How to get the coordinates of wall in a floorplan image

I am a beginner in the matlab. I need your help.

I have a floorplan image in which objects will be there. I am able to find the coordinates of objects in the image. But I need the wall coordinates also. I want the coordinates of walls of each room. Can somebody help me please?

Iam here attaching the code. classify_code_testing is the code which I use for object identification and signature_find_t is a function which is used by classify_code_testing.