...
      tool->UpdatePreview();
    }
    catch (...)
    {
      MITK_INFO << "In QmitkOtsuTool3DGUI catch";
      this->setCursor(Qt::ArrowCursor);
      QMessageBox *messageBox =
        new QMessageBox(QMessageBox::Critical,
                        nullptr,
                        "itkOtsuFilter error: image dimension must be in {2, 3} and no RGB images can be handled.");
      messageBox->exec();
      delete messageBox;
      return;
    }