Enum Class DataType

Object

Enum<DataType>

DataType

All Implemented Interfaces:

Serializable, Comparable<Data­Type>, Constable

public enum DataType
extends Enum<DataType>

Identification of the primitive type used for storing sample values in an image. This is a type-safe version of the TYPE_* constants defined in Data­Buffer, except that this enumeration distinguishes signed and unsigned 32 bits integers.

Since:

1.1

Nested Class Summary

Nested classes/interfaces inherited from class Enum

Enum.Enum­Desc<E extends Enum<E>>

Enum Constant Summary

Enum Constants

Enum Constant	Description
BYTE	Unsigned 8-bits data.
DOUBLE	Double precision (64-bits) floating point data.
FLOAT	Single precision (32-bits) floating point data.
INT	Signed 32-bits data.
SHORT	Signed 16-bits data.
UINT	Unsigned 32-bits data.
USHORT	Unsigned 16-bits data.

Method Summary

Modifier and Type	Method	Description
final int	bytes()	Returns the size in bytes of this data type.
final Number	fill­Value()	Returns the default fill value, which is 0 for integer types and NaN for floating point types.
static Data­Type	for­Bands(Rendered­Image image)	Returns the data type of the bands in the given image.
static Data­Type	for­Bands(Sample­Model sm)	Returns the data type of the bands managed by the given the sample model.
static Data­Type	for­Data­Buffer­Type(int type)	Returns the enumeration value for the given Data­Buffer constant.
static Data­Type	for­Number­Of­Bits(int size, boolean real, boolean signed)	Returns the enumeration value for the given number of bits.
static Data­Type	for­Primitive­Type(Class<?> type, boolean unsigned)	Returns the data type for the given primitive type.
static Data­Type	for­Range(Number­Range<?> range, boolean force­Integer)	Returns the smallest data type capable to store the given range of values.
final boolean	is­Integer()	Returns whether this type is an integer type, signed or not.
static boolean	is­Integer(Sample­Model sm)	Returns true if the given sample model uses an integer type.
final boolean	is­Unsigned()	Returns whether this type is an unsigned integer type.
static boolean	is­Unsigned(Sample­Model sm)	Returns true if the type of sample values is an unsigned integer type.
final int	size()	Returns the size in bits of this data type.
final int	to­Data­Buffer­Type()	Returns the Data­Buffer constant for this enumeration value.
final Data­Type	to­Float()	Returns the smallest floating point type capable to store all values of this type without precision lost.
final Data­Type	to­Primitive()	Returns the primitive (signed) variant of this data type.
static Data­Type	value­Of(String name)	Returns the enum constant of this class with the specified name.
static Data­Type[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.

Methods inherited from class Enum

clone, compare­To, describe­Constable, equals, finalize, get­Declaring­Class, hash­Code, name, ordinal, to­String, value­Of

Methods inherited from class Object

get­Class, notify, notify­All, wait, wait, wait

Enum Constant Details

BYTE

public static final DataType BYTE

Unsigned 8-bits data. Mapped to Data­Buffer.TYPE_BYTE in Java2D API.

USHORT

public static final DataType USHORT

Unsigned 16-bits data. Mapped to Data­Buffer.TYPE_USHORT in Java2D API.

SHORT

public static final DataType SHORT

Signed 16-bits data. Mapped to Data­Buffer.TYPE_SHORT in Java2D API.

INT

public static final DataType INT

Signed 32-bits data. Mapped to Data­Buffer.TYPE_INT in Java2D API. Note that the sign of the latter Java2D type is ambiguous. See for­Data­Buffer­Type(int) for more information.

This type is selected by default for all Data­Buffer.TYPE_INT cases that cannot be resolved as an UINT case.

UINT

public static final DataType UINT

Unsigned 32-bits data. Mapped to Data­Buffer.TYPE_INT in Java2D API. Note that the sign of the latter Java2D type is ambiguous. See for­Data­Buffer­Type(int) for more information.

This case is selected when the data are used with any packed sample model: Single­Pixel­Packed­Sample­Model or Multi­Pixel­Packed­Sample­Model.

Since:

1.5

FLOAT

public static final DataType FLOAT

Single precision (32-bits) floating point data. Mapped to Data­Buffer.TYPE_FLOAT in Java2D API.

DOUBLE

public static final DataType DOUBLE

Double precision (64-bits) floating point data. Mapped to Data­Buffer.TYPE_DOUBLE in Java2D API.

Method Details

values

public static DataType[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static DataType valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

Illegal­Argument­Exception - if this enum class has no constant with the specified name

Null­Pointer­Exception - if the argument is null

forBands

public static DataType forBands(RenderedImage image)

Returns the data type of the bands in the given image. This is often the storage data type, but not necessarily. See for­Bands(Sample­Model) for more information.

Parameters:

image - the image for which to get the band data type.

Returns:

type of sample values in the given image (never null).

Throws:

Raster­Format­Exception - if the image does not use a recognized data type.

forBands

public static DataType forBands(SampleModel sm)

Returns the data type of the bands managed by the given the sample model. This is often the storage data type, but not necessarily. For example, if an ARGB image uses a storage mode where the sample values in the four bands are packed in a single 32-bits integer, then this method returns BYTE (the type of a single band) rather than INT (the type of a whole pixel).

Parameters:

sm - the sample model for which to get the band data type.

Returns:

type of sample values in the bands managed by the given sample model (never null).

Throws:

Raster­Format­Exception - if the sample model does not use a recognized data type.

