ColorModel abstract class encapsulates the
methods for translating a pixel value to color components
(for example, red, green, and blue) and an alpha component.
In order to render an image to the screen, a printer, or another
image, pixel values must be converted to color and alpha components.
As arguments to or return values from methods of this class,
pixels are represented as 32-bit ints or as arrays of primitive types.
The number, order, and interpretation of color components for a
ColorModel is specified by its ColorSpace.
A ColorModel used with pixel data that does not include
alpha information treats all pixels as opaque, which is an alpha
value of 1.0.
This ColorModel class supports two representations of
pixel values. A pixel value can be a single 32-bit int or an
array of primitive types. The Java(tm) Platform 1.0 and 1.1 APIs
represented pixels as single byte or single
int values. For purposes of the ColorModel
class, pixel value arguments were passed as ints. The Java(tm) 2
Platform API introduced additional classes for representing images.
With BufferedImage
or RenderedImage
objects, based on Raster
and SampleModel
classes, pixel
values might not be conveniently representable as a single int.
Consequently, ColorModel now has methods that accept
pixel values represented as arrays of primitive types. The primitive
type used by a particular ColorModel object is called its
transfer type.
ColorModel objects used with images for which pixel values
are not conveniently representable as a single int throw an
IllegalArgumentException
when methods taking a single int pixel
argument are called. Subclasses of ColorModel must
specify the conditions under which this occurs. This does not
occur with DirectColorModel
or IndexColorModel
objects.
Currently, the transfer types supported by the Java 2D(tm) API are
DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, DataBuffer.TYPE_INT,
DataBuffer.TYPE_SHORT, DataBuffer.TYPE_FLOAT, and DataBuffer.TYPE_DOUBLE.
Most rendering operations will perform much faster when using ColorModels
and images based on the first three of these types. In addition, some
image filtering operations are not supported for ColorModels and
images based on the latter three types.
The transfer type for a particular ColorModel object is
specified when the object is created, either explicitly or by default.
All subclasses of ColorModel must specify what the
possible transfer types are and how the number of elements in the
primitive arrays representing pixels is determined.
For BufferedImages, the transfer type of its
Raster and of the Raster object's
SampleModel (available from the
getTransferType methods of these classes) must match that
of the ColorModel. The number of elements in an array
representing a pixel for the Raster and
SampleModel (available from the
getNumDataElements methods of these classes) must match
that of the ColorModel.
The algorithm used to convert from pixel values to color and alpha
components varies by subclass. For example, there is not necessarily
a one-to-one correspondence between samples obtained from the
SampleModel of a BufferedImage object's
Raster and color/alpha components. Even when
there is such a correspondence, the number of bits in a sample is not
necessarily the same as the number of bits in the corresponding color/alpha
component. Each subclass must specify how the translation from
pixel values to color/alpha components is done.
Methods in the ColorModel class use two different
representations of color and alpha components - a normalized form
and an unnormalized form. In the normalized form, each component is a
float value between some minimum and maximum values. For
the alpha component, the minimum is 0.0 and the maximum is 1.0. For
color components the minimum and maximum values for each component can
be obtained from the ColorSpace object. These values
will often be 0.0 and 1.0 (e.g. normalized component values for the
default sRGB color space range from 0.0 to 1.0), but some color spaces
have component values with different upper and lower limits. These
limits can be obtained using the getMinValue and
getMaxValue methods of the ColorSpace
class. Normalized color component values are not premultiplied.
All ColorModels must support the normalized form.
In the unnormalized
form, each component is an unsigned integral value between 0 and
2n - 1, where n is the number of significant bits for a
particular component. If pixel values for a particular
ColorModel represent color samples premultiplied by
the alpha sample, unnormalized color component values are
also premultiplied. The unnormalized form is used only with instances
of ColorModel whose ColorSpace has minimum
component values of 0.0 for all components and maximum values of
1.0 for all components.
The unnormalized form for color and alpha components can be a convenient
representation for ColorModels whose normalized component
values all lie
between 0.0 and 1.0. In such cases the integral value 0 maps to 0.0 and
the value 2n - 1 maps to 1.0. In other cases, such as
when the normalized component values can be either negative or positive,
the unnormalized form is not convenient. Such ColorModel
objects throw an IllegalArgumentException
when methods involving
an unnormalized argument are called. Subclasses of ColorModel
must specify the conditions under which this occurs.
