We're not quite sure why anyone would need it, but NEC's latest piece of biometric wizardry is a face-recognition system that can look at video clips and rank people according to how frequently they appear.

The company, which has a long history of using face recognition for security purposes, suggests users might want to apply the technique to online video to create a ready-reckoner of who's in each clip.

Mug's game

Using complex algorithms that take account of lighting and movement, the system is currently running at 80 per cent accuracy, something NEC hopes to improve before commercialisation.

Mysteriously, it also recommends the method for use in "home appliances, mobile devices, video-sharing websites and video archives for companies." We can't see any of that becoming a boom market for NEC, but it might want to take a look at the crowd-control arena in European football stadia if it fancies a Big Brother-style policing role.