ruby-oily-png 1.2.1~dfsg-1build2 (ppc64el binary) in ubuntu cosmic

 OilyPNG is a Ruby C extension to speed up the pure Ruby ChunkyPNG
 library. It is a standalone module, so it does not require LibPNG,
 ImageMagick or any other library. Currently it has an alternative
 implementation of decoding and encoding PNGs, making these operations
 much faster, especially for PNG images that apply filtering.