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Java™ Platform Standard Ed. 6 |
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java.lang.Object java.awt.image.ColorModel java.awt.image.PackedColorModel
public abstract class PackedColorModel
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:
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.
DirectColorModel
,
SinglePixelPackedSampleModel
,
BufferedImage
Field Summary |
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Fields inherited from class java.awt.image.ColorModel |
---|
pixel_bits, transferType |
Fields inherited from interface java.awt.Transparency |
---|
BITMASK, OPAQUE, TRANSLUCENT |
Constructor Summary | |
---|---|
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. |
|
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. |
Method Summary | |
---|---|
SampleModel |
createCompatibleSampleModel(int w,
int h)
Creates a SampleModel with the specified width and
height that has a data layout compatible with this
ColorModel . |
boolean |
equals(Object obj)
Tests if the specified Object is an instance
of PackedColorModel and equals this
PackedColorModel . |
WritableRaster |
getAlphaRaster(WritableRaster raster)
Returns a WritableRaster representing the alpha channel of
an image, extracted from the input WritableRaster . |
int |
getMask(int index)
Returns the mask indicating which bits in a pixel contain the specified color/alpha sample. |
int[] |
getMasks()
Returns a mask array indicating which bits in a pixel contain the color and alpha samples. |
boolean |
isCompatibleSampleModel(SampleModel sm)
Checks if the specified SampleModel is compatible
with this ColorModel . |
Methods inherited from class java.lang.Object |
---|
clone, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
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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 values
IllegalArgumentException
- 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 values
IllegalArgumentException
- if space
is not a
TYPE_RGB spaceColorSpace
Method Detail |
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public 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 sample
int
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
described
SampleModel
.
IllegalArgumentException
- if w
or
h
is not greater than 0SampleModel
public 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.SampleModel
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 image
WritableRaster
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 equality
true
if the specified Object
is an instance of PackedColorModel
and equals this
PackedColorModel
; false
otherwise.Object.hashCode()
,
Hashtable
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Java™ Platform Standard Ed. 6 |
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