SYDNEY, AUSTRALIA: Scientists have programmed computers to read human expressions and to tell whether one is in pain.

"Each facial expression is made up of many different components - a twitch of the mouth here, a widening of the eyes there - some lasting only a fraction of a second," said Simon Lucey of Commonwealth Scientific and Industrial Research Organisation (CSIRO).

"Our computer program looks at these components, matches them against a list drawn up by expert psychologists and decides what expression just flitted across a face," said Lucey, a computer scientist.

It turns out that most human expressions are the same, regardless of background. And, as anyone who has been naughty knows, it's also very hard to fake an expression.

While a guilty person might fool a human with their look of pure innocence, it is very hard to fool Lucey's computer.

The system uses a technique called machine learning. After being programmed with what to look for and what it means, each observation taken or analysis performed is used to refine the computer's technique so it gets better at its assigned task over time.

Lucey's system uses a webcam and will work against any background, provided there is enough light.

"Our expression work is still mostly from front-on, but we're teaching the system to do what we do and recognise expressions when only one side of the face is visible."

One of the applications for Lucey's research is in detecting whether someone who cannot communicate is in pain and how intense that pain is, said a CSIRO release.

Another is in making 'telecollaboration' between people using video and computers in different locations more natural by recognizing gestures such as someone pointing at an object.

 ©IANS