A New Skeleton Feature Extraction Method for Terrain Model Using Profile Recognition and Morphological Simplification

Algorithm 5

Recognize the outbranches.

Input: Array 𝐴_𝑏 with branch points signs.

Output: Array 𝐴_𝑜 with out-branching points signs.

1. Let 𝑛 as the count of the adjacent branch points of

 the current point.

2. For each branch point 𝑝_𝑏 in 𝐴_𝑏, do:

 2.1 Set 𝑛=0;

 2.2 For each branch connected with 𝑝_𝑏, do:

   2.2.1 Find the end point 𝑝_𝑎 of each branch

     connected with 𝑝_𝑏, according to the

     direction coefficients of 𝑝_𝑏;

   2.2.2 If 𝑝_𝑎 is an end point that has not any

     direction coefficient, then go to 2.2;

     otherwise, if 𝑝_𝑎 is an out-branching

     point then set 𝑛=𝑛+1, and go to 2.2.

 2.3 If 𝑛 is equal to 1, denote 𝑝_𝑏 as out-branch

   point in 𝐴_𝑜.

3. Algorithm end.