Human Computer Interaction (HCI) as the name suggests, is related to humans and computers and the way, both interact with each other.Because human-computer interaction studies a human and a machine in conjunction, it draws from supporting knowledge on both the machine and the human side. On the machine side, techniques in computer graphics, operating systems, programming languages, and development environments are relevant. On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology, and human factors are relevant. Attention to human-machine interaction is important, because poorly designed human- machine interfaces can lead to many unexpected problems.In particular, core vision techniques (body, gesture, gaze) and affective interaction (facial expression recognition, and emotion in audio) which are needed for Multimodal Human Computer Interaction (MMHCI) research.