Sputnik Tracker: Having a Companion Improves Robustness of the Tracker

Tracked objects rarely move alone. They are often temporarily accompanied by other objects undergoing similar motion. We propose a novel tracking algorithm called Sputnik (Sputnik, pronounced sput-nik in Russian, was the first Earth-orbiting satellite launched in 1957. According to Merriam-Webster dictionary, the English translation of the Russian word sputnik is a travelling companion.) Tracker. It is capable of identifying which image regions move coherently with the tracked object. This information is used to stabilize tracking in the presence of occlusions or fluctuations in the appearance of the tracked object, without the need to model its dynamics. In addition, Sputnik Tracker is based on a novel template tracker integrating foreground and background appearance cues. The time varying shape of the target is also estimated in each video frame, together with the target position. The time varying shape is used as another cue when estimating the target position in the next frame.