com.sun.media.imageio.plugins.tiff

Class TIFFField

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

See Also: TIFFDirectory TIFFTag

Constructor Summary
TIFFField(TIFFTag tag, int type, int count, Object data)
Constructs a TIFFField with arbitrary data.
TIFFField(TIFFTag tag, int type, int count)
Constructs a data array using createArrayForType() and invokes TIFFField with the supplied parameters and the created array.
TIFFField(TIFFTag tag, int value)
Constructs a TIFFField with a single integral value.
Method Summary
intcompareTo(Object o)
Compares this TIFFField with another TIFFField by comparing the tags.
static ObjectcreateArrayForType(int dataType, int count)
Creates an array appropriate for the indicated data type.
static TIFFFieldcreateFromMetadataNode(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).
doublegetAsDouble(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).
floatgetAsFloat(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).
intgetAsInt(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).
longgetAsLong(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).
NodegetAsNativeNode()
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.
StringgetAsString(int index)
Returns a TIFFTag.TIFF_ASCII value as a String.
intgetCount()
Returns the number of data items present in the field.
ObjectgetData()
Returns a reference to the data object associated with the field.
TIFFTaggetTag()
Retrieves the tag associated with this field.
intgetTagNumber()
Retrieves the tag number in the range [0, 65535].
intgetType()
Returns the type of the data stored in the field.
static intgetTypeByName(String typeName)
Returns the data type constant corresponding to the supplied data type name.
static StringgetTypeName(int dataType)
Returns the name of the supplied data type constant.
StringgetValueAsString(int index)
Returns a String containing a human-readable version of the data item.
booleanisIntegral()
Indicates whether the value associated with the field is of integral data type.

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 with the supplied parameters and the created array.

See Also: TIFFField

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

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().

Throws: IllegalArgumentException if the parameter is null. ClassCastException if the parameter is not a TIFFField.

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.

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".

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.

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.

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.

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.

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.

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.

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.

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.

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.

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".

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

isIntegral

public boolean isIntegral()
Indicates whether the value associated with the field is of integral data type.

Returns: Whether the field type is integral.