Multi-Object Real-Time Tracking Method Based on Multi-View Near-Infrared Vision

Near-infrared optical tracking systems can restore the movement of tracked objects in real time based on the markers attached to the tracked objects. This technology has now been widely adopted across numerous fields. This paper proposed a real-time tracking method for muli-objects that is robust to target loss. First, based on the imaging characteristics of reflective marker balls in near-infrared cameras, the geometric center of each marker was extracted using the grayscale centroid method. Then, the SORT algorithm was used as a multi-objetcs tracking method in each monocular camera to match each marker point between frames. The matching relationship of the image points of the markers in each camera was determined based on the principle of epipolar geometry combined with the weighted bipartite graph matching method, and the three-dimensional spatial coordinates of each tracked marker were calculated in real time based on the triangulation method. Next, the markers were grouped based on their spatial relationships during motion to identify markers belonging to the same object. Spatial feature vectors were established for tracked objects using the Euclidean distances between markers within the same group, serving as matching references for reappearing lost objects. When a fully lost object reproduced , re-matching is performed using cosine distance of these feature vectors. Finally, the proposed algorithm was experimentally verified. The experiment shows that the tracking accuracy of the proposed algorithm can reach about 0.5 mm at a speed of not less than 60 f/s. In addition, the lost reproduced objects and markers can be correctly re-matched.