This module implements the AMSS 
\index{affine!scale space}
model as a stack filter (osher-Sethian 
scheme)\index{filter!stack}. It decomposes all level sets of the input image,
applies the module \verb+amss+ to the characteristic functions of
these level sets\index{level set},
binarizes the result to obtain a new set, an then
reconstructs the output image from these new level sets. 
The (algorithm obtained this way commutes with any contrast change
$u\mapsto g(u)$, where $g$ is an increasing scalar function.
\index{contrast!invariance}

