def METHOD_NAME(geom, image_mask) -> MorphologyContainer:
    """
    Compute image morphology parameters
    Parameters
    ----------
    geom: ctapipe.instrument.camera.CameraGeometry
        camera description
    image_mask: np.ndarray(bool)
       image of pixels surviving cleaning (True=survives)
    Returns
    -------
    MorphologyContainer: parameters related to the morphology
    """
    n_islands, island_labels = number_of_islands(geom=geom, mask=image_mask)
    n_small, n_medium, n_large = number_of_island_sizes(island_labels)
    return MorphologyContainer(
        n_pixels=np.count_nonzero(image_mask),
        n_islands=n_islands,
        n_small_islands=n_small,
        n_medium_islands=n_medium,
        n_large_islands=n_large,
    )