code: def get_area_extent(self, size, offsets, factors, platform_height):
          
          nlines, ncols = size
          h = platform_height
  
          # count starts at 1
          cols = 1 - 0.5
          lines = 1 - 0.5
          ll_x, ll_y = self.get_xy_from_linecol(lines, cols, offsets, factors)
  
          cols += ncols
          lines += nlines
          ur_x, ur_y = self.get_xy_from_linecol(lines, cols, offsets, factors)
  
          return (np.deg2rad(ll_x) * h, np.deg2rad(ll_y) * h,
                  np.deg2rad(ur_x) * h, np.deg2rad(ur_y) * h)
docs: Get the area extent of the file.