def _shrink_level_to_arg(level):
    """Converts level to ratio by which we shrink the image content."""
    if level == 0:
        return (1.0, )  # if level is zero, do not shrink the image
    # Maximum shrinking ratio is 2.9.
    level = 2. / (_MAX_LEVEL / level) + 0.9
    return (level, )
Converts level to ratio by which we shrink the image content.
ppdet/data/transform/autoaugment_utils.py