def check_cgal_params(max_facet_distance, max_cell_circumradius, voxelsize):
    """Check CGAL mesher parameters.
    # https://github.com/nschloe/pygalmesh#volume-meshes-from-surface-meshes

    Parameters
    ----------
    max_facet_distance
    max_cell_circumradius

    voxelsize : float
        Image voxel size.

    Returns
    -------
    max_facet_distance : float
    max_cell_circumradius : float
    """

    if len(voxelsize) > 1:
        voxelsize = voxelsize[0]

    if max_facet_distance is None:
        max_facet_distance = 1 * voxelsize

    if max_cell_circumradius is None:
        max_cell_circumradius = 5 * voxelsize

    return max_facet_distance, max_cell_circumradius