This release adds the "-ow" option to overwrite the input file with the compressed file. If an output filename is given on the command line, it will be used as a temporary file and removed after compression. If not, "pngout.png" is used as a temporary file.
Deprecated use of libpng png_struct members and use of non-exported libpng functions have been eliminated. Pngcrush can now be built with system libpng-1.5.x.
This version is built with libpng 1.2.40. There are some additional checks for the "verbose" setting when printing to make the "-s" option more silent.