how to find connectivity of line segments of the truss object in image

Hello, I would like to know the way to write matlab code to find the connectivity of line components after giving the truss image attached as an input. I will have 11 connectivities in the attached image. Thank you so much.

[Image Analyst]

They are all connected to each other. It's just one big network.

[Cedric]

For reference, this is the continuation of this other thread:

https://www.mathworks.com/matlabcentral/answers/359002-how-to-find-intersection-coordinates-of-node-points-in-truss-image?s_tid=prof_contriblnk

(PS: thank you for the boost ImageAnalyst!)

[Cedric]

If your trusses are always regular, you can compute the connectivity once you know the position of the nodes.

[Image Analyst]

I've been voting for you. We need you to get over 3000 to get full privileges, and you're so close.

The thing about this post, is that I'm not sure if it's really an image that they're wondering about, or an abstract network. And if an image, are the lines really that thick, or are they just one pixel wide and it's just blown up so we can see it better. Because the problem is when you erode/skeletonize thick things, you don't always get crossings and connections like you think you should because a fat crossing may skeletonize down to two "Y" crossings instead of a single "X" crossing like you would with single pixel wide lines.

[Cedric]

Thank you, I had full privilege already (I am an editor), but I appreciate the boost and the intention nonetheless! :-)

I am not sure about the image. Except for some noise, the horizontal and vertical bars seem to be always 3 pixels wide and the bars are exactly vertical or horizontal so it doesn't seem to be a scan (that could be slightly rotated).

I played a little with the image processing toolbox since you mentioned it, but .. I'll have to play more obviously ;-)

[Image Analyst]

You get a few more privileges at 3000: https://www.mathworks.com/matlabcentral/answers/help?s_tid=al_priv#reputation

ayemoe, please say where this image came from, and if you have any more, and will they all look exactly like this, or slightly or greatly different. Say whether this is a simulated image you created, and if your "actual" images will be something a lot different, like you have a robot that is picking up and moving boxes or items using a mobile camera. Sometimes algorithms that work for a perfect, simulated image don't work in the real world.

[Cedric]

Editors have the privileges given to 3000'ers actually (this was a way for TMW to give trustees who were under 3k the possibility to do all the forum maintenance). You've been above 3k for so long that you never needed this ;-)

[KSSV]

@ayemoe aung:

I guess you are solving and FEM problem. You should have plotted this truss with some coordinates, if you have those coordinates, you can get the nodal connectivity.

[ayemoe aung]

Thank you all.