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java.awt.image

Class IndexColorModel

Implemented Interfaces:
Transparency
public class IndexColorModel
extends ColorModel
Color model similar to pseudo visual in X11.

This color model maps linear pixel values to actual RGB and alpha colors. Thus, pixel values are indexes into the color map. Each color component is an 8-bit unsigned value.

The IndexColorModel supports a map of valid pixels, allowing the representation of holes in the the color map. The valid map is represented as a BigInteger where each bit indicates the validity of the map entry with the same index.

Colors can have alpha components for transparency support. If alpha component values aren't given, color values are opaque. The model also supports a reserved pixel value to represent completely transparent colors, no matter what the actual color component values are.

IndexColorModel supports anywhere from 1 to 16 bit index values. The allowed transfer types are DataBuffer.TYPE_BYTE and DataBuffer.TYPE_USHORT.

Field Summary

Fields inherited from class java.awt.image.ColorModel

pixel_bits, transferType

Fields inherited from interface java.awt.Transparency

BITMASK, OPAQUE, TRANSLUCENT

Constructor Summary

IndexColorModel(int bits, int size, byte[] reds, byte[] greens, byte[] blues)
Creates a new indexed color model for size color elements with no alpha component.
IndexColorModel(int bits, int size, byte[] reds, byte[] greens, byte[] blues, byte[] alphas)
Creates a new indexed color model for size color elements including alpha.
IndexColorModel(int bits, int size, byte[] reds, byte[] greens, byte[] blues, int trans)
Creates a new indexed color model for size color elements.
IndexColorModel(int bits, int size, byte[] cmap, int start, boolean hasAlpha)
Creates a new indexed color model using the color components in cmap.
IndexColorModel(int bits, int size, byte[] cmap, int start, boolean hasAlpha, int trans)
Construct an IndexColorModel from an array of red, green, blue, and optional alpha components.
IndexColorModel(int bits, int size, int[] cmap, int start, boolean hasAlpha, int trans, int transferType)
Construct an IndexColorModel from an array of size packed colors.
IndexColorModel(int bits, int size, int[] cmap, int start, int transferType, BigInteger validBits)
Construct an IndexColorModel using a colormap with holes.

Method Summary

BufferedImage
convertToIntDiscrete(Raster raster, boolean forceARGB)
Construct a BufferedImage with rgb pixel values from a Raster.
SampleModel
createCompatibleSampleModel(int w, int h)
Creates a SampleModel that is compatible to this color model.
int
getAlpha(int pixel)
Returns the alpha component of the color in the lookup table for the given pixel value.
void
getAlphas(byte[] a)
Fills the supplied array with the alpha component of each color in the lookup table.
int
getBlue(int pixel)
Returns the blue component of the color in the lookup table for the given pixel value.
void
getBlues(byte[] b)
Fills the supplied array with the blue component of each color in the lookup table.
int
getGreen(int pixel)
Returns the green component of the color in the lookup table for the given pixel value.
void
getGreens(byte[] g)
Fills the supplied array with the green component of each color in the lookup table.
int
getMapSize()
Returns the size of the color lookup table.
int
getRGB(int pixel)
Get the RGB color value of the given pixel using the default RGB color model.
void
getRGBs(int[] rgb)
Get the RGB color values of all pixels in the map using the default RGB color model.
int
getRed(int pixel)
Returns the red component of the color in the lookup table for the given pixel value.
void
getReds(byte[] r)
Fills the supplied array with the red component of each color in the lookup table.
int
getTransparentPixel()
Get the index of the transparent color in this color model.
BigInteger
getValidPixels()
Returns a binary value (BigInteger) where each bit represents an entry in the color lookup table.
boolean
isValid()
Return true if all pixels are valid, false otherwise.
boolean
isValid(int pixel)
Return true if the lookup table contains valid data for pixel, and false otherwise.

Methods inherited from class java.awt.image.ColorModel

coerceData, createCompatibleSampleModel, createCompatibleWritableRaster, equals, finalize, getAlpha, getAlpha, getAlphaRaster, getBlue, getBlue, getColorSpace, getComponentSize, getComponentSize, getComponents, getComponents, getDataElement, getDataElement, getDataElements, getDataElements, getDataElements, getGreen, getGreen, getNormalizedComponents, getNormalizedComponents, getNumColorComponents, getNumComponents, getPixelSize, getRGB, getRGB, getRGBdefault, getRed, getRed, getTransferType, getTransparency, getUnnormalizedComponents, hasAlpha, isAlphaPremultiplied, isCompatibleRaster, isCompatibleSampleModel, toString

