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IndexColorModel

Name

IndexColorModel

[Graphic: Figure from the text]

Description

The IndexColorModel class is a ColorModel that uses a color map lookup table (with a maximum size of 256) to convert pixel values into their alpha, red, green, and blue component parts.

Class Definition

public class java.awt.image.IndexColorModel
    extends java.awt.image.ColorModel {
  // Constructors
  public IndexColorModel (int bits, int size, 
      byte[] colorMap, int start, boolean hasalpha);
  public IndexColorModel (int bits, int size, 
      byte[] colorMap, int start, boolean hasalpha, int transparent);
  public IndexColorModel (int bits, int size, 
      byte[] red, byte[] green, byte[] blue);
  public IndexColorModel (int bits, int size, 
      byte[] red, byte[] green, byte[] blue, byte[] alpha);
  public IndexColorModel (int bits, int size, 
      byte[] red, byte[] green, byte[] blue, int transparent);
  // Instance Methods
  public final int getAlpha (int pixel);
  public final void getAlphas (byte[] alphas);
  public final int getBlue (int pixel);
  public final void getBlues (byte[] blues);
  public final int getGreen (int pixel);
  public final void getGreens (byte[] greens);
  public final int getMapSize();
  public final int getRed (int pixel);
  public final void getReds (byte[] reds);
  public final int getRGB (int pixel);
  public final int getTransparentPixel();
}

Constructors

IndexColorModel

public IndexColorModel (int bits, int size, byte[] colorMap, int start, boolean hasalpha)

Parameters

bits

The number of bits in a pixel.

size

The number of entries in the color map. Note: this is not the size of the colorMap parameter.

colorMap

Color component values in red, green, blue, alpha order; the alpha component is optional, and may not be present.

start

The starting position in colorMap array.

hasalpha

If hasalpha is true, alpha components are present in colorMap array.

Throws

ArrayIndexOutOfBoundsException

If size is invalid.

Description

Constructs an IndexColorModel object with the given component settings. The size of colorMap must be at least 3*size+start, if hasalpha is false; if hasalpha is true, colorMap.length must be at least 4*size+start.

public IndexColorModel (int bits, int size, byte[] colorMap, int start, boolean hasalpha, int transparent)

Parameters

bits

The number of bits in a pixel.

size

The number of entries in the color map. Note: this is not the size of the colorMap parameter.

colorMap

Color component values in red, green, blue, alpha order; the alpha component is optional, and may not be present.

start

The starting position in colorMap array.

hasalpha

If hasalpha is true, alpha components are present in colorMap array.

transparent

Position of colorMap entry for transparent pixel entry.

Throws

ArrayIndexOutOfBoundsException

If size invalid.

Description

Constructs an IndexColorModel object with the given component settings. The size of colorMap must be at least 3*size+start, if hasalpha is false; if hasalpha is true, colorMap.length must be at least 4*size+start. The color map has a transparent pixel; its location is given by transparent.

public IndexColorModel (int bits, int size, byte[] red, byte[] green, byte[] blue)

Parameters

bits

The number of bits in a pixel.

size

The number of entries in the color map.

red

Red color component values.

green

Green color component values.

blue

Blue color component values.

Throws

ArrayIndexOutOfBoundsException

If size invalid.

Description

Constructs an IndexColorModel object with the given component settings. There is no alpha component. The length of the red, green, and blue arrays must be greater than size.

public IndexColorModel (int bits, int size, byte[] red, byte[] green, byte[] blue, byte[] alpha)

Parameters

bits

The number of bits in a pixel.

size

The number of entries in the color map.

red

Red color component values.

green

Green color component values.

blue

Blue color component values.

alpha

Alpha component values.

Throws

ArrayIndexOutOfBoundsException

If size is invalid.

NullPointerException

If size is positive and alpha array is null.

Description

Constructs an IndexColorModel object with the given component settings. The length of the red, green, blue, and alpha arrays must be greater than size.

public IndexColorModel (int bits, int size, byte[] red, byte[] green, byte[] blue, int transparent)

Parameters

bits

The number of bits in a pixel.

size

The number of entries in the color map.

red

Red color component values.

green

Green color component values.

blue

Blue color component values.

transparent

Position of transparent pixel entry.

Throws

ArrayIndexOutOfBoundsException

If size is invalid.

Description

Constructs an IndexColorModel object with the given component settings. The length of the red, green, blue, and alpha arrays must be greater than size. The color map has a transparent pixel; its location is given by transparent.

Instance Methods

getAlpha

public final int getAlpha (int pixel)

Parameters

pixel

A pixel encoded with this ColorModel.

Returns

The current alpha setting of the pixel.

Overrides

ColorModel.getAlpha(int)

getAlphas

public final void getAlphas (byte[] alphas)

Parameters

alphas

The alpha values of the pixels in the color model.

Description

Copies the alpha values from the color map into the array alphas[].

getBlue

public final int getBlue (int pixel)

Parameters

pixel

A pixel encoded with this ColorModel.

Returns

The current blue setting of the pixel.

Overrides

ColorModel.getBlue(int)

getBlues

public final void getBlues (byte[] blues)

Parameters

blues

The blue values of the pixels in the color model.

Description

Copies the blue values from the color map into the array blues[].

getGreen

public final int getGreen (int pixel)

Parameters

pixel

A pixel encoded with this ColorModel.

Returns

The current green setting of the pixel.

Overrides

ColorModel.getGreen(int)

getGreens

public final void getGreens (byte[] greens)

Parameters

greens

The green values of the pixels in the color model.

Description

Copies the green values from the color map into the array greens[].

getMapSize

public final int getMapSize()

Returns

The current size of the color map table.

getRed

public final int getRed (int pixel)

Parameters

pixel

A pixel encoded with this ColorModel.

Returns

The current red setting of the pixel.

Overrides

ColorModel.getRed(int)

getReds

public final void getReds (byte[] reds)

Parameters

reds

The red values of the pixels in the color model.

Description

Copies the red values from the color map into the array reds[].

getRGB

public final int getRGB (int pixel)

Parameters

pixel

A pixel encoded with this ColorModel.

Returns

The current combined red, green, and blue settings of the pixel.

Overrides

ColorModel.getRGB(int)

Description

Gets the color of pixel in the default RGB color model.

getTransparentPixel

public final int getTransparentPixel()

Returns

The array index for the transparent pixel in the color model.

See Also

ColorModel


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