code: def preprocess_frame(frame):
    
    # Normalize from [0.0, 1.0] -> [-0.5, 0.5]
    frame = common_layers.convert_rgb_to_real(frame)
    frame = frame - 0.5
    frame, _ = glow_ops.uniform_binning_correction(frame)
    return frame
docs: Preprocess frame.
  
    1. Converts [0, 255] to [-0.5, 0.5]
    2. Adds uniform noise.
  
    Args:
      frame: 3-D Tensor representing pixels.
    Returns:
      frame: 3-D Tensor with values in between [-0.5, 0.5]