MiniMagick gives you access to all the command-line options ImageMagick
has (found at http://www.imagemagick.org/script/mogrify.php).  Using
MiniMagick as an alternative to RMagick allows the Ruby processes memory
to remain small because it spawns ImageMagick's mogrify program, which
has much lower memory usage than RMagick.

Homepage:
https://github.com/probablycorey/mini_magick
