Transparency
DirectColorModel
public abstract class PackedColorModel extends ColorModel
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: getNumComponents
- 1. getNumColorComponents
indices refer to color samples. 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.
pixel_bits, transferType
BITMASK, OPAQUE, TRANSLUCENT
Constructor | Description |
---|---|
PackedColorModel |
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. |
PackedColorModel |
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. |
Modifier and Type | Method | Description |
---|---|---|
SampleModel |
createCompatibleSampleModel |
Creates a SampleModel with the specified width and height that has a data layout compatible with this ColorModel . |
boolean |
equals |
Tests if the specified Object is an instance of PackedColorModel and equals this PackedColorModel . |
WritableRaster |
getAlphaRaster |
Returns a WritableRaster representing the alpha channel of an image, extracted from the input WritableRaster . |
final int |
getMask |
Returns the mask indicating which bits in a pixel contain the specified color/alpha sample. |
final int[] |
getMasks() |
Returns a mask array indicating which bits in a pixel contain the color and alpha samples. |
int |
hashCode() |
Returns the hash code for this PackedColorModel. |
boolean |
isCompatibleSampleModel |
Checks if the specified SampleModel is compatible with this ColorModel . |
coerceData, createCompatibleWritableRaster, getAlpha, getAlpha, getBlue, getBlue, getColorSpace, getComponents, getComponents, getComponentSize, getComponentSize, getDataElement, getDataElement, getDataElements, getDataElements, getDataElements, getGreen, getGreen, getNormalizedComponents, getNormalizedComponents, getNumColorComponents, getNumComponents, getPixelSize, getRed, getRed, getRGB, getRGB, getRGBdefault, getTransferType, getTransparency, getUnnormalizedComponents, hasAlpha, isAlphaPremultiplied, isCompatibleRaster, toString
public PackedColorModel(ColorSpace space, int bits, int[] colorMaskArray, int alphaMask, boolean isAlphaPremultiplied, int trans, int transferType)
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.space
- the specified ColorSpace
bits
- the number of bits in the pixel valuescolorMaskArray
- array that specifies the masks representing the bits of the pixel values that represent the color componentsalphaMask
- specifies the mask representing the bits of the pixel values that represent the alpha componentisAlphaPremultiplied
- true
if color samples are premultiplied by the alpha sample; false
otherwisetrans
- specifies the alpha value that can be represented by this color modeltransferType
- the type of array used to represent pixel valuesIllegalArgumentException
- if bits
is less than 1 or greater than 32public PackedColorModel(ColorSpace space, int bits, int rmask, int gmask, int bmask, int amask, boolean isAlphaPremultiplied, int trans, int transferType)
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.space
- the specified ColorSpace
bits
- the number of bits in the pixel valuesrmask
- specifies the mask representing the bits of the pixel values that represent the red color componentgmask
- specifies the mask representing the bits of the pixel values that represent the green color componentbmask
- specifies the mask representing the bits of the pixel values that represent the blue color componentamask
- specifies the mask representing the bits of the pixel values that represent the alpha componentisAlphaPremultiplied
- true
if color samples are premultiplied by the alpha sample; false
otherwisetrans
- specifies the alpha value that can be represented by this color modeltransferType
- the type of array used to represent pixel valuesIllegalArgumentException
- if space
is not a TYPE_RGB spacepublic final int getMask(int index)
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;
index
- the specified color or alpha sampleint
pixel representation contain the color or alpha sample specified by index
.ArrayIndexOutOfBoundsException
- if index
is greater than the number of components minus 1 in this PackedColorModel
or if index
is less than zeropublic final int[] getMasks()
int
pixel representation contain the color or alpha samples.public SampleModel createCompatibleSampleModel(int w, int h)
SampleModel
with the specified width and height that has a data layout compatible with this ColorModel
.createCompatibleSampleModel
in class ColorModel
w
- the width (in pixels) of the region of the image data describedh
- the height (in pixels) of the region of the image data describedSampleModel
.IllegalArgumentException
- if w
or h
is not greater than 0public boolean isCompatibleSampleModel(SampleModel sm)
SampleModel
is compatible with this ColorModel
. If sm
is null
, this method returns false
.isCompatibleSampleModel
in class ColorModel
sm
- the specified SampleModel
, or null
true
if the specified SampleModel
is compatible with this ColorModel
; false
otherwise.public WritableRaster getAlphaRaster(WritableRaster raster)
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.getAlphaRaster
in class ColorModel
raster
- a WritableRaster
containing an imageWritableRaster
that represents the alpha channel of the image contained in raster
.public boolean equals(Object obj)
Object
is an instance of PackedColorModel
and equals this PackedColorModel
.equals
in class ColorModel
obj
- the Object
to test for equalitytrue
if the specified Object
is an instance of PackedColorModel
and equals this PackedColorModel
; false
otherwise.public int hashCode()
hashCode
in class ColorModel
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