import tensorflow as tf

  image_width = static_shape.get_width(image_shape)
  if image_height is None or image_width is None:
    shape_assert = tf.Assert(
        tf.logical_and(tf.greater_equal(tf.shape(image_tensor)[1], min_dim),
                       tf.greater_equal(tf.shape(image_tensor)[2], min_dim)),
        ['image size must be >= {} in both height and width.'.format(min_dim)])
    with tf.control_dependencies([shape_assert]):
      return tf.identity(image_tensor)
