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

java.lang.Object
  com.sun.media.imageio.plugins.tiff.TIFFField

All Implemented Interfaces:

Comparable

public class TIFFField

extends Object

implements Comparable

A class representing a field in a TIFF 6.0 Image File Directory.

A field in a TIFF Image File Directory (IFD) is defined as a tag number accompanied by a sequence of values of identical data type. TIFF 6.0 defines 12 data types; a 13th type IFD is defined in TIFF Tech Note 1 of TIFF Specification Supplement 1. These TIFF data types are referred to by Java constants and mapped internally onto Java language data types and type names as follows:

TIFF Data Type	Java Constant	Java Data Type	Java Type Name
BYTE	TIFFTag.TIFF_BYTE	byte	"Byte"
ASCII	TIFFTag.TIFF_ASCII	String	"Ascii"
SHORT	TIFFTag.TIFF_SHORT	char	"Short"
LONG	TIFFTag.TIFF_LONG	long	"Long"
RATIONAL	TIFFTag.TIFF_RATIONAL	long[2] {numerator, denominator}	"Rational"
SBYTE	TIFFTag.TIFF_SBYTE	byte	"SByte"
UNDEFINED	TIFFTag.TIFF_UNDEFINED	byte	"Undefined"
SSHORT	TIFFTag.TIFF_SSHORT	short	"SShort"
SLONG	TIFFTag.TIFF_SLONG	int	"SLong"
SRATIONAL	TIFFTag.TIFF_SRATIONAL	int[2] {numerator, denominator}	"SRational"
FLOAT	TIFFTag.TIFF_FLOAT	float	"Float"
DOUBLE	TIFFTag.TIFF_DOUBLE	double	"Double"
IFD	TIFFTag.TIFF_IFD_POINTER	long	"IFDPointer"

See Also:

TIFFDirectory, TIFFTag

Constructor Summary

TIFFField(TIFFTag tag, int value)
Constructs a TIFFField with a single integral value.

TIFFField(TIFFTag tag, int type, int count)
Constructs a data array using createArrayForType() and invokes TIFFField(TIFFTag,int,int,Object) with the supplied parameters and the created array.

TIFFField(TIFFTag tag, int type, int count, Object data)
Constructs a TIFFField with arbitrary data.

Method Summary

int	compareTo(Object o) Compares this TIFFField with another TIFFField by comparing the tags.
static Object	createArrayForType(int dataType, int count) Creates an array appropriate for the indicated data type.
static TIFFField	createFromMetadataNode(TIFFTagSet tagSet, Node node) Creates a TIFFField from a TIFF native image metadata node.
byte[]	getAsBytes() Returns the data as an uninterpreted array of bytes.
char[]	getAsChars() Returns TIFFTag.TIFF_SHORT data as an array of chars (unsigned 16-bit integers).
double	getAsDouble(int index) Returns data in any format as a double.
double[]	getAsDoubles() Returns TIFFTag.TIFF_DOUBLE data as an array of doubles (64-bit floating-point values).
float	getAsFloat(int index) Returns data in any format as a float.
float[]	getAsFloats() Returns TIFFTag.TIFF_FLOAT data as an array of floats (32-bit floating-point values).
int	getAsInt(int index) Returns data in any format as an int.
int[]	getAsInts() Returns TIFFTag.TIFF_SLONG data as an array of ints (signed 32-bit integers).
long	getAsLong(int index) Returns data in any format as a long.
long[]	getAsLongs() Returns TIFFTag.TIFF_LONG or TIFF_IFD_POINTER data as an array of longs (signed 64-bit integers).
Node	getAsNativeNode() Returns the TIFFField as a node named either "TIFFField" or "TIFFIFD" as described in the TIFF native image metadata specification.
long[]	getAsRational(int index) Returns a TIFFTag.TIFF_RATIONAL data item as a two-element array of ints.
long[][]	getAsRationals() Returns TIFFTag.TIFF_RATIONAL data as an array of 2-element arrays of longs.
short[]	getAsShorts() Returns TIFFTag.TIFF_SSHORT data as an array of shorts (signed 16-bit integers).
int[]	getAsSRational(int index) Returns a TIFFTag.TIFF_SRATIONAL data item as a two-element array of ints.
int[][]	getAsSRationals() Returns TIFFTag.TIFF_SRATIONAL data as an array of 2-element arrays of ints.
String	getAsString(int index) Returns a TIFFTag.TIFF_ASCII value as a String.
int	getCount() Returns the number of data items present in the field.
Object	getData() Returns a reference to the data object associated with the field.
TIFFTag	getTag() Retrieves the tag associated with this field.
int	getTagNumber() Retrieves the tag number in the range [0, 65535].
int	getType() Returns the type of the data stored in the field.
static int	getTypeByName(String typeName) Returns the data type constant corresponding to the supplied data type name.
static String	getTypeName(int dataType) Returns the name of the supplied data type constant.
String	getValueAsString(int index) Returns a String containing a human-readable version of the data item.
boolean	isIntegral() Indicates whether the value associated with the field is of integral data type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TIFFField

