An method for separating people and background in images

I am looking for a way to separate the part of an image开发者_StackOverflow中文版 that contains a person from the background in an image. It does not have to be very accurate, rough borders will do too. It can be an algorithm, a software lib (pref. open source), or even a reference to a relevant AI or image processing material. Having to train the solver is acceptable. However, the final application have to be reasonably lightweight, as it would have to run on a smartphone.

Start with OpenCV. It's an open-source computer-vision library that already contains some algorithms for that. Try what it's got and see if it's good enough for your needs.

The “Learning OpenCV” book will give good introduction into computer vision and machine learning.

if you are looking for algorithms then check this out http://www.face-rec.org/algorithms/

they have also some source code samples (although for Mathematica)...