Remove the spurious edge of skeleton

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Recently, I've had an object to get it's skeleton,and then simplified the skeleton
but my problem is how to remove the edge of the skeleton for simplified the skeleton
here is my few steps:
First,I've got the skeleton from my object with bwmorph(ima,'skel',Inf)
here is the object which has been filled and the skeleton below:
filling the object:
the skeleton:
Second,for the skeleton, I've mark the branch points and end points
to mark the branch points and end points,I use bwmorph(skel, 'branchpoints') and
bwmorph(skel, 'endpoints');
here is the figure that I marked the points below:
the reds are branch points
the blues are end points
and the last step,
from the above figure, I want to remove the edges between branch point and end point (here I call the edge is spurious edge)
here is the resulting figure that I want
my problem is how can I remove the spurious edges
I've referenced this article
and the suggestions are set the threshold of the distance
but in my situation,the lengths of the spurious edges may have too long or too short...

Accepted Answer

Teja Muppirala
Teja Muppirala on 26 Sep 2013
I think there must be a more efficient way to do it, but this at least works. BWDISTGEODESIC starts at a given point, and then calculates the distance as you travel along the path. Start at a endpoint, start walking and find all pixels that are closer than the nearest branchpoint. Then remove those pixels.
skel= bwmorph(ima,'skel',Inf);
B = bwmorph(skel, 'branchpoints');
E = bwmorph(skel, 'endpoints');
[y,x] = find(E);
B_loc = find(B);
Dmask = false(size(skel));
for k = 1:numel(x)
D = bwdistgeodesic(skel,x(k),y(k));
distanceToBranchPt = min(D(B_loc));
Dmask(D < distanceToBranchPt) =true;
skelD = skel - Dmask;
hold all;
[y,x] = find(B); plot(x,y,'ro')
Lukas Pollmann
Lukas Pollmann on 6 May 2020
Dear Ms. Muppirala,
is there a way to use this code for 3d-sceleton images
Thank you a lot

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More Answers (2)

Liana Norazmi
Liana Norazmi on 7 May 2015
May i know how to remove the lines of this image
become like this?
  1 Comment
Karthick Jayaraman
Karthick Jayaraman on 29 Aug 2019
Is there any possibility yo do this in 3D logical array. I guess bwdistgeodesic doest work well in 3D. Any suggestions would be helful!?

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Hong on 30 Sep 2013
thanks to Teja Muppirala
this solution is really help me a lot
as your method, it could worked ^^
thanks to you again :")

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