pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
| Tags | multimedia Graphics Graphics Conversion Archiving Compression |
|---|---|
| Licenses | zlib/libpng |
| Implementation | C |
Recent releases


Release Notes: This release fixes a bug introduced in 1.7.52 which caused the -reduce option to produce a tRNS chunk which had more entries than the PLTE chunk (which is invalid).


Release Notes: This release fixes initialization problems introduced in version 1.7.51, reinitializes settings before processing each file, and makes the "-reduce" option work properly.


Release Notes: This version implements the "-reduce" option properly. This examines the input file to see if the color type, bit depth, and palette length can be reduced without loss, and if there is an opaque alpha channel which can be removed.


Release Notes: This release fixes a bug introduced in version 1.7.39 which caused failure to write an output file.


Release Notes: A bug in the handling of indexed PNG files was fixed.
Recent comments
12 Jul 2002 19:37
Great program.
This is excellent.
29 Jul 2000 12:49
libPNG example
I would prefer this as a second libPNG example... Pefect to demonstrate.
ciao
08 Dec 1999 18:11
makefile?
Version 1.2.2 will include a rudimentary makefile for people
who don't want to type
gcc -O -o pngcrush *.c
07 Dec 1999 11:37
Makefile?
Badly needs a makefile or configure script.