2013-01-12 07:28:35 +00:00
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libjpeg-turbo note: This file has been modified by The libjpeg-turbo Project
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to include only information relevant to libjpeg-turbo, to wordsmith certain
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sections, and to remove impolitic language that existed in the libjpeg v8
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2015-10-10 10:25:46 -05:00
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README. It is included only for reference. Please see README.md for
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2013-01-12 07:28:35 +00:00
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information specific to libjpeg-turbo.
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2010-02-21 15:45:00 +00:00
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2013-01-12 07:29:53 +00:00
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1991-10-07 00:00:00 +00:00
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The Independent JPEG Group's JPEG software
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==========================================
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2010-10-12 01:55:31 +00:00
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This distribution contains a release of the Independent JPEG Group's free JPEG
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software. You are welcome to redistribute this software and to use it for any
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purpose, subject to the conditions under LEGAL ISSUES, below.
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1991-10-07 00:00:00 +00:00
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2009-06-27 00:00:00 +00:00
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This software is the work of Tom Lane, Guido Vollbeding, Philip Gladstone,
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Bill Allombert, Jim Boucher, Lee Crocker, Bob Friesenhahn, Ben Jackson,
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Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Ge' Weijers,
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and other members of the Independent JPEG Group.
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1991-10-07 00:00:00 +00:00
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2012-01-15 00:00:00 +00:00
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IJG is not affiliated with the ISO/IEC JTC1/SC29/WG1 standards committee
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(also known as JPEG, together with ITU-T SG16).
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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DOCUMENTATION ROADMAP
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=====================
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This file contains the following sections:
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OVERVIEW General description of JPEG and the IJG software.
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LEGAL ISSUES Copyright, lack of warranty, terms of distribution.
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REFERENCES Where to learn more about JPEG.
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ARCHIVE LOCATIONS Where to find newer versions of this software.
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FILE FORMAT WARS Software *not* to get.
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TO DO Plans for future IJG releases.
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Other documentation files in the distribution are:
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User documentation:
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Reorganize source to make things easier to find
- Move all libjpeg documentation, except for README.ijg, into the doc/
subdirectory.
- Move the TurboJPEG C API documentation from doc/html/ into
doc/turbojpeg/.
- Move all C source code and headers into a src/ subdirectory.
- Move turbojpeg-jni.c into the java/ subdirectory.
Referring to #226, there is no ideal solution to this problem. A
semantically ideal solution would have involved placing all source code,
including the SIMD and Java source code, under src/ (or perhaps placing
C library source code under lib/ and C test program source code under
test/), all header files under include/, and all documentation under
doc/. However:
- To me it makes more sense to have separate top-level directories for
each language, since the SIMD extensions and the Java API are
technically optional features. src/ now contains only the code that
is relevant to the core C API libraries and associated programs.
- I didn't want to bury the java/ and simd/ directories or add a level
of depth to them, since both directories already contain source code
that is 3-4 levels deep.
- I would prefer not to separate the header files from the C source
code, because:
1. It would be disruptive. libjpeg and libjpeg-turbo have
historically placed C source code and headers in the same
directory, and people who are familiar with both projects (self
included) are used to looking for the headers in the same directory
as the C source code.
2. In terms of how the headers are used internally in libjpeg-turbo,
the distinction between public and private headers is a bit fuzzy.
- It didn't make sense to separate the test source code from the library
source code, since there is not a clear distinction in some cases.
(For instance, the IJG image I/O functions are used by cjpeg and djpeg
as well as by the TurboJPEG API.)
This solution is minimally disruptive, since it keeps all C source code
and headers together and keeps java/ and simd/ as top-level directories.
It is a bit awkward, because java/ and simd/ technically contain source
code, even though they are not under src/. However, other solutions
would have been more awkward for different reasons.
Closes #226
2024-01-23 13:26:41 -05:00
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doc/usage.txt Usage instructions for cjpeg, djpeg, jpegtran,
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rdjpgcom, and wrjpgcom.
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doc/*.1 Unix-style man pages for programs (same info as
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usage.txt).
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doc/wizard.txt Advanced usage instructions for JPEG wizards only.
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doc/change.log Version-to-version change highlights.
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1994-09-24 00:00:00 +00:00
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Programmer and internal documentation:
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Reorganize source to make things easier to find
- Move all libjpeg documentation, except for README.ijg, into the doc/
subdirectory.
