code: def _sim_fill(r1, r2, imsize):
      
      bbsize = (
          (max(r1["max_x"], r2["max_x"]) - min(r1["min_x"], r2["min_x"]))
          * (max(r1["max_y"], r2["max_y"]) - min(r1["min_y"], r2["min_y"]))
      )
      return 1.0 - (bbsize - r1["size"] - r2["size"]) / imsize
docs: calculate the fill similarity over the image