diff options
Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README | 702 |
1 files changed, 351 insertions, 351 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README index 07bb50b..0a23c19 100644 --- a/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README +++ b/libraries/irrlicht-1.8/source/Irrlicht/jpeglib/README | |||
@@ -1,351 +1,351 @@ | |||
1 | The Independent JPEG Group's JPEG software | 1 | The Independent JPEG Group's JPEG software |
2 | ========================================== | 2 | ========================================== |
3 | 3 | ||
4 | README for release 8d of 15-Jan-2012 | 4 | README for release 8d of 15-Jan-2012 |
5 | ==================================== | 5 | ==================================== |
6 | 6 | ||
7 | This distribution contains the eighth public release of the Independent JPEG | 7 | This distribution contains the eighth public release of the Independent JPEG |
8 | Group's free JPEG software. You are welcome to redistribute this software and | 8 | Group's free JPEG software. You are welcome to redistribute this software and |
9 | to use it for any purpose, subject to the conditions under LEGAL ISSUES, below. | 9 | to use it for any purpose, subject to the conditions under LEGAL ISSUES, below. |
10 | 10 | ||
11 | This software is the work of Tom Lane, Guido Vollbeding, Philip Gladstone, | 11 | This software is the work of Tom Lane, Guido Vollbeding, Philip Gladstone, |
12 | Bill Allombert, Jim Boucher, Lee Crocker, Bob Friesenhahn, Ben Jackson, | 12 | Bill Allombert, Jim Boucher, Lee Crocker, Bob Friesenhahn, Ben Jackson, |
13 | Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Ge' Weijers, | 13 | Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Ge' Weijers, |
14 | and other members of the Independent JPEG Group. | 14 | and other members of the Independent JPEG Group. |
15 | 15 | ||
16 | IJG is not affiliated with the ISO/IEC JTC1/SC29/WG1 standards committee | 16 | IJG is not affiliated with the ISO/IEC JTC1/SC29/WG1 standards committee |
17 | (also known as JPEG, together with ITU-T SG16). | 17 | (also known as JPEG, together with ITU-T SG16). |
18 | 18 | ||
19 | 19 | ||
20 | DOCUMENTATION ROADMAP | 20 | DOCUMENTATION ROADMAP |
21 | ===================== | 21 | ===================== |
22 | 22 | ||
23 | This file contains the following sections: | 23 | This file contains the following sections: |
24 | 24 | ||
25 | OVERVIEW General description of JPEG and the IJG software. | 25 | OVERVIEW General description of JPEG and the IJG software. |
26 | LEGAL ISSUES Copyright, lack of warranty, terms of distribution. | 26 | LEGAL ISSUES Copyright, lack of warranty, terms of distribution. |
27 | REFERENCES Where to learn more about JPEG. | 27 | REFERENCES Where to learn more about JPEG. |
28 | ARCHIVE LOCATIONS Where to find newer versions of this software. | 28 | ARCHIVE LOCATIONS Where to find newer versions of this software. |
29 | ACKNOWLEDGMENTS Special thanks. | 29 | ACKNOWLEDGMENTS Special thanks. |
30 | FILE FORMAT WARS Software *not* to get. | 30 | FILE FORMAT WARS Software *not* to get. |
31 | TO DO Plans for future IJG releases. | 31 | TO DO Plans for future IJG releases. |
32 | 32 | ||
33 | Other documentation files in the distribution are: | 33 | Other documentation files in the distribution are: |
34 | 34 | ||
35 | User documentation: | 35 | User documentation: |
36 | install.txt How to configure and install the IJG software. | 36 | install.txt How to configure and install the IJG software. |
37 | usage.txt Usage instructions for cjpeg, djpeg, jpegtran, | 37 | usage.txt Usage instructions for cjpeg, djpeg, jpegtran, |
38 | rdjpgcom, and wrjpgcom. | 38 | rdjpgcom, and wrjpgcom. |
39 | *.1 Unix-style man pages for programs (same info as usage.txt). | 39 | *.1 Unix-style man pages for programs (same info as usage.txt). |
40 | wizard.txt Advanced usage instructions for JPEG wizards only. | 40 | wizard.txt Advanced usage instructions for JPEG wizards only. |
41 | change.log Version-to-version change highlights. | 41 | change.log Version-to-version change highlights. |
42 | Programmer and internal documentation: | 42 | Programmer and internal documentation: |
43 | libjpeg.txt How to use the JPEG library in your own programs. | 43 | libjpeg.txt How to use the JPEG library in your own programs. |
44 | example.c Sample code for calling the JPEG library. | 44 | example.c Sample code for calling the JPEG library. |
45 | structure.txt Overview of the JPEG library's internal structure. | 45 | structure.txt Overview of the JPEG library's internal structure. |
46 | filelist.txt Road map of IJG files. | 46 | filelist.txt Road map of IJG files. |
47 | coderules.txt Coding style rules --- please read if you contribute code. | 47 | coderules.txt Coding style rules --- please read if you contribute code. |
48 | 48 | ||
49 | Please read at least the files install.txt and usage.txt. Some information | 49 | Please read at least the files install.txt and usage.txt. Some information |
