'Open the first image in a TIFF file'

def _open(self):

    ifh = self.fp.read(8)
    self.tag_v2 = ImageFileDirectory_v2(ifh)
    self.tag = self.ifd = None
    self.__first = self.__next = self.tag_v2.next
    self.__frame = (-1)
    self.__fp = self.fp
    self._frame_pos = []
    self._n_frames = None
    self._is_animated = None
    if DEBUG:
        print('***    TiffImageFile._open    ***')
        print('-    __first:', self.__first)
        print('-    ifh:    ', ifh)
    self._seek(0)
