def _update_imageinfo(self):
        """
        calls get_imageinfo() if data image missing info
        """
        missing = self._missing_imageinfo()
        deferred = self.flags.get('defer_imageinfo')
        continuing = self.data.get('continue')

        if missing and not deferred and not continuing:
            self.get_imageinfo(show=False)
calls get_imageinfo() if data image missing info