50 | can also be found in the JPEG FAQ (Frequently Asked Questions) article. See | 50 | can also be found in the JPEG FAQ (Frequently Asked Questions) article. See |
51 | ARCHIVE LOCATIONS below to find out where to obtain the FAQ article. | 51 | ARCHIVE LOCATIONS below to find out where to obtain the FAQ article. |
52 | 52 | ||
53 | If you want to understand how the JPEG code works, we suggest reading one or | 53 | If you want to understand how the JPEG code works, we suggest reading one or |
54 | more of the REFERENCES, then looking at the documentation files (in roughly | 54 | more of the REFERENCES, then looking at the documentation files (in roughly |
55 | the order listed) before diving into the code. | 55 | the order listed) before diving into the code. |
56 | 56 | ||
57 | 57 | ||
58 | OVERVIEW | 58 | OVERVIEW |
59 | ======== | 59 | ======== |
60 | 60 | ||
61 | This package contains C software to implement JPEG image encoding, decoding, | 61 | This package contains C software to implement JPEG image encoding, decoding, |
62 | and transcoding. JPEG (pronounced "jay-peg") is a standardized compression | 62 | and transcoding. JPEG (pronounced "jay-peg") is a standardized compression |
63 | method for full-color and gray-scale images. | 63 | method for full-color and gray-scale images. |
64 | 64 | ||
65 | This software implements JPEG baseline, extended-sequential, and progressive | 65 | This software implements JPEG baseline, extended-sequential, and progressive |
66 | compression processes. Provision is made for supporting all variants of these | 66 | compression processes. Provision is made for supporting all variants of these |
67 | processes, although some uncommon parameter settings aren't implemented yet. | 67 | processes, although some uncommon parameter settings aren't implemented yet. |
68 | We have made no provision for supporting the hierarchical or lossless | 68 | We have made no provision for supporting the hierarchical or lossless |
69 | processes defined in the standard. | 69 | processes defined in the standard. |
70 | 70 | ||
71 | We provide a set of library routines for reading and writing JPEG image files, | 71 | We provide a set of library routines for reading and writing JPEG image files, |
72 | plus two sample applications "cjpeg" and "djpeg", which use the library to | 72 | plus two sample applications "cjpeg" and "djpeg", which use the library to |
73 | perform conversion between JPEG and some other popular image file formats. | 73 | perform conversion between JPEG and some other popular image file formats. |
74 | The library is intended to be reused in other applications. | 74 | The library is intended to be reused in other applications. |
75 | 75 | ||
76 | In order to support file conversion and viewing software, we have included | 76 | In order to support file conversion and viewing software, we have included |
77 | considerable functionality beyond the bare JPEG coding/decoding capability; | 77 | considerable functionality beyond the bare JPEG coding/decoding capability; |
78 | for example, the color quantization modules are not strictly part of JPEG | 78 | for example, the color quantization modules are not strictly part of JPEG |
79 | decoding, but they are essential for output to colormapped file formats or | 79 | decoding, but they are essential for output to colormapped file formats or |
80 | colormapped displays. These extra functions can be compiled out of the | 80 | colormapped displays. These extra functions can be compiled out of the |
81 | library if not required for a particular application. | 81 | library if not required for a particular application. |
82 | 82 | ||
83 | We have also included "jpegtran", a utility for lossless transcoding between | 83 | We have also included "jpegtran", a utility for lossless transcoding between |
84 | different JPEG processes, and "rdjpgcom" and "wrjpgcom", two simple | 84 | different JPEG processes, and "rdjpgcom" and "wrjpgcom", two simple |
85 | applications for inserting and extracting textual comments in JFIF files. | 85 | applications for inserting and extracting textual comments in JFIF files. |
86 | 86 | ||
87 | The emphasis in designing this software has been on achieving portability and | 87 | The emphasis in designing this software has been on achieving portability and |
88 | flexibility, while also making it fast enough to be useful. In particular, | 88 | flexibility, while also making it fast enough to be useful. In particular, |
89 | the software is not intended to be read as a tutorial on JPEG. (See the | 89 | the software is not intended to be read as a tutorial on JPEG. (See the |
90 | REFERENCES section for introductory material.) Rather, it is intended to | 90 | REFERENCES section for introductory material.) Rather, it is intended to |
