Input: , the dip angle set corresponding to M, and the threshold angle
Output: The classification result set E of branch edges’ points
Initialize: Set the set E = NULL
Main steps of algorithm:
Define a matrix H and initialize H = null; and then compute all the elements of the matrix
  according to the equation
Calculate the position of the maximal value of H; assuming the maximum is at ( ), set = null,
   and , and then, compute the classification center
Update , and by all angles that satisfy the condition ) searched
  from the set ;
Repeat step until the angle set that satisfies the condition never change and place
  the junction points corresponding to the angle set into E;
Repeat steps , and until all the elements of H are null, and then return E.
Algorithm 1: Junction point classification algorithm.