OpenJDK 27 · java.awt.image.PackedColorModel · APIdia, the JavaDoc alternative

The PackedColorModel class is an abstract ColorModel class that works with pixel values which represent color and alpha information as separate samples and which pack all samples for a single pixel into a single int, short, or byte quantity. This class can be used with an arbitrary ColorSpace. The number of color samples in the pixel values must be the same as the number of color components in the ColorSpace. There can be a single alpha sample. The array length is always 1 for those methods that use a primitive array pixel representation of type transferType. The transfer types supported are DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, and DataBuffer.TYPE_INT. Color and alpha samples are stored in the single element of the array in bits indicated by bit masks. Each bit mask must be contiguous and masks must not overlap. The same masks apply to the single int pixel representation used by other methods. The correspondence of masks and color/alpha samples is as follows:

Masks are identified by indices running from 0 through getNumComponents - 1.
The first getNumColorComponents indices refer to color samples.
If an alpha sample is present, it corresponds the last index.
The order of the color indices is specified by the ColorSpace. Typically, this reflects the name of the color space type (for example, TYPE_RGB), index 0 corresponds to red, index 1 to green, and index 2 to blue.

The translation from pixel values to color/alpha components for display or processing purposes is a one-to-one correspondence of samples to components. A PackedColorModel is typically used with image data that uses masks to define packed samples. For example, a PackedColorModel can be used in conjunction with a SinglePixelPackedSampleModel to construct a BufferedImage. Normally the masks used by the SampleModel and the ColorModel would be the same. However, if they are different, the color interpretation of pixel data is done according to the masks of the ColorModel.

A single int pixel representation is valid for all objects of this class since it is always possible to represent pixel values used with this class in a single int. Therefore, methods that use this representation do not throw an IllegalArgumentException due to an invalid pixel value.

A subclass of PackedColorModel is DirectColorModel, which is similar to an X11 TrueColor visual.

Field Summary

Modifier and Type	Field and Description
private volatile int	hashCode
pack-priv int[]	maskArray
pack-priv int[]	maskOffsets
pack-priv float[]	scaleFactors

Constructor Summary

Access Constructor and Description

Access	Constructor and Description
public	PackedColorModel(ColorSpace the specified `ColorSpace` space, int the number of bits in the pixel values bits, int[] array that specifies the masks representing the bits of the pixel values that represent the color components colorMaskArray, int specifies the mask representing the bits of the pixel values that represent the alpha component alphaMask, boolean `true` if color samples are premultiplied by the alpha sample; `false` otherwise isAlphaPremultiplied, int specifies the alpha value that can be represented by this color model trans, int the type of array used to represent pixel values transferType) Constructs a `PackedColorModel` from a color mask array, which specifies which bits in an `int` pixel representation contain each of the color samples, and an alpha mask.
public	PackedColorModel(ColorSpace the specified `ColorSpace` space, int the number of bits in the pixel values bits, int specifies the mask representing the bits of the pixel values that represent the red color component rmask, int specifies the mask representing the bits of the pixel values that represent the green color component gmask, int specifies the mask representing the bits of the pixel values that represent the blue color component bmask, int specifies the mask representing the bits of the pixel values that represent the alpha component amask, boolean `true` if color samples are premultiplied by the alpha sample; `false` otherwise isAlphaPremultiplied, int specifies the alpha value that can be represented by this color model trans, int the type of array used to represent pixel values transferType) Constructs a `PackedColorModel` from the specified masks which indicate which bits in an `int` pixel representation contain the alpha, red, green and blue color samples.

public

PackedColorModel(ColorSpace

the specified ColorSpace

space, int

the number of bits in the pixel values

bits, int[]

array that specifies the masks representing the bits of the pixel values that represent the color components

colorMaskArray, int

specifies the mask representing the bits of the pixel values that represent the alpha component

alphaMask, boolean

true if color samples are premultiplied by the alpha sample; false otherwise

isAlphaPremultiplied, int

specifies the alpha value that can be represented by this color model

trans, int

the type of array used to represent pixel values

transferType)