91 | be reliable, portable, industrial-strength code. We do not claim to have | 91 | be reliable, portable, industrial-strength code. We do not claim to have |
92 | achieved that goal in every aspect of the software, but we strive for it. | 92 | achieved that goal in every aspect of the software, but we strive for it. |
93 | 93 | ||
94 | We welcome the use of this software as a component of commercial products. | 94 | We welcome the use of this software as a component of commercial products. |
95 | No royalty is required, but we do ask for an acknowledgement in product | 95 | No royalty is required, but we do ask for an acknowledgement in product |
96 | documentation, as described under LEGAL ISSUES. | 96 | documentation, as described under LEGAL ISSUES. |
97 | 97 | ||
98 | 98 | ||
99 | LEGAL ISSUES | 99 | LEGAL ISSUES |
100 | ============ | 100 | ============ |
101 | 101 | ||
102 | In plain English: | 102 | In plain English: |
103 | 103 | ||
104 | 1. We don't promise that this software works. (But if you find any bugs, | 104 | 1. We don't promise that this software works. (But if you find any bugs, |
105 | please let us know!) | 105 | please let us know!) |
106 | 2. You can use this software for whatever you want. You don't have to pay us. | 106 | 2. You can use this software for whatever you want. You don't have to pay us. |
107 | 3. You may not pretend that you wrote this software. If you use it in a | 107 | 3. You may not pretend that you wrote this software. If you use it in a |
108 | program, you must acknowledge somewhere in your documentation that | 108 | program, you must acknowledge somewhere in your documentation that |
109 | you've used the IJG code. | 109 | you've used the IJG code. |
110 | 110 | ||
111 | In legalese: | 111 | In legalese: |
112 | 112 | ||
113 | The authors make NO WARRANTY or representation, either express or implied, | 113 | The authors make NO WARRANTY or representation, either express or implied, |
114 | with respect to this software, its quality, accuracy, merchantability, or | 114 | with respect to this software, its quality, accuracy, merchantability, or |
115 | fitness for a particular purpose. This software is provided "AS IS", and you, | 115 | fitness for a particular purpose. This software is provided "AS IS", and you, |
116 | its user, assume the entire risk as to its quality and accuracy. | 116 | its user, assume the entire risk as to its quality and accuracy. |
117 | 117 | ||
118 | This software is copyright (C) 1991-2012, Thomas G. Lane, Guido Vollbeding. | 118 | This software is copyright (C) 1991-2012, Thomas G. Lane, Guido Vollbeding. |
119 | All Rights Reserved except as specified below. | 119 | All Rights Reserved except as specified below. |
120 | 120 | ||
121 | Permission is hereby granted to use, copy, modify, and distribute this | 121 | Permission is hereby granted to use, copy, modify, and distribute this |
122 | software (or portions thereof) for any purpose, without fee, subject to these | 122 | software (or portions thereof) for any purpose, without fee, subject to these |
123 | conditions: | 123 | conditions: |
124 | (1) If any part of the source code for this software is distributed, then this | 124 | (1) If any part of the source code for this software is distributed, then this |
125 | README file must be included, with this copyright and no-warranty notice | 125 | README file must be included, with this copyright and no-warranty notice |
126 | unaltered; and any additions, deletions, or changes to the original files | 126 | unaltered; and any additions, deletions, or changes to the original files |
127 | must be clearly indicated in accompanying documentation. | 127 | must be clearly indicated in accompanying documentation. |
128 | (2) If only executable code is distributed, then the accompanying | 128 | (2) If only executable code is distributed, then the accompanying |
129 | documentation must state that "this software is based in part on the work of | 129 | documentation must state that "this software is based in part on the work of |
130 | the Independent JPEG Group". | 130 | the Independent JPEG Group". |
131 | (3) Permission for use of this software is granted only if the user accepts | 131 | (3) Permission for use of this software is granted only if the user accepts |
132 | full responsibility for any undesirable consequences; the authors accept | 132 | full responsibility for any undesirable consequences; the authors accept |
133 | NO LIABILITY for damages of any kind. | 133 | NO LIABILITY for damages of any kind. |
134 | 134 | ||
135 | These conditions apply to any software derived from or based on the IJG code, | 135 | These conditions apply to any software derived from or based on the IJG code, |
136 | not just to the unmodified library. If you use our work, you ought to | 136 | not just to the unmodified library. If you use our work, you ought to |
137 | acknowledge us. | 137 | acknowledge us. |
138 | 138 | ||
