Neural networks (NNs) have been a fundamental part of computerised pattern recognition tasks for more than half a century, and continue to be used in a very broad range of problem domains. The two main reasons for their widespread usage are: 1) power (the sophisticated techniques used in NNs allow a capability of modeling quite complex functions); and 2) ease of use (as NNs learn by example it is only necessary for a user to gather a highly representative data set and then invoke training algorithms to learn the underlying structure of the data).
The HSV process parallels this learning mechanism. There are many ways to structure the NN training, but a very simple approach is to firstly extract a feature set representing the signature (details like length, height, duration, etc.), with several samples from different signers. The second step is for the NN to learn the relationship between a signature and its class (either “genuine” or “forgery”). Once this relationship has been learned, the network can be presented with test signatures that can be classified as belonging to a particular signer. NNs therefore are highly suited to modeling global aspects of handwritten signatures.