This module implements the fundamental equation of movie analysis~\cite{alvarez.guichard.ea:axioms},
\begin{equation}
\frac{\partial u}{\partial t} = |\nabla u| \,(t curv(u))^{\frac{1}{3}} \left(\left[curv(u) accel(u) |t curv(u)|^{-\frac{1}{3}} \right] ^+ \right)^q.
\end{equation}
The parameters are~:
\begin{itemize}
\item time (-t option)~: time discretization step.
\item n\_iter (-n option)~: number of iterations processed.
\item ppower (-r option)~: power of accel in (1), i.e. $q$.
\item pMAXvit (-q option)~: maximal allowed velocity (for accel estimation).
\item pMINvit (-w option)~: minimal allowed velocity.
\item pfmxa (-a option)~: maximal allowed acceleration (for accel estimation).
\end{itemize}

Note that the first and last images of the input movie $u$ are not processed, because the acceleration is not defined on the temporal frontier of a movie. 
The complexity of the algorithm is $O(|u|.n_{iter}.(2*fmxa+1)^2.\Delta ^2)$, where $\Delta =MAXvit-MINvit+1$.
Processing one iteration on a 256x256x10 movie with default velocity parameters and $fmxa=0$ takes 30 minutes on a Sparc 10. For a description
of the algorithm used to compute the curvature, see the module \verb+amss+.
