Fix mask for multi object persam (persam_f_multi_obj.py)

[anikaweinmann]

The mask in persam_f_multi_obj.py does not show all objects. E.g. buildings detection:

• 5 objects are detected
  
• but only one is shown in saved mask
  

This MR fixes this:

[pipilatiao]

Hello, I apologize for the long message and for bothering you. I’m a beginner in this field, and I would like to know about the multi-object segmentation script in persam. Currently, I can only segment a single object. How did you manage to segment multiple objects (like the multiple houses in your remote sensing work)? Which parts of the code would need modification? I would greatly appreciate any advice you could offer.

[anikaweinmann]

Hello, I apologize for the long message and for bothering you. I’m a beginner in this field, and I would like to know about the multi-object segmentation script in persam. Currently, I can only segment a single object. How did you manage to segment multiple objects (like the multiple houses in your remote sensing work)? Which parts of the code would need modification? I would greatly appreciate any advice you could offer.

The change I made is this. If you change it then multiple objects can be extracted with persam.