Class ArbitraryPaletteQuantizer
java.lang.Object
net.sourceforge.jiu.ops.Operation
net.sourceforge.jiu.ops.ImageToImageOperation
net.sourceforge.jiu.color.quantization.ArbitraryPaletteQuantizer
- All Implemented Interfaces:
RGBQuantizer
,RGBIndex
public class ArbitraryPaletteQuantizer
extends ImageToImageOperation
implements RGBIndex, RGBQuantizer
A color quantizer that maps an
RGBImage
to any given palette.
This operation is restricted to RGB24Image and palettes with up to 256 colors.
It picks the color from the palette which is closest to the
color to be quantized (with the minimum distance).
This is a rather naive implementation which, for any given color
to be quantized, computes the distance between it and each color
in the palette (read: this operation is rather slow with a large palette and input image).
It uses Manhattan distance (L1) instead of Euclidean distance (L2). This saves a square root operation per distance computation.
There are more sophisticated nearest neighbor algorithms available, left for future extensions.
Usage example
This example maps an RGB truecolor image to some palette we create.
RGB24Image image = ...; // initialize this // create some Palette object that you want to map the image to Palette palette = new Palette(3); // create palette with three entries palette.put(0, 33, 00, 244); // set first color palette.put(1, 0, 240, 193); // set second color palette.put(2, 245, 126, 136); // set third color ArbitraryPaletteQuantizer quantizer = new ArbitraryPaletteQuantizer(palette); quantizer.setInputImage(image); quantizer.process(); PixelImage quantizedImage = quantizer.getOutputImage();
- Since:
- 0.5.0
- Author:
- Marco Schmidt
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final int[]
private final int[]
private int
private Palette
private final int[]
Fields inherited from interface net.sourceforge.jiu.data.RGBIndex
INDEX_BLUE, INDEX_GREEN, INDEX_RED
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Constructor Summary
ConstructorsConstructorDescriptionArbitraryPaletteQuantizer
(Palette palette) Creates a quantizer that will be able to map pixels (or a complete image) to the argument palette. -
Method Summary
Modifier and TypeMethodDescriptionReturns a copy of the palette that was given to the constructor of this class.int
map
(int[] origRgb, int[] quantizedRgb) This method maps a triplet of intensity values to its quantized counterpart and returns the palette index of that quantized color.int
map
(int red, int green, int blue) Finds the best match for the argument color in the palette and returns its index.void
process()
Maps the input image to an output image, using the palette given to the constructor.private void
process
(RGB24Image in, Paletted8Image out) 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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RED
private final int[] RED -
GREEN
private final int[] GREEN -
BLUE
private final int[] BLUE -
palette
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numEntries
private int numEntries
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Constructor Details
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ArbitraryPaletteQuantizer
Creates a quantizer that will be able to map pixels (or a complete image) to the argument palette.
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Method Details
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createPalette
Returns a copy of the palette that was given to the constructor of this class.- Specified by:
createPalette
in interfaceRGBQuantizer
- Returns:
- new copy of the palette this quantizer works on
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map
public int map(int[] origRgb, int[] quantizedRgb) Description copied from interface:RGBQuantizer
This method maps a triplet of intensity values to its quantized counterpart and returns the palette index of that quantized color. The index values for the two arrays are taken from RGBIndex.- Specified by:
map
in interfaceRGBQuantizer
- Parameters:
origRgb
- the three samples red, green and blue for which a good match is searched in the palettequantizedRgb
- will hold the three samples found to be closest to origRgb after the call to this method- Returns:
- int index in the palette of the match quantizedRgb
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map
public int map(int red, int green, int blue) Finds the best match for the argument color in the palette and returns its index. Similar tomap(int[], int[])
, the quantized color is not required and thus a few assignemnts are saved by this method.- Parameters:
red
- red sample of the pixel to be quantizedgreen
- green sample of the pixel to be quantizedblue
- blue sample of the pixel to be quantized- Returns:
- index of the color in the palette that is closest to the argument color
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process
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process
Maps the input image to an output image, using the palette given to the constructor.- 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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