======================================================================== * AUTHORS ======================================================================== PNG REFERENCE LIBRARY AUTHORS ============================= This is the list of PNG Reference Library ("libpng") Contributing Authors, for copyright and licensing purposes. * Andreas Dilger * Cosmin Truta * Dave Martindale * Eric S. Raymond * Gilles Vollant * Glenn Randers-Pehrson * Greg Roelofs * Guy Eric Schalnat * James Yu * John Bowler * Kevin Bracey * Magnus Holmgren * Mandar Sahastrabuddhe * Mans Rullgard * Matt Sarett * Mike Klein * Paul Schmidt * Sam Bushell * Samuel Williams * Simon-Pierre Cadieux * Tim Wegner * Tom Lane * Tom Tanner * Vadim Barkov * Willem van Schaik * Zhijie Liang * Arm Holdings - Richard Townsend * Google Inc. - Matt Sarett - Mike Klein The build projects, the build scripts, the test scripts, and other files in the "projects", "scripts" and "tests" directories, have other copyright owners, but are released under the libpng license. Some files in the "contrib" directory, and some tools-generated files that are distributed with libpng, have other copyright owners, and are released under other open source licenses. ======================================================================== * contrib/oss-fuzz/README.txt ======================================================================== Last changed in libpng 1.6.33 [September 28, 2017] Copyright (c) 2017 Glenn Randers-Pehrson This code is released under the libpng license. For conditions of distribution and use, see the disclaimer and license in png.h Files in this directory are used by the oss-fuzz project (https://github.com/google/oss-fuzz/tree/master/projects/libpng). for "fuzzing" libpng. They were licensed by Google Inc, using the BSD-like Chromium license, which may be found at https://cs.chromium.org/chromium/src/LICENSE, or, if noted in the source, under the Apache-2.0 license, which may be found at http://www.apache.org/licenses/LICENSE-2.0 . If they have been modified, the derivatives are copyright Glenn Randers-Pehrson and are released under the same licenses as the originals. Several of the original files (libpng_read_fuzzer.options, png.dict, project.yaml) had no licensing information; we assumed that these were under the Chromium license. Any new files are released under the libpng license (see png.h). The files are Original Filename or derived Copyright License ========================= ========== ================ ========== Dockerfile* derived 2017, Glenn R-P Apache 2.0 build.sh derived 2017, Glenn R-P Apache 2.0 libpng_read_fuzzer.cc derived 2017, Glenn R-P Chromium libpng_read_fuzzer.options original 2015, Chrome Devs Chromium png.dict original 2015, Chrome Devs Chromium README.txt (this file) original 2017, Glenn R-P libpng * Dockerfile is a copy of the file used by oss-fuzz. build.sh, png.dict and libpng_read_fuzzer.* are the actual files used by oss-fuzz, which retrieves them from the libpng repository at Github. To do: exercise the progressive reader and the png encoder. ======================================================================== * contrib/pngminus/README.txt ======================================================================== PngMinus -------- (copyright Willem van Schaik, 1999-2019) Some history ------------ Soon after the creation of PNG in 1995, the need was felt for a set of pnmtopng / pngtopnm utilities. Independently Alexander Lehmann and I (Willem van Schaik) started such a project. Luckily we discovered this and merged the two, which later became part of NetPBM, available from SourceForge. These two utilities have many, many options and make use of most of the features of PNG, like gamma, alpha, sbit, text-chunks, etc. This makes the utilities quite complex and by now not anymore very maintainable. When we wrote these programs, libpng was still in an early stage. Therefore, lots of the functionality that we put in our software can now be done using transform-functions in libpng. Finally, to compile these programs, you need to have installed and compiled three libraries: libpng, zlib and netpbm. Especially the latter makes the whole setup a bit bulky. But that's unavoidable given the many features of pnmtopng. What now (1999) --------------- At this moment libpng is in a very stable state and can do much of the work done in pnmtopng. Also, pnmtopng needs to be upgraded to the new interface of libpng. Hence, it is time for a rewrite from the ground up of pnmtopng and pngtopnm. This will happen in the near future (stay tuned). The new package will get a different name to distinguish it from the old one: PngPlus. To experiment a bit with the new interface of libpng, I started off with a small prototype that contains only the basic functionality. It doesn't have any of the options to read or write special chunks and it will do no gamma correction. But this makes it also a simple program that is quite easy to understand and can serve well as a template for other software developments. By now there are of course a couple of programs, like Greg Roelofs' rpng/wpng, that can be used