Constructs a PackedColorModel from a color mask array, which specifies which bits in an int pixel representation contain each of the color samples, and an alpha mask.

public

PackedColorModel(ColorSpace

the specified ColorSpace

space, int

the number of bits in the pixel values

bits, int

specifies the mask representing the bits of the pixel values that represent the red color component

rmask, int

specifies the mask representing the bits of the pixel values that represent the green color component

gmask, int

specifies the mask representing the bits of the pixel values that represent the blue color component

bmask, int

specifies the mask representing the bits of the pixel values that represent the alpha component

amask, boolean

true if color samples are premultiplied by the alpha sample; false otherwise

isAlphaPremultiplied, int

specifies the alpha value that can be represented by this color model

trans, int

the type of array used to represent pixel values

transferType)

Constructs a PackedColorModel from the specified masks which indicate which bits in an int pixel representation contain the alpha, red, green and blue color samples.

Method Summary

Modifier and Type	Method and Description
private static final int	countBits(int mask)
private static final int[]	createBitsArray(int[] colorMaskArray, int alphaMask)
private static final int[]	createBitsArray(int rmask, int gmask, int bmask, int amask)
public SampleModel	Returns: the newly created `SampleModel`. createCompatibleSampleModel(int the width (in pixels) of the region of the image data described w, int the height (in pixels) of the region of the image data described h) Overrides java.awt.image.ColorModel.createCompatibleSampleModel. Creates a `SampleModel` with the specified width and height that has a data layout compatible with this `ColorModel`.
private void	DecomposeMask(int mask, int idx, String componentName)
public boolean	Returns: `true` if the specified `Object` is an instance of `PackedColorModel` and equals this `PackedColorModel`; `false` otherwise. equals(Object the `Object` to test for equality obj) Overrides java.awt.image.ColorModel.equals. Tests if the specified `Object` is an instance of `PackedColorModel` and equals this `PackedColorModel`.
public WritableRaster	Returns: a `WritableRaster` that represents the alpha channel of the image contained in `raster`. getAlphaRaster(WritableRaster a `WritableRaster` containing an image raster) Overrides java.awt.image.ColorModel.getAlphaRaster. Returns a `WritableRaster` representing the alpha channel of an image, extracted from the input `WritableRaster`.
public final int	Returns: the mask, which indicates which bits of the `int` pixel representation contain the color or alpha sample specified by `index`. getMask(int the specified color or alpha sample index) Returns the mask indicating which bits in a pixel contain the specified color/alpha sample.
public final int[]	Returns: the mask array , which indicates which bits of the `int` pixel representation contain the color or alpha samples. getMasks() Returns a mask array indicating which bits in a pixel contain the color and alpha samples.
public int	Returns: a hash code for this PackedColorModel. hashCode() Overrides java.awt.image.ColorModel.hashCode. Returns the hash code for this PackedColorModel.
public boolean	Returns: `true` if the specified `SampleModel` is compatible with this `ColorModel`; `false` otherwise. isCompatibleSampleModel(SampleModel the specified `SampleModel`, or `null` sm) Overrides java.awt.image.ColorModel.isCompatibleSampleModel. Checks if the specified `SampleModel` is compatible with this `ColorModel`.

