message: Added code for preprocessing of YUB images before feeding yub_to_rgb
diff: @@ -3293,6 +3293,31 @@ def yuv_to_rgb(images):
  The output is only well defined if the Y value in images are in [0,1],
  U and V value are in [-0.5,0.5].
  + As per the above description, you need to scale your YUV images if their
  + pixel values are not in the required range. Below given example illustrates
  + preprocessing of each channel of images before feeding them to `yub_to_rgb`.
  +
  + ```python
  + yub_images = tf.random.uniform(shape=[100, 64, 64, 3], maxval=255)
  + last_dimension_axis = len(yub_images.shape) - 1
  + yub_tensor_images = tf.truediv(
  + tf.subtract(
  + yub_images,
  + tf.reduce_min(yub_images)
  + ),
  + tf.subtract(
  + tf.reduce_max(yub_images),
  + tf.reduce_min(yub_images)
  + )
  + )
  + y, u, v = tf.split(yub_tensor_images, 3, axis=last_dimension_axis)
  + target_uv_min, target_uv_max = -0.5, 0.5
  + u = u * (target_uv_max - target_uv_min) + target_uv_min
  + v = v * (target_uv_max - target_uv_min) + target_uv_min
  + preprocessed_yub_images = tf.concat([y, u, v], axis=last_dimension_axis)
  + rgb_tensor_images = tf.image.yuv_to_rgb(preprocessed_yub_images)
  + ```
  +
  Args:
  images: 2-D or higher rank. Image data to convert. Last dimension must be
  size 3.
  