docs: def _original_frame(self, x, y):
          """
          Return x/y in the original frame, based on a guess as much as anything.
          :param x: x pixel coordinate
          :type x: float
          :param y: y pixel coordinate
          :type y: float
          :return: x,y
          :rtype: float, float
          """
          if self._inverted:
              return self.obs.naxis1 - x, self.obs.naxis2 - y
          return x, y