code: def ioa(masks1, masks2):
      """Computes pairwise intersection-over-area between box collections.
  
      Intersection-over-area (ioa) between two masks, mask1 and mask2 is defined as
      their intersection area over mask2's area. Note that ioa is not symmetric,
      that is, IOA(mask1, mask2) != IOA(mask2, mask1).
  
      Args:
        masks1: a numpy array with shape [N, height, width] holding N masks. Masks
          values are of type np.uint8 and values are in {0,1}.
        masks2: a numpy array with shape [M, height, width] holding N masks. Masks
          values are of type np.uint8 and values are in {0,1}.
  
      Returns:
        a numpy array with shape [N, M] representing pairwise ioa scores.
  
      Raises:
        ValueError: If masks1 and masks2 are not of type np.uint8.
      """
      if masks1.dtype != np.uint8 or masks2.dtype != np.uint8:
          raise ValueError(
              "masks1 and masks2 should be of type np.uint8"
          )
      intersect = intersection(masks1, masks2)
      areas = np.expand_dims(area(masks2), axis=0)
      return intersect / (areas + EPSILON)
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: ioa(masks1, masks2) and returns: unknown