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..03-Jan-20144 KiB

aclocal.m403-Jan-2014310.8 KiB

Android.mk03-Jan-20142.3 KiB

ANNOUNCE03-Jan-20141.9 KiB

autogen.sh03-Jan-2014639

CHANGES03-Jan-2014130.5 KiB

CleanSpec.mk03-Jan-20142.2 KiB

CMakeLists.txt03-Jan-20147.5 KiB

config.guess03-Jan-201445.2 KiB

config.h.in03-Jan-20142.2 KiB

config.sub03-Jan-201433.2 KiB

configure03-Jan-2014399.6 KiB

configure.ac03-Jan-20144.3 KiB

contrib/03-Jan-20144 KiB

depcomp03-Jan-201418.2 KiB

example.c03-Jan-201429.9 KiB

INSTALL03-Jan-20145.7 KiB

install-sh03-Jan-201413.3 KiB

KNOWNBUG03-Jan-2014848

libpng-1.2.44.txt03-Jan-2014132.8 KiB

libpng-1.2.46.txt03-Jan-2014132.8 KiB

libpng.303-Jan-2014176.9 KiB

libpngpf.303-Jan-201418.1 KiB

LICENSE03-Jan-20144.1 KiB

ltmain.sh03-Jan-2014237.5 KiB

Makefile.am03-Jan-20145 KiB

Makefile.in03-Jan-201470.3 KiB

missing03-Jan-201411.2 KiB

mkinstalldirs03-Jan-20143.5 KiB

MODULE_LICENSE_BSD_LIKE03-Jan-20140

NOTICE03-Jan-20144.1 KiB

png.503-Jan-20142.3 KiB

png.c03-Jan-201429.9 KiB

png.h03-Jan-2014160.1 KiB

pngbar.jpg03-Jan-20142.4 KiB

pngbar.png03-Jan-20142.3 KiB

pngconf.h03-Jan-201448.9 KiB

pngerror.c03-Jan-201411.5 KiB

pnggccrd.c03-Jan-20144.7 KiB

pngget.c03-Jan-201423.7 KiB

pngmem.c03-Jan-201417.2 KiB

pngnow.png03-Jan-20142 KiB

pngpread.c03-Jan-201447.8 KiB

pngread.c03-Jan-201451.9 KiB

pngrio.c03-Jan-20146.1 KiB

pngrtran.c03-Jan-2014144.8 KiB

pngrutil.c03-Jan-201497.7 KiB

pngset.c03-Jan-201435.7 KiB

pngtest.c03-Jan-201449.9 KiB

pngtest.png03-Jan-20148.4 KiB

pngtrans.c03-Jan-201420.6 KiB

pngusr.h03-Jan-2014153

pngvcrd.c03-Jan-201448

pngwio.c03-Jan-20147.9 KiB

pngwrite.c03-Jan-201448.9 KiB

pngwtran.c03-Jan-201416.9 KiB

pngwutil.c03-Jan-201483.1 KiB

projects/03-Jan-20144 KiB

README03-Jan-201414.3 KiB

scripts/03-Jan-20144 KiB

test-pngtest.sh03-Jan-201443

TODO03-Jan-20141.2 KiB

Y2KINFO03-Jan-20142.3 KiB

README

1README for libpng version 1.2.46 - July 9, 2011 (shared library 12.0)
2See the note about version numbers near the top of png.h
3
4See INSTALL for instructions on how to install libpng.
5
6Libpng comes in several distribution formats.  Get libpng-*.tar.gz,
7libpng-*.tar.xz, or libpng-*.tar.bz2 if you want UNIX-style line
8endings in the text files, or lpng*.7z or lpng*.zip if you want DOS-style
9line endings.  You can get UNIX-style line endings from the *.zip file
10by using "unzip -a" but there seems to be no simple way to recover
11UNIX-style line endings from the *.7z file.  The *.tar.xz file is
12recommended for *NIX users instead.
13
14Version 0.89 was the first official release of libpng.  Don't let the
15fact that it's the first release fool you.  The libpng library has been in
16extensive use and testing since mid-1995.  By late 1997 it had
17finally gotten to the stage where there hadn't been significant
18changes to the API in some time, and people have a bad feeling about
19libraries with versions < 1.0.  Version 1.0.0 was released in
20March 1998.
21
22****
23Note that some of the changes to the png_info structure render this
24version of the library binary incompatible with libpng-0.89 or
25earlier versions if you are using a shared library.  The type of the
26"filler" parameter for png_set_filler() has changed from png_byte to
27png_uint_32, which will affect shared-library applications that use
28this function.
29
30To avoid problems with changes to the internals of png_info_struct,
31new APIs have been made available in 0.95 to avoid direct application
32access to info_ptr.  These functions are the png_set_<chunk> and
33png_get_<chunk> functions.  These functions should be used when
34accessing/storing the info_struct data, rather than manipulating it
35directly, to avoid such problems in the future.
36
37It is important to note that the APIs do not make current programs
38that access the info struct directly incompatible with the new
39library.  However, it is strongly suggested that new programs use
40the new APIs (as shown in example.c and pngtest.c), and older programs
41be converted to the new format, to facilitate upgrades in the future.
42****
43
44Additions since 0.90 include the ability to compile libpng as a
45Windows DLL, and new APIs for accessing data in the info struct.
46Experimental functions include the ability to set weighting and cost
