Internet search engine Infoseek Germany is implementing a visual search feature which can locate faces of particular people.

The service implements image detection and recognition technology developed by Cobion GmbH, according to Infoseek service provider WSI Webseek Infoservice GmbH.

Users can, for example, type in the name of a celebrity and locate images of the person's face, the companies said.

The search engine offers a star directory that automatically scans the Web and catalogues new images of movie and music personalities.

Users can also locate images of people associated with a certain keyword, for example, a search for "Armani" and "people" returns images of models wearing fashion designer Armani's designs, the companies said.

"This is the first time that you can search for human beings within the Internet," said Cobion CEO J"rg Lamprecht.

The technology works by means of pattern matching, by measuring and assigning numbers to facial features, such as the distance between eyes.

"You can compare faces by comparing these numbers. You kind of extract the mathematical fingerprint of everybody's face." The technology, he added, was developed over the past year in cooperation with universities including the University of California at Berkeley, and the University of Bonn in Germany.

"Face recognition is not new," he said, citing the example of security systems that grant entry, say, to a bank.

But a Web search engine faces special challenges. "The people don't know you want to recognise them, they're non-cooperative. Also, internet resolution is much lower. And third, you're dealing with hundreds of millions of images."