A Single Camera Motion Capture System dedicated to Gestures Imitation ∗

Abstract — This article describes a method to track 3D articulated structures from a monocular perspective image sequence using a particle filter. This structure is composed of a set of linked degenerated quadrics (cones) which are truncated by pairs of planes also modelled as degenerated quadrics. This set of truncated cones is connected by joints containing one or more degrees of freedom. The method is based upon the estimation of the contours of the structure’s silhouette projected on the image plane, to validate each of the particles which correspond to proposed configurations. This validation is performed using a criterion that combines a measure based on the contours, a measure of similarity between the colour distribution around a point on the structure and a reference distribution, and other criteria that reinforce the overall cost function. The results show the feasibility of the approach when using a single camera to track a 3D model containing eight degrees of freedom. Index Terms — 3D tracking, monocular vision, articulated structures, particle filters, gesture imitation I