pngcrush reads in a PNG image, and writes it out again, with the optimum filter_type and zlib_level. It uses brute force (trying filter_type none, and libpng adaptive filtering, with compression levels 3 and 9). It does the most time-consuming method last in case it turns out to be the best. Optionally, it can remove unwanted chunks or add gAMA and sRGB chunks.
pngcrush reads in a PNG image, and writes it out again, with the optimum filter_type and zlib_level. It uses brute force (trying filter_type none, and libpng adaptive filtering, with compression levels 3 and 9). It does the most time-consuming method last in case it turns out to be the best. Optionally, it can remove unwanted chunks or add gAMA and sRGB chunks.
To install pngcrush, run the following command in macOS terminal (Applications->Utilities->Terminal)
sudo port install pngcrush
To see what files were installed by pngcrush, run:
port contents pngcrush
To later upgrade pngcrush, run:
sudo port selfupdate && sudo port upgrade pngcrush
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