139 | Permission is NOT granted for the use of any IJG author's name or company name | 139 | Permission is NOT granted for the use of any IJG author's name or company name |
140 | in advertising or publicity relating to this software or products derived from | 140 | in advertising or publicity relating to this software or products derived from |
141 | it. This software may be referred to only as "the Independent JPEG Group's | 141 | it. This software may be referred to only as "the Independent JPEG Group's |
142 | software". | 142 | software". |
143 | 143 | ||
144 | We specifically permit and encourage the use of this software as the basis of | 144 | We specifically permit and encourage the use of this software as the basis of |
145 | commercial products, provided that all warranty or liability claims are | 145 | commercial products, provided that all warranty or liability claims are |
146 | assumed by the product vendor. | 146 | assumed by the product vendor. |
147 | 147 | ||
148 | 148 | ||
149 | ansi2knr.c is included in this distribution by permission of L. Peter Deutsch, | 149 | ansi2knr.c is included in this distribution by permission of L. Peter Deutsch, |
150 | sole proprietor of its copyright holder, Aladdin Enterprises of Menlo Park, CA. | 150 | sole proprietor of its copyright holder, Aladdin Enterprises of Menlo Park, CA. |
151 | ansi2knr.c is NOT covered by the above copyright and conditions, but instead | 151 | ansi2knr.c is NOT covered by the above copyright and conditions, but instead |
152 | by the usual distribution terms of the Free Software Foundation; principally, | 152 | by the usual distribution terms of the Free Software Foundation; principally, |
153 | that you must include source code if you redistribute it. (See the file | 153 | that you must include source code if you redistribute it. (See the file |
154 | ansi2knr.c for full details.) However, since ansi2knr.c is not needed as part | 154 | ansi2knr.c for full details.) However, since ansi2knr.c is not needed as part |
155 | of any program generated from the IJG code, this does not limit you more than | 155 | of any program generated from the IJG code, this does not limit you more than |
156 | the foregoing paragraphs do. | 156 | the foregoing paragraphs do. |
157 | 157 | ||
158 | The Unix configuration script "configure" was produced with GNU Autoconf. | 158 | The Unix configuration script "configure" was produced with GNU Autoconf. |
159 | It is copyright by the Free Software Foundation but is freely distributable. | 159 | It is copyright by the Free Software Foundation but is freely distributable. |
160 | The same holds for its supporting scripts (config.guess, config.sub, | 160 | The same holds for its supporting scripts (config.guess, config.sub, |
161 | ltmain.sh). Another support script, install-sh, is copyright by X Consortium | 161 | ltmain.sh). Another support script, install-sh, is copyright by X Consortium |
162 | but is also freely distributable. | 162 | but is also freely distributable. |
163 | 163 | ||
164 | The IJG distribution formerly included code to read and write GIF files. | 164 | The IJG distribution formerly included code to read and write GIF files. |
165 | To avoid entanglement with the Unisys LZW patent, GIF reading support has | 165 | To avoid entanglement with the Unisys LZW patent, GIF reading support has |
166 | been removed altogether, and the GIF writer has been simplified to produce | 166 | been removed altogether, and the GIF writer has been simplified to produce |
167 | "uncompressed GIFs". This technique does not use the LZW algorithm; the | 167 | "uncompressed GIFs". This technique does not use the LZW algorithm; the |
168 | resulting GIF files are larger than usual, but are readable by all standard | 168 | resulting GIF files are larger than usual, but are readable by all standard |
169 | GIF decoders. | 169 | GIF decoders. |
170 | 170 | ||
171 | We are required to state that | 171 | We are required to state that |
172 | "The Graphics Interchange Format(c) is the Copyright property of | 172 | "The Graphics Interchange Format(c) is the Copyright property of |
173 | CompuServe Incorporated. GIF(sm) is a Service Mark property of | 173 | CompuServe Incorporated. GIF(sm) is a Service Mark property of |
174 | CompuServe Incorporated." | 174 | CompuServe Incorporated." |
175 | 175 | ||
176 | 176 | ||
177 | REFERENCES | 177 | REFERENCES |
178 | ========== | 178 | ========== |
179 | 179 | ||
180 | We recommend reading one or more of these references before trying to | 180 | We recommend reading one or more of these references before trying to |
181 | understand the innards of the JPEG software. | 181 | understand the innards of the JPEG software. |
182 | 182 | ||
183 | The best short technical introduction to the JPEG compression algorithm is | 183 | The best short technical introduction to the JPEG compression algorithm is |
