BOUNDARYGRAPH Get boundary of image as a graph.

   [NODES, EDGES] = boundaryGraph(IMG)         (2D)
   [NODES, EDGES, FACES] = boundaryGraph(IMG)  (3D)
   Create a graph on the boundary of binary image IMG. Each pixel is
   considered as a unit square (or cube), centered on integer coordinates. 
   Boundary of the shape is selected as a graph.

   Result is a set of nodes with (x,y) or (x,y,z) coordinates, a set of
   edges linking two neighbour nodes, and in 3D also a set of square
   faces, containing reference to each 4-tuple of nodes.
   
   The resulting shell is open if the binary structure touches edges of
   image.

   See also :
   imPatch, drawMesh

Package: matgeom