47factors for row filter selection, direct reads of integers from buffers
48on big-endian processors that support misaligned data access, faster
49methods of doing alpha composition, and more accurate 16->8 bit color
50conversion.
51
52The additions since 0.89 include the ability to read from a PNG stream
53which has had some (or all) of the signature bytes read by the calling
54application.  This also allows the reading of embedded PNG streams that
55do not have the PNG file signature.  As well, it is now possible to set
56the library action on the detection of chunk CRC errors.  It is possible
57to set different actions based on whether the CRC error occurred in a
58critical or an ancillary chunk.
59
60The changes made to the library, and bugs fixed are based on discussions
61on the png-mng-implement mailing list and not on material submitted
62privately to Guy, Andreas, or Glenn.  They will forward any good
63suggestions to the list.
64
65For a detailed description on using libpng, read libpng.txt.  For
66examples of libpng in a program, see example.c and pngtest.c.  For usage
67information and restrictions (what little they are) on libpng, see
68png.h.  For a description on using zlib (the compression library used by
69libpng) and zlib's restrictions, see zlib.h
70
71I have included a general makefile, as well as several machine and
72compiler specific ones, but you may have to modify one for your own needs.
73
74You should use zlib 1.0.4 or later to run this, but it MAY work with
75versions as old as zlib 0.95.  Even so, there are bugs in older zlib
76versions which can cause the output of invalid compression streams for
77some images.  You will definitely need zlib 1.0.4 or later if you are
78taking advantage of the MS-DOS "far" structure allocation for the small
79and medium memory models.  You should also note that zlib is a
80compression library that is useful for more things than just PNG files.
81You can use zlib as a drop-in replacement for fread() and fwrite() if
82you are so inclined.
83
84zlib should be available at the same place that libpng is, or at
85ftp://ftp.simplesystems.org/pub/png/src/
86
87You may also want a copy of the PNG specification.  It is available
88as an RFC, a W3C Recommendation, and an ISO/IEC Standard.  You can find
89these at http://www.libpng.org/pub/png/pngdocs.html
90
91This code is currently being archived at libpng.sf.net in the
92[DOWNLOAD] area, and on CompuServe, Lib 20 (PNG SUPPORT)
93at GO GRAPHSUP.  If you can't find it in any of those places,
94e-mail me, and I'll help you find it.
95
96If you have any code changes, requests, problems, etc., please e-mail
97them to me.  Also, I'd appreciate any make files or project files,
98and any modifications you needed to make to get libpng to compile,
99along with a #define variable to tell what compiler/system you are on.
100If you needed to add transformations to libpng, or wish libpng would
101provide the image in a different way, drop me a note (and code, if
102possible), so I can consider supporting the transformation.
103Finally, if you get any warning messages when compiling libpng
104(note: not zlib), and they are easy to fix, I'd appreciate the
105fix.  Please mention "libpng" somewhere in the subject line.  Thanks.
106
107This release was created and will be supported by myself (of course
108based in a large way on Guy's and Andreas' earlier work), and the PNG
109development group.
110
111Send comments/corrections/commendations to png-mng-implement at lists.sf.net
112(subscription required; visit 
113https://lists.sourceforge.net/lists/listinfo/png-mng-implement
114to subscribe) or to glennrp at users.sourceforge.net
115
116You can't reach Guy, the original libpng author, at the addresses
117given in previous versions of this document.  He and Andreas will
118read mail addressed to the png-mng-implement list, however.
119
120Please do not send general questions about PNG.  Send them to
121the (png-mng-misc at lists.sourceforge.net, subscription required, visit
122https://lists.sourceforge.net/lists/listinfo/png-mng-misc to
123subscribe). On the other hand, please do not send libpng questions to
124that address, send them to me or to the png-mng-implement list.  I'll
125get them in the end anyway.  If you have a question about something
