java.awt.image
Class RescaleOp

java.lang.Object
  extended by java.awt.image.RescaleOp
All Implemented Interfaces:
BufferedImageOp, RasterOp

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)
          Returns a new BufferedImage that can be used by this BufferedImageOp as the destination image when filtering the specified source image.
 WritableRaster createCompatibleDestRaster(Raster src)
          Returns a raster that can be used by this RasterOp as the destination raster when operating on the specified source raster.
 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)
          Performs an operation on the source raster, returning the result in a writable raster.
 Rectangle2D getBounds2D(BufferedImage src)
          Returns the bounds of the destination image on the basis of this BufferedImageOp being applied to the specified source image.
 Rectangle2D getBounds2D(Raster src)
          Returns the bounds of the destination raster on the basis of this RasterOp being applied to the specified source raster.
 int getNumFactors()
          Returns the number of scaling factors / offsets.
 float[] getOffsets(float[] offsets)
          Returns the offsets.
 Point2D getPoint2D(Point2D src, Point2D dst)
          Returns the point on the destination image that corresponds to the given point on the source image.
 RenderingHints getRenderingHints()
          Returns the rendering hints for this operation.
 float[] getScaleFactors(float[] scaleFactors)
          Returns the scaling factors.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

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

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.

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.

getNumFactors

public final int getNumFactors()
Returns the number of scaling factors / offsets.

Returns:
the number of scaling factors / offsets.

getRenderingHints

public final RenderingHints getRenderingHints()
Description copied from interface: BufferedImageOp
Returns the rendering hints for this operation.

Specified by:
getRenderingHints in interface BufferedImageOp
Specified by:
getRenderingHints in interface RasterOp
Returns:
The rendering hints.

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.

Specified by:
filter in interface BufferedImageOp
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)
Description copied from interface: RasterOp
Performs an operation on the source raster, returning the result in a writable raster. If dest is null, a new WritableRaster will be created by calling the RasterOp.createCompatibleDestRaster(Raster) method. If dest is not null, the result is written to dest then returned (this avoids creating a new WritableRaster each time this method is called).

Specified by:
filter in interface RasterOp
Parameters:
src - the source raster.
dest - the destination raster (null permitted).
Returns:
The filtered raster.

createCompatibleDestImage

public BufferedImage createCompatibleDestImage(BufferedImage src,
                                               ColorModel dstCM)
Description copied from interface: BufferedImageOp
Returns a new BufferedImage that can be used by this BufferedImageOp as the destination image when filtering the specified source image.

Specified by:
createCompatibleDestImage in interface BufferedImageOp
Parameters:
src - the source image.
dstCM - the color model for the destination image.
Returns:
A new image that can be used as the destination image.

createCompatibleDestRaster

public WritableRaster createCompatibleDestRaster(Raster src)
Description copied from interface: RasterOp
Returns a raster that can be used by this RasterOp as the destination raster when operating on the specified source raster.

Specified by:
createCompatibleDestRaster in interface RasterOp
Parameters:
src - the source raster.
Returns:
A new writable raster that can be used as the destination raster.

getBounds2D

public final Rectangle2D getBounds2D(BufferedImage src)
Description copied from interface: BufferedImageOp
Returns the bounds of the destination image on the basis of this BufferedImageOp being applied to the specified source image.

Specified by:
getBounds2D in interface BufferedImageOp
Parameters:
src - the source image.
Returns:
The destination bounds.

getBounds2D

public final Rectangle2D getBounds2D(Raster src)
Description copied from interface: RasterOp
Returns the bounds of the destination raster on the basis of this RasterOp being applied to the specified source raster.

Specified by:
getBounds2D in interface RasterOp
Parameters:
src - the source raster.
Returns:
The destination bounds.

getPoint2D

public final Point2D getPoint2D(Point2D src,
                                Point2D dst)
Description copied from interface: BufferedImageOp
Returns the point on the destination image that corresponds to the given point on the source image.

Specified by:
getPoint2D in interface BufferedImageOp
Specified by:
getPoint2D in interface RasterOp
Parameters:
src - the source point.
dst - the destination point (null permitted).
Returns:
The destination point.