We've been using this module for over a year now, and it is happily resizing thousands of images every day. We switched to it from some nasty old code that shelled out to ImageMagick. Whilst ImageMagick is great, shelling out to it is not. There are Perl interfaces to ImageMagick, but I still found it awkward to install and the interface was a bit clumsy.
Image::Imlib2 solves those problems: it's simple to install on a Linux box, it's small and it's fast, and it has a reasonably sane interface. Thanks!