TweakPNG:  A low-level PNG image file manipulation utility
Version 1.4.6
Copyright (c) 1999-2014 Jason Summers  <jason1@pobox.com>

==================== License ====================

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 3 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


A copy of the GNU General Public License is included in the file 
COPYING.txt.


========================================================


The following files should be included in the source distribution:

charset.cpp
chunk.cpp
COPYING.txt
drag2.cur
iccprof.cpp
icon_1.ico
icon_2.ico
pngtodib.cpp
pngtodib.h
tweakpng-src.txt    (this file)
resource.h
twpng-config.h
tweakpng.cpp
tweakpng.h
tweakpng.rc
tweakpng.sln     (VC9 workspace file)
tweakpng.vcproj  (VC9 project file)
viewer.cpp


To get the latest version of TweakPNG, visit the TweakPNG home page at 
<http://entropymine.com/jason/tweakpng/>.

The source code should be compatible with Microsoft Visual C++ version 5 
and higher. It might also work in other modern C++ packages.

Basically, to compile TweakPNG, you need to include the following files in 
your project:

charset.cpp
tweakpng.cpp
chunk.cpp
viewer.cpp
pngtodib.cpp
pngtodib.h
tweakpng.rc
tweakpng.h
twpng-config.h
resource.h
icon_1.ico
icon_2.ico
drag2.cur

Make sure you include the following potentially nondefault libraries:

comdlg32.lib
comctl32.lib


There are three configurations available:


1. With image viewing support

All features will be available. Requires libpng (version 1.2.2 or higher
recommended), and zlib (version 1.1.4 or higher recommended).

This is the default configuration.

 libpng: <http://www.libpng.org/pub/png/>
 zlib: <http://zlib.net/>

2. With compression support (but no image viewing support)

Requires zlib, but not libpng. The image viewer tool will be unavailable. 
You will be able to edit compressed text chunks.

- comment out the 
#define TWPNG_SUPPORT_VIEWER
line in twpng-config.h


3. With no image viewing or compression support

Does not require any third-party libraries. The image viewer will be 
unavailable, and you won't be able to view or edit compressed text chunks.

- comment out the 
#define TWPNG_SUPPORT_VIEWER
#define TWPNG_USE_ZLIB
lines in twpng-config.h


Also, the program can be compiled as a Unicode application (DebugU and 
ReleaseU configurations if you use the included project file) or a 
non-Unicode application (Debug and Release configurations). Non-Unicode 
configurations do not support iTXt chunks.

