message: Added usage example on tf.image.rgb_to_grayscale and tf.image.rgb_to_yiq
diff: @@ -1874,6 +1874,14 @@ def rgb_to_grayscale(images, name=None):
  Returns:
  The converted grayscale image(s).
  +
  + Usage Example:
  + ```python
  + >>> import tensorflow as tf
  + >>> x = tf.random.normal(shape=(256, 256, 3))
  + >>> tf.image.rgb_to_grayscale(x)
  + ```
  +
  """
  with ops.name_scope(name, 'rgb_to_grayscale', [images]) as name:
  images = ops.convert_to_tensor(images, name='images')
  @@ -2920,6 +2928,14 @@ def rgb_to_yiq(images):
  Returns:
  images: tensor with the same shape as `images`.
  +
  + Usage Example:
  + ```python
  + >>> import tensorflow as tf
  + >>> x = tf.random.normal(shape=(256, 256, 3))
  + >>> tf.image.rgb_to_yiq(x)
  + ```
  +
  """
  images = ops.convert_to_tensor(images, name='images')
  kernel = ops.convert_to_tensor(
  