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

This class implements a convolution from the source to the destination. Convolution using a convolution kernel is a spatial operation that computes the output pixel from an input pixel by multiplying the kernel with the surround of the input pixel. This allows the output pixel to be affected by the immediate neighborhood in a way that can be mathematically specified with a kernel.

This class operates with BufferedImage data in which color components are premultiplied with the alpha component. If the Source BufferedImage has an alpha component, and the color components are not premultiplied with the alpha component, then the data are premultiplied before being convolved. If the Destination has color components which are not premultiplied, then alpha is divided out before storing into the Destination (if alpha is 0, the color components are set to 0). If the Destination has no alpha component, then the resulting alpha is discarded after first dividing it out of the color components.

Rasters are treated as having no alpha channel. If the above treatment of the alpha channel in BufferedImages is not desired, it may be avoided by getting the Raster of a source BufferedImage and using the filter method of this class which works with Rasters.

If a RenderingHints object is specified in the constructor, the color rendering hint and the dithering hint may be used when color conversion is required.

Note that the Source and the Destination may not be the same object.

Field Summary

Modifier and Type	Field and Description
public static final int	EDGE_NO_OP Pixels at the edge of the source image are copied to the corresponding pixels in the destination without modification.
public static final int	EDGE_ZERO_FILL Pixels at the edge of the destination image are set to zero.
pack-priv int	edgeHint
pack-priv RenderingHints	hints
pack-priv Kernel	kernel

Constructor Summary

Access	Constructor and Description
public	ConvolveOp(Kernel the specified `Kernel` kernel, int the specified edge condition edgeCondition, RenderingHints the specified `RenderingHints` object hints) Constructs a ConvolveOp given a Kernel, an edge condition, and a RenderingHints object (which may be null).
public	ConvolveOp(Kernel the specified `Kernel` kernel) Constructs a ConvolveOp given a Kernel.

Method Summary

Modifier and Type	Method and Description
public BufferedImage	Returns: a destination `BufferedImage` with the correct size and number of bands. createCompatibleDestImage(BufferedImage Source image for the filter operation. src, ColorModel ColorModel of the destination. Can be null. destCM) Implements java.awt.image.BufferedImageOp.createCompatibleDestImage. Creates a zeroed destination image with the correct size and number of bands.
public WritableRaster	createCompatibleDestRaster(Raster src) Implements java.awt.image.RasterOp.createCompatibleDestRaster. Creates a zeroed destination Raster with the correct size and number of bands, given this source.
public final BufferedImage	Returns: the filtered `BufferedImage` filter(BufferedImage the source `BufferedImage` to filter src, BufferedImage the destination `BufferedImage` for the filtered `src` dst) Implements java.awt.image.BufferedImageOp.filter. Performs a convolution on BufferedImages.
public final WritableRaster	Returns: the filtered `WritableRaster` filter(Raster the source `Raster` to filter src, WritableRaster the destination `WritableRaster` for the filtered `src` dst) Implements java.awt.image.RasterOp.filter. Performs a convolution on Rasters.
public final Rectangle2D	getBounds2D(BufferedImage src) Implements java.awt.image.BufferedImageOp.getBounds2D. Returns the bounding box of the filtered destination image.
public final Rectangle2D	getBounds2D(Raster src) Implements java.awt.image.RasterOp.getBounds2D. Returns the bounding box of the filtered destination Raster.
public int	Returns: the edge condition of this `ConvolveOp`. getEdgeCondition() Returns the edge condition.
public final Kernel	Returns: the `Kernel` of this `ConvolveOp`. getKernel() Returns the Kernel.
public final Point2D	getPoint2D(Point2D srcPt, Point2D dstPt) Implements java.awt.image.BufferedImageOp.getPoint2D, java.awt.image.RasterOp.getPoint2D. Returns the location of the destination point given a point in the source.
public final RenderingHints	getRenderingHints() Implements java.awt.image.BufferedImageOp.getRenderingHints, java.awt.image.RasterOp.getRenderingHints. Returns the rendering hints for this op.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

EDGE_NO_OP	back to summary
public static final int EDGE_NO_OP Pixels at the edge of the source image are copied to the corresponding pixels in the destination without modification. Annotations @Native

