code: def interactivity(self, min_val=None, max_val=None, qt_app=None):
          
          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  # .astype(np.int16)
          window_w = max_val - min_val  # .astype(np.int16)
  
          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_()
docs: Interactive seed setting with 3d seed editor