Fast Time-Space Tracking of Smoothly Moving Fine Structures in Image Sequences

We address the problem of temporal tracking fine pointlike and filamentary structures exhibiting smooth motions in image sequences. By taking these specific restrictions into account, we put forward an original tracking method based on the search of integral lines in time-space structure tensor fields. The method is simple and very efficient regarding computation time and tracking precision, which allows a sub-pixel accuracy in both spatial and temporal domains. We suggest a numerical implementation of the algorithm which is based on a modified constrained Runge-Kutta scheme. Its performance and potential applicability are illustrated through two real cases : the tracking of internal linear features in composite materials observed with X-rays and the tracking of granular-shaped objects moving in a gas flow.