just as good. Can and can not --------------- As this is the small brother of the future PngPlus, I called this fellow PngMinus. Because I started this development in good-old Turbo-C, I avoided the use the netpbm library, which requires DOS extenders. Again, another reason to call it PngMinus (minus netpbm :-). So, part of the program are some elementary routines to read / write pgm- and ppm-files. It does not handle B&W pbm-files, but instead you could do pgm with bit- depth 1. The downside of this approach is that you can not use them on images that require blocks of memory bigger than 64k (the DOS version). For larger images you will get an out-of-memory error. As said before, PngMinus doesn't correct for gamma. When reading png-files you can do this just as well by piping the output of png2pnm to pnmgamma, one of the standard PbmPlus tools. This same scenario will most probably also be followed in the full-blown future PngPlus, with the addition of course of the possibility to create gamma-chunks when writing png-files. On the other hand it supports alpha-channels. When reading a png-image you can write the alpha-channel into a pgm-file. And when creating an RGB+A png-image, you just combine a ppm-file with a corresponding pgm-file containing the alpha-channel. When reading, transparency chunks are converted into an alpha-channel and from there on treated the same way. Finally you can opt for writing ascii or binary pgm- and ppm-files. When the bit-depth is 16, the format will always be ascii. Using it -------- To distinguish them from pnmtopng and PngPlus, the utilities are named png2pnm and pnm2png (2 instead of to). The input- and output-files can be given as parameters or through redirection. Therefore the programs can be part of a pipe. To list the options type "png2pnm -h" or "pnm2png -h". Just like Scandinavian furniture -------------------------------- You have to put it together yourself. I developed the software on MS-DOS with Turbo-C 3.0 and RedHat Linux 4.2 with gcc. In both cases I used libpng-1.0.4 and zlib-1.1.3. By now (2019) it is twenty years later and more current versions are OK. The makefile assumes that the libpng libraries can be found in ../.. and libz in ../../../zlib. But you can change this to for example ../libpng and ../zlib. The makefile creates two versions of each program, one with static library support and the other using shared libraries. If you create a ../pngsuite directory and then store the basn####.png files from PngSuite (http://www.schaik.com/pngsuite/) in there, you can test the proper functioning of PngMinus by running pngminus.sh. Warranty ------- Please, remember that this was just a small experiment to learn a few things. It will have many unforeseen features ... who said bugs? Use it when you are in need for something simple or when you want a starting point for developing your own stuff. The end ------- Willem van Schaik mailto:willem at schaik dot com http://www.schaik.com/png/ Oct 1999, Jan 2019 ======================================================================== * contrib/pngsuite/README ======================================================================== pngsuite -------- Copyright (c) Willem van Schaik, 1999, 2011, 2012 Two images (ftbbn0g01.png and ftbbn0g02.png) are by Glenn Randers-Pehrson, 2012 Permission to use, copy, modify, and distribute these images for any purpose and without fee is hereby granted. The 15 "bas*.png" images are part of the much larger PngSuite test-set of images, available for developers of PNG supporting software. The complete set, available at http:/www.schaik.com/pngsuite/, contains a variety of images to test interlacing, gamma settings, ancillary chunks, etc. The "ft*.png" images are "free/libre" replacements for the transparent corresponding t*.png images in the PngSuite. The "i*.png" images are the same images, but interlaced. The images in this directory represent the basic PNG color-types: grayscale (1-16 bit deep), full color (8 or 16 bit), paletted (1-8 bit) and grayscale or color images with alpha channel. You can use them to test the proper functioning of PNG software. filename depth type ------------ ------ -------------- basn0g01.png 1-bit grayscale basn0g02.png 2-bit grayscale basn0g04.png 4-bit grayscale basn0g08.png 8-bit grayscale basn0g16.png 16-bit grayscale basn2c08.png 8-bit truecolor basn2c16.png 16-bit truecolor basn3p01.png 1-bit paletted basn3p02.png 2-bit paletted basn3p04.png 4-bit paletted basn3p08.png 8-bit paletted basn4a08.png 8-bit gray with alpha basn4a16.png 16-bit gray with alpha basn6a08.png 8-bit RGBA basn6a16.png 16-bit RGBA ftbbn0g01.png 1-bit grayscale, black bKGD ftbbn0g02.png 2-bit grayscale, black bKGD ftbbn0g04.png 4-bit grayscale, black bKGD ftbbn2c16.png 16-bit truecolor, black bKGD ftbbn3p08.png 8-bit paletted, black bKGD ftbgn2c16.png 16-bit truecolor, gray bKGD ftbgn3p08.png 8-bit paletted, gray bKGD ftbrn2c08.png 8-bit truecolor, red bKGD ftbwn0g16.png 16-bit gray, white bKGD ftbwn3p08.png 8-bit paletted, white bKGD ftbyn3p08.png 8-bit paletted, yellow bKGD ftp0n0g08.png 8-bit grayscale, opaque ftp0n2c08.png 