java.awt.image

Class RescaleOp

public class RescaleOp extends Object implements BufferedImageOp, RasterOp

RescaleOp is a filter that changes each pixel by a scaling factor and offset. For filtering Rasters, either one scaling factor and offset can be specified, which will be applied to all bands; or a scaling factor and offset can be specified for each band. For BufferedImages, the scaling may apply to both color and alpha components. If only one scaling factor is provided, or if the number of factors provided equals the number of color components, the scaling is performed on all color components. Otherwise, the scaling is performed on all components including alpha. Alpha premultiplication is ignored. After filtering, if color conversion is necessary, the conversion happens, taking alpha premultiplication into account.

Constructor Summary
	RescaleOp(float[] scaleFactors, float[] offsets, RenderingHints hints) Create a new RescaleOp object using the given scale factors and offsets.
	RescaleOp(float scaleFactor, float offset, RenderingHints hints) Create a new RescaleOp object using the given scale factor and offset.

Method Summary
BufferedImage	createCompatibleDestImage(BufferedImage src, ColorModel dstCM)
WritableRaster	createCompatibleDestRaster(Raster src)
BufferedImage	filter(BufferedImage src, BufferedImage dst) Converts the source image using the scale factors and offsets specified in the constructor.
WritableRaster	filter(Raster src, WritableRaster dest)
Rectangle2D	getBounds2D(BufferedImage src)
Rectangle2D	getBounds2D(Raster src)
int	getNumFactors() Returns the number of scaling factors / offsets.
float[]	getOffsets(float[] offsets) Returns the offsets.
Point2D	getPoint2D(Point2D src, Point2D dst)
RenderingHints	getRenderingHints()
float[]	getScaleFactors(float[] scaleFactors) Returns the scaling factors.

Constructor Detail

RescaleOp

public RescaleOp(float[] scaleFactors, float[] offsets, RenderingHints hints)

Create a new RescaleOp object using the given scale factors and offsets. The length of the arrays must be equal to the number of bands (or number of data or color components) of the raster/image that this Op will be used on, otherwise an IllegalArgumentException will be thrown when calling the filter method.

Parameters: scaleFactors an array of scale factors. offsets an array of offsets. hints any rendering hints to use (can be null).

Throws: NullPointerException if the scaleFactors or offsets array is null.

RescaleOp

public RescaleOp(float scaleFactor, float offset, RenderingHints hints)

Create a new RescaleOp object using the given scale factor and offset. The same scale factor and offset will be used on all bands/components.

Parameters: scaleFactor the scale factor to use. offset the offset to use. hints any rendering hints to use (can be null).

Method Detail

createCompatibleDestImage

public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel dstCM)

createCompatibleDestRaster

public WritableRaster createCompatibleDestRaster(Raster src)

filter

public final BufferedImage filter(BufferedImage src, BufferedImage dst)

Converts the source image using the scale factors and offsets 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 image cannot use an IndexColorModel, and the destination image (if one is provided) must have the same size. If the final value of a sample is beyond the range of the color model, it will be clipped to the appropriate maximum / minimum.

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

Returns: The rescaled image.

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

filter

public final WritableRaster filter(Raster src, WritableRaster dest)

getBounds2D

public final Rectangle2D getBounds2D(BufferedImage src)

getBounds2D

public final Rectangle2D getBounds2D(Raster src)

getNumFactors

public final int getNumFactors()

Returns the number of scaling factors / offsets.

Returns: the number of scaling factors / offsets.

getOffsets

public final float[] getOffsets(float[] offsets)

Returns the offsets. This method accepts an optional array, which will be used to store the offsets if not null (this avoids allocating a new array). If this array is too small to hold all the offsets, the array will be filled and the remaining factors discarded.

Parameters: offsets array to store the offsets in (can be null).

Returns: an array of offsets.

getPoint2D

public final Point2D getPoint2D(Point2D src, Point2D dst)

getRenderingHints

public final RenderingHints getRenderingHints()

getScaleFactors

public final float[] getScaleFactors(float[] scaleFactors)

Returns the scaling factors. This method accepts an optional array, which will be used to store the factors if not null (this avoids allocating a new array). If this array is too small to hold all the scaling factors, the array will be filled and the remaining factors discarded.

Parameters: scaleFactors array to store the scaling factors in (can be null).

Returns: an array of scaling factors.