def blend()

in autoaugment.py [0:0]


def blend(image1, image2, factor):
  """Blend image1 and image2 using 'factor'.
  Factor can be above 0.0.  A value of 0.0 means only image1 is used.
  A value of 1.0 means only image2 is used.  A value between 0.0 and
  1.0 means we linearly interpolate the pixel values between the two
  images.  A value greater than 1.0 "extrapolates" the difference
  between the two pixel values, and we clip the results to values
  between 0 and 255.
  Args:
    image1: An image Tensor of type uint8.
    image2: An image Tensor of type uint8.
    factor: A floating point value above 0.0.
  Returns:
    A blended image Tensor of type uint8.
  """
  if factor == 0.0:
    return tf.convert_to_tensor(image1)
  if factor == 1.0:
    return tf.convert_to_tensor(image2)

  image1 = tf.to_float(image1)
  image2 = tf.to_float(image2)

  difference = image2 - image1
  scaled = factor * difference

  # Do addition in float.
  temp = tf.to_float(image1) + scaled

  # Interpolate
  if factor > 0.0 and factor < 1.0:
    # Interpolation means we always stay within 0 and 255.
    return tf.cast(temp, tf.uint8)

  # Extrapolate:
  #
  # We need to clip and then cast.
  return tf.cast(tf.clip_by_value(temp, 0.0, 255.0), tf.uint8)