How to get a list of polygon coordinates from predictor_mask

[IAmOZRules]

Hi
I have trained a custom instance segmentation model which works great at giving the segmentation mask. What i am unable to get are the x,y coordinates of each point on the mask / segmentation boundry. I need to find the centroid of the mask as well as define the interconnection points between 2 object classes. Can someone pls help how i can go about it?

Thanks