def interactivity(self, min_val=None, max_val=None, qt_app=None):
    """pass"""
    from .seed_editor_qt import QTSeedEditor
    from PyQt4.QtGui import QApplication
    if min_val is None:
        min_val = np.min(self.img)
    if max_val is None:
        max_val = np.max(self.img)
    window_c = (max_val + min_val) / 2
    window_w = max_val - min_val
    if qt_app is None:
        qt_app = QApplication(sys.argv)
    pyed = QTSeedEditor(self.img, modeFun=self.interactivity_loop, voxelSize=self.voxelsize, seeds=self.seeds, volume_unit=self.volume_unit)
    pyed.changeC(window_c)
    pyed.changeW(window_w)
    qt_app.exec_()