- Move the TurboJPEG C API documentation from doc/html/ into
doc/turbojpeg/.
- Move all C source code and headers into a src/ subdirectory.
- Move turbojpeg-jni.c into the java/ subdirectory.
Referring to #226, there is no ideal solution to this problem. A
semantically ideal solution would have involved placing all source code,
including the SIMD and Java source code, under src/ (or perhaps placing
C library source code under lib/ and C test program source code under
test/), all header files under include/, and all documentation under
doc/. However:
- To me it makes more sense to have separate top-level directories for
each language, since the SIMD extensions and the Java API are
technically optional features. src/ now contains only the code that
is relevant to the core C API libraries and associated programs.
- I didn't want to bury the java/ and simd/ directories or add a level
of depth to them, since both directories already contain source code
that is 3-4 levels deep.
- I would prefer not to separate the header files from the C source
code, because:
1. It would be disruptive. libjpeg and libjpeg-turbo have
historically placed C source code and headers in the same
directory, and people who are familiar with both projects (self
included) are used to looking for the headers in the same directory
as the C source code.
2. In terms of how the headers are used internally in libjpeg-turbo,
the distinction between public and private headers is a bit fuzzy.
- It didn't make sense to separate the test source code from the library
source code, since there is not a clear distinction in some cases.
(For instance, the IJG image I/O functions are used by cjpeg and djpeg
as well as by the TurboJPEG API.)
This solution is minimally disruptive, since it keeps all C source code
and headers together and keeps java/ and simd/ as top-level directories.
It is a bit awkward, because java/ and simd/ technically contain source
code, even though they are not under src/. However, other solutions
would have been more awkward for different reasons.
Closes #226
2024-01-23 13:26:41 -05:00
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doc/libjpeg.txt How to use the JPEG library in your own programs.
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src/example.c Sample code for calling the JPEG library.
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doc/structure.txt Overview of the JPEG library's internal structure.
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doc/coderules.txt Coding style rules --- please read if you contribute
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code.
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1994-09-24 00:00:00 +00:00
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2014-12-19 18:07:04 +00:00
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Please read at least usage.txt. Some information can also be found in the JPEG
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FAQ (Frequently Asked Questions) article. See ARCHIVE LOCATIONS below to find
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out where to obtain the FAQ article.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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If you want to understand how the JPEG code works, we suggest reading one or
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more of the REFERENCES, then looking at the documentation files (in roughly
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the order listed) before diving into the code.
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1991-12-13 00:00:00 +00:00
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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OVERVIEW
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========
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1991-10-07 00:00:00 +00:00
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2009-06-27 00:00:00 +00:00
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This package contains C software to implement JPEG image encoding, decoding,
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and transcoding. JPEG (pronounced "jay-peg") is a standardized compression
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2014-05-12 09:08:39 +00:00
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method for full-color and grayscale images. JPEG's strong suit is compressing
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2011-12-15 13:12:59 +00:00
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photographic images or other types of images that have smooth color and
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2010-10-12 01:55:31 +00:00
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brightness transitions between neighboring pixels. Images with sharp lines or
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other abrupt features may not compress well with JPEG, and a higher JPEG
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quality may have to be used to avoid visible compression artifacts with such
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images.
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2022-11-14 15:36:25 -06:00
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JPEG is normally lossy, meaning that the output pixels are not necessarily
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identical to the input pixels. However, on photographic content and other
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"smooth" images, very good compression ratios can be obtained with no visible
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compression artifacts, and extremely high compression ratios are possible if
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you are willing to sacrifice image quality (by reducing the "quality" setting
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in the compressor.)
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This software implements JPEG baseline, extended-sequential, progressive, and
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lossless compression processes. Provision is made for supporting all variants
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of these processes, although some uncommon parameter settings aren't
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implemented yet. We have made no provision for supporting the hierarchical
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2009-06-27 00:00:00 +00:00
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processes defined in the standard.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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We provide a set of library routines for reading and writing JPEG image files,
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1995-08-02 00:00:00 +00:00
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plus two sample applications "cjpeg" and "djpeg", which use the library to
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1994-09-24 00:00:00 +00:00
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perform conversion between JPEG and some other popular image file formats.
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The library is intended to be reused in other applications.
