The standard PNG utility pngcrush has been modified by Apple, which makes it produce technically invalid PNGs: a new chunk is inserted before the mandatory first chunk IHDR, RGB(A) order of pixel data is inverted, and RGB pixels get premultiplied with their alpha.
Hence, I'd rather call these PNGs "fried", rather than just "crushed".
Try my own pngdefry. The source code is written on a Mac OSX machine but it should be compilable for other OSes as well; it's pretty straightforward C code.
The standard PNG utility
pngcrushhas been modified by Apple, which makes it produce technically invalid PNGs: a new chunk is inserted before the mandatory first chunkIHDR, RGB(A) order of pixel data is inverted, and RGB pixels get premultiplied with their alpha.Hence, I'd rather call these PNGs "fried", rather than just "crushed".
Try my own
pngdefry. The source code is written on a Mac OSX machine but it should be compilable for other OSes as well; it's pretty straightforward C code.