A system that instantly searches images stored on a database and compares them with those taken by a security camera is being piloted at an electronics store in Chiyoda Ward, Tokyo.

The system will be used to combat crime by recognizing individuals whose images have been captured previously, as well as by analyzing customer buying patterns.

Until now, searching for a specific person required someone to look at every image filmed. However, the new system developed by Hitachi, Ltd., is capable of dramatically narrowing down likely matches from a list of about 10,000 faces in only a second once a specific face from the camera is selected.

The system works by storing facial features as data that can be easily compared with images taken from security cameras. The new system is said to be straightforward to use, with an ordinary personal computer able to handle images taken by about 20 security cameras.

Recognition accuracy of the system is said to be about 90 percent, and the company plans to use the pilot to see how accuracy is affected by altering conditions of the camera, such as changing the position and location, as well as the brightness of the surroundings.

"We also need to consider how we can protect individuals' privacy before it's rolled out widely," Shigeru Hagiya, head engineer of Hitachi, said.