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1992-12-10 00:00:00 +00:00
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In order to support file conversion and viewing software, we have included
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considerable functionality beyond the bare JPEG coding/decoding capability;
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for example, the color quantization modules are not strictly part of JPEG
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Various doc tweaks
- "bits per component" = "bits per sample"
Describing the data precision of a JPEG image using "bits per
component" is technically correct, but "bits per sample" is the
terminology that the JPEG-1 spec uses. Also, "bits per component" is
more commonly used to describe the precision of packed-pixel formats
(as opposed to "bits per pixel") rather than planar formats, in which
all components are grouped together.
- Unmention legacy display technologies. Colormapped and monochrome
displays aren't a thing anymore, and even when they were still a
thing, it was possible to display full-color images to them. In 1991,
when JPEG decompression time was measured in minutes per megapixel, it
made sense to keep a decompressed copy of JPEG images on disk, in a
format that could be displayed without further color conversion (since
color conversion was slow and memory-intensive.) In 2024, JPEG
decompression time is measured in milliseconds per megapixel, and
color conversion is even faster. Thus, JPEG images can be
decompressed, displayed, and color-converted (if necessary) "on the
fly" at speeds too fast for human vision to perceive. (In fact, your
TV performs much more complicated decompression algorithms at least 60
times per second.)
- Document that color quantization (and associated features), GIF
input/output, Targa input/output, and OS/2 BMP input/output are legacy
features. Legacy status doesn't necessarily mean that the features
are deprecated. Rather, it is meant to discourage users from using
features that may be of little or no benefit on modern machines (such
as low-quality modes that had significant performance advantages in
the early 1990s but no longer do) and that are maintained on a
break/fix basis only.
- General wordsmithing, grammar/punctuation policing, and formatting
tweaks
- Clarify which data precisions each cjpeg input format and each djpeg
output format supports.
- cjpeg.1: Remove unnecessary and impolitic statement about the -targa
switch.
- Adjust or remove performance claims to reflect the fact that:
* On modern machines, the djpeg "-fast" switch has a negligible effect
on performance.
* There is a measurable difference between the performance of Floyd-
Steinberg dithering and no dithering, but it is not likely
perceptible to most users.
* There is a measurable difference between the performance of 1-pass
and 2-pass color quantization, but it is not likely perceptible to
most users.
* There is a measurable difference between the performance of
full-color and grayscale output when decompressing a full-color JPEG
image, but it is not likely perceptible to most users.
* IDCT scaling does not necessarily improve performance. (It
generally does if the scaling factor is <= 1/2 and generally doesn't
if the scaling factor is > 1/2, at least on my machine. The
performance claim made in jpeg-6b was probably invalidated when we
merged the additional scaling factors from jpeg-7.)
- Clarify which djpeg switches/output formats cannot be used when
decompressing lossless JPEG images.
- Remove djpeg hints, since those involve quality vs. speed tradeoffs
that are no longer relevant for modern machines.
- Remove documentation regarding using color quantization with 16-bit
data precision. (Color quantization requires lossy mode.)
- Java: Fix typos in TJDecompressor.decompress12() and
TJDecompressor.decompress16() documentation.
- jpegtran.1: Fix truncated paragraph
In a man page, a single quote at the start of a line is interpreted as
a macro.
Closes #775
- libjpeg.txt:
* Mention J16SAMPLE data type (oversight.)
* Remove statement about extending jdcolor.c. (libjpeg-turbo is not
quite as DIY as libjpeg once was.)
* Remove paragraph about tweaking the various typedefs in jmorecfg.h.
It is no longer relevant for modern machines.
* Remove caveat regarding systems with ints less than 16 bits wide.
(ANSI/ISO C requires an int to be at least 16 bits wide, and
libjpeg-turbo has never supported non-ANSI compilers.)
- usage.txt:
* Add copyright header.
* Document cjpeg -icc, -memdst, -report, -strict, and -version
switches.
* Document djpeg -icc, -maxscans, -memsrc, -report, -skip, -crop,
-strict, and -version switches.
* Document jpegtran -icc, -maxscans, -report, -strict, and -version
switches.
2024-06-17 20:27:57 -04:00
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decoding, but they are essential for output to colormapped file formats. These
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extra functions can be compiled out of the library if not required for a
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particular application.