EDGE_ZERO_FILL	back to summary
public static final int EDGE_ZERO_FILL Pixels at the edge of the destination image are set to zero. This is the default. Annotations @Native

edgeHint	back to summary
pack-priv int edgeHint

hints	back to summary
pack-priv RenderingHints hints

kernel	back to summary
pack-priv Kernel kernel

Constructor Detail

ConvolveOp back to summary

ConvolveOp	back to summary
public ConvolveOp(Kernel kernel, int edgeCondition, RenderingHints hints) Constructs a ConvolveOp given a Kernel, an edge condition, and a RenderingHints object (which may be null). Parameters kernel:Kernel the specified `Kernel` edgeCondition:int the specified edge condition hints:RenderingHints the specified `RenderingHints` object See Also `Kernel`, `EDGE_NO_OP`, `EDGE_ZERO_FILL`, `java.awt.RenderingHints`

public ConvolveOp(Kernel kernel, int edgeCondition, RenderingHints hints)

Constructs a ConvolveOp given a Kernel, an edge condition, and a RenderingHints object (which may be null).

Parameters

kernel:Kernel: the specified Kernel
edgeCondition:int: the specified edge condition
hints:RenderingHints: the specified RenderingHints object

ConvolveOp back to summary

ConvolveOp	back to summary
public ConvolveOp(Kernel kernel) Constructs a ConvolveOp given a Kernel. The edge condition will be EDGE_ZERO_FILL. Parameters kernel:Kernel the specified `Kernel` See Also `Kernel`, `EDGE_ZERO_FILL`

public ConvolveOp(Kernel kernel)

Constructs a ConvolveOp given a Kernel. The edge condition will be EDGE_ZERO_FILL.

Parameters

kernel:Kernel: the specified Kernel

See Also

Kernel, EDGE_ZERO_FILL

Method Detail

createCompatibleDestImage back to summary

createCompatibleDestImage	back to summary
public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel destCM) Implements java.awt.image.BufferedImageOp.createCompatibleDestImage. Creates a zeroed destination image with the correct size and number of bands. If destCM is null, an appropriate ColorModel will be used. Parameters src:BufferedImage Source image for the filter operation. destCM:ColorModel ColorModel of the destination. Can be null. Returns:BufferedImage a destination `BufferedImage` with the correct size and number of bands.

public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel destCM)

Implements java.awt.image.BufferedImageOp.createCompatibleDestImage.

Creates a zeroed destination image with the correct size and number of bands. If destCM is null, an appropriate ColorModel will be used.

Parameters

src:BufferedImage: Source image for the filter operation.
destCM:ColorModel: ColorModel of the destination. Can be null.

Returns:BufferedImage

a destination BufferedImage with the correct size and number of bands.

createCompatibleDestRaster	back to summary
public WritableRaster createCompatibleDestRaster(Raster src) Implements java.awt.image.RasterOp.createCompatibleDestRaster. Creates a zeroed destination Raster with the correct size and number of bands, given this source.

createCompatibleDestRaster

back to summary

public WritableRaster createCompatibleDestRaster(Raster src)

Implements java.awt.image.RasterOp.createCompatibleDestRaster.

Creates a zeroed destination Raster with the correct size and number of bands, given this source.

filter back to summary

filter	back to summary
public final BufferedImage filter(BufferedImage src, BufferedImage dst) Implements java.awt.image.BufferedImageOp.filter. Performs a convolution on BufferedImages. Each component of the source image will be convolved (including the alpha component, if present). If the color model in the source image is not the same as that in the destination image, the pixels will be converted in the destination. If the destination image is null, a BufferedImage will be created with the source ColorModel. The IllegalArgumentException may be thrown if the source is the same as the destination. Parameters src:BufferedImage the source `BufferedImage` to filter dst:BufferedImage the destination `BufferedImage` for the filtered `src` Returns:BufferedImage the filtered `BufferedImage` Exceptions NullPointerException: if `src` is `null` IllegalArgumentException: if `src` equals `dst` ImagingOpException: if `src` cannot be filtered

public final BufferedImage filter(BufferedImage src, BufferedImage dst)

Implements java.awt.image.BufferedImageOp.filter.

Performs a convolution on BufferedImages. Each component of the source image will be convolved (including the alpha component, if present). If the color model in the source image is not the same as that in the destination image, the pixels will be converted in the destination. If the destination image is null, a BufferedImage will be created with the source ColorModel. The IllegalArgumentException may be thrown if the source is the same as the destination.