184 | Wallace, Gregory K. "The JPEG Still Picture Compression Standard", | 184 | Wallace, Gregory K. "The JPEG Still Picture Compression Standard", |
185 | Communications of the ACM, April 1991 (vol. 34 no. 4), pp. 30-44. | 185 | Communications of the ACM, April 1991 (vol. 34 no. 4), pp. 30-44. |
186 | (Adjacent articles in that issue discuss MPEG motion picture compression, | 186 | (Adjacent articles in that issue discuss MPEG motion picture compression, |
187 | applications of JPEG, and related topics.) If you don't have the CACM issue | 187 | applications of JPEG, and related topics.) If you don't have the CACM issue |
188 | handy, a PostScript file containing a revised version of Wallace's article is | 188 | handy, a PostScript file containing a revised version of Wallace's article is |
189 | available at http://www.ijg.org/files/wallace.ps.gz. The file (actually | 189 | available at http://www.ijg.org/files/wallace.ps.gz. The file (actually |
190 | a preprint for an article that appeared in IEEE Trans. Consumer Electronics) | 190 | a preprint for an article that appeared in IEEE Trans. Consumer Electronics) |
191 | omits the sample images that appeared in CACM, but it includes corrections | 191 | omits the sample images that appeared in CACM, but it includes corrections |
192 | and some added material. Note: the Wallace article is copyright ACM and IEEE, | 192 | and some added material. Note: the Wallace article is copyright ACM and IEEE, |
193 | and it may not be used for commercial purposes. | 193 | and it may not be used for commercial purposes. |
194 | 194 | ||
195 | A somewhat less technical, more leisurely introduction to JPEG can be found in | 195 | A somewhat less technical, more leisurely introduction to JPEG can be found in |
196 | "The Data Compression Book" by Mark Nelson and Jean-loup Gailly, published by | 196 | "The Data Compression Book" by Mark Nelson and Jean-loup Gailly, published by |
197 | M&T Books (New York), 2nd ed. 1996, ISBN 1-55851-434-1. This book provides | 197 | M&T Books (New York), 2nd ed. 1996, ISBN 1-55851-434-1. This book provides |
198 | good explanations and example C code for a multitude of compression methods | 198 | good explanations and example C code for a multitude of compression methods |
199 | including JPEG. It is an excellent source if you are comfortable reading C | 199 | including JPEG. It is an excellent source if you are comfortable reading C |
200 | code but don't know much about data compression in general. The book's JPEG | 200 | code but don't know much about data compression in general. The book's JPEG |
201 | sample code is far from industrial-strength, but when you are ready to look | 201 | sample code is far from industrial-strength, but when you are ready to look |
202 | at a full implementation, you've got one here... | 202 | at a full implementation, you've got one here... |
203 | 203 | ||
204 | The best currently available description of JPEG is the textbook "JPEG Still | 204 | The best currently available description of JPEG is the textbook "JPEG Still |
205 | Image Data Compression Standard" by William B. Pennebaker and Joan L. | 205 | Image Data Compression Standard" by William B. Pennebaker and Joan L. |
206 | Mitchell, published by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1. | 206 | Mitchell, published by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1. |
207 | Price US$59.95, 638 pp. The book includes the complete text of the ISO JPEG | 207 | Price US$59.95, 638 pp. The book includes the complete text of the ISO JPEG |
208 | standards (DIS 10918-1 and draft DIS 10918-2). | 208 | standards (DIS 10918-1 and draft DIS 10918-2). |
209 | Although this is by far the most detailed and comprehensive exposition of | 209 | Although this is by far the most detailed and comprehensive exposition of |
210 | JPEG publicly available, we point out that it is still missing an explanation | 210 | JPEG publicly available, we point out that it is still missing an explanation |
211 | of the most essential properties and algorithms of the underlying DCT | 211 | of the most essential properties and algorithms of the underlying DCT |
212 | technology. | 212 | technology. |
213 | If you think that you know about DCT-based JPEG after reading this book, | 213 | If you think that you know about DCT-based JPEG after reading this book, |
214 | then you are in delusion. The real fundamentals and corresponding potential | 214 | then you are in delusion. The real fundamentals and corresponding potential |
215 | of DCT-based JPEG are not publicly known so far, and that is the reason for | 215 | of DCT-based JPEG are not publicly known so far, and that is the reason for |
216 | all the mistaken developments taking place in the image coding domain. | 216 | all the mistaken developments taking place in the image coding domain. |
217 | 217 | ||
218 | The original JPEG standard is divided into two parts, Part 1 being the actual | 218 | The original JPEG standard is divided into two parts, Part 1 being the actual |
