| java.lang.Object
 java.awt.image.RescaleOp
| RescaleOp | | public class RescaleOp implements BufferedImageOp,RasterOp(Code) | | This class performs a pixel-by-pixel rescaling of the data in the
source image by multiplying the sample values for each pixel by a scale
factor and then adding an offset. The scaled sample values are clipped
to the minimum/maximum representable in the destination image.
The pseudo code for the rescaling operation is as follows:
for each pixel from Source object {
for each band/component of the pixel {
dstElement = (srcElement*scaleFactor) + offset
}
}
For Rasters, rescaling operates on bands. The number of
sets of scaling constants may be one, in which case the same constants
are applied to all bands, or it must equal the number of Source
Raster bands.
For BufferedImages, rescaling operates on color and alpha components.
The number of sets of scaling constants may be one, in which case the
same constants are applied to all color (but not alpha) components.
Otherwise, the number of sets of scaling constants may
equal the number of Source color components, in which case no
rescaling of the alpha component (if present) is performed.
If neither of these cases apply, the number of sets of scaling constants
must equal the number of Source color components plus alpha components,
in which case all color and alpha components are rescaled.
BufferedImage sources with premultiplied alpha data are treated in the same
manner as non-premultiplied images for purposes of rescaling. That is,
the rescaling is done per band on the raw data of the BufferedImage source
without regard to whether the data is premultiplied. If a color conversion
is required to the destination ColorModel, the premultiplied state of
both source and destination will be taken into account for this step.
Images with an IndexColorModel cannot be rescaled.
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 in-place operation is allowed (i.e. the source and destination can
be the same object).
version:
10 Feb 1997
See Also: java.awt.RenderingHints.KEY_COLOR_RENDERING
See Also: java.awt.RenderingHints.KEY_DITHERING |
| Constructor Summary | |
| public | RescaleOp(float[] scaleFactors, float[] offsets, RenderingHints hints)
Constructs a new RescaleOp with the desired scale factors
and offsets. | | public | RescaleOp(float scaleFactor, float offset, RenderingHints hints)
Constructs a new RescaleOp with the desired scale factor
and offset. |
| scaleFactors | | float[] scaleFactors(Code) | | |
| RescaleOp | | public RescaleOp(float[] scaleFactors, float[] offsets, RenderingHints hints)(Code) | | Constructs a new RescaleOp with the desired scale factors
and offsets. The length of the scaleFactor and offset arrays
must meet the restrictions stated in the class comments above.
The RenderingHints argument may be null.
Parameters:
scaleFactors - the specified scale factors
Parameters:
offsets - the specified offsets
Parameters:
hints - the specified RenderingHints, ornull |
| RescaleOp | | public RescaleOp(float scaleFactor, float offset, RenderingHints hints)(Code) | | Constructs a new RescaleOp with the desired scale factor
and offset. The scaleFactor and offset will be applied to
all bands in a source Raster and to all color (but not alpha)
components in a BufferedImage.
The RenderingHints argument may be null.
Parameters:
scaleFactor - the specified scale factor
Parameters:
offset - the specified offset
Parameters:
hints - the specified RenderingHints, ornull |
| createCompatibleDestImage | | public BufferedImage createCompatibleDestImage(BufferedImage src, ColorModel destCM)(Code) | | Creates a zeroed destination image with the correct size and number of
bands.
Parameters:
src - Source image for the filter operation.
Parameters:
destCM - ColorModel of the destination. If null, theColorModel of the source will be used. the zeroed-destination image. |
| createCompatibleDestRaster | | public WritableRaster createCompatibleDestRaster(Raster src)(Code) | | Creates a zeroed-destination Raster with the correct
size and number of bands, given this source.
Parameters:
src - the source Raster the zeroed-destination Raster. |
| filter | | final public BufferedImage filter(BufferedImage src, BufferedImage dst)(Code) | | Rescales the source BufferedImage.
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.
An IllegalArgumentException may be thrown if the number of
scaling factors/offsets in this object does not meet the
restrictions stated in the class comments above, or if the
source image has an IndexColorModel.
Parameters:
src - the BufferedImage to be filtered
Parameters:
dst - the destination for the filtering operation or null the filtered BufferedImage.
throws:
IllegalArgumentException - if the ColorModelof src is an IndexColorModel, or if the number of scaling factors and offsets in thisRescaleOp do not meet the requirements stated in the class comments. |
| filter | | final public WritableRaster filter(Raster src, WritableRaster dst)(Code) | | Rescales the pixel data in the source Raster.
If the destination Raster is null, a new Raster will be created.
The source and destination must have the same number of bands.
Otherwise, an IllegalArgumentException is thrown.
Note that the number of scaling factors/offsets in this object must
meet the restrictions stated in the class comments above.
Otherwise, an IllegalArgumentException is thrown.
Parameters:
src - the Raster to be filtered
Parameters:
dst - the destination for the filtering operation or null the filtered WritableRaster.
throws:
IllegalArgumentException - if src anddst do not have the same number of bands, or if the number of scaling factors and offsets in thisRescaleOp do not meet the requirements stated in the class comments. |
| getBounds2D | | final public Rectangle2D getBounds2D(BufferedImage src)(Code) | | Returns the bounding box of the rescaled destination image. Since
this is not a geometric operation, the bounding box does not
change.
|
| getBounds2D | | final public Rectangle2D getBounds2D(Raster src)(Code) | | Returns the bounding box of the rescaled destination Raster. Since
this is not a geometric operation, the bounding box does not
change.
Parameters:
src - the rescaled destination Raster the bounds of the specified Raster. |
| getNumFactors | | final public int getNumFactors()(Code) | | Returns the number of scaling factors and offsets used in this
RescaleOp.
the number of scaling factors and offsets of this RescaleOp. |
| getOffsets | | final public float[] getOffsets(float offsets)(Code) | | Returns the offsets in the given array. The array is also returned
for convenience. If offsets is null, a new array
will be allocated.
Parameters:
offsets - the array to contain the offsets of this RescaleOp the offsets of this RescaleOp. |
| getPoint2D | | final public Point2D getPoint2D(Point2D srcPt, Point2D dstPt)(Code) | | 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.
Parameters:
srcPt - a point in the source image
Parameters:
dstPt - the destination point or null the location of the destination point. |
| getRenderingHints | | final public RenderingHints getRenderingHints()(Code) | | Returns the rendering hints for this op.
the rendering hints of this RescaleOp. |
| getScaleFactors | | final public float[] getScaleFactors(float scaleFactors)(Code) | | Returns the scale factors in the given array. The array is also
returned for convenience. If scaleFactors is null, a new array
will be allocated.
Parameters:
scaleFactors - the array to contain the scale factors of this RescaleOp the scale factors of this RescaleOp. |
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