Field Detail

hashCode	back to summary
private volatile int hashCode

maskArray	back to summary
pack-priv int[] maskArray

maskOffsets	back to summary
pack-priv int[] maskOffsets

scaleFactors	back to summary
pack-priv float[] scaleFactors

Constructor Detail

PackedColorModel back to summary

PackedColorModel	back to summary
public PackedColorModel(ColorSpace space, int bits, int[] colorMaskArray, int alphaMask, boolean isAlphaPremultiplied, int trans, int transferType) Constructs a `PackedColorModel` from a color mask array, which specifies which bits in an `int` pixel representation contain each of the color samples, and an alpha mask. Color components are in the specified `ColorSpace`. The length of `colorMaskArray` should be the number of components in the `ColorSpace`. All of the bits in each mask must be contiguous and fit in the specified number of least significant bits of an `int` pixel representation. If the `alphaMask` is 0, there is no alpha. If there is alpha, the `boolean isAlphaPremultiplied` specifies how to interpret color and alpha samples in pixel values. If the `boolean` is `true`, color samples are assumed to have been multiplied by the alpha sample. The transparency, `trans`, specifies what alpha values can be represented by this color model. The transfer type is the type of primitive array used to represent pixel values. Parameters space:ColorSpace the specified `ColorSpace` bits:int the number of bits in the pixel values colorMaskArray:int[] array that specifies the masks representing the bits of the pixel values that represent the color components alphaMask:int specifies the mask representing the bits of the pixel values that represent the alpha component isAlphaPremultiplied:boolean `true` if color samples are premultiplied by the alpha sample; `false` otherwise trans:int specifies the alpha value that can be represented by this color model transferType:int the type of array used to represent pixel values Exceptions IllegalArgumentException: if `bits` is less than 1 or greater than 32

public PackedColorModel(ColorSpace space, int bits, int[] colorMaskArray, int alphaMask, boolean isAlphaPremultiplied, int trans, int transferType)

Constructs a PackedColorModel from a color mask array, which specifies which bits in an int pixel representation contain each of the color samples, and an alpha mask. Color components are in the specified ColorSpace. The length of colorMaskArray should be the number of components in the ColorSpace. All of the bits in each mask must be contiguous and fit in the specified number of least significant bits of an int pixel representation. If the alphaMask is 0, there is no alpha. If there is alpha, the boolean isAlphaPremultiplied specifies how to interpret color and alpha samples in pixel values. If the boolean is true, color samples are assumed to have been multiplied by the alpha sample. The transparency, trans, specifies what alpha values can be represented by this color model. The transfer type is the type of primitive array used to represent pixel values.

Parameters

space:ColorSpace: the specified ColorSpace
bits:int: the number of bits in the pixel values
colorMaskArray:int[]: array that specifies the masks representing the bits of the pixel values that represent the color components
alphaMask:int: specifies the mask representing the bits of the pixel values that represent the alpha component
isAlphaPremultiplied:boolean: true if color samples are premultiplied by the alpha sample; false otherwise
trans:int: specifies the alpha value that can be represented by this color model
transferType:int: the type of array used to represent pixel values

Exceptions

IllegalArgumentException:: if bits is less than 1 or greater than 32

PackedColorModel back to summary

PackedColorModel	back to summary
public PackedColorModel(ColorSpace space, int bits, int rmask, int gmask, int bmask, int amask, boolean isAlphaPremultiplied, int trans, int transferType) Constructs a `PackedColorModel` from the specified masks which indicate which bits in an `int` pixel representation contain the alpha, red, green and blue color samples. Color components are in the specified `ColorSpace`, which must be of type ColorSpace.TYPE_RGB. All of the bits in each mask must be contiguous and fit in the specified number of least significant bits of an `int` pixel representation. If `amask` is 0, there is no alpha. If there is alpha, the `boolean isAlphaPremultiplied` specifies how to interpret color and alpha samples in pixel values. If the `boolean` is `true`, color samples are assumed to have been multiplied by the alpha sample. The transparency, `trans`, specifies what alpha values can be represented by this color model. The transfer type is the type of primitive array used to represent pixel values. Parameters space:ColorSpace the specified `ColorSpace` bits:int the number of bits in the pixel values rmask:int specifies the mask representing the bits of the pixel values that represent the red color component gmask:int specifies the mask representing the bits of the pixel values that represent the green color component bmask:int specifies the mask representing the bits of the pixel values that represent the blue color component amask:int specifies the mask representing the bits of the pixel values that represent the alpha component isAlphaPremultiplied:boolean `true` if color samples are premultiplied by the alpha sample; `false` otherwise trans:int specifies the alpha value that can be represented by this color model transferType:int the type of array used to represent pixel values Exceptions IllegalArgumentException: if `space` is not a TYPE_RGB space See Also `ColorSpace`

public PackedColorModel(ColorSpace space, int bits, int rmask, int gmask, int bmask, int amask, boolean isAlphaPremultiplied, int trans, int transferType)

Constructs a PackedColorModel from the specified masks which indicate which bits in an int pixel representation contain the alpha, red, green and blue color samples. Color components are in the specified ColorSpace, which must be of type ColorSpace.TYPE_RGB. All of the bits in each mask must be contiguous and fit in the specified number of least significant bits of an int pixel representation. If amask is 0, there is no alpha. If there is alpha, the boolean isAlphaPremultiplied specifies how to interpret color and alpha samples in pixel values. If the boolean is true, color samples are assumed to have been multiplied by the alpha sample. The transparency, trans, specifies what alpha values can be represented by this color model. The transfer type is the type of primitive array used to represent pixel values.

