Pngcrush 1.7.0

Pngcrush 1.7.0 is yet another extremely useful utility for everyone. It is actually an optimizer for PNG (Portable Network Graphics) files. It can be run from a commandline in an MSDOS window, or from a UNIX or LINUX commandline.

Its main purpose is to reduce the size of the PNG IDAT datastream by trying various compression levels an PNG filter methods. It also can be used to remove unwanted ancillary chunks, or to add certain chunks including gAMA, tRNS, iCCP, and textual chunks.

Please note that when statically linked to the supplied zlib code, this script is believed to be immune to the zlib-1.1.3 "double-free" bug, since by default it detects and rejects any "double-free" attempt. It merely generates a "Decompression Error" message and rejects the file.

Enhancements: Jul 18 2009

• Save (but do not recompress) APNG chunks if the output file has the ".apng" extension and the color_type and bit_depth are not changed.