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2009-06-27 00:00:00 +00:00
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We have also included "jpegtran", a utility for lossless transcoding between
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different JPEG processes, and "rdjpgcom" and "wrjpgcom", two simple
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applications for inserting and extracting textual comments in JFIF files.
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1991-10-07 00:00:00 +00:00
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The emphasis in designing this software has been on achieving portability and
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1992-12-10 00:00:00 +00:00
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flexibility, while also making it fast enough to be useful. In particular,
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the software is not intended to be read as a tutorial on JPEG. (See the
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1995-08-02 00:00:00 +00:00
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REFERENCES section for introductory material.) Rather, it is intended to
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be reliable, portable, industrial-strength code. We do not claim to have
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achieved that goal in every aspect of the software, but we strive for it.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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We welcome the use of this software as a component of commercial products.
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No royalty is required, but we do ask for an acknowledgement in product
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documentation, as described under LEGAL ISSUES.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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LEGAL ISSUES
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============
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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In plain English:
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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1. We don't promise that this software works. (But if you find any bugs,
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please let us know!)
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2. You can use this software for whatever you want. You don't have to pay us.
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3. You may not pretend that you wrote this software. If you use it in a
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program, you must acknowledge somewhere in your documentation that
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you've used the IJG code.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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In legalese:
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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The authors make NO WARRANTY or representation, either express or implied,
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with respect to this software, its quality, accuracy, merchantability, or
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fitness for a particular purpose. This software is provided "AS IS", and you,
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its user, assume the entire risk as to its quality and accuracy.
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1991-10-07 00:00:00 +00:00
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2020-10-27 13:28:56 -05:00
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This software is copyright (C) 1991-2020, Thomas G. Lane, Guido Vollbeding.
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1994-09-24 00:00:00 +00:00
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All Rights Reserved except as specified below.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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Permission is hereby granted to use, copy, modify, and distribute this
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software (or portions thereof) for any purpose, without fee, subject to these
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conditions:
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(1) If any part of the source code for this software is distributed, then this
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README file must be included, with this copyright and no-warranty notice
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unaltered; and any additions, deletions, or changes to the original files
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must be clearly indicated in accompanying documentation.
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(2) If only executable code is distributed, then the accompanying
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documentation must state that "this software is based in part on the work of
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the Independent JPEG Group".
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(3) Permission for use of this software is granted only if the user accepts
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full responsibility for any undesirable consequences; the authors accept
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NO LIABILITY for damages of any kind.
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1993-02-18 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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These conditions apply to any software derived from or based on the IJG code,
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not just to the unmodified library. If you use our work, you ought to
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acknowledge us.
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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Permission is NOT granted for the use of any IJG author's name or company name
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in advertising or publicity relating to this software or products derived from
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it. This software may be referred to only as "the Independent JPEG Group's
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software".
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1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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We specifically permit and encourage the use of this software as the basis of
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commercial products, provided that all warranty or liability claims are
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assumed by the product vendor.
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1991-10-07 00:00:00 +00:00
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REFERENCES
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==========
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2009-06-27 00:00:00 +00:00
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We recommend reading one or more of these references before trying to
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1994-09-24 00:00:00 +00:00
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understand the innards of the JPEG software.
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1992-12-10 00:00:00 +00:00
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The best short technical introduction to the JPEG compression algorithm is
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Improve code formatting consistency
With rare exceptions ...
- Always separate line continuation characters by one space from
preceding code.
- Always use two-space indentation. Never use tabs.
- Always use K&R-style conditional blocks.
- Always surround operators with spaces, except in raw assembly code.
- Always put a space after, but not before, a comma.
- Never put a space between type casts and variables/function calls.
- Never put a space between the function name and the argument list in
function declarations and prototypes.
- Always surround braces ('{' and '}') with spaces.
- Always surround statements (if, for, else, catch, while, do, switch)
with spaces.
- Always attach pointer symbols ('*' and '**') to the variable or
function name.
- Always precede pointer symbols ('*' and '**') by a space in type
casts.
- Use the MIN() macro from jpegint.h within the libjpeg and TurboJPEG
API libraries (using min() from tjutil.h is still necessary for
TJBench.)
- Where it makes sense (particularly in the TurboJPEG code), put a blank
line after variable declaration blocks.
- Always separate statements in one-liners by two spaces.
