code: def star(a, dtype=np.uint8):
      """Generates a star shaped footprint.
  
      Start has 8 vertices and is an overlap of square of size `2*a + 1`
      with its 45 degree rotated version.
      The slanted sides are 45 or 135 degrees to the horizontal axis.
  
      Parameters
      ----------
      a : int
          Parameter deciding the size of the star structural element. The side
          of the square array returned is `2*a + 1 + 2*floor(a / 2)`.
  
      Other Parameters
      ----------------
      dtype : data-type, optional
          The data type of the footprint.
  
      Returns
      -------
      footprint : ndarray
          The footprint where elements of the neighborhood are 1 and 0 otherwise.
  
      """
      from . import convex_hull_image
  
      if a == 1:
          bfilter = np.zeros((3, 3), dtype)
          bfilter[:] = 1
          return bfilter
  
      m = 2 * a + 1
      n = a // 2
      footprint_square = np.zeros((m + 2 * n, m + 2 * n))
      footprint_square[n : m + n, n : m + n] = 1
  
      c = (m + 2 * n - 1) // 2
      footprint_rotated = np.zeros((m + 2 * n, m + 2 * n))
      footprint_rotated[0, c] = footprint_rotated[-1, c] = 1
      footprint_rotated[c, 0] = footprint_rotated[c, -1] = 1
      footprint_rotated = convex_hull_image(footprint_rotated).astype(
          int
      )
  
      footprint = footprint_square + footprint_rotated
      footprint[footprint > 0] = 1
  
      return footprint.astype(dtype)
  
imports: import os
  from collections.abc import Sequence
  from numbers import Integral
  import numpy
  from ..None import draw
  from skimage import morphology
label_desc: Use image node_id 18 for calling a global function with example usage: star(a, dtype) and returns: footprint, bfilter