This [Alloy Build Configuration File](http://docs.appcelerator.com/titanium/3.0/#!/guide/Build_Configuration_File_(alloy.jmk) automatically generates non-retina and Android XXHDPI, XHDPI, HDPI and MDPI images for all new and changed retina (@3x
) images before each compile.
Read more about it at: http://fokkezb.nl/2013/07/29/generate-non-retina-images/