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A package of the Java Image I/O API dealing with reading and writing
metadata.
<p>
When reading an image, its per-stream and per-image metadata is made
available as an <code>IIOMetadata</code> object. The internals of
this object are specific to the plug-in that created it. Its contents
may be accessed in the form of an XML <code>Document</code>, which is
implemented as a tree of <code>IIOMetadataNode</code> objects.
<p>
When writing an image, its metadata may be set by defining or
modifying an <code>IIOMetadata</code> object. Such an object may be
obtained from an <code>ImageWriter</code> or
<code>ImageTranscoder</code> (from the
been obtained, its contents may be set of modified via a
<code>Document</code> consisting of <code>IIOMetadataNode</code>s.
The document format may optionally be described using an
<code>IIOMetadataFormat</code> object.
<p>
The format of the metadata contained in the XML <code>Document</code>
is identified by a string which appears as the root node of the tree
of <code>IIOMetadataNode</code> objects. This string contains a version
number, e.g. "javax_imageio_jpeg_image_1.0". Readers and writers may
support multiple versions of the same basic format and the Image I/O
API has methods that allow specifying which version to use by passing
object. In some cases, a more recent version may not be strictly
compatible with a program written expecting an older version (for
an example, see the Native Metadata Format section of the JPEG Metadata
Usage Notes below).
<p>
Plug-ins may choose to support a <A
HREF="doc-files/standard_metadata.html">standard (plug-in neutral)
format</A>. This format does not provide lossless encoding of
metadata, but allows a portion of the metadata to be accessed in a
generic manner.
<p>
Each of the standard plug-ins supports a so-called "native" metadata
format, which encodes its metadata losslessly:
<ul>
<li>
<A HREF="doc-files/gif_metadata.html">
GIF metadata
</A>
<li>
<A HREF="doc-files/jpeg_metadata.html">
JPEG metadata
</A>
<li>
<A HREF="doc-files/png_metadata.html">
PNG metadata
</A>
<li>
<A HREF="doc-files/bmp_metadata.html">
BMP metadata
</A>
<li>
<A HREF="doc-files/wbmp_metadata.html">
WBMP metadata
</A>
</ul>
@since 1.4
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