com.sun.media.imageio.plugins.tiff
Class TIFFDirectory

java.lang.Object
  extended bycom.sun.media.imageio.plugins.tiff.TIFFDirectory
All Implemented Interfaces:
Cloneable

public class TIFFDirectory
extends Object
implements Cloneable

A convenience class for simplifying interaction with TIFF native image metadata. A TIFF image metadata tree represents an Image File Directory (IFD) from a TIFF 6.0 stream. An IFD consists of a number of IFD Entries each of which associates an identifying tag number with a compatible value. A TIFFDirectory instance corresponds to an IFD and contains a set of TIFFFields each of which corresponds to an IFD Entry in the IFD.

When reading, a TIFFDirectory may be created by passing the value returned by ImageReader.getImageMetadata() to createFromMetadata(). The TIFFFields in the directory may then be obtained using the accessor methods provided in this class.

When writing, an IIOMetadata object for use by one of the write() methods of ImageWriter may be created from a TIFFDirectory by getAsMetadata(). The TIFFDirectory itself may be created by construction or from the IIOMetadata object returned by ImageWriter.getDefaultImageMetadata(). The TIFFFields in the directory may be set using the mutator methods provided in this class.

A TIFFDirectory is aware of the tag numbers in the group of TIFFTagSets associated with it. When a TIFFDirectory is created from a native image metadata object, these tag sets are derived from the tagSets attribute of the TIFFIFD node.

A TIFFDirectory might also have a parent TIFFTag. This will occur if the directory represents an IFD other than the root IFD of the image. The parent tag is the tag of the IFD Entry which is a pointer to the IFD represented by this TIFFDirectory. The TIFFTag.isIFDPointer() method of this parent TIFFTag must return true. When a TIFFDirectory is created from a native image metadata object, the parent tag set is set from the parentTagName attribute of the corresponding TIFFIFD node. Note that a TIFFDirectory instance which has a non-null parent tag will be contained in the data field of a TIFFField instance which has a tag field equal to the contained directory's parent tag.

As an example consider an EXIF image. The TIFFDirectory instance corresponding to the EXIF IFD in the EXIF stream would have parent tag TAG_EXIF_IFD_POINTER and would include EXIFTIFFTagSet in its group of known tag sets. The TIFFDirectory corresponding to this EXIF IFD will be contained in the data field of a TIFFField which will in turn be contained in the TIFFDirectory corresponding to the primary IFD of the EXIF image which will itself have a null-valued parent tag.

Note that this implementation is not synchronized. If multiple threads use a TIFFDirectory instance concurrently, and at least one of the threads modifies the directory, for example, by adding or removing TIFFFields or TIFFTagSets, it must be synchronized externally.

Since:
1.1-beta
See Also:
IIOMetadata, TIFFField, TIFFTag, TIFFTagSet

Constructor Summary
TIFFDirectory(TIFFTagSet[] tagSets, TIFFTag parentTag)
          Constructs a TIFFDirectory which is aware of a given group of TIFFTagSets.
 
Method Summary
 void addTagSet(TIFFTagSet tagSet)
          Adds an element to the group of TIFFTagSets of which this directory is aware.
 void addTIFFField(TIFFField f)
          Adds a TIFF field to the directory.
 Object clone()
          Clones the directory and all the fields contained therein.
 boolean containsTIFFField(int tagNumber)
          Determines whether a TIFF field with the given tag number is contained in this directory.
static TIFFDirectory createFromMetadata(IIOMetadata tiffImageMetadata)
          Creates a TIFFDirectory instance from the contents of an image metadata object.
 IIOMetadata getAsMetadata()
          Converts the directory to a metadata object.
 int getNumTIFFFields()
          Returns the number of TIFFFields in this directory.
 TIFFTag getParentTag()
          Returns the parent TIFFTag of this directory if one has been defined or null otherwise.
 TIFFTag getTag(int tagNumber)
          Returns the TIFFTag which has tag number equal to tagNumber or null if no such tag exists in the TIFFTagSets associated with this directory.
 TIFFTagSet[] getTagSets()
          Returns the TIFFTagSets of which this directory is aware.
 TIFFField getTIFFField(int tagNumber)
          Retrieves a TIFF field from the directory.
 TIFFField[] getTIFFFields()
          Retrieves all TIFF fields from the directory.
 void removeTagSet(TIFFTagSet tagSet)
          Removes an element from the group of TIFFTagSets of which this directory is aware.
 void removeTIFFField(int tagNumber)
          Removes a TIFF field from the directory.
 void removeTIFFFields()
          Removes all TIFF fields from the directory.
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TIFFDirectory

public TIFFDirectory(TIFFTagSet[] tagSets,
                     TIFFTag parentTag)
Constructs a TIFFDirectory which is aware of a given group of TIFFTagSets. An optional parent TIFFTag may also be specified.

