title: Tensorflow : IOU per class
body: <p>I'm trying to use deeplab for semantic segmentation. I'd like to calculate IOU per class(IOU for person only) instead of mean IOU.</p>
  <p>At L142 of
  <a href="https://github.com/tensorflow/models/blob/master/research/deeplab/eval.py" rel="nofollow noreferrer">https://github.com/tensorflow/models/blob/master/research/deeplab/eval.py</a>,
  I tried to get confusion matrix instead of mean IOU by</p>
  <pre><code>miou, cmat = tf.metrics.mean_iou(...)
  metric_map['cmat'] = cmat
  </code></pre>
  <p>but it did not work.
  I'd appreciate if someone suggest me how to get around.</p>