Segment nodes in an image

Hi,

I am new in image processing and I am trying to learn it by myself using Matlab.

I have a question based on an image I found and attached:

-How can I segment the left image that each node (I am not sure I use the correct terminology) will get different color and number (right image), is it also possible get other information like area in pixels?

Thanks a lot

Answer 1

[Image Analyst]

You can skeletonize the image

bwSkel = bwmorph(binaryImage, 'skel', inf);

then find the branchpoints:

bp = bwmorph(bwSkel, 'branchpoints');

then remove them

binaryImage = bwSkel  & ~bp;

then label

labeledImage = bwlabel(binaryImage);

That's just off the top of my head - I have not tested it.

[hu]

Unfortunately it does not work

[Image Analyst]

OK, well, keep working at it because the algorithm should work but might need a tweak or two.

Answer 2

[Yannick]

See if this example helps: Measuring Angle of Intersection

Basically, it takes an image in which we want to measure the angle between two straight objects, identifies these objects, then finds the intersection point and the angle between them. Maybe you can use these ideas to find the intersection points / nodes and detect the branches in your image.

And this may help to find areas in pixels: BWAREA.