Class ClusteredDotDither
java.lang.Object
net.sourceforge.jiu.ops.Operation
net.sourceforge.jiu.ops.ImageToImageOperation
net.sourceforge.jiu.color.dithering.ClusteredDotDither
Apply a clustered dot ordered dither to a grayscale image, converting
it to a bilevel image in the process.
Works with
GrayIntegerImage
objects
as input and BilevelImage
objects
as output.
Resolution of both must be the same.
Use one of the predefined dither matrices or have one compiled from
a spot function (given by an object of a class implementing
SpotFunction
).
There are a couple of classes implementing that spot function interface
in the dithering package.
If no matrix is specified, process()
creates a default matrix
by calling setOrder3DitherMatrix()
.
Usage example
ClusteredDotDither dither = new ClusteredDotDither(); dither.setInputImage(image); // some GrayIntegerImage dither.setDitherMatrix(8, 8, new DiamondSpotFunction()); dither.process(); PixelImage ditheredImage = dither.getOutputImage();
Credits
The predefined dither matrices were taken from Netpbm'spgmtopbm
program (the matrices are stored in the
file dithers.h
).
I learned about spot functions and their use from Austin Donnelly's GIMP plugin newsprint - it has extensive comments, and the newsprint website explains the theoretical background.
- Since:
- 0.9.0
- Author:
- Marco Schmidt
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate int[]
private int
private int
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
process()
This method does the actual work of the operation.private void
process
(GrayIntegerImage in, BilevelImage out) private void
void
setDitherMatrix
(int width, int height, int[] data) Sets the dither matrix to be used in this operation.void
setDitherMatrix
(int width, int height, SpotFunction f) Creates and sets a dither matrix of user-defined size and compiles it from a spot function.void
Sets a 6 times 6 elements matrix to be used for dithering.void
Sets an 8 times 8 elements matrix to be used for dithering.void
Sets a 16 times 16 elements matrix to be used for dithering.Methods inherited from class net.sourceforge.jiu.ops.ImageToImageOperation
canInputAndOutputBeEqual, ensureImagesHaveSameResolution, ensureInputImageIsAvailable, ensureOutputImageResolution, getInputImage, getOutputImage, setCanInputAndOutputBeEqual, setInputImage, setOutputImage
Methods inherited from class net.sourceforge.jiu.ops.Operation
addProgressListener, addProgressListeners, getAbort, removeProgressListener, setAbort, setProgress, setProgress
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Field Details
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ditherHeight
private int ditherHeight -
ditherWidth
private int ditherWidth -
ditherData
private int[] ditherData
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Constructor Details
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ClusteredDotDither
public ClusteredDotDither()
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Method Details
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process
Description copied from class:Operation
This method does the actual work of the operation. It must be called after all parameters have been given to the operation object.- Overrides:
process
in classOperation
- Throws:
MissingParameterException
- if any mandatory parameter was not given to the operationWrongParameterException
- if at least one of the input parameters was not initialized appropriately (values out of the valid interval, etc.)
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process
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setDefaults
private void setDefaults() -
setDitherMatrix
public void setDitherMatrix(int width, int height, int[] data) Sets the dither matrix to be used in this operation.- Parameters:
width
- number of entries in horizontal directionheight
- number of entries in vertical directiondata
- matrix entries, in order top to bottom, and in each row left to right- Throws:
IllegalArgumentException
- if width or height are smaller than one or data isnull
or has not at least width times height entries
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setDitherMatrix
Creates and sets a dither matrix of user-defined size and compiles it from a spot function. Creates a matrix from the spot function and callssetDitherMatrix(int, int, int[])
.- Parameters:
width
- width of matrix, must be one or largerheight
- height of matrix, must be one or largerf
- the spot function to be used for compiling the matrix
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setOrder3DitherMatrix
public void setOrder3DitherMatrix()Sets a 6 times 6 elements matrix to be used for dithering. -
setOrder4DitherMatrix
public void setOrder4DitherMatrix()Sets an 8 times 8 elements matrix to be used for dithering. -
setOrder8DitherMatrix
public void setOrder8DitherMatrix()Sets a 16 times 16 elements matrix to be used for dithering.
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