def rowdf_into_imagerdd(df, final_num_partition=1):
    """
    Reshape a DataFrame of rows into a RDD containing the full image
    in one partition.

    Parameters
    ----------
    df : DataFrame
        DataFrame of image rows.
    final_num_partition : Int
        The final number of partitions. Must be one (default) unless you
        know what you are doing.

    Returns
    ----------
    imageRDD : RDD
        RDD containing the full image in one partition
    """
    return df.rdd.coalesce(final_num_partition).glom()