ColorModel that translates pixels of the
specified number of bits to color/alpha components. The color
space is the default RGB ColorSpace, which is sRGB.
Pixel values are assumed to include alpha information. If color
and alpha information are represented in the pixel value as
separate spatial bands, the color bands are assumed not to be
premultiplied with the alpha value. The transparency type is
java.awt.Transparency.TRANSLUCENT. The transfer type will be the
smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT,
or DataBuffer.TYPE_INT that can hold a single pixel
(or DataBuffer.TYPE_UNDEFINED if bits is greater
than 32). Since this constructor has no information about the
number of bits per color and alpha component, any subclass calling
this constructor should override any method that requires this
information.isAlphaPremultiplied variable, assuming the data is
currently correctly described by this ColorModel. It
may multiply or divide the color raster data by alpha, or do
nothing if the data is in the correct state. If the data needs to
be coerced, this method will also return an instance of this
ColorModel with the isAlphaPremultiplied
flag set appropriately. This method will throw a
UnsupportedOperationException if it is not supported
by this ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.SampleModel with the specified width and
height that has a data layout compatible with this
ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.WritableRaster with the specified width and
height that has a data layout (SampleModel) compatible
with this ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.Object is an instance of
ColorModel and if it equals this
ColorModel.ColorModel once this ColorModel is no
longer referenced.IllegalArgumentException is thrown if pixel
values for this ColorModel are not conveniently
representable as a single int.ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
inData is not large enough to hold a pixel value for
this ColorModel.
If this transferType is not supported, a
UnsupportedOperationException will be
thrown. Since
ColorModel is an abstract class, any instance
must be an instance of a subclass. Subclasses inherit the
implementation of this method and if they don't override it, this
method throws an exception if the subclass uses a
transferType other than
DataBuffer.TYPE_BYTE,
DataBuffer.TYPE_USHORT, or
DataBuffer.TYPE_INT.Raster representing the alpha channel of an
image, extracted from the input Raster, provided that
pixel values of this ColorModel represent color and
alpha information as separate spatial bands (e.g.
ComponentColorModel
and DirectColorModel).
This method assumes that Raster objects associated
with such a 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. If this is an
IndexColorModel which has alpha in the lookup table,
this method will return null since
there is no spatially discrete alpha channel.
This method will create a new Raster (but will share
the data array).
Since ColorModel is an abstract class, any instance
is an instance of a subclass. Subclasses must override this
method to get any behavior other than returning null
because the implementation in this abstract class returns
null.IllegalArgumentException is thrown if pixel values
for this ColorModel are not conveniently representable
as a single int. The returned value is a non pre-multiplied
value, for example, if the alpha is premultiplied, this method
divides it out before returning the value. If the alpha value is
0, the blue value is 0.ColorSpace, sRGB. A
color conversion is done if necessary. The pixel value is
specified by an array of data elements of type transferType passed
in as an object reference. The returned value is a non
pre-multiplied value. For example, if the alpha is premultiplied,
this method divides it out before returning the value. If the
alpha value is 0, the blue value will be 0. If
inData is not a primitive array of type transferType,
a ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is
thrown if inData is not large enough to hold a pixel
value for this ColorModel.
If this transferType is not supported, a
UnsupportedOperationException will be
thrown. Since
ColorModel is an abstract class, any instance
must be an instance of a subclass. Subclasses inherit the
implementation of this method and if they don't override it, this
method throws an exception if the subclass uses a
transferType other than
DataBuffer.TYPE_BYTE,
DataBuffer.TYPE_USHORT, or
DataBuffer.TYPE_INT.ColorSpace associated with this
ColorModel.ColorModel. The pixel value is specified as
an int. An IllegalArgumentException
will be thrown if pixel values for this ColorModel are
not conveniently representable as a single int or if
color component values for this ColorModel are not
conveniently representable in the unnormalized form.
For example, this method can be used to retrieve the
components for a specific pixel value in a
DirectColorModel. If the components array is
null, a new array will be allocated. The
components array will be returned. Color/alpha components are
stored in the components array starting at offset
(even if the array is allocated by this method). An
ArrayIndexOutOfBoundsException is thrown if the
components array is not null and is not large
enough to hold all the color and alpha components (starting at offset).
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.ColorModel. The pixel value is specified by
an array of data elements of type transferType passed in as an
object reference. If pixel is not a primitive array
of type transferType, a ClassCastException is thrown.
