Gait-based screening: walking to fruition?

Discussions on applying biometrics to airport security have traditionally focused on iris, facial or fingerprint verification technology, but gait-based concepts are emerging as part of a multimodal solution.

One project investigating the reliability of gait involves researchers from the University of Southampton in the UK, where a biometric 'tunnel' has been created to analyse unique characteristics that individuals exhibit when they walk.

In testing at the university, synchronised closed-circuit television (CCTV) cameras follow subjects as they walk through the tunnel. With the application of complex software, the imagery is then duplicated digitally in three-dimensional (3-D) format for categorisation and storage on a database. This is then matched against CCTV footage when the subject next passes through the tunnel.

"It's a computer vision-based system" remarks Professor Mark Nixon of Southampton University's School of Electronics and Computer Science (ECS). "The information from the cameras is then interpreted by computer. The cameras are arranged to watch somebody walking through a controlled environment – from that camera information we gain some indication as to the identity of the subject."

Four cameras are mounted on either side of the tunnel. Nixon points out that the synchronised operation of the cameras is significant – while each individual camera has a finite field of view, eight of them operating simultaneously can give a wider picture. Full image capture is ensured by colour-coding the tunnel background in red, blue and green squares. All the data is recorded to disk.