/p>
  <p>
    If the file already exists it is first truncated to zero length.
  </p>
  <table>
    <tr>
      <td valign=top><img src="images/warning.gif" width="40" height="40" alt=""></td>
      <td><i>Note that unlike the stdio library TIFF image files may not be
        opened for both reading and writing;
        there is no support for altering the contents of a TIFF file.</i></td>
    </tr>
  </table>
  <p>
    <tt>libtiff</tt> buffers much information associated with writing a
    valid TIFF image.