An IllegalArgumentException will be thrown if color
component values for this ColorModel are not
conveniently representable in the unnormalized form.
An ArrayIndexOutOfBoundsException is
thrown if pixel is not large enough to hold a pixel
value for this ColorModel.
This method can be used to retrieve the components for a specific
pixel value in any ColorModel. If the components
array is null, a new array will be allocated. The
components array will be returned. Color/alpha components are
stored in the components array starting at
offset (even if the array is allocated by this
method). An ArrayIndexOutOfBoundsException
is thrown if the components array is not null and is
not large enough to hold all the color and alpha components
(starting at offset).
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.ColorSpace, followed by the alpha component, if
present.ColorSpace. Typically, this order reflects the name
of the color space type. For example, for TYPE_RGB, index 0
corresponds to red, index 1 to green, and index 2
to blue. If this ColorModel supports alpha, the alpha
component corresponds to the index following the last color
component.int in this
ColorModel, given an array of normalized color/alpha
components. This method will throw an
IllegalArgumentException if pixel values for this
ColorModel are not conveniently representable as a
single int. An
ArrayIndexOutOfBoundsException is thrown if the
normComponents array is not large enough to hold all the
color and alpha components (starting at normOffset).
Since ColorModel is an abstract class,
any instance is an instance of a subclass. The default implementation
of this method in this abstract class first converts from the
normalized form to the unnormalized form and then calls
getDataElement(int[], int). Subclasses which may
have instances which do not support the unnormalized form must
override this method.int in this
ColorModel, given an array of unnormalized color/alpha
components. This method will throw an
IllegalArgumentException if component values for this
ColorModel are not conveniently representable as a
single int or if color component values for this
ColorModel are not conveniently representable in the
unnormalized form. An
ArrayIndexOutOfBoundsException is thrown if the
components array is not large enough to hold all the
color and alpha components (starting at offset).
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.ColorModel, given an array of normalized color/alpha
components. This array can then be passed to the
setDataElements method of a WritableRaster
object. An ArrayIndexOutOfBoundsException is thrown
if the normComponents array is not large enough to hold
all the color and alpha components (starting at
normOffset). If the obj variable is
null, a new array will be allocated. If
obj is not null, it must be a primitive
array of type transferType; otherwise, a
ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
obj is not large enough to hold a pixel value for this
ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. The default implementation
of this method in this abstract class first converts from the
normalized form to the unnormalized form and then calls
getDataElement(int[], int, Object). Subclasses which may
have instances which do not support the unnormalized form must
override this method.ColorModel, given an array of unnormalized color/alpha
components. This array can then be passed to the
setDataElements method of a WritableRaster
object. This method will throw an IllegalArgumentException
if color component values for this ColorModel are not
conveniently representable in the unnormalized form.
An ArrayIndexOutOfBoundsException is thrown
if the components array is not large enough to hold
all the color and alpha components (starting at
offset). If the obj variable is
null, a new array will be allocated. If
obj is not null, it must be a primitive
array of type transferType; otherwise, a
ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
obj is not large enough to hold a pixel value for this
ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.ColorModel, given an integer pixel representation in
the default RGB color model.
This array can then be passed to the
WritableRaster#setDataElements
method of
a WritableRaster
object. If the pixel variable is
null, a new array will be allocated. If
pixel is not
null, it must be a primitive array of type
transferType; otherwise, a
ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
pixel is
not large enough to hold a pixel value for this
ColorModel. The pixel array is returned.
If this transferType is not supported, a
UnsupportedOperationException will be
thrown. Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.IllegalArgumentException is thrown if pixel
values for this ColorModel are not conveniently
representable as a single int. The returned value is a non
pre-multiplied value. For example, if the alpha is premultiplied,
this method divides it out before returning
the value. If the alpha value is 0, the green value is 0.ColorSpace, sRGB. A
color conversion is done if necessary. The pixel value is
specified by an array of data elements of type transferType passed
in as an object reference. The returned value will be a non
pre-multiplied value. For example, if the alpha is premultiplied,
this method divides it out before returning the value. If the
alpha value is 0, the green value is 0. If inData is
not a primitive array of type transferType, a
ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
inData is not large enough to hold a pixel value for
this ColorModel.
