ion
   and replicative expansion).  See morphseq.c.

   The structuring element is represented by a simple Sel data structure
   defined in morph.h.  We provide (at least) seven ways to generate
   Sels in sel1.c, and several simple methods to generate hit-miss
   Sels for pattern finding in selgen.c.

   In use, the most common morphological Sels are separable bricks,
   of dimension n x m (where either n or m, but not both, is commonly 1).
   Accordingly, we provide separable morphological operations on b