def available_dt_filters():
    """
    Iterable of available wavelet filters compatible with the dual-tree complex wavelet transform.

    Returns
    -------
    wavelets : iterable
        List of sorted string names. The wavelet numerical values can be 
        retrieved from the :func:`dualtree_wavelet` function.
    """
    return sorted(['qshift1', 'qshift2', 'qshift3', 'qshift4', 'qshift5',
        'qshift6'])