219 | specification, while Part 2 covers compliance testing methods. Part 1 is | 219 | specification, while Part 2 covers compliance testing methods. Part 1 is |
220 | titled "Digital Compression and Coding of Continuous-tone Still Images, | 220 | titled "Digital Compression and Coding of Continuous-tone Still Images, |
221 | Part 1: Requirements and guidelines" and has document numbers ISO/IEC IS | 221 | Part 1: Requirements and guidelines" and has document numbers ISO/IEC IS |
222 | 10918-1, ITU-T T.81. Part 2 is titled "Digital Compression and Coding of | 222 | 10918-1, ITU-T T.81. Part 2 is titled "Digital Compression and Coding of |
223 | Continuous-tone Still Images, Part 2: Compliance testing" and has document | 223 | Continuous-tone Still Images, Part 2: Compliance testing" and has document |
224 | numbers ISO/IEC IS 10918-2, ITU-T T.83. | 224 | numbers ISO/IEC IS 10918-2, ITU-T T.83. |
225 | IJG JPEG 8 introduces an implementation of the JPEG SmartScale extension | 225 | IJG JPEG 8 introduces an implementation of the JPEG SmartScale extension |
226 | which is specified in two documents: A contributed document at ITU and ISO | 226 | which is specified in two documents: A contributed document at ITU and ISO |
227 | with title "ITU-T JPEG-Plus Proposal for Extending ITU-T T.81 for Advanced | 227 | with title "ITU-T JPEG-Plus Proposal for Extending ITU-T T.81 for Advanced |
228 | Image Coding", April 2006, Geneva, Switzerland. The latest version of this | 228 | Image Coding", April 2006, Geneva, Switzerland. The latest version of this |
229 | document is Revision 3. And a contributed document ISO/IEC JTC1/SC29/WG1 N | 229 | document is Revision 3. And a contributed document ISO/IEC JTC1/SC29/WG1 N |
230 | 5799 with title "Evolution of JPEG", June/July 2011, Berlin, Germany. | 230 | 5799 with title "Evolution of JPEG", June/July 2011, Berlin, Germany. |
231 | 231 | ||
232 | The JPEG standard does not specify all details of an interchangeable file | 232 | The JPEG standard does not specify all details of an interchangeable file |
233 | format. For the omitted details we follow the "JFIF" conventions, revision | 233 | format. For the omitted details we follow the "JFIF" conventions, revision |
234 | 1.02. JFIF 1.02 has been adopted as an Ecma International Technical Report | 234 | 1.02. JFIF 1.02 has been adopted as an Ecma International Technical Report |
235 | and thus received a formal publication status. It is available as a free | 235 | and thus received a formal publication status. It is available as a free |
236 | download in PDF format from | 236 | download in PDF format from |
237 | http://www.ecma-international.org/publications/techreports/E-TR-098.htm. | 237 | http://www.ecma-international.org/publications/techreports/E-TR-098.htm. |
238 | A PostScript version of the JFIF document is available at | 238 | A PostScript version of the JFIF document is available at |
239 | http://www.ijg.org/files/jfif.ps.gz. There is also a plain text version at | 239 | http://www.ijg.org/files/jfif.ps.gz. There is also a plain text version at |
240 | http://www.ijg.org/files/jfif.txt.gz, but it is missing the figures. | 240 | http://www.ijg.org/files/jfif.txt.gz, but it is missing the figures. |
241 | 241 | ||
242 | The TIFF 6.0 file format specification can be obtained by FTP from | 242 | The TIFF 6.0 file format specification can be obtained by FTP from |
243 | ftp://ftp.sgi.com/graphics/tiff/TIFF6.ps.gz. The JPEG incorporation scheme | 243 | ftp://ftp.sgi.com/graphics/tiff/TIFF6.ps.gz. The JPEG incorporation scheme |
244 | found in the TIFF 6.0 spec of 3-June-92 has a number of serious problems. | 244 | found in the TIFF 6.0 spec of 3-June-92 has a number of serious problems. |
245 | IJG does not recommend use of the TIFF 6.0 design (TIFF Compression tag 6). | 245 | IJG does not recommend use of the TIFF 6.0 design (TIFF Compression tag 6). |
246 | Instead, we recommend the JPEG design proposed by TIFF Technical Note #2 | 246 | Instead, we recommend the JPEG design proposed by TIFF Technical Note #2 |
247 | (Compression tag 7). Copies of this Note can be obtained from | 247 | (Compression tag 7). Copies of this Note can be obtained from |
248 | http://www.ijg.org/files/. It is expected that the next revision | 248 | http://www.ijg.org/files/. It is expected that the next revision |
249 | of the TIFF spec will replace the 6.0 JPEG design with the Note's design. | 249 | of the TIFF spec will replace the 6.0 JPEG design with the Note's design. |
250 | Although IJG's own code does not support TIFF/JPEG, the free libtiff library | 250 | Although IJG's own code does not support TIFF/JPEG, the free libtiff library |
251 | uses our library to implement TIFF/JPEG per the Note. | 251 | uses our library to implement TIFF/JPEG per the Note. |
252 | 252 | ||
253 | 253 | ||
254 | ARCHIVE LOCATIONS | 254 | ARCHIVE LOCATIONS |
