Our face is one of the strongest indicators of emotions; as we laugh or cry, we put our emotions on display, allowing others to glimpse into our minds. It's a form of nonverbal communication that, apparently, accounts for over 50% of our communication with others. Forty independently controlled muscles make the face one of the most complex systems we possess, which could be the reason we use it as a medium for communicating something so important as our current emotional state. But can we classify it?
In 2013, the International Conference on Machine Learning (ICML) ran a competition inviting contestants to build a facial expression classifier using a training dataset of over 28,000 grayscale images. They were labeled as either anger, disgust, fear, happiness, sadness, surprise, or neutral. The following are a few samples of this training data...