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       byte[] reds,
                       byte[] greens,
                       byte[] blues)
Creates a new indexed color model for size color elements with no alpha component. Each array must contain at least size elements. For each array, the i-th color is described by reds[i], greens[i] and blues[i].
Parameters:
bits - the number of bits needed to represent size colors.
size - the number of colors in the color map.
reds - the red component of all colors.
greens - the green component of all colors.
blues - the blue component of all colors.
Throws:
IllegalArgumentException - if bits < 1 or bits > 16.
NullPointerException - if any of the arrays is null.
ArrayIndexOutOfBoundsException - if size is greater than the length of the component arrays.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       byte[] reds,
                       byte[] greens,
                       byte[] blues,
                       byte[] alphas)
Creates a new indexed color model for size color elements including alpha. Each array must contain at least size elements. For each array, the i-th color is described by reds[i], greens[i], blues[i] and alphas[i].
Parameters:
bits - the number of bits needed to represent size colors.
size - the number of colors in the color map.
reds - the red component of all colors.
greens - the green component of all colors.
blues - the blue component of all colors.
alphas - the alpha component of all colors (null permitted).
Throws:
IllegalArgumentException - if bits < 1 or bits > 16.
NullPointerException - if reds, greens or blues is null.
ArrayIndexOutOfBoundsException - if size is greater than the length of the component arrays.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       byte[] reds,
                       byte[] greens,
                       byte[] blues,
                       int trans)
Creates a new indexed color model for size color elements. Each array must contain at least size elements. For each array, the i-th color is described by reds[i], greens[i] and blues[i]. All the colors are opaque except for the transparent color.
Parameters:
bits - the number of bits needed to represent size colors
size - the number of colors in the color map
reds - the red component of all colors
greens - the green component of all colors
blues - the blue component of all colors
trans - the index of the transparent color (use -1 for no transparent color).
Throws:
IllegalArgumentException - if bits < 1 or bits > 16.
NullPointerException - if any of the arrays is null.
ArrayIndexOutOfBoundsException - if size is greater than the length of the component arrays.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       byte[] cmap,
                       int start,
                       boolean hasAlpha)
Creates a new indexed color model using the color components in cmap. If hasAlpha is true then cmap contains an alpha component after each of the red, green and blue components.
Parameters:
bits - the number of bits needed to represent size colors
size - the number of colors in the color map
cmap - packed color components
start - the offset of the first color component in cmap
hasAlpha - cmap has alpha values
Throws:
IllegalArgumentException - if bits < 1, bits > 16, or size < 1.
NullPointerException - if cmap is null.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       byte[] cmap,
                       int start,
                       boolean hasAlpha,
                       int trans)
Construct an IndexColorModel from an array of red, green, blue, and optional alpha components. The component values are interleaved as RGB(A).
Parameters:
bits - the number of bits needed to represent size colors
size - the number of colors in the color map
cmap - interleaved color components
start - the offset of the first color component in cmap
hasAlpha - cmap has alpha values
trans - the index of the transparent color
Throws:
IllegalArgumentException - if bits < 1, bits > 16, or size < 1.
NullPointerException - if cmap is null.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       int[] cmap,
                       int start,
                       boolean hasAlpha,
                       int trans,
                       int transferType)
Construct an IndexColorModel from an array of size packed colors. Each int element contains 8-bit red, green, blue, and optional alpha values packed in order. If hasAlpha is false, then all the colors are opaque except for the transparent color.
Parameters:
bits - the number of bits needed to represent size colors
size - the number of colors in the color map
cmap - packed color components
start - the offset of the first color component in cmap
hasAlpha - cmap has alpha values
trans - the index of the transparent color
transferType - DataBuffer.TYPE_BYTE or DataBuffer.TYPE_USHORT.
Throws:
IllegalArgumentException - if bits < 1, bits > 16, or size < 1.
IllegalArgumentException - if transferType is something other than DataBuffer.TYPE_BYTE or DataBuffer.TYPE_USHORT.

IndexColorModel

public IndexColorModel(int bits,
                       int size,
                       int[] cmap,
                       int start,
                       int transferType,
                       BigInteger validBits)
Construct an IndexColorModel using a colormap with holes.

The IndexColorModel is built from the array of ints defining the colormap. Each element contains red, green, blue, and alpha components. The ColorSpace is sRGB. The transparency value is automatically determined.

This constructor permits indicating which colormap entries are valid, using the validBits argument. Each entry in cmap is valid if the corresponding bit in validBits is set.
Parameters:
bits - the number of bits needed to represent size colors.
size - the number of colors in the color map.
cmap - packed color components.
start - the offset of the first color component in cmap.
transferType - DataBuffer.TYPE_BYTE or DataBuffer.TYPE_USHORT.
validBits - a map of the valid entries in cmap.
Throws:
IllegalArgumentException - if bits < 1, bits > 16, or size < 1.
IllegalArgumentException - if transferType is something other than DataBuffer.TYPE_BYTE or DataBuffer.TYPE_USHORT.

