Pieter,
The diagram came up deformed in the previous mail,
hope this one looks better:
/------\ +-----+ /------\ +-----+ /------------\ +----+
|Reader|->|Image|->| Cast |->|Image|->|Deformable3D|->|Mesh|
\------/ |float| |Filter| |short| \------------/ | |
+-----+ \------/ +-----+ +----+
Luis