Synchronization of Video Sequences from Free-Moving Cameras

We present a new method for the synchronization of a pair of video sequences and the spatial registration of all the temporally corresponding frames. This is a mandatory step to perform a pixel wise comparison of a pair of videos. Several proposals for video matching can be found in the literature, with a variety of applications like object detection, visual sensor fusion, high dynamic range and action recognition. The main contribution of our method is that it is free from three common restrictions assumed in previous works. First, it does not impose any condition on the relative position of the two cameras, since they can move freely. Second, it does not assume a parametric temporal mapping relating the time stamps of the two videos, like a constant or linear time shift. Third, it does not rely on the complete trajectories of image features (points or lines) along time, something difficult to obtain automatically in general. We present our results in the context of the comparison of videos captured from a camera mounted on moving vehicles