Target Tracking Using Multiple Patches and Weighted Vector Median Filters

This paper presents an approach for object tracking based on multiple disjoint patches. Initially, the target is subdivided into a set of rectangular patches, and each patch is represented parametrically by the mean vector and covariance matrix computed from a set of feature vectors that represent each pixel of the target. Each patch is tracked independently based on the Bhattacharyya distance, and the displacement of the whole template is obtained using a Weighted Vector Median Filter (WVMF), which reduces the influence of incoherently tracked patches. To smooth the obtained trajectory and also cope with short-term total occlusions, a predicted displacement vector based on the motion of the target in the previous frames is also used, and an updating scheme is applied to deal with appearance changes of the template. Experimental results indicate that the proposed scheme is robust to partial and short-time total occlusions, presenting a good compromise between accuracy and execution time when compared to other approaches.