Identifying People by the Way They Walk

ByABC News
January 3, 2003, 3:37 PM

Oct. 25 -- Michael Jackson has his infamous moonwalk, John Wayne had that memorable cowboy swagger, and Mae West was noted for her remarkable sashay.

But according to scientists, one day it may be possible to recognize anyone by the way they walk, or their gait.

Several universities have been working with the Defense Advanced Research Projects Agency to develop gait recognition as another viable biometric tool.

It's hoped that if gaits are as unique as say voice patterns or fingerprints, advanced surveillance systems could identify and track people by the way they walk through sensitive areas such as airports or around government buildings.

From the Way That You Walk

To study gait, most of the various research projects use video cameras and computers to capture and create so-called "movement signatures."

When a person walks, body parts the legs, knee joints, arms, elbows, and so on create a particular repeating pattern as they each move through space. The video camera captures these points of movements and sends them to a computer for analysis. The computer notes the movements and establishes mathematical relationships for each point to create the "signature" patterns it needs to recognize for each individual.

Researchers at the Massachusetts Institute of Technology and Carnegie Mellon University have been testing such gait recognition as part of the DARPA project with impressive results so far.

These experimental setups use signatures captured from volunteers walking on treadmills. When the systems capture a test subject walking in front of a different background, researchers report the machines make a correct match 90 percent to 95 percent of the time.

But there are still difficulties in such systems.

The biggest challenge: Since actual video images must be captured and analyzed, such gait recognition systems could only be used in well-lit areas. What's more, such systems would have a very difficult time picking up distinct movement points of a person far away and wearing bulky, concealing clothing such as a heavy coat.