-README for libpng version 1.6.21 - January 15, 2016 (shared library 16.0)
-See the note about version numbers near the top of png.h
+README for libpng version 1.6.37 - April 14, 2019
+=================================================
+See the note about version numbers near the top of png.h.
See INSTALL for instructions on how to install libpng.
Libpng comes in several distribution formats. Get libpng-*.tar.gz or
-libpng-*.tar.xz or if you want UNIX-style line endings in the text files,
-or lpng*.7z or lpng*.zip if you want DOS-style line endings.
+libpng-*.tar.xz or if you want UNIX-style line endings in the text
+files, or lpng*.7z or lpng*.zip if you want DOS-style line endings.
Version 0.89 was the first official release of libpng. Don't let the
-fact that it's the first release fool you. The libpng library has been in
-extensive use and testing since mid-1995. By late 1997 it had
+fact that it's the first release fool you. The libpng library has been
+in extensive use and testing since mid-1995. By late 1997 it had
finally gotten to the stage where there hadn't been significant
changes to the API in some time, and people have a bad feeling about
libraries with versions < 1.0. Version 1.0.0 was released in
png_uint_32, which will affect shared-library applications that use
this function.
-To avoid problems with changes to the internals of png info_struct,
+To avoid problems with changes to the internals of the png info_struct,
new APIs have been made available in 0.95 to avoid direct application
access to info_ptr. These functions are the png_set_<chunk> and
png_get_<chunk> functions. These functions should be used when
to set different actions based on whether the CRC error occurred in a
critical or an ancillary chunk.
-The changes made to the library, and bugs fixed are based on discussions
-on the PNG-implement mailing list and not on material submitted
-privately to Guy, Andreas, or Glenn. They will forward any good
-suggestions to the list.
-
-For a detailed description on using libpng, read libpng-manual.txt. For
-examples of libpng in a program, see example.c and pngtest.c. For usage
-information and restrictions (what little they are) on libpng, see
-png.h. For a description on using zlib (the compression library used by
-libpng) and zlib's restrictions, see zlib.h
+For a detailed description on using libpng, read libpng-manual.txt.
+For examples of libpng in a program, see example.c and pngtest.c. For
+usage information and restrictions (what little they are) on libpng,
+see png.h. For a description on using zlib (the compression library
+used by libpng) and zlib's restrictions, see zlib.h
I have included a general makefile, as well as several machine and
-compiler specific ones, but you may have to modify one for your own needs.
+compiler specific ones, but you may have to modify one for your own
+needs.
You should use zlib 1.0.4 or later to run this, but it MAY work with
versions as old as zlib 0.95. Even so, there are bugs in older zlib
versions which can cause the output of invalid compression streams for
-some images. You will definitely need zlib 1.0.4 or later if you are
-taking advantage of the MS-DOS "far" structure allocation for the small
-and medium memory models. You should also note that zlib is a
-compression library that is useful for more things than just PNG files.
-You can use zlib as a drop-in replacement for fread() and fwrite() if
-you are so inclined.
+some images.
+
+You should also note that zlib is a compression library that is useful
+for more things than just PNG files. You can use zlib as a drop-in
+replacement for fread() and fwrite(), if you are so inclined.
-zlib should be available at the same place that libpng is, or at zlib.net.
+zlib should be available at the same place that libpng is, or at
+https://zlib.net.
You may also want a copy of the PNG specification. It is available
as an RFC, a W3C Recommendation, and an ISO/IEC Standard. You can find
-these at http://www.libpng.org/pub/png/documents/
-
-This code is currently being archived at libpng.sf.net in the
-[DOWNLOAD] area, and at ftp://ftp.simplesystems.org. If you can't find it
-in any of those places, e-mail me, and I'll help you find it.
-
-I am not a lawyer, but I believe that the Export Control Classification
-Number (ECCN) for libpng is EAR99, which means not subject to export
-controls or International Traffic in Arms Regulations (ITAR) because it
-is open source, publicly available software, that does not contain any
-encryption software. See the EAR, paragraphs 734.3(b)(3) and 734.7(b).
-
-If you have any code changes, requests, problems, etc., please e-mail
-them to me. Also, I'd appreciate any make files or project files,
-and any modifications you needed to make to get libpng to compile,
-along with a #define variable to tell what compiler/system you are on.
-If you needed to add transformations to libpng, or wish libpng would
-provide the image in a different way, drop me a note (and code, if
-possible), so I can consider supporting the transformation.
