Real-Time Monocular Three-Dimensional Motion Tracking Using a Multithread Active Vision System

In this study, we developed a monocular stereo tracking system to be used as a marker-based, threedimensional (3-D) motion capture system. This system aims to localize dozens of markers on multiple moving objects in real time by switching five hundred different views in 1 s. The ultrafast mirror-drive active vision used in our catadioptric stereo tracking system can accelerate a series of operations for multithread gaze control with video shooting, computation, and actuation within 2 ms. By switching between five hundred different views in 1 s, with real-time video processing for marker extraction, our system can function as J virtual left and right pan-tilt tracking cameras, operating at 250/J fps to simultaneously capture and process J pairs of 512 × 512 stereo images with different views via the catadioptric mirror system. We conducted several real-time 3-D motion experiments to capture multiple fast-moving objects with markers. The results demonstrated the effectiveness of our monocular 3-D motion tracking system.