German researchers have come up with a method of identifying a user by looking at their shoes.
According to Technology Review, the Hasso Plattner Institute in Potsdam, Germany, worked out that when several people use a single touch screen they can be driven nuts by authentication problems.
So they created a project, called Bootstrapper, which uses cameras below a table to identify different users by their shoes. Each set of shoes is linked to an account that keeps track of a person's actions and preferences.
Bootstrapper uses cheap and cheerful hardware and means that a person's hands are free to interact with the surface. User preferences can be stored according to their shoes, so when someone leaves the table, it's easier to resume an activity when they return.
Until now those who want to share large touch screen computers have needed sensors to chairs, or using cameras positioned above a table. One approach required users to wear a ring that emits infrared which was then tracked by the touch-table's cameras.
Bootstrapper collects video of shoes using cameras positioned below the surface of the table. It then extracts information about the texture of the shoe and links it with actions on the touch screen that correspond to hands and arms aligned with the shoes.
Patrick Baudisch, professor of computer science at the Hasso Plattner Institute, said that shoes are ideal to track because they offer distinct features such as colours, seams, laces, logos, or stripes. They also typically maintain contact with the ground, unlike hands on a tabletop or bottoms in chairs, so they're easier to track.
Bootstrapper is not intended as a security feature because people can spoof the system by buying the same shoes as someone else. But it is designed so that the computer can identify who is doing inputting what.