Folks,

First I'd like you guys to have a look at this app "Image cut": <https://play.google.com/store/apps/details?id=jp.zx1234567890.imagecut>.

This app very neatly cuts an object of importance from a user defined area
inside an image. You can simple sketch an area around the object you want to
cut out by moving around your finger on the screen. Then the app takes out
the object with a great preciseness.

I am no Image Processing kid, but I can try playing with algorithms.My question is 
to all you Image-Processing/Algorithm guys that how should I go about implementing
this. I mean if you can describe how complex problem is this to solve and how should I
approach this problem. I did google around but wasn't able to get a concrete picture
of the possible solution. Since the above mentioned app has achieved this, it seems the problem
should be solvable. I'll highly appreciate any help here.

Thank you!