Wavelet domain processing for trajectory extraction

This work presents a novel approach to the extraction of trajectories in video. It has the advantage of simultaneously processing all spatiotemporal information, i.e. all the video frames, and thus overcoming disadvantages of local approaches. A projection of the video frames over time is used to create a frequency modulated signal, which is then processed with the continuous wavelet transform (CWT). The CWT´s power is concentrated around the prominent time-varying frequencies, which are proportional to the object trajectory. Consequently it can extract the time-varying motion trajectories, which can be used in future extensions to fully characterize the type motion taking place. This approach is robust to local measurement noise and occlusions, since it processes the available data in a global, integrated manner. Experiments take place with synthetic and real sequences demonstrate the capabilities of this approach.