We try to accomplish a human-computer communication based on human behaviour. Will a computer be able to understand humans and not just take orders via the mouse or the keyboard? Will it be able to recognise the mood of its user and respond accordingly? Moreover, the recognition process must be non-invasive to the convenience of the user. Thus, we try to develop recognition algorithms based on images or videos. We are currently working on facial expression recognition. Though non-verbal cues exist in voice pitch or in gestures, facial expressions reveal best human emotions. Psychologists claim that there are six basic expressions (anger, disgust, happiness, sadness, fear and surprise) that people perform independent of their cultural background. The recognition of the six basic expressions is just a start, since the facial muscles can make several actions. It is a long way to go until computers can socialize with humans.