docs: def bounding_box(alpha, threshold=0.1):
      """
      Returns a bounding box of the support.
  
      Parameters
      ----------
      alpha : ndarray, ndim=2
          Any one-channel image where the background has zero or low intensity.
      threshold : float
          The threshold that divides background from foreground.
  
      Returns
      -------
      bounding_box : (top, left, bottom, right)
          The bounding box describing the smallest rectangle containing the
          foreground object, as defined by the threshold.
      """
      assert alpha.ndim == 2
  
      # Take the bounding box of the support, with a certain threshold.
      supp_axs = [alpha.max(axis=1-i) for i in range(2)]
  
      # Check first and last value of that threshold
      bb = [np.where(supp_axs[i] > threshold)[0][[0, -1]] for i in range(2)]
  
      return (bb[0][0], bb[1][0], bb[0][1], bb[1][1])