8-bit truecolor, opaque ftp0n3p08.png 8-bit paletted, opaque ftp1n3p08.png 8-bit paletted, no bKGD Here is the correct result of typing "pngtest -m bas*.png" in this directory: Testing basn0g01.png: PASS (524 zero samples) Filter 0 was used 32 times Testing basn0g02.png: PASS (448 zero samples) Filter 0 was used 32 times Testing basn0g04.png: PASS (520 zero samples) Filter 0 was used 32 times Testing basn0g08.png: PASS (3 zero samples) Filter 1 was used 9 times Filter 4 was used 23 times Testing basn0g16.png: PASS (1 zero samples) Filter 1 was used 1 times Filter 2 was used 31 times Testing basn2c08.png: PASS (6 zero samples) Filter 1 was used 5 times Filter 4 was used 27 times Testing basn2c16.png: PASS (592 zero samples) Filter 1 was used 1 times Filter 4 was used 31 times Testing basn3p01.png: PASS (512 zero samples) Filter 0 was used 32 times Testing basn3p02.png: PASS (448 zero samples) Filter 0 was used 32 times Testing basn3p04.png: PASS (544 zero samples) Filter 0 was used 32 times Testing basn3p08.png: PASS (4 zero samples) Filter 0 was used 32 times Testing basn4a08.png: PASS (32 zero samples) Filter 1 was used 1 times Filter 4 was used 31 times Testing basn4a16.png: PASS (64 zero samples) Filter 0 was used 1 times Filter 1 was used 2 times Filter 2 was used 1 times Filter 4 was used 28 times Testing basn6a08.png: PASS (160 zero samples) Filter 1 was used 1 times Filter 4 was used 31 times Testing basn6a16.png: PASS (1072 zero samples) Filter 1 was used 4 times Filter 4 was used 28 times libpng passes test Willem van Schaik October 1999 ======================================================================== * contrib/tools/README.txt ======================================================================== This directory (contrib/tools) contains tools used by the authors of libpng. Code and data placed in this directory is not required to build libpng, however the code in this directory has been used to generate data or code in the body of the libpng source. The source code identifies where this has been done. Code in this directory may not compile on all operating systems that libpng supports. NO COPYRIGHT RIGHTS ARE CLAIMED TO ANY OF THE FILES IN THIS DIRECTORY. To the extent possible under law, the authors have waived all copyright and related or neighboring rights to this work. This work is published from: United States. The files may be used freely in any way. The source code and comments in this directory are the original work of the people named below. No other person or organization has made contributions to the work in this directory. ORIGINAL AUTHORS The following people have contributed to the code in this directory. None of the people below claim any rights with regard to the contents of this directory. John Bowler Glenn Randers-Pehrson ======================================================================== * contrib/visupng/README.txt ======================================================================== Microsoft Developer Studio Build File, Format Version 6.00 for VisualPng ------------------------------------------------------------------------ Copyright 2000, Willem van Schaik. This code is released under the libpng license. For conditions of distribution and use, see the disclaimer and license in png.h As a PNG .dll demo VisualPng is finished. More features would only hinder the program's objective. However, further extensions (like support for other graphics formats) are in development. To get these, or for pre-compiled binaries, go to "http://www.schaik.com/png/visualpng.html". ------------------------------------------------------------------------ Assumes that libpng DLLs and LIBs are in ..\..\projects\msvc\win32\libpng zlib DLLs and LIBs are in ..\..\projects\msvc\win32\zlib libpng header files are in ..\..\..\libpng zlib header files are in ..\..\..\zlib the pngsuite images are in ..\pngsuite To build: 1) On the main menu Select "Build|Set Active configuration". Choose the configuration that corresponds to the library you want to test. This library must have been built using the libpng MS project located in the "..\..\mscv" subdirectory. 2) Select "Build|Clean" 3) Select "Build|Rebuild All" 4) After compiling and linking VisualPng will be started to view an image from the PngSuite directory. Press Ctrl-N (and Ctrl-V) for other images. To install: When distributing VisualPng (or a further development) the following options are available: 1) Build the program with the configuration "Win32 LIB" and you only need to include the executable from the ./lib directory in your distribution. 2) Build the program with the configuration "Win32 DLL" and you need to put in your distribution the executable from the ./dll directory and the dll's libpng1.dll, zlib.dll and msvcrt.dll. These need to be in the user's PATH. Willem van Schaik Calgary, June 6th 2000 P.S. VisualPng was written based on preliminary work of: - Simon-Pierre Cadieux - Glenn Randers-Pehrson - Greg Roelofs ======================================================================== * projects/visualc71/README.txt ======================================================================== Microsoft Developer Studio Project File, Format Version 7.10 for libpng. Copyright (C) 2004 Simon-Pierre Cadieux. This code is released under the libpng license. For conditions of distribution and use, see copyright notice in png.h NOTE: This project will be removed from libpng-1.5.0. It has been replaced with the "vstudio" project. Assumptions: * The libpng source files are in ..