory material.)In the USA, copies of the standard may be ordered from ANSI Salesat (212) 642-4900, or from Global Engineering Documents at (800)854-7179. (ANSI doesn’t take credit card orders, but Global does.)It’s not cheap: as of 1992, ANSI was charging $95 for Part 1 and $47for Part 2, plus 7% shipping/handling. The standard is divided intotwo parts, Part 1 being the actual specification, while Part 2 coverscompliance testing methods. Part 1 is titled “Digital Compressionand Coding of Continuous-tone Still Images, Part 1: Requirementsand guidelines” and has document numbers ISO/IEC IS 10918-1, ITU-T T.81. Part 2 is titled “Digital Compression and Coding ofContinuous-tone Still Images, Part 2: Compliance testing” and hasdocument numbers ISO/IEC IS 10918-2, ITU-T T.83.Some extensions to the original JPEG standard are defined in JPEGPart 3, a newer ISO standard numbered ISO/IEC IS 10918-3 and ITU-T T.84. IJG currently does not support any Part 3 extensions.The JPEG standard does not specify all details of an interchangeablefile format. For the omitted details we follow the “JFIF” conventions,revision 1.02. A copy of the JFIF spec is available from:Literature DepartmentC-Cube Microsystems, Inc.1778 McCarthy Blvd.Milpitas, CA 95035phone (408) 944-6300, fax (408) 944-6314A PostScript version of this document is available by FTP at ftp://ftp.uu.net/graphics/jpeg/jfif.ps.gz. There is also a plain text version atftp://ftp.uu.net/graphics/jpeg/jfif.txt.gz, but it is missing the figures.The TIFF 6.0 file format specification can be obtained by FTP fromftp://ftp.sgi.com/graphics/tiff/TIFF6.ps.gz. The JPEG incorporationscheme found in the TIFF 6.0 spec of 3-June-92 has a number ofserious problems.IJG does not recommend use of the TIFF 6.0 design (TIFFCompression tag 6).Instead, we recommend the JPEG design proposed by TIFF TechnicalNote #2 (Compression tag 7). Copies of this Note can be obtainedfrom ftp.sgi.com or from ftp://ftp.uu.net/graphics/jpeg/. It is expectedthat the next revision of the TIFF spec will replace the 6.0 JPEGdesign with the Note’s design.Although IJG’s own code does not support TIFF/JPEG, the free libtifflibrary uses our library to implement TIFF/JPEG per the Note. libtiffis available from ftp://ftp.sgi.com/graphics/tiff/.ARCHIVE LOCATIONSThe “official” archive site for this software is ftp.uu.net (Internetaddress 192.48.96.9). The most recent released version can alwaysbe found there in directory graphics/jpeg. This particular version willbe archived as ftp://ftp.uu.net/graphics/jpeg/jpegsrc.v6b.tar.gz.If you don’t have direct Internet access, UUNET’s archives are alsoavailable via UUCP; contact help@uunet.uu.net for information onretrieving files that way.Numerous Internet sites maintain copies of the UUNET files.However, only ftp.uu.net is guaranteed to have the latest officialversion.You can also obtain this software in DOS-compatible “zip” archiveformat from the SimTel archives (ftp://ftp.simtel.net/pub/simtelnet/msdos/graphics/), or on CompuServe in the Graphics Support forum(GO CIS:GRAPHSUP), library 12 “JPEG Tools”. Again, these versionsmay sometimes lag behind the ftp.uu.net release.The JPEG FAQ (Frequently Asked Questions) article is a usefulsource of general information about JPEG. It is updated constantlyand therefore is not included in this distribution. The FAQ is postedevery two weeks to Usenet newsgroups comp.graphics.misc, news.answers, and other groups.It is available on the World Wide Web at http://www.faqs.org/faqs/jpeg-faq/ and other news.answers archive sites, including the officialnews.answers archive at rtfm.mit.edu: ftp://rtfm.mit.edu/pub/usenet/news.answers/jpeg-faq/.If you don’t have Web or FTP access, send e-mail to mail-server@rtfm.mit.edu with bodysend usenet/news.answers/jpeg-faq/part1send usenet/news.answers/jpeg-faq/part2RELATED SOFTWARENumerous viewing and image manipulation programs now supportJPEG. (Quite a few of them use this library to do so.) The JPEG FAQdescribed above lists some of the more popular free and sharewareviewers, and tells where to obtain them on Internet.If you are on a Unix machine, we highly recommend Jef Poskanzer’sfree PBMPLUS software, which provides many useful operations onPPM-format image files. In particular, it can convert PPM images toand from a wide range of other formats, thus making cjpeg/djpegconsiderably more useful. The latest version is distributed by theNetPBM group, and is available from numerous sites, notably ftp://wuarchive.wustl.edu/graphics/graphics/packages/NetPBM/.Unfortunately PBMPLUS/NETPBM is not nearly as portable as theIJG software is; you are likely to have difficulty making it work on anynon-Unix machine.A different free JPEG implementation, written by the PVRG groupat Stanford,is available from ftp://havefun.stanford.edu/pub/jpeg/. This programis designed for research and experimentation rather than productionuse; it is slower, harder to use, and less portable than the IJG code,but it is easier to read and modify. Also, the PVRG code supportslossless JPEG, which we do not. (On the other hand, it doesn’t doprogressive JPEG.)FILE FORMAT WARSSome JPEG programs produce files that are not compatible with ourlibrary.The root of the problem is that the ISO JPEG committee failed tospecify a concrete file format. Some vendors “filled in the blanks” ontheir own, creating proprietary formats that no one else could read.(For example, none of the early commercial JPEG implementationsfor the Macintosh were able to exchange compressed files.)The file format we have adopted is called JFIF (see REFERENCES).This format has been agreed to by a number of major commercialJPEG vendors, and it has become the de facto standard. JFIF is aminimal or “low end” representation.We recommend the use of TIFF/JPEG (TIFF revision 6.0 as modifiedLICENSE