You know how it goes: you set up your app to auto-crop uploaded images and it blindly follows your orders, cropping out the most interesting part of your users' images.
Not anymore, baby! Caire uses an energy map to perform edge detection and determine the least important parts of to crop out. It's more complicatd than that, but the whole process is described in the README so click through for the nitty, gritty.
The results are pretty impressive!