\.. * The zlib source files are in ..\..\..\zlib * The zlib project file is in . /* Warning: This is until the zlib project files get integrated into the next zlib release. The final zlib project directory will then be ..\..\..\zlib\projects\visualc71. */ To use: 1) On the main menu, select "File | Open Solution". Open "libpng.sln". 2) Display the Solution Explorer view (Ctrl+Alt+L) 3) Set one of the project as the StartUp project. If you just want to build the binaries set "libpng" as the startup project (Select "libpng" tree view item + Project | Set as StartUp project). If you want to build and test the binaries set it to "pngtest" (Select "pngtest" tree view item + Project | Set as StartUp project) 4) Select "Build | Configuration Manager...". Choose the configuration you wish to build. 5) Select "Build | Clean Solution". 6) Select "Build | Build Solution (Ctrl-Shift-B)" This project builds the libpng binaries as follows: * Win32_DLL_Release\libpng16.dll DLL build * Win32_DLL_Debug\libpng16d.dll DLL build (debug version) * Win32_DLL_VB\libpng16vb.dll DLL build for Visual Basic, using stdcall * Win32_LIB_Release\libpng.lib static build * Win32_LIB_Debug\libpngd.lib static build (debug version) Notes: If you change anything in the source files, or select different compiler settings, please change the DLL name to something different than any of the above names. Also, make sure that in your "pngusr.h" you define PNG_USER_PRIVATEBUILD and PNG_USER_DLLFNAME_POSTFIX according to the instructions provided in "pngconf.h". All DLLs built by this project use the Microsoft dynamic C runtime library MSVCR71.DLL (MSVCR71D.DLL for debug versions). If you distribute any of the above mentioned libraries you may have to include this DLL in your package. For a list of files that are redistributable in Visual Studio see $(VCINSTALLDIR)\redist.txt. ======================================================================== * projects/visualc71/README_zlib.txt ======================================================================== /* WARNING: This file was put in the LibPNG distribution for convenience only. It is expected to be part of the next zlib release under "projects\visualc71\README.txt." */ Microsoft Developer Studio Project File, Format Version 7.10 for zlib. Copyright (C) 2004 Simon-Pierre Cadieux. Copyright (C) 2004 Cosmin Truta. This code is released under the libpng license. For conditions of distribution and use, see copyright notice in zlib.h. NOTE: This project will be removed from libpng-1.5.0. It has been replaced with the "vstudio" project. To use: 1) On the main menu, select "File | Open Solution". Open "zlib.sln". 2) Display the Solution Explorer view (Ctrl+Alt+L) 3) Set one of the project as the StartUp project. If you just want to build the binaries set "zlib" as the startup project (Select "zlib" tree view item + Project | Set as StartUp project). If you want to build and test the binaries set it to "example" (Select "example" tree view item + Project | Set as StartUp project), If you want to build the minigzip utility set it to "minigzip" (Select "minigzip" tree view item + Project | Set as StartUp project 4) Select "Build | Configuration Manager...". Choose the configuration you wish to build. 5) Select "Build | Clean Solution". 6) Select "Build | Build Solution (Ctrl-Shift-B)" This project builds the zlib binaries as follows: * Win32_DLL_Release\zlib1.dll DLL build * Win32_DLL_Debug\zlib1d.dll DLL build (debug version) * Win32_LIB_Release\zlib.lib static build * Win32_LIB_Debug\zlibd.lib static build (debug version) ======================================================================== * projects/vstudio/README.txt ======================================================================== Instructions for building libpng using Microsoft Visual Studio ============================================================== Copyright (c) 2018 Cosmin Truta Copyright (c) 2010,2013,2015 Glenn Randers-Pehrson This code is released under the libpng license. For conditions of distribution and use, see the disclaimer and license in png.h This directory contains a solution for building libpng under Microsoft Visual Studio 2010. It may also work under later versions of Visual Studio. You should be familiar with Visual Studio before using this solution. Initial preparations -------------------- You must enter some information in zlib.props before attempting to build with this 'solution'. Please read and edit zlib.props first. You will probably not be familiar with the contents of zlib.props - do not worry, it is mostly harmless. This is all you need to do to build the 'release' and 'release library' configurations. Debugging --------- The release configurations default to /Ox optimization. Full debugging information is produced (in the .pdb), but if you encounter a problem the optimization may make it difficult to debug. Simply rebuild with a lower optimization level (e.g. /Od.) Linking your application ------------------------ Normally you should link against the 'release' configuration. This builds a DLL for libpng with the default runtime options used by Visual Studio. In particular the runtime library is the "MultiThreaded DLL" version. If you use Visual Studio defaults to build your application, you should have no problems. If you don't use the Visual Studio defaults your application must still be built with the default runtime option (/MD). If, for some reason, it is not then your application will crash inside libpng16.dll as soon as libpng tries to read from a file handle you pass in. If you do not want to use the DLL, and prefer static linking instead, you may choose the 'release library' configuration. This is built with a non-standard runtime library - the "MultiThreaded" version. When you build your application, it must be compiled with this option (/MT), otherwise it will not build (if you are lucky) or it will crash (if you are not.) See the WARNING file that is distributed with this README. Stop reading here ----------------- You have enough information to build a working application. Debug versions have limited support ----------------------------------- This solution includes limited support for debug versions of libpng. You do not need these unless your own solution itself uses debug builds (it is far more effective to debug on the release builds, there is no point building a special debug build unless you have heap corruption problems that you can't track down.) The debug build of libpng is minimally supported. Support for debug builds of zlib is also minimal. Please keep this in mind, if you want to use it. WARNING ------- Libpng 1.6.x does not use the default run-time library when building static library builds of libpng; instead of the shared DLL runtime, it uses a static runtime. If you need to change this, make sure to change the setting on all the relevant projects: libpng zlib all the test programs The runtime library settings for each build are as follows: Release Debug DLL /MD /MDd Library /MT /MTd Also, be sure to build libpng, zlib, and your project, all for the same platform (e.g., 32-bit or 64-bit). ======================================================================== * LICENSE ======================================================================== COPYRIGHT NOTICE, DISCLAIMER, and LICENSE ========================================= PNG Reference Library License version 2 --------------------------------------- * Copyright (c) 1995-2019 The PNG Reference Library Authors. * Copyright (c) 2018-2019 Cosmin Truta. * Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson. * Copyright (c) 1996-1997 Andreas Dilger. * Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. The software is supplied "as is", without warranty of any kind, express or implied, including, without limitation, the warranties of merchantability, fitness for a particular purpose, title, and non-infringement. In no event shall the Copyright owners, or anyone distributing the software, be liable for any damages or other liability, whether in contract, tort or otherwise, arising from, out of, or in connection with the software, or the use or other dealings in the software, even if advised of the possibility of such damage. Permission is hereby granted to use, copy, modify, and distribute this software, or portions hereof, for any purpose, without fee, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated, but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This Copyright notice may not be removed or altered from any source or altered source distribution. PNG Reference Library License version 1 (for libpng 0.5 through 1.6.35) ----------------------------------------------------------------------- libpng versions 1.0.7, July 1, 2000, through 1.6.35, July 15, 2018 are Copyright (c) 2000-2002, 2004, 2006-2018 Glenn Randers-Pehrson, are derived from libpng-1.0.6, and are distributed according to the same disclaimer and license as libpng-1.0.6 with the following individuals added to the list of Contributing Authors: Simon-Pierre Cadieux Eric S. Raymond Mans Rullgard Cosmin Truta Gilles Vollant James Yu Mandar Sahastrabuddhe Google Inc. Vadim Barkov and with the following additions to the disclaimer: There is no warranty against interference with your enjoyment of the library or against infringement. There is no warranty that our efforts or the library will fulfill any of your particular purposes or needs. This library is provided with all faults, and the entire risk of satisfactory quality, performance, accuracy, and effort is with the user. Some files in the "contrib" directory and some configure-generated files that are distributed with libpng have other copyright owners, and are released under other open source licenses. libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are Copyright (c) 1998-2000 Glenn Randers-Pehrson, are