Installing FreeImage/ImageScience?

I haven't tried ImageScience yet, but it is possible to use
ImageMagick without RMagick. MiniMagick is one option but if you only
need simple operations, you can do it directly in your code. See
http://atomgiant.com/2007/01/22/dead-simple-image-processing-with-imagemagick/
as a starting point and ImageMagick commands documentation for further
possibilities...

-- bobes