22 java.awt.image Reference

22.1 AreaAveragingScaleFilter

Description

The AreaAveragingScaleFilter class scales an image using a simple smoothing algorithm.

Class Definition

public class java.awt.image.AreaAveragingScaleFilter
    extends java.awt.image.ReplicateScaleFilter {

  // Constructor
  public AreaAveragingScaleFilter (int width, int height);

  // Instance Methods
  public void setHints (int hints);
  public void setPixels (int x, int y, int w, int h, ColorModel model,
    byte[] pixels, int off, int scansize);

  public void setPixels (int x, int y, int w, int h, ColorModel model,
    int[] pixels, int off, int scansize);
}

Constructor

AreaAveragingScaleFilter

public AreaAveragingScaleFilter (int width, int height)

Parameters	width	Width of scaled image.
	height	Height of scaled image.
Description	Constructs an AverageScaleFilter that scales the original image to the specified size.

Instance Methods

setHints

public void setHints (int hints)

Parameters	hints	Flags indicating how data will be delivered.
Overrides	ImageFilter.setHints(int)
Description	Gives this filter hints about how data will be delivered.

setPixels

public void setPixels (int x, int y, int w, int h,
ColorModel model, byte[] pixels, int off, int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	w	Width of the rectangle of pixel data delivered with this method call.
	h	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	off	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ReplicateScaleFilter.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; scales these pixels and delivers them to any ImageConsumers.
public void setPixels (int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	w	Width of the rectangle of pixel data delivered with this method call.
	h	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	off	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ReplicateScaleFilter.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; scales these pixels and delivers them to any ImageConsumers.

22.2 ColorModel

Description

The abstract ColorModel class defines the way a Java program represents colors. It provides methods for extracting different color components from a pixel.

Class Definition

public class java.awt.image.ColorModel extends java.lang.Object { // Variables protected int pixel_bits; // Constructors public ColorModel (int bits); // Class Methods public static ColorModel getRGBdefault(); // Instance Methods public void finalize(); public abstract int getAlpha (int pixel); public abstract int getBlue (int pixel);

public abstract int getGreen (int pixel); public int getPixelSize(); public abstract int getRed (int pixel); public int getRGB (int pixel); }

ProtectedVariables

pixel_bits

protected int pixel_bits

The pixel_bits variable saves the ColorModel's bits setting (the total number of bits per pixel).

Constructors

ColorModel

public ColorModel (int bits)

Parameters	bits	The number of bits required per pixel using this model.
Description	Constructs a ColorModel object.

Class Methods

getRGBdefault

public static ColorModel getRGBdefault()

Returns

The default ColorModel format, which uses 8 bits for each of a pixel's color components: alpha (transparency), red, green, and blue.

Instance Methods

finalize

public void finalize()

Overrides	Object.finalize()
Description	Cleans up when this object is garbage collected.

getAlpha

public abstract int getAlpha (int pixel)

Parameters	pixel	A pixel encoded with this ColorModel.
Returns	The current alpha setting of the pixel.

getBlue

public abstract int getBlue (int pixel)

Parameters	pixel	A pixel encoded with this ColorModel.
Returns	The current blue setting of the pixel.

getGreen

public abstract int getGreen (int pixel)

Parameters	pixel	A pixel encoded with this ColorModel.
Returns	The current green setting of the pixel.

getPixelSize

public int getPixelSize()

Returns

The current pixel size for the color model.

getRed

public abstract int getRed (int pixel)

Parameters	pixel	A pixel encoded with this ColorModel.
Returns	The current red setting of the pixel.

getRGB

public int getRGB (int pixel)

Parameters	pixel	A pixel encoded with this ColorModel.
Returns	The current combined red, green, and blue settings of the pixel.
Description	Gets the color of pixel in the default RGB color model.

22.3 CropImageFilter

Description

The CropImageFilter class creates a smaller image by cropping (i.e., extracting a rectangular region from) a larger image.

Class Definition

public class java.awt.image.CropImageFilter
    extends java.awt.image.ImageFilter {

  // Constructors
  public CropImageFilter (int x, int y, int width, int height);

  // Instance Methods
  public void setDimensions (int width, int height);
  public void setPixels (int x, int y, int width, int height, ColorModel model,
    byte[] pixels, int offset, int scansize);
  public void setPixels (int x, int y, int width, int height, ColorModel model,
    int[] pixels, int offset, int scansize);
  public void setProperties (Hashtable properties);
}

Constructors

CropImageFilter

public CropImageFilter (int x, int y, int width, int
height)

Parameters	x	x-coordinate of top-left corner of piece to crop.
	y	y-coordinate of top-left corner of piece to crop.
	width	Width of image to crop.
	height	Height of image to crop.
Description	Constructs a CropImageFilter that crops the specified region from the original image.

Instance Methods

setDimensions

public void setDimensions (int width, int height)

Parameters	width	Ignored parameter.
	height	Ignored parameter.
Overrides	ImageFilter.setDimensions(int, int)
Description	Called with the original image's dimensions; these dimensions are ignored. The method in turn calls the ImageConsumer with the dimensions of the cropped image.

setPixels

public void setPixels (int x, int y, int width, int
height, ColorModel model, byte[] pixels, int offset, int
scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; crops these pixels and delivers them to any ImageConsumers.
public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; crops these pixels and delivers them to any ImageConsumers.

setProperties

public void setProperties (Hashtable properties)

Parameters	properties	The properties for the image.
Overrides	ImageFilter.setProperties(Hashtable)
Description	Adds the “croprect” image property to the properties list.

