Editing Affective computing (section)

===Body gesture===
{{Main|Gesture recognition}}
Gestures could be efficiently used as a means of detecting a particular emotional state of the user, especially when used in conjunction with speech and face recognition. Depending on the specific action, gestures could be simple reflexive responses, like lifting your shoulders when you don't know the answer to a question, or they could be complex and meaningful as when communicating with sign language. Without making use of any object or surrounding environment, we can wave our hands, clap or beckon. On the other hand, when using objects, we can point at them, move, touch or handle these. A computer should be able to recognize these, analyze the context and respond in a meaningful way, in order to be efficiently used for Human–Computer Interaction.

There are many proposed methods<ref name="JK">J. K. Aggarwal, Q. Cai, Human Motion Analysis: A Review, Computer Vision and Image Understanding, Vol. 73, No. 3, 1999</ref> to detect the body gesture. Some literature differentiates 2 different approaches in gesture recognition: a 3D model based and an appearance-based.<ref name="Vladimir">{{cite journal | first1 = Vladimir I. | last1 = Pavlovic | first2 = Rajeev | last2 = Sharma | first3 = Thomas S. | last3 = Huang | url = http://www.cs.rutgers.edu/~vladimir/pub/pavlovic97pami.pdf | title = Visual Interpretation of Hand Gestures for Human–Computer Interaction: A Review | journal = [[IEEE Transactions on Pattern Analysis and Machine Intelligence]] | volume = 19 | issue = 7 | pages = 677–695 | year = 1997 | doi = 10.1109/34.598226 | s2cid = 7185733 }}</ref> The foremost method makes use of 3D information of key elements of the body parts in order to obtain several important parameters, like palm position or joint angles. On the other hand, appearance-based systems use images or videos to for direct interpretation. Hand gestures have been a common focus of body gesture detection methods.<ref name="Vladimir"/>