def _get_name(index, hdf5_data):
    """Retrieves the image file name from hdf5 data for a specific index.

    Args:
        index (int): Index of image.
        hdf5_data (obj): h5py file containing bounding box information.

    Returns:
        (str): Image file name.

    """
    ref = hdf5_data['/digitStruct/name'][index, 0]
    file_name = ''.join([chr(item) for item in hdf5_data[ref][:]])
    return file_name