Method Details

convertToIntDiscrete

public BufferedImage convertToIntDiscrete(Raster raster,
                                          boolean forceARGB)
Construct a BufferedImage with rgb pixel values from a Raster. Constructs a new BufferedImage in which each pixel is an RGBA int from a Raster with index-valued pixels. If this model has no alpha component or transparent pixel, the type of the new BufferedImage is TYPE_INT_RGB. Otherwise the type is TYPE_INT_ARGB. If forceARGB is true, the type is forced to be TYPE_INT_ARGB no matter what.
Parameters:
raster - The source of pixel values.
forceARGB - True if type must be TYPE_INT_ARGB.
Returns:
New BufferedImage with RBGA int pixel values.

createCompatibleSampleModel

public SampleModel createCompatibleSampleModel(int w,
                                               int h)
Creates a SampleModel that is compatible to this color model. This will be a MultiPixelPackedSampleModel for bits/pixel of 1, 2 or 4, or a ComponentColorModel for the other cases.
Overrides:
createCompatibleSampleModel in interface ColorModel
Parameters:
w - the width of the sample model to create
h - the height of the sample model to create
Returns:
a compatible sample model

getAlpha

public final int getAlpha(int pixel)
Returns the alpha component of the color in the lookup table for the given pixel value. If no alpha channel was specified when the color model was created, then 255 is returned for all pixels except the transparent pixel (if one is defined - see getTransparentPixel()) which returns an alpha of 0.
Overrides:
getAlpha in interface ColorModel
Parameters:
pixel - the pixel lookup value.
Returns:
The alpha component of the color in the lookup table (in the range 0 to 255).
Throws:
ArrayIndexOutOfBoundsException - if pixel is negative.

getAlphas

public final void getAlphas(byte[] a)
Fills the supplied array with the alpha component of each color in the lookup table. If the model has a transparent pixel specified, the alpha for that pixel will be 0.
Parameters:
a - an array that is at least as large as getMapSize().
Throws:
NullPointerException - if a is null.
ArrayIndexOutOfBoundsException - if a has less than getMapSize() elements.

getBlue

public final int getBlue(int pixel)
Returns the blue component of the color in the lookup table for the given pixel value.
Overrides:
getBlue in interface ColorModel
Parameters:
pixel - the pixel lookup value.
Returns:
The blue component of the color in the lookup table.
Throws:
ArrayIndexOutOfBoundsException - if pixel is negative.

getBlues

public final void getBlues(byte[] b)
Fills the supplied array with the blue component of each color in the lookup table.
Parameters:
b - an array that is at least as large as getMapSize().
Throws:
NullPointerException - if b is null.
ArrayIndexOutOfBoundsException - if b has less than getMapSize() elements.

getGreen

public final int getGreen(int pixel)
Returns the green component of the color in the lookup table for the given pixel value.
Overrides:
getGreen in interface ColorModel
Parameters:
pixel - the pixel lookup value.
Returns:
The green component of the color in the lookup table.
Throws:
ArrayIndexOutOfBoundsException - if pixel is negative.

getGreens

public final void getGreens(byte[] g)
Fills the supplied array with the green component of each color in the lookup table.
Parameters:
g - an array that is at least as large as getMapSize().
Throws:
NullPointerException - if g is null.
ArrayIndexOutOfBoundsException - if g has less than getMapSize() elements.

getMapSize

public final int getMapSize()
Returns the size of the color lookup table.
Returns:
The size of the color lookup table.

getRGB

public final int getRGB(int pixel)
Get the RGB color value of the given pixel using the default RGB color model.
Overrides:
getRGB in interface ColorModel
Parameters:
pixel - the pixel lookup value.
Returns:
The RGB color value.
Throws:
ArrayIndexOutOfBoundsException - if pixel is negative.

getRGBs

public final void getRGBs(int[] rgb)
Get the RGB color values of all pixels in the map using the default RGB color model.
Parameters:
rgb - The destination array.

getRed

public final int getRed(int pixel)
Returns the red component of the color in the lookup table for the given pixel value.
Overrides:
getRed in interface ColorModel
Parameters:
pixel - the pixel lookup value.
Returns:
The red component of the color in the lookup table.
Throws:
ArrayIndexOutOfBoundsException - if pixel is negative.

getReds

public final void getReds(byte[] r)
Fills the supplied array with the red component of each color in the lookup table.
Parameters:
r - an array that is at least as large as getMapSize().
Throws:
NullPointerException - if r is null.
ArrayIndexOutOfBoundsException - if r has less than getMapSize() elements.

getTransparentPixel

public final int getTransparentPixel()
Get the index of the transparent color in this color model.
Returns:
The index of the color that is considered transparent, or -1 if there is no transparent color.

getValidPixels

public BigInteger getValidPixels()
Returns a binary value (BigInteger) where each bit represents an entry in the color lookup table. If the bit is on, the entry is valid.
Returns:
The binary value.

isValid

public boolean isValid()
Return true if all pixels are valid, false otherwise.
Returns:
true if all pixels are valid, false otherwise.

isValid

public boolean isValid(int pixel)
Return true if the lookup table contains valid data for pixel, and false otherwise.
Parameters:
pixel - the pixel value used to index the color lookup table.
Returns:
true if pixel is valid, false otherwise.
IndexColorModel.java -- Java class for interpreting Pixel objects Copyright (C) 1999, 2005 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.

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