Parameters:
tagSets - The TIFFTagSets associated with this directory.
parentTag - The parent TIFFTag of this directory; may be null.
Throws:
IllegalArgumentException - if tagSets is null.
Method Detail

createFromMetadata

public static TIFFDirectory createFromMetadata(IIOMetadata tiffImageMetadata)
                                        throws IIOInvalidTreeException
Creates a TIFFDirectory instance from the contents of an image metadata object. The supplied object must support an image metadata format supported by the TIFF ImageWriter plug-in. This will usually be either the TIFF native image metadata format com_sun_media_imageio_plugins_tiff_1.0 or the Java Image I/O standard metadata format javax_imageio_1.0.

Parameters:
tiffImageMetadata - A metadata object which supports a compatible image metadata format.
Returns:
A TIFFDirectory populated from the contents of the supplied metadata object.
Throws:
IllegalArgumentException - if tiffImageMetadata is null.
IllegalArgumentException - if tiffImageMetadata does not support a compatible image metadata format.
IIOInvalidTreeException - if the supplied metadata object cannot be parsed.

getTagSets

public TIFFTagSet[] getTagSets()
Returns the TIFFTagSets of which this directory is aware.

Returns:
The TIFFTagSets associated with this TIFFDirectory.

addTagSet

public void addTagSet(TIFFTagSet tagSet)
Adds an element to the group of TIFFTagSets of which this directory is aware.

Parameters:
tagSet - The TIFFTagSet to add.
Throws:
IllegalArgumentException - if tagSet is null.

removeTagSet

public void removeTagSet(TIFFTagSet tagSet)
Removes an element from the group of TIFFTagSets of which this directory is aware.

Parameters:
tagSet - The TIFFTagSet to remove.
Throws:
IllegalArgumentException - if tagSet is null.

getParentTag

public TIFFTag getParentTag()
Returns the parent TIFFTag of this directory if one has been defined or null otherwise.

Returns:
The parent TIFFTag of this TIFFDiectory or null.

getTag

public TIFFTag getTag(int tagNumber)
Returns the TIFFTag which has tag number equal to tagNumber or null if no such tag exists in the TIFFTagSets associated with this directory.

Parameters:
tagNumber - The tag number of interest.
Returns:
The corresponding TIFFTag or null.

getNumTIFFFields

public int getNumTIFFFields()
Returns the number of TIFFFields in this directory.

Returns:
The number of TIFFFields in this TIFFDirectory.

containsTIFFField

public boolean containsTIFFField(int tagNumber)
Determines whether a TIFF field with the given tag number is contained in this directory.

Returns:
Whether a TIFFTag with tag number equal to tagNumber is present in this TIFFDirectory.

addTIFFField

public void addTIFFField(TIFFField f)
Adds a TIFF field to the directory.

Parameters:
f - The field to add.
Throws:
IllegalArgumentException - if f is null.

getTIFFField

public TIFFField getTIFFField(int tagNumber)
Retrieves a TIFF field from the directory.

Parameters:
tagNumber - The tag number of the tag associated with the field.
Returns:
A TIFFField with the requested tag number of null if no such field is present.

removeTIFFField

public void removeTIFFField(int tagNumber)
Removes a TIFF field from the directory.

Parameters:
tagNumber - The tag number of the tag associated with the field.

getTIFFFields

public TIFFField[] getTIFFFields()
Retrieves all TIFF fields from the directory.

Returns:
An array of all TIFF fields in order of numerically increasing tag number.

removeTIFFFields

public void removeTIFFFields()
Removes all TIFF fields from the directory.


getAsMetadata

public IIOMetadata getAsMetadata()
Converts the directory to a metadata object.

Returns:
A metadata instance initialized from the contents of this TIFFDirectory.

clone

public Object clone()
Clones the directory and all the fields contained therein.

Returns:
A clone of this TIFFDirectory.