java.lang.Object | |
↳ | java.awt.image.RescaleOp |
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).
Public Constructors | |||||||||||
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Constructs a new RescaleOp with the desired scale factors
and offsets.
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Constructs a new RescaleOp with the desired scale factor
and offset.
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Public Methods | |||||||||||
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Creates a zeroed destination image with the correct size and number of
bands.
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Creates a zeroed-destination
Raster with the correct
size and number of bands, given this source. | |||||||||||
Rescales the source BufferedImage.
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Rescales the pixel data in the source Raster.
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Returns the bounding box of the rescaled destination image.
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Returns the bounding box of the rescaled destination Raster.
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Returns the number of scaling factors and offsets used in this
RescaleOp.
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Returns the offsets in the given array.
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Returns the location of the destination point given a
point in the source.
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Returns the rendering hints for this op.
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Returns the scale factors in the given array.
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Inherited Methods | |||||||||||
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From class
java.lang.Object
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From interface
java.awt.image.BufferedImageOp
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From interface
java.awt.image.RasterOp
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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.
scaleFactors | the specified scale factors |
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offsets | the specified offsets |
hints | the specified RenderingHints , or
null
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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.
scaleFactor | the specified scale factor |
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offset | the specified offset |
hints | the specified RenderingHints , or
null
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Creates a zeroed destination image with the correct size and number of bands.
src | Source image for the filter operation. |
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destCM | ColorModel of the destination. If null, the ColorModel of the source will be used. |
Creates a zeroed-destination Raster
with the correct
size and number of bands, given this source.
src | the source Raster |
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Raster
.
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.
src | the BufferedImage to be filtered |
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dst | the destination for the filtering operation
or null |
BufferedImage
.IllegalArgumentException | if the ColorModel
of src is an IndexColorModel ,
or if the number of scaling factors and offsets in this
RescaleOp do not meet the requirements
stated in the class comments.
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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.
src | the Raster to be filtered |
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dst | the destination for the filtering operation
or null |
WritableRaster
.IllegalArgumentException | if src and
dst do not have the same number of bands,
or if the number of scaling factors and offsets in this
RescaleOp do not meet the requirements
stated in the class comments.
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Returns the bounding box of the rescaled destination image. Since this is not a geometric operation, the bounding box does not change.
src | The BufferedImage to be filtered |
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Rectangle2D
representing the destination
image's bounding box.
Returns the bounding box of the rescaled destination Raster. Since this is not a geometric operation, the bounding box does not change.
src | the rescaled destination Raster |
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Raster
.
Returns the number of scaling factors and offsets used in this RescaleOp.
RescaleOp
.
Returns the offsets in the given array. The array is also returned for convenience. If offsets is null, a new array will be allocated.
offsets | the array to contain the offsets of
this RescaleOp |
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RescaleOp
.
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.
srcPt | a point in the source image |
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dstPt | the destination point or null |
Returns the rendering hints for this op.
RescaleOp
.
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.
scaleFactors | the array to contain the scale factors of
this RescaleOp |
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RescaleOp
.