TweakPNG
TweakPNG is a low-level utility for examining and modifying PNG image files.
It runs on Windows 95 or higher (98, ME, 2000, XP, etc.).
In order to use it, you will need to be at least somewhat familiar with
the internal format of PNG files. For information about PNG, see the
PNG home page.
A screenshot of TweakPNG:
To download TweakPNG, save the following link:
tweakpng-1.2.1.zip (about 200K)
11 Dec 2004
You can also view the README file.
To install it, just create a directory and unzip the files into it. To run
it, open tweakpng.exe.
TweakPNG is available for free under the terms of the
GNU General Public License (GPL).
The C++ source code for TweakPNG is included the zip file.
History
v1.2.1 (11 Dec 2004):
- Updated the binary to use the latest versions of zlib (1.2.2)
and libpng (1.2.8).
- Two or three very small improvements and fixes.
v1.2.0 (29 Dec 2003):
- Added an image viewer (Tools->Show Image Viewer). This makes
use of another project of mine, PNGDIB.
- Palette editor now used for selecting grayscale background
and transparent colors.
- A few other minor changes.
v1.1.2 (24 Nov 2003):
- Option to add TweakPNG to Windows Explorer context menus.
- Warns when you try to exit without saving changes.
- Compiles cleanly in MSVC6.
v1.1.1 (3 Jan 2001):
- Fixed problem with writing wrong CRC after editing IHDR chunk.
v1.1.0 (28 Dec 2000):
- Palette editing, including bKGD and tRNS chunks
for paletted images.
- Persistent window sizes and column widths, and
persistent position of text chunk editor and palette editor.
- Rearranged some menus
- Edit IHDR chunk (not much reason to do this though...)
- Context menu
- "Combine all IDAT" function
- Fixed some bugs here and there...
v1.0.1 (27 Dec 1999): A few minor bugfixes;
more graceful handling of most
invalid files; automatic validation on Save; uses standard color picker
when appropriate (but usually it's not)
v1.0.0 (3 Dec 1999): Initial release
TweakPNG was written by Jason Summers. You may send
comments and inquiries concerning TweakPNG to
jason1@pobox.com.
Comments are welcome, but please keep in mind that this
program is not even intended to be friendly to non-technical people,
and is no longer being actively developed (at least not by me).
See also pngrewrite, a utility to help
optimize paletted PNG images.
The official location of this page is
<http://pobox.com/~jason1/tweakpng/>.