An independently developed 'biometric face recognition system' has been approved and will be used for public identification, its leading inventor said yesterday.

The invention, developed by Su Guangda, an Electronic Engineering Department professor with Beijing-based Tsinghua University, has been approved by a panel of experts from the Ministry of Public Security.

The system captures moving facial images and features multi-camera technology to lower the error chances of possible mismatching. It will be used in many locations including airports, post and customs offices and possibly residential communities as well.

Facial recognition systems, which have been subject of increasing interest since September 11 terrorist attacks, are computer-based security systems which can automatically detect and identify the human face..

The system 'lifts' the human face from its surroundings and measures various facial points such as the distance between the eyes, the shape of the cheekbones and a number of other distinguishing features. It then compares them to the nodal points computed from a database of pictures to see a match. Some countries already use the technology in public places as part of their security systems.

In China it's limited to police use. In recent years the technology has helped Beijing police solve a number of criminal cases involving child abduction and supermarket blackmail attempts. "It has a very promising future for the public use," Su said in a telephone interview yesterday.

"It has an advantage over fingerprint identification because the country doesn't have a general public fingerprint database for the general public," he said. He pointed out that as there is a photograph on everyone's ID card it might simplify the establishment of a facial database.

However, like systems in other countries, the technology has proved open to mistakes. If a picture lacks sharp definition or a person's facial features are influenced by a number of factors -- age, expression, lighting and or camera angles -- errors in identification are possible. As the size of any database rises the potential for mistakes also goes up.

The professor said his laboratory is working on these problems although his system has tackled the 'angle issue' by taking pictures with several cameras.

The privacy implication is a further concern. Presently there is much debate over the use of face recognition and other surveillance technologies.

"As long as you don't save the picture in the computer and just scan individual faces quickly the privacy violation is not an issue," Su said.

"And we could give assurances of that by not adding a picture saving function to the technology," he said.

(China Daily February 20, 2006)