-Finally, if you get any warning messages when compiling libpng
-(note: not zlib), and they are easy to fix, I'd appreciate the
-fix. Please mention "libpng" somewhere in the subject line. Thanks.
-
-This release was created and will be supported by myself (of course
-based in a large way on Guy's and Andreas' earlier work), and the PNG
+these at http://www.libpng.org/pub/png/pngdocs.html .
+
+This code is currently being archived at libpng.sourceforge.io in the
+[DOWNLOAD] area, and at http://libpng.download/src .
+
+This release, based in a large way on Glenn's, Guy's and Andreas'
+earlier work, was created and will be supported by myself and the PNG
development group.
Send comments/corrections/commendations to png-mng-implement at
lists.sourceforge.net (subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-implement
-to subscribe) or to glennrp at users.sourceforge.net
+to subscribe).
-You can't reach Guy, the original libpng author, at the addresses
-given in previous versions of this document. He and Andreas will
-read mail addressed to the png-implement list, however.
-
-Please do not send general questions about PNG. Send them to
-png-mng-misc at lists.sf.net (subscription required; visit
+Send general questions about the PNG specification to png-mng-misc
+at lists.sourceforge.net (subscription required; visit
https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
-subscribe). If you have a question about something
-in the PNG specification that is related to using libpng, send it
-to me. Send me any questions that start with "I was using libpng,
-and ...". If in doubt, send questions to me. I'll bounce them
-to others, if necessary.
-
-Please do not send suggestions on how to change PNG. We have
-been discussing PNG for twenty years now, and it is official and
-finished. If you have suggestions for libpng, however, I'll
-gladly listen. Even if your suggestion is not used immediately,
-it may be used later.
+subscribe).
Files in this distribution:
ANNOUNCE => Announcement of this version, with recent changes
+ AUTHORS => List of contributing authors
CHANGES => Description of changes between libpng versions
KNOWNBUG => List of known bugs and deficiencies
LICENSE => License to use and redistribute libpng
README => This file
TODO => Things not implemented in the current library
- Y2KINFO => Statement of Y2K compliance
+ TRADEMARK => Trademark information
example.c => Example code for using libpng functions
libpng.3 => manual page for libpng (includes libpng-manual.txt)
libpng-manual.txt => Description of libpng and its functions
pngwtran.c => Write data transformations
pngwutil.c => Write utility functions
arm => Contains optimized code for the ARM platform
+ powerpc => Contains optimized code for the PowerPC platform
contrib => Contributions
+ arm-neon => Optimized code for ARM-NEON platform
+ powerpc-vsx => Optimized code for POWERPC-VSX platform
examples => Example programs
gregbook => source code for PNG reading and writing, from
Greg Roelofs' "PNG: The Definitive Guide",
O'Reilly, 1999
libtests => Test programs
+ mips-msa => Optimized code for MIPS-MSA platform
pngminim => Minimal decoder, encoder, and progressive decoder
programs demonstrating use of pngusr.dfa
pngminus => Simple pnm2png and png2pnm programs
pngsuite => Test images
+ testpngs
tools => Various tools
visupng => Contains a MSVC workspace for VisualPng
+ intel => Optimized code for INTEL-SSE2 platform
+ mips => Optimized code for MIPS platform
projects => Contains project files and workspaces for
building a DLL
owatcom => Contains a WATCOM project for building libpng
scripts => Directory containing scripts for building libpng:
(see scripts/README.txt for the list of scripts)
-Good luck, and happy coding.
-
--Glenn Randers-Pehrson (current maintainer, since 1998)
- Internet: glennrp at users.sourceforge.net
-
--Andreas Eric Dilger (former maintainer, 1996-1997)
- Internet: adilger at enel.ucalgary.ca
- Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/
+Good luck, and happy coding!
--Guy Eric Schalnat (original author and former maintainer, 1995-1996)
- (formerly of Group 42, Inc)
- Internet: gschal at infinet.com
+ * Cosmin Truta (current maintainer, since 2018)
+ * Glenn Randers-Pehrson (former maintainer, 1998-2018)
+ * Andreas Eric Dilger (former maintainer, 1996-1997)
+ * Guy Eric Schalnat (original author and former maintainer, 1995-1996)
+ (formerly of Group 42, Inc.)
projects / platform / upstream / libpng.git / blobdiff