If this transferType is not supported, a
UnsupportedOperationException will be
thrown. Since
ColorModel is an abstract class, any instance
must be an instance of a subclass. Subclasses inherit the
implementation of this method and if they don't override it, this
method throws an exception if the subclass uses a
transferType other than
DataBuffer.TYPE_BYTE,
DataBuffer.TYPE_USHORT, or
DataBuffer.TYPE_INT.ColorSpace object for this
ColorModel. An IllegalArgumentException
will be thrown if color component values for this
ColorModel are not conveniently representable in the
unnormalized form. If the
normComponents array is null, a new array
will be allocated. The normComponents array
will be returned. Color/alpha components are stored in the
normComponents array starting at
normOffset (even if the array is allocated by this
method). An ArrayIndexOutOfBoundsException is thrown
if the normComponents array is not null
and is not large enough to hold all the color and alpha components
(starting at normOffset). An
IllegalArgumentException is thrown if the
components array is not large enough to hold all the
color and alpha components starting at offset.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. The default implementation
of this method in this abstract class assumes that component values
for this class are conveniently representable in the unnormalized
form. Therefore, subclasses which may
have instances which do not support the unnormalized form must
override this method.
ColorModel. The pixel
value is specified by an array of data elements of type transferType
passed in as an object reference. If pixel is not a primitive array
of type transferType, a ClassCastException is thrown.
An ArrayIndexOutOfBoundsException is thrown if
pixel is not large enough to hold a pixel value for this
ColorModel.
Normalized components are float values between a per component minimum
and maximum specified by the ColorSpace object for this
ColorModel. If the
normComponents array is null, a new array
will be allocated. The normComponents array
will be returned. Color/alpha components are stored in the
normComponents array starting at
normOffset (even if the array is allocated by this
method). An ArrayIndexOutOfBoundsException is thrown
if the normComponents array is not null
and is not large enough to hold all the color and alpha components
(starting at normOffset).
Since ColorModel is an abstract class,
any instance is an instance of a subclass. The default implementation
of this method in this abstract class first retrieves color and alpha
components in the unnormalized form using
getComponents(Object, int[], int) and then calls
getNormalizedComponents(int[], int, float[], int).
Subclasses which may
have instances which do not support the unnormalized form must
override this method.ColorModel.
This is the number of components returned by
ColorSpace#getNumComponents
.ColorModel. This is equal to the number of color
components, optionally plus one, if there is an alpha component.ColorModel.IllegalArgumentException is thrown if pixel
values for this ColorModel are not conveniently
representable as a single int. The returned value is not a
pre-multiplied value. For example, if the
alpha is premultiplied, this method divides it out before returning
the value. If the alpha value is 0, the red value is 0.ColorSpace, sRGB. A
color conversion is done if necessary. The pixel value is
specified by an array of data elements of type transferType passed
in as an object reference. The returned value is a non
pre-multiplied value. For example, if alpha is premultiplied,
this method divides it out before returning
the value. If the alpha value is 0, the red value is 0.
If inData is not a primitive array of type
transferType, a ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is thrown if
inData is not large enough to hold a pixel value for
this ColorModel.
If this transferType is not supported, a
UnsupportedOperationException will be
thrown. Since
ColorModel is an abstract class, any instance
must be an instance of a subclass. Subclasses inherit the
implementation of this method and if they don't override it, this
method throws an exception if the subclass uses a
transferType other than
DataBuffer.TYPE_BYTE,
DataBuffer.TYPE_USHORT, or
DataBuffer.TYPE_INT.IllegalArgumentException thrown if pixel values
for this ColorModel are not conveniently representable
as a single int. The returned value is in a non
pre-multiplied format. For example, if the alpha is premultiplied,
this method divides it out of the color components. If the alpha
value is 0, the color values are 0.ClassCastException is thrown. An
ArrayIndexOutOfBoundsException is
thrown if inData is not large enough to hold a pixel
value for this ColorModel.
The returned value will be in a non pre-multiplied format, i.e. if
the alpha is premultiplied, this method will divide it out of the
color components (if the alpha value is 0, the color values will be 0).DirectColorModel that describes the default
format for integer RGB values used in many of the methods in the
AWT image interfaces for the convenience of the programmer.
The color space is the default ColorSpace
, sRGB.
The format for the RGB values is an integer with 8 bits
each of alpha, red, green, and blue color components ordered
correspondingly from the most significant byte to the least
significant byte, as in: 0xAARRGGBB. Color components are
not premultiplied by the alpha component. This format does not
necessarily represent the native or the most efficient
ColorModel for a particular device or for all images.
