Surveillance in public places can be considered an invasion of privacy, but it could also be used to find lost children, track down persons of interest or provide data to retailers.

Speaking at the annual Safe Cities Conference in Brisbane on Wednesday, Advanced Surveillance Group director Professor Brian Lovell said surveillance was very Big Brother, and unashamedly so.

Facial recognition technology has also been used in retail to monitor who was looking at advertising billboards in New York's Times Square and in Chicago, as well as monitoring the ages and genders of those entering retail stores.

Professor Lovell said the 2005 London bombings led former prime minister John Howard to recognise the value of surveillance.

"He started up some programs for research and I got an inaugural funding from that and got some follow-up funding ... that's how I got into this area," Professor Lovell said.