Parameters

space:ColorSpace: the specified ColorSpace
bits:int: the number of bits in the pixel values
rmask:int: specifies the mask representing the bits of the pixel values that represent the red color component
gmask:int: specifies the mask representing the bits of the pixel values that represent the green color component
bmask:int: specifies the mask representing the bits of the pixel values that represent the blue color component
amask:int: specifies the mask representing the bits of the pixel values that represent the alpha component
isAlphaPremultiplied:boolean: true if color samples are premultiplied by the alpha sample; false otherwise
trans:int: specifies the alpha value that can be represented by this color model
transferType:int: the type of array used to represent pixel values

Exceptions

IllegalArgumentException:: if space is not a TYPE_RGB space

See Also

ColorSpace

Method Detail

countBits	back to summary
private static final int countBits(int mask)

createBitsArray	back to summary
private static final int[] createBitsArray(int[] colorMaskArray, int alphaMask)

createBitsArray	back to summary
private static final int[] createBitsArray(int rmask, int gmask, int bmask, int amask)

createCompatibleSampleModel back to summary

createCompatibleSampleModel	back to summary
public SampleModel createCompatibleSampleModel(int w, int h) Overrides java.awt.image.ColorModel.createCompatibleSampleModel. Creates a `SampleModel` with the specified width and height that has a data layout compatible with this `ColorModel`. Parameters w:int the width (in pixels) of the region of the image data described h:int the height (in pixels) of the region of the image data described Returns:SampleModel the newly created `SampleModel`. Exceptions IllegalArgumentException: if `w` or `h` is not greater than 0 See Also `SampleModel`

public SampleModel createCompatibleSampleModel(int w, int h)

Overrides java.awt.image.ColorModel.createCompatibleSampleModel.

Creates a SampleModel with the specified width and height that has a data layout compatible with this ColorModel.

Parameters

w:int: the width (in pixels) of the region of the image data described
h:int: the height (in pixels) of the region of the image data described

Returns:SampleModel

the newly created SampleModel.

Exceptions

IllegalArgumentException:: if w or h is not greater than 0

See Also

SampleModel

DecomposeMask	back to summary
private void DecomposeMask(int mask, int idx, String componentName)

equals back to summary

equals	back to summary
public boolean equals(Object obj) Overrides java.awt.image.ColorModel.equals. Tests if the specified `Object` is an instance of `PackedColorModel` and equals this `PackedColorModel`. Parameters obj:Object the `Object` to test for equality Returns:boolean `true` if the specified `Object` is an instance of `PackedColorModel` and equals this `PackedColorModel`; `false` otherwise. Annotations @Override

public boolean equals(Object obj)

Overrides java.awt.image.ColorModel.equals.

Tests if the specified Object is an instance of PackedColorModel and equals this PackedColorModel.

Parameters

obj:Object: the Object to test for equality

Returns:boolean

true if the specified Object is an instance of PackedColorModel and equals this PackedColorModel; false otherwise.

Annotations

@Override

getAlphaRaster back to summary

getAlphaRaster	back to summary
public WritableRaster getAlphaRaster(WritableRaster raster) Overrides java.awt.image.ColorModel.getAlphaRaster. Returns a `WritableRaster` representing the alpha channel of an image, extracted from the input `WritableRaster`. This method assumes that `WritableRaster` objects associated with this `ColorModel` store the alpha band, if present, as the last band of image data. Returns `null` if there is no separate spatial alpha channel associated with this `ColorModel`. This method creates a new `WritableRaster`, but shares the data array. Parameters raster:WritableRaster a `WritableRaster` containing an image Returns:WritableRaster a `WritableRaster` that represents the alpha channel of the image contained in `raster`.

public WritableRaster getAlphaRaster(WritableRaster raster)

Overrides java.awt.image.ColorModel.getAlphaRaster.

