def METHOD_NAME(radial_mode_image):
    pf, mode = radial_mode_image
    # Set DC component to zero.
    pf[:, 0] = 0
    # Check that all rays are close.
    assert abs(abs(pf) - abs(pf[0])).all() < 1e-4
    # Check that correct mode is most prominent.
    # Mode could be off by a pixel depending on resolution and mode.
    # Since all rays are close will just test one.
    mode_window = [mode - 1, mode, mode + 1]
    ray = 3
    assert np.argmax(abs(pf[ray])) in mode_window