Auslan is the language of the Australian Deaf community. It is considered by researchers to be a dialect of British Sign Language (BSL) and is also closely related to New Zealand Sign Language (NZSL). Auslan has approximately 4000 to 5000 ``well-defined'' signs, but this underestimates the richness of the language, since fingerspelling can be used for any spoken word that doesn't have a sign and also because the visual medium can be employed in ways that the aural can not (e.g.\ in the detailed description of the appearance of objects). There are approximately 15,000 Auslan signers. A sign consists of a number of physical components, such as the handshape, location, palm orientation, movement of the palms and facial expression. Facial expression is minor in the formation of individual signs, but is fundamental in the construction of phrases [Joh89].
A small selection of isolated Auslan signs were captured using an
instrumented glove called the PowerGlove. This glove is relatively
primitive, providing only low-resolution information about position
and finger bend of the the first four fingers and roll of the hand,
and failing altogether to give any information about pitch, yaw and
the bending of the little finger
. In addition, it only provides
information about one hand, not both.
Still, it is possible to perform some recognition using these data. In
previous results [Kad95], it was shown that by manually
selecting a set of global attributes and extracting them and trying
different learners, recognition with accuracies up to approximately 80
per cent on seen signers could be achieved with a vocabulary of 95
signs. These signs were intentionally selected to be
representative.
Its performance on unseen signers
(i.e. trained on four signers, tested on fifth) was not so good, achieving
only approximately 30 per cent accuracy.
A small subset of these signs (ten) were selected from a single signer for testing purposes. A total of 20 examples of each sign were used, with 15 of these used for training instances and 5 for testing.