Package javax.imageio.metadata
When reading an image, its per-stream and per-image metadata is made
available as an IIOMetadata
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 Document
, which is implemented as a tree of
IIOMetadataNode
objects.
When writing an image, its metadata may be set by defining or modifying an
IIOMetadata
object. Such an object may be obtained from an
ImageWriter
or ImageTranscoder
(from the
javax.imageio
package). Once such an object has been obtained, its
contents may be set of modified via a Document
consisting of
IIOMetadataNode
s. The document format may optionally be described
using an IIOMetadataFormat
object.
The format of the metadata contained in the XML Document
is
identified by a string which appears as the root node of the tree of
IIOMetadataNode
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 the string to the
method/constructor used to obtain an IIOMetadata
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).
Plug-ins may choose to support a standard (plug-in neutral) format . This format does not provide lossless encoding of metadata, but allows a portion of the metadata to be accessed in a generic manner.
Each of the standard plug-ins supports a so-called "native" metadata format, which encodes its metadata losslessly:
- Since:
- 1.4
-
ClassDescriptionAn
IIOInvalidTreeException
is thrown when an attempt by anIIOMetadata
object to parse a tree ofIIOMetadataNode
s fails.An abstract class to be extended by objects that represent metadata (non-image data) associated with images and streams.An interface to be implemented by objects that can determine the settings of anIIOMetadata
object, either by putting up a GUI to obtain values from a user, or by other means.An object describing the structure of metadata documents returned fromIIOMetadata.getAsTree
and passed toIIOMetadata.setFromTree
andmergeTree
.A concrete class providing a reusable implementation of theIIOMetadataFormat
interface.A class representing a node in a meta-data tree, which implements theorg.w3c.dom.Element
interface and additionally allows for the storage of non-textual objects via thegetUserObject
andsetUserObject
methods.