This module take a single curve (Dlist) as input and computes its evolution
by Affine Scale Space 
\index{affine!scale space}
(see \verb+gass+ module) at $N=niter$ scale steps
$S,2S,...,NS$ ($S=scale$). The \verb+-e+, \verb+-s+ and \verb+-n+ parameters
are given to the \verb+gass+ module. 