126in the PNG specification that is related to using libpng, send it
127to me.  Send me any questions that start with "I was using libpng,
128and ...".  If in doubt, send questions to me.  I'll bounce them
129to others, if necessary.
130
131Please do not send suggestions on how to change PNG.  We have
132been discussing PNG for twelve years now, and it is official and
133finished.  If you have suggestions for libpng, however, I'll
134gladly listen.  Even if your suggestion is not used immediately,
135it may be used later.
136
137Files in this distribution:
138
139      ANNOUNCE      =>  Announcement of this version, with recent changes
140      CHANGES       =>  Description of changes between libpng versions
141      KNOWNBUG      =>  List of known bugs and deficiencies
142      LICENSE       =>  License to use and redistribute libpng
143      README        =>  This file
144      TODO          =>  Things not implemented in the current library
145      Y2KINFO       =>  Statement of Y2K compliance
146      example.c     =>  Example code for using libpng functions
147      libpng-*-*-diff.txt => Diff from previous release
148      libpng.3      =>  manual page for libpng (includes libpng.txt)
149      libpng.txt    =>  Description of libpng and its functions
150      libpngpf.3    =>  manual page for libpng's private functions
151      png.5         =>  manual page for the PNG format
152      png.c         =>  Basic interface functions common to library
153      png.h         =>  Library function and interface declarations
154      pngconf.h     =>  System specific library configuration
155      pngerror.c    =>  Error/warning message I/O functions
156      pngget.c      =>  Functions for retrieving info from struct
157      pngmem.c      =>  Memory handling functions
158      pngbar.png    =>  PNG logo, 88x31
159      pngnow.png    =>  PNG logo, 98x31
160      pngpread.c    =>  Progressive reading functions
161      pngread.c     =>  Read data/helper high-level functions
162      pngrio.c      =>  Lowest-level data read I/O functions
163      pngrtran.c    =>  Read data transformation functions
164      pngrutil.c    =>  Read data utility functions
165      pngset.c      =>  Functions for storing data into the info_struct
166      pngtest.c     =>  Library test program
167      pngtest.png   =>  Library test sample image
168      pngtrans.c    =>  Common data transformation functions
169      pngwio.c      =>  Lowest-level write I/O functions
170      pngwrite.c    =>  High-level write functions
171      pngwtran.c    =>  Write data transformations
172      pngwutil.c    =>  Write utility functions
173      contrib       =>  Contributions
174       gregbook         =>  source code for PNG reading and writing, from
175                            Greg Roelofs' "PNG: The Definitive Guide",
176                            O'Reilly, 1999
177       msvctest     =>  Builds and runs pngtest using a MSVC workspace
178       pngminim     =>  Simple pnm2pngm and png2pnmm programs
179       pngminus     =>  Simple pnm2png and png2pnm programs
180       pngsuite     =>  Test images
181       visupng      =>  Contains a MSVC workspace for VisualPng
182      projects      =>  Contains project files and workspaces for
183                        building a DLL
184       beos             =>  Contains a Beos workspace for building libpng
185       c5builder        =>  Contains a Borland workspace for building
186                            libpng and zlib
187       netware.txt      =>  Contains instructions for downloading a set
188                            of project files for building libpng and
189                            zlib on Netware.
190       visualc6         =>  Contains a Microsoft Visual C++ (MSVC)
191                            workspace for building libpng and zlib
192       wince.txt        =>  Contains instructions for downloading a
193                            Microsoft Visual C++ (Windows CD Toolkit)
194                            workspace for building libpng and zlib on
195                            WindowsCE
196       xcode            =>  Contains xcode project files
197      scripts       =>  Directory containing scripts for building libpng:
198       descrip.mms      =>  VMS makefile for MMS or MMK
