If you want to identify people, what could be more natural than looking at their faces? Humans identify each other in this way, accurately and quickly, even in poor light or with a partially obscured view. Yet for computers, facial recognition has proved extremely difficult - restricting its commercial application - until now.
In the past two years, technological advances have led to facial recognition being used for applications including access control, time and attendance recording, and security checking. Analysts are forecasting strong market growth. 'Facial recognition is now a viable technology,' says Emma Newham, an analyst at SJB Services, a market research company based in Somerset.
'Its share of the "biometrics" market has risen from zero to 11.8% since the end of 1996.' The technology measures the distance between facial features such as the eyes, nose, mouth and ears. This is effective even if an individual is wearing glasses rather than contact lenses, has a new hairstyle, or has grown a beard while on holiday.
Until now, most facial-recognition systems have been two dimensional - the subject must be looking directly at the camera in a good light.
This has limited its use to situations where people are facing a screen - at their PC or withdrawing cash from a bank's ATM. Solicitors are among those interested in software costing around £100 per screen, says Pat Oldcorn, marketing manager at Slough-based SSI, a software house specialising in biometrics. 'If a secretary goes off and makes a coffee, the screen blots off. Anyone trying to access it gets their photo taken and can leave a voice message.' Ideally, systems should work in three dimensions as the subject is walking past the camera. This has been the focus of research for Cambridge-based Neurodynamics. 'Two dimensional recognition is no use for companies that want surveillance of secure areas or if they want covertly to capture the image of somebody walking into a room,' says its marketing manager Emma Barnes.
Neurodynamics is working on a system for a UK airport. It looks out for known terrorists and unusual behaviour. If either is spotted, it triggers an alarm and transmits a video image to central monitors. 'It could be used by banks to check that the correct number of people enter a vault, and that they are the right people,' says Barnes. Supermarkets can use it to deal with shoplifting and to supervise self-scanning.
A similar system, developed by SSI, has been installed in the London Borough of Newham to look out for known muggers and shoplifters via 120 CCTV cameras. 'Unlike people, computers do not find their eyes glazing over with boredom as they watch screens, nor do they need to go to the loo,' says Oldcorn. The system could be used by schools to watch out for known paedophiles, or by the police to deal with known hooligans at football matches.
Three dimension facial recognition systems like these don't come cheap - prices start at around £25,000. Moreover, there may be social obstacles - civil rights campaigners have already protested against the Newham scheme.
Ultimately, facial recognition will have to compete with other biometrics such as fingerprint recognition and scanning the iris or hand. The signs are promising, however, and the UK is at the forefront of technology.
SJB believes that 1999 will be the year facial recognition comes of age.