 content of the
    image data.
    Images in a file are usually related but they do not need to be; it
    is perfectly alright to store a color image together with a black and
    white image.
    Note however that while images may be related their directories are
    not.
    That is, each directory stands on its own; their is no need to read
    an unrelated directory in order to properly interpret the contents
    of an image.
  </p>
  <p>
    <tt>libtiff</tt> provides several routines for reading and 