Hand gesture recognition from video images is of considerable interest
as a means of providing simple and intuitive man-machine interfaces.
Possible applications range from replacing the mouse as a pointing dev
ice to virtual reality and communication with the deaf. We describe an
approach to tracking a hand in an image sequence and recognising, in
each video frame. which of five gestures it has adopted. A statistical
ly based Point Distribution Model (PDM) is used to provide a compact p
arametrised description of the shape of the hand for any of the gestur
es or the transitions between them. The values of the resulting shape
parameters are used in a statistical classifier to identify gestures.
The model can be used as a deformable template to track a hand through
a video sequence but this proves unreliable. We describe how a set of
models, one for each of the five gestures, can be used for tracking w
ith the appropriate model selected automatically. We show that this re
sults in reliable tracking and gesture recognition for two 'unseen' vi
deo sequences in which all the gestures are used.