The purpose of this was to ease maintenance on my part and also to make
it easier for contributors to figure out how to format patch
submissions. This was admittedly confusing (even to me sometimes) when
we had 3 or 4 different style conventions in the same source tree. The
new convention is more consistent with the formatting of other OSS code
bases.
This commit corrects deviations from the chosen formatting style in the
libjpeg API code and reformats the TurboJPEG API code such that it
conforms to the same standard.
NOTES:
- Although it is no longer necessary for the function name in function
declarations to begin in Column 1 (this was historically necessary
because of the ansi2knr utility, which allowed libjpeg to be built
with non-ANSI compilers), we retain that formatting for the libjpeg
code because it improves readability when using libjpeg's function
attribute macros (GLOBAL(), etc.)
- This reformatting project was accomplished with the help of AStyle and
Uncrustify, although neither was completely up to the task, and thus
a great deal of manual tweaking was required. Note to developers of
code formatting utilities: the libjpeg-turbo code base is an
excellent test bed, because AFAICT, it breaks every single one of the
utilities that are currently available.
- The legacy (MMX, SSE, 3DNow!) assembly code for i386 has been
formatted to match the SSE2 code (refer to
ff5685d5344273df321eb63a005eaae19d2496e3.) I hadn't intended to
bother with this, but the Loongson MMI implementation demonstrated
that there is still academic value to the MMX implementation, as an
algorithmic model for other 64-bit vector implementations. Thus, it
is desirable to improve its readability in the same manner as that of
the SSE2 implementation.
2018-03-08 10:55:20 -06:00
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Wallace, Gregory K. "The JPEG Still Picture Compression Standard",
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Communications of the ACM, April 1991 (vol. 34 no. 4), pp. 30-44.
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1991-10-07 00:00:00 +00:00
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(Adjacent articles in that issue discuss MPEG motion picture compression,
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1992-12-10 00:00:00 +00:00
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applications of JPEG, and related topics.) If you don't have the CACM issue
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2016-01-17 00:00:00 +00:00
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handy, a PDF file containing a revised version of Wallace's article is
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available at http://www.ijg.org/files/Wallace.JPEG.pdf. The file (actually
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1994-12-07 00:00:00 +00:00
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a preprint for an article that appeared in IEEE Trans. Consumer Electronics)
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omits the sample images that appeared in CACM, but it includes corrections
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1998-03-27 00:00:00 +00:00
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and some added material. Note: the Wallace article is copyright ACM and IEEE,
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and it may not be used for commercial purposes.
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1992-12-10 00:00:00 +00:00
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A somewhat less technical, more leisurely introduction to JPEG can be found in
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1998-03-27 00:00:00 +00:00
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"The Data Compression Book" by Mark Nelson and Jean-loup Gailly, published by
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M&T Books (New York), 2nd ed. 1996, ISBN 1-55851-434-1. This book provides
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good explanations and example C code for a multitude of compression methods
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including JPEG. It is an excellent source if you are comfortable reading C
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code but don't know much about data compression in general. The book's JPEG
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sample code is far from industrial-strength, but when you are ready to look
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at a full implementation, you've got one here...
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1992-12-10 00:00:00 +00:00
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2009-06-27 00:00:00 +00:00
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The best currently available description of JPEG is the textbook "JPEG Still
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Image Data Compression Standard" by William B. Pennebaker and Joan L.
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Mitchell, published by Van Nostrand Reinhold, 1993, ISBN 0-442-01272-1.
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Price US$59.95, 638 pp. The book includes the complete text of the ISO JPEG
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standards (DIS 10918-1 and draft DIS 10918-2).
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The original JPEG standard is divided into two parts, Part 1 being the actual
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specification, while Part 2 covers compliance testing methods. Part 1 is
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titled "Digital Compression and Coding of Continuous-tone Still Images,
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1996-02-07 00:00:00 +00:00
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Part 1: Requirements and guidelines" and has document numbers ISO/IEC IS
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10918-1, ITU-T T.81. Part 2 is titled "Digital Compression and Coding of
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Continuous-tone Still Images, Part 2: Compliance testing" and has document
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numbers ISO/IEC IS 10918-2, ITU-T T.83.
