Wiizards: 3D Gesture Recognition for Game Play Input (Kratz, et al – 2007)

Current Mood: studious

Blogs I Commented On:

• Aaron Wolin
• Brandon Paulson
• Katie Dahmen

Summary:
This is another applications paper that uses the Wiimote. Their application is called Wiizards, a multiplayer game which uses HMMs for gesture recognition. The game itself is a two player zero-sum game, where the player tries to damage to the other while limiting damage to one’s self. Gestures dictate spell casting, and players are more successful in the game if they use a variety of them. The three main components for the game is the Wiimote, gesture recognizer, and the game. Observations for the model are accelerometer data from the Wiimote, and then normalized using calibration information. Each gesture, which is an observation vector, is a collection of oberservations trained on the Baum-Welch algorithm, and also has a separate model associated with them for recognition. As calculated by the Viterbi Algorithm, the probability of a gesture given a model is the distribution of the observations and hidden states. To train the models, data was collected from 7 users. Each user were shown the gestures and performed them 40 times, and an HMM was created from the user data.

Discussion:
There are relatively few gesture recognition papers that cater to the Wiimote, since it’s a new device, and given the number of Wiimote papers on the topic matter, this would be considered a pretty good paper. It’s interesting that they built a nice application to demonstrate their recognizer using an HMM approach, but the system does have some kinks since the paper states about 50% accuracy by users whom hadn’t used the system before.