derived from libpng-0.96, and are distributed according to the same disclaimer and license as libpng-0.96, with the following individuals added to the list of Contributing Authors: Tom Lane Glenn Randers-Pehrson Willem van Schaik libpng versions 0.89, June 1996, through 0.96, May 1997, are Copyright (c) 1996-1997 Andreas Dilger, are derived from libpng-0.88, and are distributed according to the same disclaimer and license as libpng-0.88, with the following individuals added to the list of Contributing Authors: John Bowler Kevin Bracey Sam Bushell Magnus Holmgren Greg Roelofs Tom Tanner Some files in the "scripts" directory have other copyright owners, but are released under this license. libpng versions 0.5, May 1995, through 0.88, January 1996, are Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc. For the purposes of this copyright and license, "Contributing Authors" is defined as the following set of individuals: Andreas Dilger Dave Martindale Guy Eric Schalnat Paul Schmidt Tim Wegner The PNG Reference Library is supplied "AS IS". The Contributing Authors and Group 42, Inc. disclaim all warranties, expressed or implied, including, without limitation, the warranties of merchantability and of fitness for any purpose. The Contributing Authors and Group 42, Inc. assume no liability for direct, indirect, incidental, special, exemplary, or consequential damages, which may result from the use of the PNG Reference Library, even if advised of the possibility of such damage. Permission is hereby granted to use, copy, modify, and distribute this source code, or portions hereof, for any purpose, without fee, subject to the following restrictions: 1. The origin of this source code must not be misrepresented. 2. Altered versions must be plainly marked as such and must not be misrepresented as being the original source. 3. This Copyright notice may not be removed or altered from any source or altered source distribution. The Contributing Authors and Group 42, Inc. specifically permit, without fee, and encourage the use of this source code as a component to supporting the PNG file format in commercial products. If you use this source code in a product, acknowledgment is not required but would be appreciated. ======================================================================== * contrib/gregbook/COPYING ======================================================================== GNU GENERAL PUBLIC LICENSE Version 2, June 1991 Copyright (C) 1989, 1991 Free Software Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed. Preamble The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too. When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. 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(Exception: if the Program itself is interactive but does not normally print such an announcement, your work based on the Program is not required to print an announcement.) These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it. Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program. In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License. 3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following: a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, b) Accompany it with a written offer, valid for at least three years, to give any third party, for a charge no more than your cost of physically performing source distribution, a complete machine-readable copy of the corresponding source code, to be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or, c) Accompany it with the information you received as to the offer to distribute corresponding source code. (This alternative is allowed only for noncommercial distribution and only if you received the program in object code or executable form with such an offer, in accord with Subsection b above.) The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable. If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code. 4. You may not copy, modify, sublicense, or distribute the Program except as expressly provided under this License. Any attempt otherwise to copy, modify, sublicense or distribute the Program is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance. 5. You are not required to accept this License, since you have not signed it. However, nothing else grants you permission to modify or distribute the Program or its derivative works. These actions are prohibited by law if you do not accept this License. Therefore, by modifying or distributing the Program (or any work based on the Program), you indicate your acceptance of this License to do so, and all its terms and conditions for copying, distributing or modifying the Program or works based on it. 6. Each time you redistribute the Program (or any work based on the Program), the recipient automatically receives a license from the original licensor to copy, distribute or modify the Program subject to these terms and conditions. You may not impose any further restrictions on the recipients' exercise of the rights granted herein. You are not responsible for enforcing compliance by third parties to this License. 