public TIFFField(TIFFTag tag,
                 int type,
                 int count,
                 Object data)

Constructs a TIFFField with arbitrary data. The type parameter must be a value for which tag.isDataTypeOK() returns true. The data parameter must be an array of a Java type appropriate for the type of the TIFF field unless tag.isIFDPointer() returns true in which case it must be a TIFFDirectory instance.

Neither the legality of type with respect to tag nor that or data with respect to type is verified by this constructor. The methods TIFFTag.isDataTypeOK() and createArrayForType() should be used programmatically to ensure that subsequent errors such as ClassCastExceptions do not occur as a result of providing inconsitent parameters to this constructor.

Note that the value (data) of the TIFFField will always be the actual field value regardless of the number of bytes required for that value. This is the case despite the fact that the TIFF IFD Entry corresponding to the field may actually contain the offset to the field's value rather than the value itself (the latter occurring if and only if the value fits into 4 bytes). In other words, the value of the field will already have been read from the TIFF stream. This subsumes the case where tag.isIFDPointer() returns true and the value will be a TIFFDirectory rather than an array.

Parameters:

tag - The tag to associated with this field.

type - One of the TIFFTag.TIFF_* constants indicating the data type of the field as written to the TIFF stream.

count - The number of data values.

data - The actual data content of the field.

Throws:

IllegalArgumentException - if tag == null.

IllegalArgumentException - if dataType is not one of the TIFFTag.TIFF_* data type constants.

IllegalArgumentException - if count < 0.

TIFFField

public TIFFField(TIFFTag tag,
                 int type,
                 int count)

Constructs a data array using createArrayForType() and invokes TIFFField(TIFFTag,int,int,Object) with the supplied parameters and the created array.

See Also:

TIFFField(TIFFTag,int,int,Object)

TIFFField

public TIFFField(TIFFTag tag,
                 int value)

Constructs a TIFFField with a single integral value. The field will have type TIFF_SHORT if val < 65536 and type TIFF_LONG otherwise. It is not verified whether the resulting type is legal for tag.

Parameters:

tag - The tag to associate with this field.

value - The value to associate with this field.

Throws:

IllegalArgumentException - if tag == null.

IllegalArgumentException - if value < 0.

Method Detail

createFromMetadataNode

public static TIFFField createFromMetadataNode(TIFFTagSet tagSet,
                                               Node node)

Creates a TIFFField from a TIFF native image metadata node. If the value of the "tagNumber" attribute of the node is not found in tagSet then a new TIFFTag with name "unknown" will be created and assigned to the field.

Parameters:

tagSet - The TIFFTagSet to which the TIFFTag of the field belongs.

node - A native TIFF image metadata TIFFField node.

Throws:

IllegalArgumentException - if node is null.

IllegalArgumentException - if the name of the node is not "TIFFField".

getTag

public TIFFTag getTag()

Retrieves the tag associated with this field.

Returns:

The associated TIFFTag.

getTagNumber

public int getTagNumber()

Retrieves the tag number in the range [0, 65535].

