def bbox(self):
        """
        The bounding box ``(ymin, xmin, ymax, xmax)`` of the minimal
        rectangular region containing the source segment.
        """

        # (stop - 1) to return the max pixel location, not the slice index
        return (self._slice[0].start, self._slice[1].start,
                self._slice[0].stop - 1, self._slice[1].stop - 1) * u.pix