java.awt.image

Class ConvolveOp

public class ConvolveOp extends Object implements BufferedImageOp, RasterOp

Convolution filter. ConvolveOp convolves the source image with a Kernel to generate a destination image. This involves multiplying each pixel and its neighbors with elements in the kernel to compute a new pixel. Each band in a Raster is convolved and copied to the destination Raster. For BufferedImages, convolution is applied to all components. Color conversion will be applied if needed. Note that this filter ignores whether the source or destination is alpha premultiplied. The reference spec states that data will be premultiplied prior to convolving and divided back out afterwards (if needed), but testing has shown that this is not the case with their implementation.

Field Summary
static int	EDGE_NO_OP Edge pixels are copied from the source.
static int	EDGE_ZERO_FILL Edge pixels are set to 0.

Constructor Summary
	ConvolveOp(Kernel kernel, int edgeCondition, RenderingHints hints) Construct a ConvolveOp.
	ConvolveOp(Kernel kernel) Construct a ConvolveOp.

Method Summary
BufferedImage	createCompatibleDestImage(BufferedImage src, ColorModel dstCM) Creates an empty BufferedImage with the size equal to the source and the correct number of bands.
WritableRaster	createCompatibleDestRaster(Raster src)
BufferedImage	filter(BufferedImage src, BufferedImage dst) Converts the source image using the kernel specified in the constructor.
WritableRaster	filter(Raster src, WritableRaster dest) Converts the source raster using the kernel specified in the constructor.
Rectangle2D	getBounds2D(BufferedImage src)
Rectangle2D	getBounds2D(Raster src)
int	getEdgeCondition() Get the edge condition for this Op.
Kernel	getKernel() Returns (a clone of) the convolution kernel.
Point2D	getPoint2D(Point2D src, Point2D dst) Returns the corresponding destination point for a source point.
RenderingHints	getRenderingHints()

Field Detail

EDGE_NO_OP

public static final int EDGE_NO_OP

Edge pixels are copied from the source.

EDGE_ZERO_FILL

public static final int EDGE_ZERO_FILL

Edge pixels are set to 0.

Constructor Detail

ConvolveOp

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

Construct a ConvolveOp. The edge condition specifies that pixels outside the area that can be filtered are either set to 0 or copied from the source image.

Parameters: kernel The kernel to convolve with. edgeCondition Either EDGE_ZERO_FILL or EDGE_NO_OP. hints Rendering hints for color conversion, or null.

ConvolveOp

public ConvolveOp(Kernel kernel)

Construct a ConvolveOp. The edge condition defaults to EDGE_ZERO_FILL.

Parameters: kernel The kernel to convolve with.

Method Detail

createCompatibleDestImage

public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel dstCM)

Creates an empty BufferedImage with the size equal to the source and the correct number of bands. The new image is created with the specified ColorModel, or if no ColorModel is supplied, an appropriate one is chosen.

Parameters: src The source image. dstCM A color model for the destination image (may be null).

Returns: The new compatible destination image.

createCompatibleDestRaster

public WritableRaster createCompatibleDestRaster(Raster src)

filter

public final BufferedImage filter(BufferedImage src, BufferedImage dst)

Converts the source image using the kernel specified in the constructor. The resulting image is stored in the destination image if one is provided; otherwise a new BufferedImage is created and returned. The source and destination BufferedImage (if one is supplied) must have the same dimensions.

Parameters: src The source image. dst The destination image.

Returns: The convolved image.

Throws: IllegalArgumentException if the rasters and/or color spaces are incompatible.

filter

public final WritableRaster filter(Raster src, WritableRaster dest)

Converts the source raster using the kernel specified in the constructor. The resulting raster is stored in the destination raster if one is provided; otherwise a new WritableRaster is created and returned. If the convolved value for a sample is outside the range of [0-255], it will be clipped. The source and destination raster (if one is supplied) cannot be the same, and must also have the same dimensions.

Parameters: src The source raster. dest The destination raster.

Returns: The transformed raster.

Throws: IllegalArgumentException if the rasters identical. ImagingOpException if the convolution is not possible.

Returns: The edge condition.

getKernel

public final Kernel getKernel()

Returns (a clone of) the convolution kernel.

Returns: The convolution kernel.

getPoint2D

public final Point2D getPoint2D(Point2D src, Point2D dst)

Returns the corresponding destination point for a source point. Because this is not a geometric operation, the destination and source points will be identical.

Parameters: src The source point. dst The transformed destination point.

Returns: The transformed destination point.

getRenderingHints

public final RenderingHints getRenderingHints()