Returns:

The tag number.

getType

public int getType()

Returns the type of the data stored in the field. For a TIFF 6.0 stream, the value will equal one of the TIFFTag.TIFF_* constants. For future revisions of TIFF, higher values are possible.

Returns:

The data type of the field value.

getTypeName

public static String getTypeName(int dataType)

Returns the name of the supplied data type constant.

Parameters:

dataType - One of the TIFFTag.TIFF_* constants indicating the data type of the field as written to the TIFF stream.

Returns:

The type name corresponding to the supplied type constant.

Throws:

IllegalArgumentException - if dataType is not one of the TIFFTag.TIFF_* data type constants.

getTypeByName

public static int getTypeByName(String typeName)

Returns the data type constant corresponding to the supplied data type name. If the name is unknown -1 will be returned.

Returns:

One of the TIFFTag.TIFF_* constants or -1 if the name is not recognized.

createArrayForType

public static Object createArrayForType(int dataType,
                                        int count)

Creates an array appropriate for the indicated data type.

Parameters:

dataType - One of the TIFFTag.TIFF_* data type constants.

count - The number of values in the array.

Throws:

IllegalArgumentException - if dataType is not one of the TIFFTag.TIFF_* data type constants.

IllegalArgumentException - if count < 0.

getAsNativeNode

public Node getAsNativeNode()

Returns the TIFFField as a node named either "TIFFField" or "TIFFIFD" as described in the TIFF native image metadata specification. The node will be named "TIFFIFD" if and only if the field's data object is an instance of TIFFDirectory or equivalently getTag.isIFDPointer() returns true.

Returns:

a Node named "TIFFField" or "TIFFIFD".

isIntegral

public boolean isIntegral()

Indicates whether the value associated with the field is of integral data type.

Returns:

Whether the field type is integral.

getCount

public int getCount()

Returns the number of data items present in the field. For TIFFTag.TIFF_ASCII fields, the value returned is the number of Strings, not the total length of the data as in the file representation.

getData

public Object getData()

Returns a reference to the data object associated with the field.

Returns:

The data object of the field.

getAsBytes

public byte[] getAsBytes()

Returns the data as an uninterpreted array of bytes. The type of the field must be one of TIFFTag.TIFF_BYTE, TIFF_SBYTE, or TIFF_UNDEFINED.

For data in TIFFTag.TIFF_BYTE format, the application must take care when promoting the data to longer integral types to avoid sign extension.

Throws:

ClassCastException - if the field is not of type TIFF_BYTE, TIFF_SBYTE, or TIFF_UNDEFINED.

getAsChars

public char[] getAsChars()

Returns TIFFTag.TIFF_SHORT data as an array of chars (unsigned 16-bit integers).

Throws:

ClassCastException - if the field is not of type TIFF_SHORT.

getAsShorts

public short[] getAsShorts()

Returns TIFFTag.TIFF_SSHORT data as an array of shorts (signed 16-bit integers).

Throws:

ClassCastException - if the field is not of type TIFF_SSHORT.

getAsInts

public int[] getAsInts()

Returns TIFFTag.TIFF_SLONG data as an array of ints (signed 32-bit integers).

Throws:

ClassCastException - if the field is not of type TIFF_SHORT, TIFF_SSHORT, or TIFF_SLONG.

getAsLongs

public long[] getAsLongs()

Returns TIFFTag.TIFF_LONG or TIFF_IFD_POINTER data as an array of longs (signed 64-bit integers).

Throws:

ClassCastException - if the field is not of type TIFF_LONG or TIFF_IFD_POINTER.

getAsFloats

public float[] getAsFloats()

Returns TIFFTag.TIFF_FLOAT data as an array of floats (32-bit floating-point values).

Throws:

ClassCastException - if the field is not of type TIFF_FLOAT.

getAsDoubles

public double[] getAsDoubles()

Returns TIFFTag.TIFF_DOUBLE data as an array of doubles (64-bit floating-point values).

Throws:

ClassCastException - if the field is not of type TIFF_DOUBLE.

getAsSRationals

public int[][] getAsSRationals()

Returns TIFFTag.TIFF_SRATIONAL data as an array of 2-element arrays of ints.

