Face Recognition Algorithm

[Solixious]

I can't imagine how exactly an application can recognize faces of people. Its not always accurate, but works well in most of the situations. Does it scan the faces pixel wise or is there some other technique to do it? Is there any particular algorithm to recognize faces? I mean how do these applications manage to work when the images' darkness level, angle, expression, etc are different?

[Deque]

Read the first part of this and you will get an answer: http://evilzone.org/tutorials/artificial-neural-networks-the-basics/msg9782/#msg9782

This is only one possibility though.

[Solixious]

Its basics but nonetheless, the concept was really cool...