def _setup_smoothing_sigmas(scale: int=1):
    """Setup the smoothing sigmas array for registration"""
    smoothing_sigmas = [0]
    if scale > 1:
        for idx in range(1, scale, 1):
            smoothing_sigmas.insert(0, 2 ** (idx - 1))
        print('No smoothing sigmas given, setting to {}'.format(
            smoothing_sigmas))
    return smoothing_sigmas