255 | ================= | 255 | ================= |
256 | 256 | ||
257 | The "official" archive site for this software is www.ijg.org. | 257 | The "official" archive site for this software is www.ijg.org. |
258 | The most recent released version can always be found there in | 258 | The most recent released version can always be found there in |
259 | directory "files". This particular version will be archived as | 259 | directory "files". This particular version will be archived as |
260 | http://www.ijg.org/files/jpegsrc.v8d.tar.gz, and in Windows-compatible | 260 | http://www.ijg.org/files/jpegsrc.v8d.tar.gz, and in Windows-compatible |
261 | "zip" archive format as http://www.ijg.org/files/jpegsr8d.zip. | 261 | "zip" archive format as http://www.ijg.org/files/jpegsr8d.zip. |
262 | 262 | ||
263 | The JPEG FAQ (Frequently Asked Questions) article is a source of some | 263 | The JPEG FAQ (Frequently Asked Questions) article is a source of some |
264 | general information about JPEG. | 264 | general information about JPEG. |
265 | It is available on the World Wide Web at http://www.faqs.org/faqs/jpeg-faq/ | 265 | It is available on the World Wide Web at http://www.faqs.org/faqs/jpeg-faq/ |
266 | and other news.answers archive sites, including the official news.answers | 266 | and other news.answers archive sites, including the official news.answers |
267 | archive at rtfm.mit.edu: ftp://rtfm.mit.edu/pub/usenet/news.answers/jpeg-faq/. | 267 | archive at rtfm.mit.edu: ftp://rtfm.mit.edu/pub/usenet/news.answers/jpeg-faq/. |
268 | If you don't have Web or FTP access, send e-mail to mail-server@rtfm.mit.edu | 268 | If you don't have Web or FTP access, send e-mail to mail-server@rtfm.mit.edu |
269 | with body | 269 | with body |
270 | send usenet/news.answers/jpeg-faq/part1 | 270 | send usenet/news.answers/jpeg-faq/part1 |
271 | send usenet/news.answers/jpeg-faq/part2 | 271 | send usenet/news.answers/jpeg-faq/part2 |
272 | 272 | ||
273 | 273 | ||
274 | ACKNOWLEDGMENTS | 274 | ACKNOWLEDGMENTS |
275 | =============== | 275 | =============== |
276 | 276 | ||
277 | Thank to Juergen Bruder for providing me with a copy of the common DCT | 277 | Thank to Juergen Bruder for providing me with a copy of the common DCT |
278 | algorithm article, only to find out that I had come to the same result | 278 | algorithm article, only to find out that I had come to the same result |
279 | in a more direct and comprehensible way with a more generative approach. | 279 | in a more direct and comprehensible way with a more generative approach. |
280 | 280 | ||
281 | Thank to Istvan Sebestyen and Joan L. Mitchell for inviting me to the | 281 | Thank to Istvan Sebestyen and Joan L. Mitchell for inviting me to the |
282 | ITU JPEG (Study Group 16) meeting in Geneva, Switzerland. | 282 | ITU JPEG (Study Group 16) meeting in Geneva, Switzerland. |
283 | 283 | ||
284 | Thank to Thomas Wiegand and Gary Sullivan for inviting me to the | 284 | Thank to Thomas Wiegand and Gary Sullivan for inviting me to the |
285 | Joint Video Team (MPEG & ITU) meeting in Geneva, Switzerland. | 285 | Joint Video Team (MPEG & ITU) meeting in Geneva, Switzerland. |
286 | 286 | ||
287 | Thank to Thomas Richter and Daniel Lee for inviting me to the | 287 | Thank to Thomas Richter and Daniel Lee for inviting me to the |
288 | ISO/IEC JTC1/SC29/WG1 (also known as JPEG, together with ITU-T SG16) | 288 | ISO/IEC JTC1/SC29/WG1 (also known as JPEG, together with ITU-T SG16) |
289 | meeting in Berlin, Germany. | 289 | meeting in Berlin, Germany. |
290 | 290 | ||
291 | Thank to John Korejwa and Massimo Ballerini for inviting me to | 291 | Thank to John Korejwa and Massimo Ballerini for inviting me to |
292 | fruitful consultations in Boston, MA and Milan, Italy. | 292 | fruitful consultations in Boston, MA and Milan, Italy. |
293 | 293 | ||
294 | Thank to Hendrik Elstner, Roland Fassauer, Simone Zuck, Guenther | 294 | Thank to Hendrik Elstner, Roland Fassauer, Simone Zuck, Guenther |
295 | Maier-Gerber, Walter Stoeber, Fred Schmitz, and Norbert Braunagel | 295 | Maier-Gerber, Walter Stoeber, Fred Schmitz, and Norbert Braunagel |
296 | for corresponding business development. | 296 | for corresponding business development. |
297 | 297 | ||
298 | Thank to Nico Zschach and Dirk Stelling of the technical support team | 298 | Thank to Nico Zschach and Dirk Stelling of the technical support team |
299 | at the Digital Images company in Halle for providing me with extra | 299 | at the Digital Images company in Halle for providing me with extra |
300 | equipment for configuration tests. | 300 | equipment for configuration tests. |
301 | 301 | ||
302 | Thank to Richard F. Lyon (then of Foveon Inc.) for fruitful | 302 | Thank to Richard F. Lyon (then of Foveon Inc.) for fruitful |
303 | communication about JPEG configuration in Sigma Photo Pro software. | 303 | communication about JPEG configuration in Sigma Photo Pro software. |
