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<h1 align="center">TIFFReadDirectory</h1>
<a href="#NAME">NAME</a><br>
<a href="#SYNOPSIS">SYNOPSIS</a><br>
<a href="#DESCRIPTION">DESCRIPTION</a><br>
<a href="#NOTES">NOTES</a><br>
<a href="#RETURN VALUES">RETURN VALUES</a><br>
<a href="#DIAGNOSTICS">DIAGNOSTICS</a><br>
<a href="#SEE ALSO">SEE ALSO</a><br>
<hr>
<h2>NAME
<a name="NAME"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">TIFFReadDirectory
− get the contents of the next directory in an open
<small>TIFF</small> file</p>
<h2>SYNOPSIS
<a name="SYNOPSIS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>#include
<tiffio.h></b></p>
<p style="margin-left:11%; margin-top: 1em"><b>int
TIFFReadDirectory(TIFF *</b><i>tif</i><b>)</b></p>
<h2>DESCRIPTION
<a name="DESCRIPTION"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">Read the next
directory in the specified file and make it the current
directory. Applications only need to call
<i>TIFFReadDirectory</i> to read multiple subfiles in a
single <small>TIFF</small> file— the first directory
in a file is automatically read when <i>TIFFOpen</i> is
called.</p>
<h2>NOTES
<a name="NOTES"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">If the library
is compiled with <small>STRIPCHOP_SUPPORT</small> enabled,
then images that have a single uncompressed strip or tile of
data are automatically treated as if they were made up of
multiple strips or tiles of approximately 8 kilobytes each.
This operation is done only in-memory; it does not alter the
contents of the file. However, the construction of the
‘‘chopped strips’’ is visible to the
application through the number of strips [tiles] returned by
<i>TIFFNumberOfStrips</i> [<i>TIFFNumberOfTiles</i>].</p>
<h2>RETURN VALUES
<a name="RETURN VALUES"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">If the next
directory was successfully read, 1 is returned. Otherwise, 0
is returned if an error was encountered, or if there are no
more directories to be read.</p>
<h2>DIAGNOSTICS
<a name="DIAGNOSTICS"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em">All error
messages are directed to the <i>TIFFError</i>(3TIFF)
routine. All warning messages are directed to the
<i>TIFFWarning</i>(3TIFF) routine.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Seek error
accessing TIFF directory</b>. An error occurred while
positioning to the location of the directory.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Wrong data
type %d for field "%s"</b>. The tag entry in the
directory had an incorrect data type. For example, an
<i>ImageDescription</i> tag with a <small>SHORT</small> data
type.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "%s" field</b>. The
specified tag is required to be present by the
<small>TIFF</small> 5.0 specification, but is missing. The
directory is (usually) unusable.</p>
<p style="margin-left:11%; margin-top: 1em"><b>%s: Rational
with zero denominator</b>. A directory tag has a
<small>RATIONAL</small> value whose denominator is zero.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Incorrect
count %d for field "%s" (%lu, expecting %lu); tag
ignored</b>. The specified tag’s count field is bad.
For example, a count other than 1 for a <i>SubFileType</i>
tag.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Cannot
handle different per-sample values for field
"%s"</b>. The tag has <i>SamplesPerPixel</i>
values and they are not all the same; e.g.
<i>BitsPerSample</i>. The library is unable to handle images
of this sort.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Count
mismatch for field "%s"; expecting %d, got %d</b>.
The count field in a tag does not agree with the number
expected by the library. This should never happen, so if it
does, the library refuses to read the directory.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Invalid TIFF
directory; tags are not sorted in ascending order</b>. The
directory tags are not properly sorted as specified in the
<small>TIFF</small> 5.0 specification. This error is not
fatal.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Ignoring
unknown field with tag %d (0x%x)</b>. An unknown tag was
encountered in the directory; the library ignores all such
tags.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "ImageLength"
field</b>. The image violates the specification by not
having a necessary field. There is no way for the library to
recover from this error.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "PlanarConfig"
field</b>. The image violates the specification by not
having a necessary field. There is no way for the library to
recover from this error.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "StripOffsets"
field</b>. The image has multiple strips, but is missing the
tag that specifies the file offset to each strip of data.
There is no way for the library to recover from this
error.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "TileOffsets"
field</b>. The image has multiple tiles, but is missing the
tag that specifies the file offset to each tile of data.
There is no way for the library to recover from this
error.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "StripByteCounts"
field</b>. The image has multiple strips, but is missing the
tag that specifies the size of each strip of data. There is
no way for the library to recover from this error.</p>
<p style="margin-left:11%; margin-top: 1em"><b>TIFF
directory is missing required "StripByteCounts"
field, calculating from imagelength</b>. The image violates
the specification by not having a necessary field. However,
when the image is comprised of only one strip or tile, the
library will estimate the missing value based on the file
size.</p>
<p style="margin-left:11%; margin-top: 1em"><b>Bogus
"StripByteCounts" field, ignoring and calculating
from imagelength</b>. Certain vendors violate the
specification by writing zero for the StripByteCounts tag
when they want to leave the value unspecified. If the image
has a single strip, the library will estimate the missing
value based on the file size.</p>
<h2>SEE ALSO
<a name="SEE ALSO"></a>
</h2>
<p style="margin-left:11%; margin-top: 1em"><b>TIFFOpen</b>(3TIFF),
<b>TIFFWriteDirectory</b>(3TIFF),
<b>TIFFSetDirectory</b>(3TIFF),
<b>TIFFSetSubDirectory</b>(3TIFF), <b>libtiff</b>(3TIFF)</p>
<p style="margin-left:11%; margin-top: 1em">Libtiff library
home page: <b>http://www.simplesystems.org/libtiff/</b></p>
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