How does this compare to something like Dragonfly (https://github.com/markevans/dragonfly/)? 1000memories's issue was with the time it took to generate 12 different versions, not the speed of Imagemagick itself. So I'm not quite sure why they needed to write their own extension. Even Carrierwave (plus caching of course) can be setup this way (https://gist.github.com/1541912).