It is merely used as a common color model format.ColorModel.
The transfer type is the type of primitive array used to represent
pixel values as arrays.Transparency.ColorSpace object for this
ColorModel. An IllegalArgumentException
will be thrown if color component values for this
ColorModel are not conveniently representable in the
unnormalized form. If the
components array is null, a new array
will be allocated. The components array will
be returned. Color/alpha components are stored in the
components array starting at offset (even
if the array is allocated by this method). An
ArrayIndexOutOfBoundsException is thrown if the
components array is not null and is not
large enough to hold all the color and alpha
components (starting at offset). An
IllegalArgumentException is thrown if the
normComponents array is not large enough to hold
all the color and alpha components starting at
normOffset.ColorModel.ColorModel.
If the boolean is true, this ColorModel
is to be used to interpret pixel values in which color and alpha
information are represented as separate spatial bands, and color
samples are assumed to have been multiplied by the
alpha sample.true if raster is compatible
with this ColorModel and false if it is
not.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.SampleModel is compatible with this
ColorModel.
Since ColorModel is an abstract class,
any instance is an instance of a subclass. Subclasses must
override this method since the implementation in this abstract
class throws an UnsupportedOperationException.wait methods.
The awakened thread will not be able to proceed until the current thread relinquishes the lock on this object. The awakened thread will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened thread enjoys no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner of this object's monitor. A thread becomes the owner of the object's monitor in one of three ways:
synchronized statement
that synchronizes on the object.
Class, by executing a
synchronized static method of that class.
Only one thread at a time can own an object's monitor.
wait methods.
The awakened threads will not be able to proceed until the current thread relinquishes the lock on this object. The awakened threads will compete in the usual manner with any other threads that might be actively competing to synchronize on this object; for example, the awakened threads enjoy no reliable privilege or disadvantage in being the next thread to lock this object.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
String representation of the contents of
this ColorModelobject.
The current thread must own this object's monitor. The thread
releases ownership of this monitor and waits until another thread
notifies threads waiting on this object's monitor to wake up
either through a call to the notify method or the
notifyAll method. The thread then waits until it can
re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait();
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.The current thread must own this object's monitor.
This method causes the current thread (call it T) to place itself in the wait set for this object and then to relinquish any and all synchronization claims on this object. Thread T becomes disabled for thread scheduling purposes and lies dormant until one of four things happens:
A thread can also wake up without being notified, interrupted, or timing out, a so-called spurious wakeup. While this will rarely occur in practice, applications must guard against it by testing for the condition that should have caused the thread to be awakened, and continuing to wait if the condition is not satisfied. In other words, waits should always occur in loops, like this one:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout);
... // Perform action appropriate to condition
}
(For more information on this topic, see Section 3.2.3 in Doug Lea's
"Concurrent Programming in Java (Second Edition)" (Addison-Wesley,
2000), or Item 50 in Joshua Bloch's "Effective Java Programming
Language Guide" (Addison-Wesley, 2001).
If the current thread is interrupted by another thread while it is waiting, then an InterruptedException is thrown. This exception is not thrown until the lock status of this object has been restored as described above.
Note that the wait method, as it places the current thread into the wait set for this object, unlocks only this object; any other objects on which the current thread may be synchronized remain locked while the thread waits.
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.
This method is similar to the wait method of one
argument, but it allows finer control over the amount of time to
wait for a notification before giving up. The amount of real time,
measured in nanoseconds, is given by:
1000000*timeout+nanos
In all other respects, this method does the same thing as the method of one argument. In particular, wait(0, 0) means the same thing as wait(0).
The current thread must own this object's monitor. The thread releases ownership of this monitor and waits until either of the following two conditions has occurred:
notify method
or the notifyAll method.
timeout
milliseconds plus nanos nanoseconds arguments, has
elapsed.
The thread then waits until it can re-obtain ownership of the monitor and resumes execution.
As in the one argument version, interrupts and spurious wakeups are possible, and this method should always be used in a loop:
synchronized (obj) {
while (<condition does not hold>)
obj.wait(timeout, nanos);
... // Perform action appropriate to condition
}
This method should only be called by a thread that is the owner
of this object's monitor. See the notify method for a
description of the ways in which a thread can become the owner of
a monitor.