Abstract

The motion of the human body can in itself be a useful human-machine interface, and computer vision can provide a method for tracking the body in an unobtrusive fashion. In this chapter, we describe a system capable of tracking the human arm in 3D using only a single camera and no special markers on the body. The real-time implementation has a manipulation resolution of 1 cm and has been tested as a novel 3D input device.

Introduction and Motivation

Visual estimation and tracking of the motion and gestures of the human body is an interesting and exciting computational problem for two reasons: (a) from the engineering standpoint, a non-invasive machine that could track body motion would be invaluable in facilitating most human-machine interactions and, (b) it is an important scientific problem in its own right. Observing the human body in motion is key to a large number of activities and applications:

Security – In museums, factories and other locations that are either dangerous or sensitive it is crucial to detect the presence of humans and monitor/classify their behavior based upon their gait and gestures.

Animation – The entertainment industry makes increasing use of actor-to-cartoon animation where the motion of cartoon figures and rendered models is obtained by tracking the motion of a real person.

Virtual reality – The motion of the user of a virtual reality system is necessary to adjust display parameters and animations.