title: how to change the shape of the image tensor? is it doable?
body: <p>this is my code</p>
  
  <pre><code>with tf.Session(config=tf_config) as sess:
      image_tensor = sess.graph.get_tensor_by_name('image_tensor:0')
  
      detection_boxes = sess.graph.get_tensor_by_name('detection_boxes:0')
      detection_scores = sess.graph.get_tensor_by_name('detection_scores:0')
      detection_classes = sess.graph.get_tensor_by_name('detection_classes:0')
      num_detections = sess.graph.get_tensor_by_name('num_detections:0')
  
      (boxes, scores, classes, num) = sess.run( [detection_boxes, detection_scores, detection_classes, num_detections],feed_dict={image_tensor: img[None, ...]})
  </code></pre>
  
  <p>i want to run the object detection in Gray frames to reduce the detection time,for that i need to change the shape of the image_tensor to (1,?,?,1), which has the shape of (1,?,?,3). is it possible to change the shape and am i asking the right question?</p>