[laconix]

Too me this is extremely creepy. It reminds of the Resident Evil security system, or the male equivalent.

I do doubt how well it would work, for example; telling the difference between laughing and crying, telling the difference between sadness and anger.

But I don't know too much about this, or what's currently going on in the field so perhaps somebody made a breakthrough. Or this may be the breakthrough.

[rahulvohra]

For a while now, computers have been able to recognise human emotions more reliably than humans can: http://www.cl.cam.ac.uk/research/rainbow/emotions/

Given a good full frontal view of a face, a computer can tell the difference between laughing and crying or sadness and anger. The real challenge is dealing with variance in pose and lighting.

(Disclosure: I was doing a PhD in that research group.)