com.jhlabs.image
Class QuantizeFilter

java.lang.Object
  com.jhlabs.image.AbstractBufferedImageOp
      com.jhlabs.image.WholeImageFilter
          com.jhlabs.image.QuantizeFilter

All Implemented Interfaces:

BufferedImageOp, Cloneable

public class QuantizeFilter
extends WholeImageFilter

A filter which quantizes an image to a set number of colors - useful for producing images which are to be encoded using an index color model. The filter can perform Floyd-Steinberg error-diffusion dithering if required. At present, the quantization is done using an octtree algorithm but I eventually hope to add more quantization methods such as median cut. Note: at present, the filter produces an image which uses the RGB color model (because the application it was written for required it). I hope to extend it to produce an IndexColorModel by request.

Field Summary

protected static int[]

matrix Floyd-Steinberg dithering matrix.

Fields inherited from class com.jhlabs.image.WholeImageFilter

originalSpace, transformedSpace

Constructor Summary

QuantizeFilter()

Method Summary

protected int[]	filterPixels(int width, int height, int[] inPixels, Rectangle transformedSpace) Actually filter the pixels.
boolean	getDither() Return the dithering setting
int	getNumColors() Get the number of colors to quantize to.
boolean	getSerpentine() Return the serpentine setting
void	quantize(int[] inPixels, int[] outPixels, int width, int height, int numColors, boolean dither, boolean serpentine)
void	setDither(boolean dither) Set whether to use dithering or not.
void	setNumColors(int numColors) Set the number of colors to quantize to.
void	setSerpentine(boolean serpentine) Set whether to use a serpentine pattern for return or not.
String	toString()

Methods inherited from class com.jhlabs.image.WholeImageFilter

filter, transformSpace

Methods inherited from class com.jhlabs.image.AbstractBufferedImageOp

clone, createCompatibleDestImage, getBounds2D, getPoint2D, getRenderingHints, getRGB, setRGB

Methods inherited from class java.lang.Object

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

Field Detail

matrix

protected static final int[] matrix

Floyd-Steinberg dithering matrix.

Constructor Detail

QuantizeFilter

public QuantizeFilter()

Method Detail

setNumColors

public void setNumColors(int numColors)

Set the number of colors to quantize to.

Parameters:

numColors - the number of colors. The default is 256.

getNumColors

public int getNumColors()

Get the number of colors to quantize to.

Returns:

the number of colors.

setDither

public void setDither(boolean dither)

Set whether to use dithering or not. If not, the image is posterized.

Parameters:

dither - true to use dithering

getDither

public boolean getDither()

Return the dithering setting

Returns:

the current setting

setSerpentine

public void setSerpentine(boolean serpentine)

Set whether to use a serpentine pattern for return or not. This can reduce 'avalanche' artifacts in the output.

Parameters:

serpentine - true to use serpentine pattern

getSerpentine

public boolean getSerpentine()

Return the serpentine setting

Returns:

the current setting

quantize

public void quantize(int[] inPixels,
                     int[] outPixels,
                     int width,
                     int height,
                     int numColors,
                     boolean dither,
                     boolean serpentine)

filterPixels

protected int[] filterPixels(int width,
                             int height,
                             int[] inPixels,
                             Rectangle transformedSpace)

Description copied from class: WholeImageFilter

Actually filter the pixels.

Specified by:

filterPixels in class WholeImageFilter

Parameters:

width - the image width

height - the image height

inPixels - the image pixels

transformedSpace - the output bounds

Returns:

the output pixels

toString

public String toString()

Overrides:

toString in class Object