Parameters

src:BufferedImage: the source BufferedImage to filter
dst:BufferedImage: the destination BufferedImage for the filtered src

Returns:BufferedImage

the filtered BufferedImage

Exceptions

NullPointerException:: if src is null
IllegalArgumentException:: if src equals dst
ImagingOpException:: if src cannot be filtered

filter back to summary

filter	back to summary
public final WritableRaster filter(Raster src, WritableRaster dst) Implements java.awt.image.RasterOp.filter. Performs a convolution on Rasters. Each band of the source Raster will be convolved. The source and destination must have the same number of bands. If the destination Raster is null, a new Raster will be created. The IllegalArgumentException may be thrown if the source is the same as the destination. Parameters src:Raster the source `Raster` to filter dst:WritableRaster the destination `WritableRaster` for the filtered `src` Returns:WritableRaster the filtered `WritableRaster` Exceptions NullPointerException: if `src` is `null` ImagingOpException: if `src` and `dst` do not have the same number of bands if `src` cannot be filtered IllegalArgumentException: if `src` equals `dst`

public final WritableRaster filter(Raster src, WritableRaster dst)

Implements java.awt.image.RasterOp.filter.

Performs a convolution on Rasters. Each band of the source Raster will be convolved. The source and destination must have the same number of bands. If the destination Raster is null, a new Raster will be created. The IllegalArgumentException may be thrown if the source is the same as the destination.

Parameters

src:Raster: the source Raster to filter
dst:WritableRaster: the destination WritableRaster for the filtered src

Returns:WritableRaster

the filtered WritableRaster

Exceptions

NullPointerException:

if src is null

ImagingOpException:

if src and dst do not have the same number of bands
if src cannot be filtered

IllegalArgumentException:

if src equals dst

getBounds2D	back to summary
public final Rectangle2D getBounds2D(BufferedImage src) Implements java.awt.image.BufferedImageOp.getBounds2D. Returns the bounding box of the filtered destination image. Since this is not a geometric operation, the bounding box does not change.

getBounds2D

back to summary

public final Rectangle2D getBounds2D(BufferedImage src)

Implements java.awt.image.BufferedImageOp.getBounds2D.

Returns the bounding box of the filtered destination image. Since this is not a geometric operation, the bounding box does not change.

getBounds2D	back to summary
public final Rectangle2D getBounds2D(Raster src) Implements java.awt.image.RasterOp.getBounds2D. Returns the bounding box of the filtered destination Raster. Since this is not a geometric operation, the bounding box does not change.

getBounds2D

back to summary

public final Rectangle2D getBounds2D(Raster src)

Implements java.awt.image.RasterOp.getBounds2D.

Returns the bounding box of the filtered destination Raster. Since this is not a geometric operation, the bounding box does not change.

getEdgeCondition back to summary

getEdgeCondition	back to summary
public int getEdgeCondition() Returns the edge condition. Returns:int the edge condition of this `ConvolveOp`. See Also `EDGE_NO_OP`, `EDGE_ZERO_FILL`

public int getEdgeCondition()

Returns the edge condition.

Returns:int: the edge condition of this ConvolveOp.
See Also: EDGE_NO_OP, EDGE_ZERO_FILL

getKernel back to summary

getKernel	back to summary
public final Kernel getKernel() Returns the Kernel. Returns:Kernel the `Kernel` of this `ConvolveOp`.

public final Kernel getKernel()

Returns the Kernel.

Returns:Kernel: the Kernel of this ConvolveOp.

getPoint2D	back to summary
public final Point2D getPoint2D(Point2D srcPt, Point2D dstPt) Implements java.awt.image.BufferedImageOp.getPoint2D, java.awt.image.RasterOp.getPoint2D. Returns the location of the destination point given a point in the source. If dstPt is non-null, it will be used to hold the return value. Since this is not a geometric operation, the srcPt will equal the dstPt.

getPoint2D

back to summary

public final Point2D getPoint2D(Point2D srcPt, Point2D dstPt)

Implements java.awt.image.BufferedImageOp.getPoint2D, java.awt.image.RasterOp.getPoint2D.

Returns the location of the destination point given a point in the source. If dstPt is non-null, it will be used to hold the return value. Since this is not a geometric operation, the srcPt will equal the dstPt.

getRenderingHints	back to summary
public final RenderingHints getRenderingHints() Implements java.awt.image.BufferedImageOp.getRenderingHints, java.awt.image.RasterOp.getRenderingHints. Returns the rendering hints for this op.

getRenderingHints

back to summary

public final RenderingHints getRenderingHints()

Implements java.awt.image.BufferedImageOp.getRenderingHints, java.awt.image.RasterOp.getRenderingHints.

Returns the rendering hints for this op.

public Class ConvolveOp

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Field Detail

Constructor Detail

Method Detail