199       makefile.std     =>  Generic UNIX makefile (cc, creates static
200                            libpng.a)
201       makefile.elf     =>  Linux/ELF gcc makefile symbol versioning,
202                            creates libpng12.so.0.1.2.46)
203       makefile.linux   =>  Linux/ELF makefile (gcc, creates
204                            libpng12.so.0.1.2.46)
205       makefile.gcmmx   =>  Linux/ELF makefile (gcc, creates
206                            libpng12.so.0.1.2.46, previously
207                            used assembler code tuned for Intel MMX
208                            platform)
209       makefile.gcc     =>  Generic makefile (gcc, creates static
210                            libpng.a)
211       makefile.knr     =>  Archaic UNIX Makefile that converts files
212                            with ansi2knr (Requires ansi2knr.c from
213                            ftp://ftp.cs.wisc.edu/ghost)
214       makefile.aix     =>  AIX makefile
215       makefile.cygwin  =>  Cygwin/gcc makefile
216       makefile.darwin  =>  Darwin makefile
217       makefile.dec     =>  DEC Alpha UNIX makefile
218       makefile.freebsd =>  FreeBSD makefile
219       makefile.hpgcc   =>  HPUX makefile using gcc
220       makefile.hpux    =>  HPUX (10.20 and 11.00) makefile
221       makefile.hp64    =>  HPUX (10.20 and 11.00) makefile, 64 bit
222       makefile.ibmc    =>  IBM C/C++ version 3.x for Win32 and OS/2
223                            (static)
224       makefile.intel   =>  Intel C/C++ version 4.0 and later
225       libpng.icc       =>  Project file, IBM VisualAge/C++ 4.0 or later
226       makefile.netbsd  =>  NetBSD/cc makefile, makes libpng.so.
227       makefile.ne12bsd  =>  NetBSD/cc makefile, makes libpng12.so
228       makefile.openbsd =>  OpenBSD makefile
229       makefile.sgi     =>  Silicon Graphics IRIX (cc, creates static lib)
230       makefile.sggcc   =>  Silicon Graphics
231                            (gcc, creates libpng12.so.0.1.2.46)
232       makefile.sunos   =>  Sun makefile
233       makefile.solaris =>  Solaris 2.X makefile
234                            (gcc, creates libpng12.so.0.1.2.46)
235       makefile.so9     =>  Solaris 9 makefile
236                            (gcc, creates libpng12.so.0.1.2.46)
237       makefile.32sunu  =>  Sun Ultra 32-bit makefile
238       makefile.64sunu  =>  Sun Ultra 64-bit makefile
239       makefile.sco     =>  For SCO OSr5  ELF and Unixware 7 with Native cc
240       makefile.mips    =>  MIPS makefile
241       makefile.acorn   =>  Acorn makefile
242       makefile.amiga   =>  Amiga makefile
243       smakefile.ppc    =>  AMIGA smakefile for SAS C V6.58/7.00 PPC
244                            compiler (Requires SCOPTIONS, copied from
245                            scripts/SCOPTIONS.ppc)
246       makefile.atari   =>  Atari makefile
247       makefile.beos    =>  BEOS makefile for X86
248       makefile.bor     =>  Borland makefile (uses bcc)
249       makefile.bc32    =>  32-bit Borland C++ (all modules compiled in C mode)
250       makefile.tc3     =>  Turbo C 3.0 makefile
251       makefile.dj2     =>  DJGPP 2 makefile
252       makefile.msc     =>  Microsoft C makefile
253       makefile.vcawin32=>  makefile for Microsoft Visual C++ 5.0 and
254                            later (previously used assembler code tuned
255                            for Intel MMX platform)
256       makefile.vcwin32 =>  makefile for Microsoft Visual C++ 4.0 and
257                            later (does not use assembler code)
258       makefile.os2     =>  OS/2 Makefile (gcc and emx, requires pngos2.def)
259       pngos2.def       =>  OS/2 module definition file used by makefile.os2
260       makefile.watcom  =>  Watcom 10a+ Makefile, 32-bit flat memory model
261       makevms.com      =>  VMS build script
262       SCOPTIONS.ppc    =>  Used with smakefile.ppc
263
264Good luck, and happy coding.
265
266-Glenn Randers-Pehrson (current maintainer, since 1998)
267 Internet: glennrp at users.sourceforge.net
268
269-Andreas Eric Dilger (former maintainer, 1996-1997)
270 Internet: adilger at enel.ucalgary.ca
271 Web: http://members.shaw.ca/adilger/
272
273-Guy Eric Schalnat (original author and former maintainer, 1995-1996)
274 (formerly of Group 42, Inc)
275 Internet: gschal at infinet.com
276