Since:

1.5

forRange

public static DataType forRange(NumberRange<?> range,
 boolean forceInteger)

Returns the smallest data type capable to store the given range of values. If the given range uses a floating point type, there there is a choice:

• If as­Integer is false, then this method returns FLOAT or DOUBLE depending on the range type.
• Otherwise, this method treats the floating point values as if they were integers, with minimum value rounded toward negative infinity and maximum value rounded toward positive infinity.

Parameters:

range - the range of values.

force­Integer - whether to handle floating point values as integers.

Returns:

smallest data type for the given range of values.

forPrimitiveType

public static DataType forPrimitiveType(Class<?> type,
 boolean unsigned)

Returns the data type for the given primitive type. The given type should be a primitive type such as Short.TYPE, but wrappers class such as Short.class are also accepted.

Parameters:

type - the primitive type or its wrapper class.

unsigned - whether the type should be considered unsigned.

Returns:

the data type (never null) for the given primitive type.

Throws:

Raster­Format­Exception - if the given type is not a recognized.

forDataBufferType

public static DataType forDataBufferType(int type)

Returns the enumeration value for the given Data­Buffer constant. This method is the converse of to­Data­Buffer­Type(). It is provided for interoperability with Java2D.

32 bit integers

The case of Data­Buffer.TYPE_INT is ambiguous. Whether this type is considered as signed or unsigned depends on the context:

• The sign is indistinguishable when using Java2D API working on integer values such as the Raster.get­Sample(…) method.
• When converted to floating point values by Java2D API such as Raster.get­Sample­Float(…), sample values are:
  • Unsigned when the raster uses Single­Pixel­Packed­Sample­Model or Multi­Pixel­Packed­Sample­Model.
  • Signed when the raster uses any other type of sample model.
• The type is unsigned when converted to a color by Component­Color­Model.

For resolving above ambiguities, consider using for­Bands(Sample­Model) instead of this method.

Parameters:

type - one of Data­Buffer.TYPE_* constants.

Returns:

the data type (never null) for the given data buffer type.

Throws:

Raster­Format­Exception - if the given type is not a recognized Data­Buffer.TYPE_* constant.

forNumberOfBits

public static DataType forNumberOfBits(int size,
 boolean real,
 boolean signed)

Returns the enumeration value for the given number of bits. Only the following combinations of argument values are accepted:

Valid combinations of argument values

size	real	signed
1	false	false
2	false	false
4	false	false
8	false	false
16	false	false or true
32	false	false or true
32	true	ignored
64	true	ignored

Parameters:

size - number of bits as a power of 2 between 1 and 64 inclusive.

real - true for floating point numbers or false for integers.

signed - true for signed numbers of false for unsigned numbers.

Returns:

the data type (never null) for the given number of bits.

Throws:

Raster­Format­Exception - if the combination of argument values is invalid.

Since:

1.2

size

public final int size()

Returns the size in bits of this data type.

Returns:

size in bits of this data type.

bytes

public final int bytes()

Returns the size in bytes of this data type.

Returns:

size in bytes of this data type, from 1 to 4 inclusive.

Since:

1.3

isInteger

public final boolean isInteger()

Returns whether this type is an integer type, signed or not. Integer types are BYTE, USHORT, SHORT, INT and UINT.

Returns:

true if this type is an integer type.

isInteger

public static boolean isInteger(SampleModel sm)

Returns true if the given sample model uses an integer type. Returns false if the type is a floating point type or in case of doubt (e.g. for Data­Buffer.TYPE_UNDEFINED).

Parameters:

sm - the sample model, or null.

Returns:

whether the given sample model uses an integer type.

Since:

1.5

isUnsigned

public final boolean isUnsigned()

Returns whether this type is an unsigned integer type. Unsigned types are BYTE, USHORT and UINT.

Returns:

true if this type is an unsigned integer type.

isUnsigned

public static boolean isUnsigned(SampleModel sm)

Returns true if the type of sample values is an unsigned integer type. Returns false if the type is a floating point type or in case of doubt (e.g. for Data­Buffer.TYPE_UNDEFINED).

Parameters:

sm - the sample model, or null.

Returns:

whether the given sample model provides unsigned sample values.

Since:

1.5

toPrimitive

public final DataType toPrimitive()

Returns the primitive (signed) variant of this data type. This method returns the value that most closely maps to a Java primitive type of the same number of bits. Since all Java primitive types are signed, this method returns the signed variant of this type except for the special case of BYTE (because Data­Type does not define signed variant of that type).

More specifically, this methods replaces UINT by INT, replaces USHORT by SHORT, and returns all other types unchanged. The purpose of this method is to simplify the switch statements with cases restricted to Java primitive types, such as mapping to specific NIO Buffer subclasses.

Returns:

the data type that most closely corresponds to a Java primitive type.

Since:

1.5

toFloat

public final DataType toFloat()

Returns the smallest floating point type capable to store all values of this type without precision lost. This method returns:

• DOUBLE if this data type is DOUBLE, INT or UINT.
• FLOAT for all other types.

The promotion of integer values to floating point values is sometimes necessary when the image may contain Float.Na­N values.

Returns:

the smallest of FLOAT or DOUBLE types which can store all values of this type without any lost.

toDataBufferType

public final int toDataBufferType()

Returns the Data­Buffer constant for this enumeration value. This method is the converse of for­Data­Buffer­Type(int). It is provided for interoperability with Java2D.

Returns:

one of the Data­Buffer constants.

fillValue

public final Number fillValue()

Returns the default fill value, which is 0 for integer types and NaN for floating point types. The class of this number is the wrapper class corresponding to the type of sample values, ignoring whether the type is signed or unsigned. For example, for USHORT, the returned fill value is an instance of the Short class.

Returns:

0 of NaN in an instance of the wrapper class of the sample values.

Since:

1.5