iou.py

import tensorflow as tf

anchor = \
[
 [0.0, 0.0, 100.0, 100.0],
 [100.0, 100.0, 160.0, 200.0],
 [100.0, 0.0, 200.0, 100.0]
]

ground_truth = \
[
 [0.0, 0.0, 100.0, 100.0],
 [100.0, 100.0, 180.0, 180.0]
]

with tf.Session() as sess:
  left1, top1, right1, bottom1 = tf.split(
      value=anchor, num_or_size_splits=4, axis=1)
  left2, top2, right2, bottom2 = tf.split(
      value=ground_truth, num_or_size_splits=4, axis=1)
  
  # Find the max values of top between ground truth and anchor boxes
  max_top = tf.maximum(top2, tf.transpose(top1))
  # Find the min values of bottom between ground truth and anchor boxes
  min_bottom = tf.minimum(bottom2, tf.transpose(bottom1))
  intersect_heights = tf.maximum(0.0, min_bottom - max_top)

  # Find the height of the intersection between ground truth and anchor boxes
  max_left = tf.maximum(left2, tf.transpose(left1))
  # Find the max values of left between ground truth and anchor boxes
  min_right = tf.minimum(right2, tf.transpose(right1))
  intersect_widths = tf.maximum(0.0, min_right - max_left)
  
  area_of_intersect = intersect_heights * intersect_widths
  
  #AREA
  area1 = (bottom1 - top1) * (right1 - left1)
  area1 = tf.squeeze(area1, 1)
  
  area2 = (bottom2 - top2) * (right2 - left2)
  area2 = tf.squeeze(area2, 1)
  
  area1 = tf.expand_dims(area1, 0)
  area2 = tf.expand_dims(area2, 1)

  union = area1 + area2 - area_of_intersect

  isEqualZero = tf.equal(area_of_intersect, 0.0)
  iou = tf.where(
      isEqualZero,
      tf.zeros_like(area_of_intersect),
      tf.truediv(area_of_intersect, union)
  )
  print(iou.eval())