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1991-10-07 00:00:00 +00:00
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The JPEG standard does not specify all details of an interchangeable file
|
2018-04-06 17:07:56 -05:00
|
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format. For the omitted details, we follow the "JFIF" conventions, revision
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1.02. JFIF version 1 has been adopted as ISO/IEC 10918-5 (05/2013) and
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Recommendation ITU-T T.871 (05/2011): Information technology - Digital
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compression and coding of continuous-tone still images: JPEG File Interchange
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Format (JFIF). It is available as a free download in PDF file format from
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https://www.iso.org/standard/54989.html and http://www.itu.int/rec/T-REC-T.871.
|
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A PDF file of the older JFIF 1.02 specification is available at
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http://www.w3.org/Graphics/JPEG/jfif3.pdf.
|
1998-03-27 00:00:00 +00:00
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2020-10-22 23:04:24 -05:00
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|
The TIFF 6.0 file format specification can be obtained from
|
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|
http://mirrors.ctan.org/graphics/tiff/TIFF6.ps.gz. The JPEG incorporation
|
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scheme found in the TIFF 6.0 spec of 3-June-92 has a number of serious
|
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problems. IJG does not recommend use of the TIFF 6.0 design (TIFF Compression
|
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tag 6). Instead, we recommend the JPEG design proposed by TIFF Technical Note
|
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#2 (Compression tag 7). Copies of this Note can be obtained from
|
2009-06-27 00:00:00 +00:00
|
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|
http://www.ijg.org/files/. It is expected that the next revision
|
1998-03-27 00:00:00 +00:00
|
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|
of the TIFF spec will replace the 6.0 JPEG design with the Note's design.
|
1995-08-02 00:00:00 +00:00
|
|
|
Although IJG's own code does not support TIFF/JPEG, the free libtiff library
|
2009-06-27 00:00:00 +00:00
|
|
|
uses our library to implement TIFF/JPEG per the Note.
|
1991-10-07 00:00:00 +00:00
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1994-09-24 00:00:00 +00:00
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ARCHIVE LOCATIONS
|
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|
|
=================
|
1991-10-07 00:00:00 +00:00
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|
2009-06-27 00:00:00 +00:00
|
|
|
The "official" archive site for this software is www.ijg.org.
|
|
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|
The most recent released version can always be found there in
|
2016-02-18 15:16:17 -06:00
|
|
|
directory "files".
|
2009-06-27 00:00:00 +00:00
|
|
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|
|
|
|
The JPEG FAQ (Frequently Asked Questions) article is a source of some
|
2020-10-22 23:04:24 -05:00
|
|
|
general information about JPEG. It is available at
|
|
|
|
|
http://www.faqs.org/faqs/jpeg-faq.
|
1991-10-07 00:00:00 +00:00
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|
2018-04-06 17:07:56 -05:00
|
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|
FILE FORMAT COMPATIBILITY
|
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|
|
=========================
|
1991-12-13 00:00:00 +00:00
|
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|
2018-04-06 17:07:56 -05:00
|
|
|
This software implements ITU T.81 | ISO/IEC 10918 with some extensions from
|
|
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|
ITU T.871 | ISO/IEC 10918-5 (JPEG File Interchange Format-- see REFERENCES).
|
|
|
|
|
Informally, the term "JPEG image" or "JPEG file" most often refers to JFIF or
|
|
|
|
|
a subset thereof, but there are other formats containing the name "JPEG" that
|
2022-11-14 15:36:25 -06:00
|
|
|
are incompatible with the original JPEG standard or with JFIF (for instance,
|
2018-04-06 17:07:56 -05:00
|
|
|
JPEG 2000 and JPEG XR). This software therefore does not support these
|
|
|
|
|
formats. Indeed, one of the original reasons for developing this free software
|
2018-07-10 15:06:46 -05:00
|
|
|
was to help force convergence on a common, interoperable format standard for
|
2018-04-06 17:07:56 -05:00
|
|
|
JPEG files.
|
|
|
|
|
|
|
|
|
|
JFIF is a minimal or "low end" representation. TIFF/JPEG (TIFF revision 6.0 as
|
|
|
|
|
modified by TIFF Technical Note #2) can be used for "high end" applications
|
|
|
|
|
that need to record a lot of additional data about an image.
|
1991-10-07 00:00:00 +00:00
|
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|
|
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|
|
TO DO
|
|
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|
|
=====
|
|
|
|
|
|
2012-01-15 00:00:00 +00:00
|
|
|
Please send bug reports, offers of help, etc. to jpeg-info@jpegclub.org.
|