The Metropolitan Police Department (MPD) of Tokyo and police forces from four other prefectures have now deployed a facial recognition system where a high-definition video camera can instantly recognize any particular person in a crowd, this according to media reports.

In the age of high-definition video, it is admittedly easier to spot faces in a crowd and this particular system has been adopted for use in anti-organized crime investigations. The main problem is that there is no clear-cut mechanism for monitoring the new system’s use and the Japanese public fear that it can be used by the police to infringe on private citizens’ privacy.

The new equipment for the police is called a mobile facial image detection and verification system and it uses a notebook computer loaded with a database of faces. Pictures taken by the high-definition video camera are cross-checked by the software with images in the database. The system is programmed to alert the operator if a face matches a database image.

According to the specifications of the system that was made public through a freedom-of-information request, the software is capable of simultaneously processing the faces of more than 10 people, detecting even those with dark eyewear or masks. The software is able to crosscheck at least 100,000 cases in a second. […]