[SciPy-User] Points with given distance to a polygon

[Thøger Emil Juul Thorsen]

I am working on a project where I am defining some regions of interest.
I have a 2200x2200 px 2D Array in which my ROI is defined by a polygon.
However, my data are smoothed by a gaussian kernel of width 300px, and I
would like to draw some lines indicating this inner 150px distance to
the borders of the ROI. I cannot come up with any way to do this, does
anyone have an idea?

Best regards; 

Emil