"People often reveal their private emotions in tiny, fleeting facial expressions, visible only to a best friend — or to a skilled poker player. Now, computer software is using frame-by-frame video analysis to read subtle muscular changes that flash across our faces in milliseconds, signaling emotions like happiness, sadness and disgust.

Companies in this field include Affectiva, based in Waltham, Mass., and Emotient, based in San Diego. Affectiva used webcams over two and a half years to accumulate and classify about 1.5 billion emotional reactions from people who gave permission to be recorded as they watched streaming video, said Rana el-Kaliouby, the company’s co-founder and chief science officer. These recordings served as a database to create the company’s face-reading software, which it will offer to mobile software developers starting in mid-January.

Face-reading technology may one day be paired with programs that have complementary ways of recognizing emotion, such as software that analyzes people’s voices, said Paul Saffo, a technology forecaster. If computers reach the point where they can combine facial coding, voice sensing, gesture tracking and gaze tracking, he said, a less stilted way of interacting with machines will ensue."


http://www.nytimes.com/2013/12/01/technology/when-algorithms-grow-accustomed-to-your-face.html