Returns a WritableRaster representing the alpha channel of an image, extracted from the input WritableRaster. This method assumes that WritableRaster objects associated with this ColorModel store the alpha band, if present, as the last band of image data. Returns null if there is no separate spatial alpha channel associated with this ColorModel. This method creates a new WritableRaster, but shares the data array.

Parameters

raster:WritableRaster: a WritableRaster containing an image

Returns:WritableRaster

a WritableRaster that represents the alpha channel of the image contained in raster.

getMask back to summary

getMask	back to summary
public final int getMask(int index) Returns the mask indicating which bits in a pixel contain the specified color/alpha sample. For color samples, `index` corresponds to the placement of color sample names in the color space. Thus, an `index` equal to 0 for a CMYK ColorSpace would correspond to Cyan and an `index` equal to 1 would correspond to Magenta. If there is alpha, the alpha `index` would be: alphaIndex = numComponents() - 1; Parameters index:int the specified color or alpha sample Returns:int the mask, which indicates which bits of the `int` pixel representation contain the color or alpha sample specified by `index`. Exceptions ArrayIndexOutOfBoundsException: if `index` is greater than the number of components minus 1 in this `PackedColorModel` or if `index` is less than zero

public final int getMask(int index)

Returns the mask indicating which bits in a pixel contain the specified color/alpha sample. For color samples, index corresponds to the placement of color sample names in the color space. Thus, an index equal to 0 for a CMYK ColorSpace would correspond to Cyan and an index equal to 1 would correspond to Magenta. If there is alpha, the alpha index would be:

     alphaIndex = numComponents() - 1;

Parameters

index:int: the specified color or alpha sample

Returns:int

the mask, which indicates which bits of the int pixel representation contain the color or alpha sample specified by index.

Exceptions

ArrayIndexOutOfBoundsException:: if index is greater than the number of components minus 1 in this PackedColorModel or if index is less than zero

getMasks back to summary

getMasks	back to summary
public final int[] getMasks() Returns a mask array indicating which bits in a pixel contain the color and alpha samples. Returns:int[] the mask array , which indicates which bits of the `int` pixel representation contain the color or alpha samples.

public final int[] getMasks()

Returns a mask array indicating which bits in a pixel contain the color and alpha samples.

Returns:int[]: the mask array , which indicates which bits of the int pixel representation contain the color or alpha samples.

hashCode	back to summary
public int hashCode() Overrides java.awt.image.ColorModel.hashCode. Returns the hash code for this PackedColorModel. Returns:int a hash code for this PackedColorModel. Annotations @Override

hashCode

back to summary

public int hashCode()

Overrides java.awt.image.ColorModel.hashCode.

Returns the hash code for this PackedColorModel.

Returns:int

a hash code for this PackedColorModel.

Annotations

@Override

isCompatibleSampleModel back to summary

isCompatibleSampleModel	back to summary
public boolean isCompatibleSampleModel(SampleModel sm) Overrides java.awt.image.ColorModel.isCompatibleSampleModel. Checks if the specified `SampleModel` is compatible with this `ColorModel`. If `sm` is `null`, this method returns `false`. Parameters sm:SampleModel the specified `SampleModel`, or `null` Returns:boolean `true` if the specified `SampleModel` is compatible with this `ColorModel`; `false` otherwise. See Also `SampleModel`

public boolean isCompatibleSampleModel(SampleModel sm)

Overrides java.awt.image.ColorModel.isCompatibleSampleModel.

Checks if the specified SampleModel is compatible with this ColorModel. If sm is null, this method returns false.

Parameters

sm:SampleModel: the specified SampleModel, or null

Returns:boolean

true if the specified SampleModel is compatible with this ColorModel; false otherwise.

See Also

SampleModel

public abstract Class PackedColorModel

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail