Photos: Picking a face in the crowd

San Francisco start-up 3VR Security's technology breaks up the footage into key scenes and creates an index of searchable thumbnails. Once it has labeled a person, the software's facial-recognition engine will pull up other scenes featuring that individual or similar-looking people.

This screen capture shows the results of a search on 3VR employee Michael Pittman's face. It picked out the six times he passed cameras that day.

In traditional systems, security officers monitor ongoing activity through a bank of monitors. Under 3VR's system, only key scenes--when someone opens the front door, when people leave a conference room--are shown to the guard.

Each scene is delivered as a static image; when clicked, it delivers a few seconds of motion. These thumbnails are also presented on a single screen.