Handbook of Multimedia for Digital Entertainment and Arts- P25: The advances in computer entertainment, multi-player and online games, technology-enabled art, culture and performance have created a new form of entertainment and art, which attracts and absorbs their participants. The fantastic success of this new field has influenced the development of the new digital entertainment industry and related products and services, which has impacted every aspect of our lives. | 726 F. Sparacino Gesture Recognition A gesture-based interface mapping interposes a layer of pattern recognition between the input features and the application control. When an application has a discrete control space this mapping allows patterns in feature space better known as gestures to be mapped to the discrete inputs. The set of patterns form a gesturelanguage that the user must learn. To navigate through the Internet 3D city the user stands in front of the screen and uses hand gestures. All gestures start from a rest position given by the two hands on the table in front of the body. Recognized command gestures are Figs. 7 and 8 follow link point-at-correspondent-location-on-screen go to previous location point left go to next location point right Fig. 7 Navigating gestures in City of News user sitting Fig. 8 Navigating gestures in City of News at SIGGRAPH 2003 user standing 32 Designing for Architecture and Entertainment 727 Fig. 9 Four state HMM used for Gesture Recognition navigate up move one hand up navigate down move hands toward body show aerial view move both hands up Gesture recognition is accomplished by HMM modeling of the navigating gestures 31 Fig. 9 . The feature vector includes velocity and position of hands and head and blobs shape and orientation. We use four states HMMs with two intermediate states plus the initial and final states. Entropic s Hidden Markov Model Toolkit HTK http is used for training 48 . For recognition we use a real-time C Viterbi recognizer. Comments I described an example of a space which could be in a section of the living room in our home or in the lobby of a museum in which perceptual intelligence modeled by computer vision and Hidden Markov Models a particular case of a Bayesian Networks provides the means for people to interact with a 3D world in a natural way. This is only a first step towards intelligence modeling. Typically an intelligent space would have a variety of sensors to perceive our .
