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java.lang.Object | +--javax.media.jai.OperationDescriptorImpl | +--javax.media.jai.operator.AffineDescriptor
An OperationDescriptor
describing the "Affine" operation.
The Affine operation performs (possibly filtered) affine mapping on a rendered or renderable source image.
The relationship between the source and the destination pixels is defined as follows. For each pixel (x, y) of the destination, the source value at the fractional subpixel position (x', y') is constructed by means of an Interpolation object and written to the destination. The mapping between the destination pixel (x, y) and the source position (x', y') is given by:
x' = m[0][0] * x + m[0][1] * y + m[0][2] y' = m[1][0] * x + m[1][1] * y + m[1][2]where m is a 3x2 transform matrix that inverts the matrix supplied as the "transform" argument.
When interpolations which require padding the source such as Bilinear
or Bicubic interpolation are specified, the source needs to be extended
such that it has the extra pixels needed to compute all the destination
pixels. This extension is performed via the BorderExtender
class. The type of Border Extension can be specified as a
RenderingHint
to the JAI.create
method.
The parameter, "backgroundValues", is defined to
fill the background with the user-specified background
values. These background values will be translated into background
colors by the ColorModel
when the image is displayed.
With the default value, {0.0}
, of this parameter,
the background pixels are filled with 0s. If the provided array
length is smaller than the number of bands, the first element of
the provided array is used for all the bands. If the provided values
are out of the data range of the destination image, they will be clamped
into the proper range.
If no BorderExtender is specified (is null), the source will not be extended. The transformed image size is still the same as if the source had been extended. However, since there is insufficient source to compute all the destination pixels, only that subset of the destination image's pixels which can be computed will be written in the destination. The rest of the destination will be set to the user-specified background values.
It may be noted that the minX, minY, width and height hints as
specified through the JAI.KEY_IMAGE_LAYOUT
hint in the
RenderingHints
object are not honored, as this operator
calculates the destination image bounds itself. The other
ImageLayout
hints, like tileWidth and tileHeight,
however are honored.
It should be noted that this operation automatically adds a
value of Boolean.TRUE
for the
JAI.KEY_REPLACE_INDEX_COLOR_MODEL
to the given
configuration
so that the operation is performed
on the pixel values instead of being performed on the indices into
the color map if the source(s) have an IndexColorModel
.
This addition will take place only if a value for the
JAI.KEY_REPLACE_INDEX_COLOR_MODEL
has not already been
provided by the user. Note that the configuration
Map
is cloned before the new hint is added to it. The operation can be
smart about the value of the JAI.KEY_REPLACE_INDEX_COLOR_MODEL
RenderingHints
, i.e. while the default value for the
JAI.KEY_REPLACE_INDEX_COLOR_MODEL
is
Boolean.TRUE
, in some cases the operator could set the
default.
"Affine" defines a PropertyGenerator that performs an identical
transformation on the "ROI" property of the source image, which can
be retrieved by calling the getProperty
method with
"ROI" as the property name.
Name | Value |
---|---|
GlobalName | Affine |
LocalName | Affine |
Vendor | com.sun.media.jai |
Description | Performs interpolated affine transform on an image. |
DocURL | http://java.sun.com/products/java-media/jai/forDevelopers/jai-apidocs/javax/media/jai/operator/AffineDescriptor.html |
Version | 1.0 |
arg0Desc | The affine transform matrix. |
arg1Desc | The interpolation method. |
Name | Class Type | Default Value |
---|---|---|
transform | java.awt.geom.AffineTransform | identity transform |
interpolation | javax.media.jai.Interpolation | InterpolationNearest |
backgroundValues | double[] | {0.0} |
AffineTransform
,
Interpolation
,
OperationDescriptor
, Serialized FormFields inherited from class javax.media.jai.OperationDescriptorImpl |
resources, sourceNames, supportedModes |
Fields inherited from interface javax.media.jai.OperationDescriptor |
NO_PARAMETER_DEFAULT |
Constructor Summary | |
AffineDescriptor()
Constructor. |
Method Summary | |
static RenderedOp |
create(RenderedImage source0,
AffineTransform transform,
Interpolation interpolation,
double[] backgroundValues,
RenderingHints hints)
Performs interpolated affine transform on an image. |
static RenderableOp |
createRenderable(RenderableImage source0,
AffineTransform transform,
Interpolation interpolation,
double[] backgroundValues,
RenderingHints hints)
Performs interpolated affine transform on an image. |
PropertyGenerator[] |
getPropertyGenerators()
Returns an array of PropertyGenerators implementing
property inheritance for the "Affine" operation. |
boolean |
isRenderableSupported()
Returns true since renderable operation is supported. |
protected boolean |
validateParameters(ParameterBlock args,
StringBuffer message)
Validates the input parameters. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
public AffineDescriptor()
Method Detail |
public boolean isRenderableSupported()
true
since renderable operation is supported.isRenderableSupported
in class OperationDescriptorImpl
javax.media.jai.OperationDescriptorImpl
OperationDescriptorImpl.isModeSupported(java.lang.String)
public PropertyGenerator[] getPropertyGenerators()
PropertyGenerators
implementing
property inheritance for the "Affine" operation.getPropertyGenerators
in class OperationDescriptorImpl
protected boolean validateParameters(ParameterBlock args, StringBuffer message)
In addition to the standard checks performed by the superclass method, this method checks that "transform" is invertible.
validateParameters
in class OperationDescriptorImpl
javax.media.jai.OperationDescriptorImpl
IllegalArgumentException
- if args
is null
.IllegalArgumentException
- if msg
is null
and the validation fails.OperationDescriptorImpl.validateParameters(java.lang.String, java.awt.image.renderable.ParameterBlock, java.lang.StringBuffer)
public static RenderedOp create(RenderedImage source0, AffineTransform transform, Interpolation interpolation, double[] backgroundValues, RenderingHints hints)
Creates a ParameterBlockJAI
from all
supplied arguments except hints
and invokes
JAI.create(String,ParameterBlock,RenderingHints)
.
source0
- RenderedImage
source 0.transform
- The affine transform matrix.
May be null
.interpolation
- The interpolation method.
May be null
.backgroundValues
- The user-specified background values.
May be null
.hints
- The RenderingHints
to use.
May be null
.RenderedOp
destination.IllegalArgumentException
- if source0
is null
.JAI
,
ParameterBlockJAI
,
RenderedOp
public static RenderableOp createRenderable(RenderableImage source0, AffineTransform transform, Interpolation interpolation, double[] backgroundValues, RenderingHints hints)
Creates a ParameterBlockJAI
from all
supplied arguments except hints
and invokes
JAI.createRenderable(String,ParameterBlock,RenderingHints)
.
source0
- RenderableImage
source 0.transform
- The affine transform matrix.
May be null
.interpolation
- The interpolation method.
May be null
.backgroundValues
- The user-specified background values.
May be null
.hints
- The RenderingHints
to use.
May be null
.RenderableOp
destination.IllegalArgumentException
- if source0
is null
.JAI
,
ParameterBlockJAI
,
RenderableOp
|
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