A Doubly Adaptive Algorithm for Edge Detection in 3D Images

Algorithm 1

(i) Input of data: , , , , , , , , , .

(ii) Initialize the node 0:

  , ;  ; ; ; ;

(iii) Split the node 0 into four discrete rectangles and initialize the nodes 1, 2, 3 and 4.

  , , , , , are obtained according to the method described in Section 2.2.4.

  for   

(iv) Complete the members of the node 0,

  for ;

(v) Initialize the current node and the counter of nodes ; ;

(vi) while ()

   ; (right child of the current node)

    (the split criterion has not been applied to the current node)

       (the current node satisfies the split criterion)

        Split into four discrete rectangles,

        compute , , , ,

        , by the method described in Section 2.2.4.

        ;

        else ;

        for (

        ;

        ;

        ; (new current node)

        ;

      else (the current node does not satisfy the split criterion)

        ;

        for ;

        ;

        ;

  else (the split criterion has been applied to the current node)

     (all the childs have been visited. Go to the parent)

      ;

      ;

    else (there exist childs not visited)

       for if ;

       ;

       ;