Throws:

ClassCastException - if the field is not of type TIFF_SRATIONAL.

getAsRationals

public long[][] getAsRationals()

Returns TIFFTag.TIFF_RATIONAL data as an array of 2-element arrays of longs.

Throws:

ClassCastException - if the field is not of type TIFF_RATIONAL.

getAsInt

public int getAsInt(int index)

Returns data in any format as an int.

TIFFTag.TIFF_BYTE values are treated as unsigned; that is, no sign extension will take place and the returned value will be in the range [0, 255]. TIFF_SBYTE data will be returned in the range [-128, 127].

A TIFF_UNDEFINED value is treated as though it were a TIFF_BYTE.

Data in TIFF_SLONG, TIFF_LONG, TIFF_FLOAT, TIFF_DOUBLE or TIFF_IFD_POINTER format are simply cast to int and may suffer from truncation.

Data in TIFF_SRATIONAL or TIFF_RATIONAL format are evaluated by dividing the numerator into the denominator using double-precision arithmetic and then casting to int. Loss of precision and truncation may occur.

Data in TIFF_ASCII format will be parsed as by the Double.parseDouble method, with the result case to int.

getAsLong

public long getAsLong(int index)

Returns data in any format as a long.

TIFFTag.TIFF_BYTE and TIFF_UNDEFINED data are treated as unsigned; that is, no sign extension will take place and the returned value will be in the range [0, 255]. TIFF_SBYTE data will be returned in the range [-128, 127].

Data in TIFF_ASCII format will be parsed as by the Double.parseDouble method, with the result cast to long.

getAsFloat

public float getAsFloat(int index)

Returns data in any format as a float.

TIFFTag.TIFF_BYTE and TIFF_UNDEFINED data are treated as unsigned; that is, no sign extension will take place and the returned value will be in the range [0, 255]. TIFF_SBYTE data will be returned in the range [-128, 127].

Data in TIFF_SLONG, TIFF_LONG, TIFF_DOUBLE, or TIFF_IFD_POINTER format are simply cast to float and may suffer from truncation.

Data in TIFF_SRATIONAL or TIFF_RATIONAL format are evaluated by dividing the numerator into the denominator using double-precision arithmetic and then casting to float.

Data in TIFF_ASCII format will be parsed as by the Double.parseDouble method, with the result cast to float.

getAsDouble

public double getAsDouble(int index)

Returns data in any format as a double.

TIFFTag.TIFF_BYTE and TIFF_UNDEFINED data are treated as unsigned; that is, no sign extension will take place and the returned value will be in the range [0, 255]. TIFF_SBYTE data will be returned in the range [-128, 127].

Data in TIFF_SRATIONAL or TIFF_RATIONAL format are evaluated by dividing the numerator into the denominator using double-precision arithmetic.

Data in TIFF_ASCII format will be parsed as by the Double.parseDouble method.

getAsString

public String getAsString(int index)

Returns a TIFFTag.TIFF_ASCII value as a String.

Throws:

ClassCastException - if the field is not of type TIFF_ASCII.

getAsSRational

public int[] getAsSRational(int index)

Returns a TIFFTag.TIFF_SRATIONAL data item as a two-element array of ints.

Throws:

ClassCastException - if the field is not of type TIFF_SRATIONAL.

getAsRational

public long[] getAsRational(int index)

Returns a TIFFTag.TIFF_RATIONAL data item as a two-element array of ints.

Throws:

ClassCastException - if the field is not of type TIFF_RATIONAL.

getValueAsString

public String getValueAsString(int index)

Returns a String containing a human-readable version of the data item. Data of type TIFFTag.TIFF_RATIONAL or TIFF_SRATIONAL are represented as a pair of integers separated by a '/' character.

Throws:

ClassCastException - if the field is not of one of the legal field types.

compareTo

public int compareTo(Object o)

Compares this TIFFField with another TIFFField by comparing the tags.

Note: this class has a natural ordering that is inconsistent with equals().

Specified by:

compareTo in interface Comparable

Throws:

IllegalArgumentException - if the parameter is null.

ClassCastException - if the parameter is not a TIFFField.