[Octave-bug-tracker] [bug #56141] [octave forge] (image) bwmorph option 'endpoints' not implemented

[Avinoam Kalma]

Follow-up Comment #12, bug #56141 (project octave):

I have tried to undestand the logic inside this function.
I took a 3x3 image, put 1 in the middle, 0/1 in other places, and see the
results of bwmorph. 
There are 256 such binary images:

0 neigbours to the center pixel (1 case) - the pixel remains:


A = [0, 0, 0; 0, 1, 0; 0, 0, 0];
bwmorph(A,'endpoints') = A;


1 neigbours (8 cases) - the pixel remains:


A = [1, 0, 0; 0, 1, 0; 0, 0, 0];
B = bwmorph(A,'endpoints') = A


2 neigbours (28 cases):

here it is a little bit complicated. If the two neigbours
are adjacent in the same row or column (4-neighbours)
the pixel remains, otherwise it is removed.

3 neigbours (56 cases):

if the 3 pixels are in the same row or column, or create
with the internal pixel a 2x2 block (e.g. [1 1 0; 1 1 0; 0 0 0]), the pixel
remains, otherwise it is removed.

7 neighbours (8 cases): the pixel remains

8 neighbours (1 case): the pixe is removed.

So, I figure out 1 + 8 + 28 + 56 + 8 + 1 = 102 out of 256.

left to  figure out:
4 neigbours - 70 cases
5 neigbours - 56 cases
6 neigbours - 28 cases 
 


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