Package org.carrot2.util

Class ColorQuantizer

java.lang.Object

org.carrot2.util.ColorQuantizer

public class ColorQuantizer
extends Object

A simple utility wrapping the Quantize class to work on BufferedImages and handle transparency.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ColorQuantizer.ColorReductionInfo	Indicates how many distinct colors an image has, whether it has partial transparency (alpha channel).

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_INDEXED_COLORS	Maximum number of colors in an indexed image, leaving one for transparency.

Method Summary

Modifier and Type	Method	Description
static ColorQuantizer.ColorReductionInfo	getColorReductionInfo(BufferedImage source)	Returns a ColorQuantizer.ColorReductionInfo for the provided image.
static BufferedImage	quantize(BufferedImage source)	Quantizes the image to MAX_INDEXED_COLORS with white matte for areas with partial transparency (full transparency will be preserved).
static BufferedImage	quantize(BufferedImage source, Color matteColor)	Quantizes the image to MAX_INDEXED_COLORS with the provided matte Color for areas with partial transparency (full transparency will be preserved).
static BufferedImage	quantize(BufferedImage source, Color matteColor, int maxColors)	Quantizes the image to the provided number of colors with the provided matte Color for areas with partial transparency (full transparency will be preserved).
static BufferedImage	reduce(BufferedImage source)	Reduces a direct color buffered image to an indexed color one without quality loss.

Methods inherited from class java.lang.Object

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

Field Details

MAX_INDEXED_COLORS

public static final int MAX_INDEXED_COLORS

Maximum number of colors in an indexed image, leaving one for transparency.

See Also:

• Constant Field Values

Method Details

quantize

public static BufferedImage quantize(BufferedImage source)

Quantizes the image to MAX_INDEXED_COLORS with white matte for areas with partial transparency (full transparency will be preserved).

Parameters:

source - the source

Returns:

BufferedImage with type BufferedImage.TYPE_BYTE_INDEXED and quantized colors

quantize

public static BufferedImage quantize(BufferedImage source,
 Color matteColor)

Quantizes the image to MAX_INDEXED_COLORS with the provided matte Color for areas with partial transparency (full transparency will be preserved).

Parameters:

source - the source

matteColor - the matte color

Returns:

BufferedImage with type BufferedImage.TYPE_BYTE_INDEXED and quantized colors

quantize

public static BufferedImage quantize(BufferedImage source,
 Color matteColor,
 int maxColors)

Quantizes the image to the provided number of colors with the provided matte Color for areas with partial transparency (full transparency will be preserved).

Parameters:

source - the source

matteColor - the matte color

maxColors - the max colors

Returns:

BufferedImage with type BufferedImage.TYPE_BYTE_INDEXED and quantized colors

reduce

public static BufferedImage reduce(BufferedImage source)

Reduces a direct color buffered image to an indexed color one without quality loss. To make sure no quality loss will occur, check the results of the getColorReductionInfo(BufferedImage) method call.

Parameters:

source - the source

Returns:

the buffered image

Throws:

IllegalArgumentException - if the application of this method would result in image quality loss

getColorReductionInfo

public static ColorQuantizer.ColorReductionInfo getColorReductionInfo(BufferedImage source)

Returns a ColorQuantizer.ColorReductionInfo for the provided image.

Parameters:

source - the source

Returns:

the color reduction info