com.github.jaiimageio.impl.common

Class PaletteBuilder

java.lang.Object

com.github.jaiimageio.impl.common.PaletteBuilder

public class PaletteBuilder
extends Object

This class implements the octree quantization method as it is described in the "Graphics Gems" (ISBN 0-12-286166-3, Chapter 4, pages 297-293)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	PaletteBuilder.ColorNode The node of color tree.

Field Summary

Fields

Modifier and Type	Field and Description
protected int	currLevel
protected int	currSize
protected static int	MAXLEVEL maximum of tree depth
protected int	maxNodes
protected int	numNodes
protected PaletteBuilder.ColorNode[]	palette
protected PaletteBuilder.ColorNode[]	reduceList
protected int	requiredSize
protected PaletteBuilder.ColorNode	root
protected RenderedImage	src
protected ColorModel	srcColorModel
protected Raster	srcRaster
protected PaletteBuilder.ColorNode	transColor
protected int	transparency

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PaletteBuilder(RenderedImage src)
protected	PaletteBuilder(RenderedImage src, int size)

Method Summary

Modifier and Type	Method and Description
protected void	buildPalette()
static boolean	canCreatePalette(ImageTypeSpecifier type) Returns true if PaletteBuilder is able to create palette for given image type.
static boolean	canCreatePalette(RenderedImage image) Returns true if PaletteBuilder is able to create palette for given rendered image.
static IndexColorModel	createIndexColorModel(RenderedImage img) Creates an palette representing colors from given image img.
static RenderedImage	createIndexedImage(RenderedImage src) Creates an image representing given image src using IndexColorModel.
protected int	findColorIndex(PaletteBuilder.ColorNode aNode, Color aColor)
protected int	findPaletteEntry(PaletteBuilder.ColorNode aNode, int index, byte[] red, byte[] green, byte[] blue)
protected PaletteBuilder.ColorNode	freeTree(PaletteBuilder.ColorNode aNode)
protected int	getBranchIndex(Color aColor, int aLevel)
protected IndexColorModel	getIndexColorModel()
protected RenderedImage	getIndexedImage()
protected PaletteBuilder.ColorNode	insertNode(PaletteBuilder.ColorNode aNode, Color aColor, int aLevel)
protected void	reduceTree()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAXLEVEL

protected static final int MAXLEVEL

maximum of tree depth

See Also:

Constant Field Values

src

protected RenderedImage src

srcColorModel

protected ColorModel srcColorModel

srcRaster

protected Raster srcRaster

requiredSize

protected int requiredSize

root

protected PaletteBuilder.ColorNode root

numNodes

protected int numNodes

maxNodes

protected int maxNodes

currLevel

protected int currLevel

currSize

protected int currSize

reduceList

protected PaletteBuilder.ColorNode[] reduceList

palette

protected PaletteBuilder.ColorNode[] palette

transparency

protected int transparency

transColor

protected PaletteBuilder.ColorNode transColor

Constructor Detail

PaletteBuilder

protected PaletteBuilder(RenderedImage src)

PaletteBuilder

protected PaletteBuilder(RenderedImage src,
                         int size)

Method Detail

createIndexedImage

public static RenderedImage createIndexedImage(RenderedImage src)

Creates an image representing given image src using IndexColorModel. Lossless conversion is not always possible (e.g. if number of colors in the given image exceeds maximum palette size). Result image then is an approximation constructed by octree quantization method.

Throws:

IllegalArgumentException - if src is null.

UnsupportedOperationException - if implemented method is unable to create approximation of src and canCreatePalette returns false.

See Also:

createIndexColorModel(RenderedImage), canCreatePalette(RenderedImage)

createIndexColorModel

public static IndexColorModel createIndexColorModel(RenderedImage img)

Creates an palette representing colors from given image img. If number of colors in the given image exceeds maximum palette size closest colors would be merged.

Throws:

IllegalArgumentException - if img is null.

UnsupportedOperationException - if implemented method is unable to create approximation of img and canCreatePalette returns false.

See Also:

createIndexedImage(RenderedImage), canCreatePalette(RenderedImage)

canCreatePalette

public static boolean canCreatePalette(ImageTypeSpecifier type)

Returns true if PaletteBuilder is able to create palette for given image type.

Parameters:

type - an instance of ImageTypeSpecifier to be indexed.

Returns:

true if the PaletteBuilder is likely to be able to create palette for this image type.

Throws:

IllegalArgumentException - if type is null.

canCreatePalette

public static boolean canCreatePalette(RenderedImage image)

Returns true if PaletteBuilder is able to create palette for given rendered image.

Parameters:

image - an instance of RenderedImage to be indexed.

Returns:

true if the PaletteBuilder is likely to be able to create palette for this image type.

Throws:

IllegalArgumentException - if image is null.

getIndexedImage

protected RenderedImage getIndexedImage()

findColorIndex

protected int findColorIndex(PaletteBuilder.ColorNode aNode,
                             Color aColor)

buildPalette

protected void buildPalette()

insertNode

protected PaletteBuilder.ColorNode insertNode(PaletteBuilder.ColorNode aNode,
                                              Color aColor,
                                              int aLevel)

getIndexColorModel

protected IndexColorModel getIndexColorModel()

findPaletteEntry

protected int findPaletteEntry(PaletteBuilder.ColorNode aNode,
                               int index,
                               byte[] red,
                               byte[] green,
                               byte[] blue)

getBranchIndex

protected int getBranchIndex(Color aColor,
                             int aLevel)

reduceTree

protected void reduceTree()

freeTree

protected PaletteBuilder.ColorNode freeTree(PaletteBuilder.ColorNode aNode)