How to find the neighbors of a 150x150 matrix?

I have a 150x150 matrix which represents grains of a of an engineering material. I wanted help with a code on how to find the neighbors of these grains and use it draw a node and vertex graph.

Answer 1

[Matt J]

You can use bwboundaries.

[Godfred]

Thank you

[Matt J]

You're welcome, but if that answers your question, please Accept-click the answer.