7. If, as a consequence of a court judgment or allegation of patent infringement or for any other reason (not limited to patent issues), conditions are imposed on you (whether by court order, agreement or otherwise) that contradict the conditions of this License, they do not excuse you from the conditions of this License. If you cannot distribute so as to satisfy simultaneously your obligations under this License and any other pertinent obligations, then as a consequence you may not distribute the Program at all. For example, if a patent license would not permit royalty-free redistribution of the Program by all those who receive copies directly or indirectly through you, then the only way you could satisfy both it and this License would be to refrain entirely from distribution of the Program. If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances. It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice. This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License. 8. If the distribution and/or use of the Program is restricted in certain countries either by patents or by copyrighted interfaces, the original copyright holder who places the Program under this License may add an explicit geographical distribution limitation excluding those countries, so that distribution is permitted only in or among countries not thus excluded. In such case, this License incorporates the limitation as if written in the body of this License. 9. The Free Software Foundation may publish revised and/or new versions of the General Public License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation. 10. If you wish to incorporate parts of the Program into other free programs whose distribution conditions are different, write to the author to ask for permission. For software which is copyrighted by the Free Software Foundation, write to the Free Software Foundation; we sometimes make exceptions for this. Our decision will be guided by the two goals of preserving the free status of all derivatives of our free software and of promoting the sharing and reuse of software generally. NO WARRANTY 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. END OF TERMS AND CONDITIONS How to Apply These Terms to Your New Programs If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms. To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found. Copyright (C) This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Also add information on how to contact you by electronic and paper mail. If the program is interactive, make it output a short notice like this when it starts in an interactive mode: Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program. You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names: Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. , 1 April 1989 Ty Coon, President of Vice This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License. ======================================================================== * contrib/gregbook/LICENSE ======================================================================== --------------------------------------------------------------------------- Copyright (c) 1998-2008 Greg Roelofs. All rights reserved. This software is provided "as is," without warranty of any kind, express or implied. In no event shall the author or contributors be held liable for any damages arising in any way from the use of this software. The contents of this file are DUAL-LICENSED. You may modify and/or redistribute this software according to the terms of one of the following two licenses (at your option): LICENSE 1 ("BSD-like with advertising clause"): Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. Redistributions of source code must retain the above copyright notice, disclaimer, and this list of conditions. 2. Redistributions in binary form must reproduce the above copyright notice, disclaimer, and this list of conditions in the documenta- tion and/or other materials provided with the distribution. 3. All advertising materials mentioning features or use of this software must display the following acknowledgment: This product includes software developed by Greg Roelofs and contributors for the book, "PNG: The Definitive Guide," published by O'Reilly and Associates. LICENSE 2 (GNU GPL v2 or later): This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA --------------------------------------------------------------------------- ======================================================================== * contrib/pngminus/LICENSE.txt ======================================================================== pnm2png / png2pnm --- conversion from PBM/PGM/PPM-file to PNG-file copyright (C) 1999-2019 by Willem van Schaik Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. The software is provided "as is", without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose and noninfringement. In no event shall the authors or copyight holders be liable for any claim, damages or other liability, whether in an action of contract, tort or otherwise, arising from, out of or in connection with the software or the use or other dealings in the software.