def rescale(low_res, high_res):
    """
    Function that rescales the pixel values of high_res to the -1 to 1 range.
    For use with the generator output tanh function.
    Args:
        low_res: The tf tensor of the low res image.
        high_res: The tf tensor of the high res image.
    Returns:
        low_res: The tf tensor of the low res image, rescaled.
        high_res: The tf tensor of the high res image, rescaled.
    """
    high_res = high_res * 2.0 - 1.0

    return low_res, high_res