Gaussian Mixture Models for CHASM Signature Verification

摘要

In this paper we report on first experimental results of a novel multimodal user authentication system based on a combined acquisition of online handwritten signature and speech modalities. In our project, the so-called CHASM signatures are recorded by asking the user to utter what he is writing. CHASM actually stands for Combined Handwriting and Speech Modalities where the pen and voice signals are simultaneously recorded. We have built a baseline CHASM signature verification system for which we have conducted a complete experimental evaluation. This baseline system is composed of two Gaussian Mixture Models sub-systems that model independently the pen and voice signal. A simple fusion of both sub-systems is performed at the score level. The evaluation of the verification system is conducted on CHASM signatures taken from the MylDea multimodal database, accordingly to the protocols provided with the database. This allows us to draw our first conclusions in regards to time variability impact, to skilled versus unskilled forgeries attacks and to some training parameters. Results are also reported for the two sub-systems evaluated separately and for the global system.