304 | 304 | ||
305 | Thank to Andrew Finkenstadt for hosting the ijg.org site. | 305 | Thank to Andrew Finkenstadt for hosting the ijg.org site. |
306 | 306 | ||
307 | Last but not least special thank to Thomas G. Lane for the original | 307 | Last but not least special thank to Thomas G. Lane for the original |
308 | design and development of this singular software package. | 308 | design and development of this singular software package. |
309 | 309 | ||
310 | 310 | ||
311 | FILE FORMAT WARS | 311 | FILE FORMAT WARS |
312 | ================ | 312 | ================ |
313 | 313 | ||
314 | The ISO/IEC JTC1/SC29/WG1 standards committee (also known as JPEG, together | 314 | The ISO/IEC JTC1/SC29/WG1 standards committee (also known as JPEG, together |
315 | with ITU-T SG16) currently promotes different formats containing the name | 315 | with ITU-T SG16) currently promotes different formats containing the name |
316 | "JPEG" which is misleading because these formats are incompatible with | 316 | "JPEG" which is misleading because these formats are incompatible with |
317 | original DCT-based JPEG and are based on faulty technologies. | 317 | original DCT-based JPEG and are based on faulty technologies. |
318 | IJG therefore does not and will not support such momentary mistakes | 318 | IJG therefore does not and will not support such momentary mistakes |
319 | (see REFERENCES). | 319 | (see REFERENCES). |
320 | There exist also distributions under the name "OpenJPEG" promoting such | 320 | There exist also distributions under the name "OpenJPEG" promoting such |
321 | kind of formats which is misleading because they don't support original | 321 | kind of formats which is misleading because they don't support original |
322 | JPEG images. | 322 | JPEG images. |
323 | We have no sympathy for the promotion of inferior formats. Indeed, one of | 323 | We have no sympathy for the promotion of inferior formats. Indeed, one of |
324 | the original reasons for developing this free software was to help force | 324 | the original reasons for developing this free software was to help force |
325 | convergence on common, interoperable format standards for JPEG files. | 325 | convergence on common, interoperable format standards for JPEG files. |
326 | Don't use an incompatible file format! | 326 | Don't use an incompatible file format! |
327 | (In any case, our decoder will remain capable of reading existing JPEG | 327 | (In any case, our decoder will remain capable of reading existing JPEG |
328 | image files indefinitely.) | 328 | image files indefinitely.) |
329 | 329 | ||
330 | Furthermore, the ISO committee pretends to be "responsible for the popular | 330 | Furthermore, the ISO committee pretends to be "responsible for the popular |
331 | JPEG" in their public reports which is not true because they don't respond to | 331 | JPEG" in their public reports which is not true because they don't respond to |
332 | actual requirements for the maintenance of the original JPEG specification. | 332 | actual requirements for the maintenance of the original JPEG specification. |
333 | 333 | ||
334 | There are currently distributions in circulation containing the name | 334 | There are currently distributions in circulation containing the name |
335 | "libjpeg" which claim to be a "derivative" or "fork" of the original | 335 | "libjpeg" which claim to be a "derivative" or "fork" of the original |
336 | libjpeg, but don't have the features and are incompatible with formats | 336 | libjpeg, but don't have the features and are incompatible with formats |
337 | supported by actual IJG libjpeg distributions. Furthermore, they | 337 | supported by actual IJG libjpeg distributions. Furthermore, they |
338 | violate the license conditions as described under LEGAL ISSUES above. | 338 | violate the license conditions as described under LEGAL ISSUES above. |
339 | We have no sympathy for the release of misleading and illegal | 339 | We have no sympathy for the release of misleading and illegal |
340 | distributions derived from obsolete code bases. | 340 | distributions derived from obsolete code bases. |
341 | Don't use an obsolete code base! | 341 | Don't use an obsolete code base! |
342 | 342 | ||
343 | 343 | ||
344 | TO DO | 344 | TO DO |
345 | ===== | 345 | ===== |
346 | 346 | ||
347 | Version 8 is the first release of a new generation JPEG standard | 347 | Version 8 is the first release of a new generation JPEG standard |
348 | to overcome the limitations of the original JPEG specification. | 348 | to overcome the limitations of the original JPEG specification. |
349 | More features are being prepared for coming releases... | 349 | More features are being prepared for coming releases... |
350 | 350 | ||
351 | Please send bug reports, offers of help, etc. to jpeg-info@jpegclub.org. | 351 | Please send bug reports, offers of help, etc. to jpeg-info@jpegclub.org. |