22.4 DirectColorModel

Description

The DirectColorModel class provides a ColorModel that specifies a translation between pixels and alpha, red, green, and blue component values, where the color values are embedded directly within the pixel.

Class Definition

public class java.awt.image.DirectColorModel
    extends java.awt.image.ColorModel {

  // Constructors
  public DirectColorModel (int bits, int redMask, int greenMask,
    int blueMask);
  public DirectColorModel (int bits, int redMask, int greenMask,
    int blueMask,
    int alphaMask);

  // Instance Methods
  public final int getAlpha (int pixel);
  public final int getAlphaMask();
  public final int getBlue (int pixel);
  public final int getBlueMask();
  public final int getGreen (int pixel);
  public final int getGreenMask()
  public final int getRed (int pixel);
  public final int getRedMask();
  public final int getRGB (int pixel);
}

Constructors

DirectColorModel

public DirectColorModel (int bits, int redMask, int
greenMask, int blueMask)

Parameters	bits	The number of bits required per pixel of an image using this model.
	redMask	The location of the red component of a pixel.
	greenMask	The location of the green component of a pixel.
	blueMask	The location of the blue component of a pixel.
Throws	IllegalArgumentException
		If the mask bits are not contiguous or overlap.
Description	Constructs a DirectColorModel object with the given size and color masks; the alpha (transparency) component is not used.
public DirectColorModel (int bits, int redMask, int greenMask, int blueMask, int alphaMask)
Parameters	bits	The number of bits required per pixel of an image using this model.
	redMask	The location of the red component of a pixel.
	greenMask	The location of the green component of a pixel.
	blueMask	The location of the blue component of a pixel.
	alphaMask	The location of the alpha component of a pixel.
Throws	IllegalArgumentException
		If the mask bits are not contiguous or overlap.
Description	Constructs a DirectColorModel object with the given size and color masks.

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)

getAlphaMask

public final int getAlphaMask()

Returns

The current alpha mask setting of the color model.

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)

getBlueMask

public final int getBlueMask()

Returns

The current blue mask setting of the color model.

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)

getGreenMask

public final int getGreenMask()

Returns

The current green mask setting of the color model.

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)

getRedMask

public final int getRedMask()

Returns

The current red mask setting of the color model.

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.

22.5 FilteredImageSource

Description

The FilteredImageSource class acts as glue to put an original ImageProducer and ImageFilter together to create a new image. As the ImageProducer for the new image, FilteredImageSource is responsible for registering image consumers for the new image.

Class Definition

public class java.awt.image.FilteredImageSource
    extends java.lang.Object
    implements java.awt.image.ImageProducer {

  // Constructors
  public FilteredImageSource (ImageProducer original,
      ImageFilter filter);

  // Instance Methods
  public synchronized void addConsumer (ImageConsumer ic);
  public synchronized boolean isConsumer (ImageConsumer ic);
  public synchronized void removeConsumer (ImageConsumer ic);
  public void requestTopDownLeftRightResend (ImageConsumer ic);
  public void startProduction (ImageConsumer ic);
}

Constructors

FilteredImageSource

public FilteredImageSource (ImageProducer original,
ImageFilter filter)

Parameters	original	An ImageProducer that generates the image to be filtered.
	filter	The ImageFilter to use to process image data delivered by original.
Description	Constructs a FilteredImageSource object to filter an image generated by an ImageProducer.

Class Methods

addConsumer

public synchronized void addConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer interested in receiving the new image.
Implements	ImageProducer.addConsumer(ImageConsumer)
Description	Registers an ImageConsumer as interested in Image information.

isConsumer

public synchronized boolean isConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to check.
Returns	true if ImageConsumer is registered with this ImageProducer, false otherwise.
Implements	ImageProducer.isConsumer(ImageConsumer)

removeConsumer

public synchronized void removeConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to remove.
Implements	ImageProducer.removeConsumer(ImageConsumer)
Description	Removes an ImageConsumer from the registered consumers for this ImageProducer.

requestTopDownLeftRightResend

public void requestTopDownLeftRightResend (ImageConsumer
ic)

Parameters	ic	ImageConsumer to communicate with.
Implements	ImageProducer.requestTopDownLeftRightResend()
Description	Requests the retransmission of the Image data in top-down, left-to-right order.

startProduction

public void startProduction (ImageConsumer ic)

Parameters	ic	ImageConsumer to communicate with.
Implements	ImageProducer.startProduction(ImageConsumer)
Description	Registers ImageConsumer as interested in Image information and tells ImageProducer to start creating the filtered Image data immediately.

22.6 ImageConsumer

Description

ImageConsumer is an interface that provides the means to consume pixel data and render it for display.

Interface Definition

public abstract interface java.awt.image.ImageConsumer {

  // Constants
  public final static int COMPLETESCANLINES;
  public final static int IMAGEABORTED;
  public final static int IMAGEERROR;
  public final static int RANDOMPIXELORDER;
  public final static int SINGLEFRAME;
  public final static int SINGLEFRAMEDONE;
  public final static int SINGLEPASS;
  public final static int STATICIMAGEDONE;
  public final static int TOPDOWNLEFTRIGHT;

  // Interface Methods
  public abstract void imageComplete (int status);
  public abstract void setColorModel (ColorModel model);
  public abstract void setDimensions (int width, int height);
  public abstract void setHints (int hints);
  public abstract void setPixels (int x, int y, int width, int height,
      ColorModel model, byte[] pixels, int offset, int scansize);
  public abstract void setPixels (int x, int y, int width, int height,
      ColorModel model, int[] pixels, int offset, int scansize);
  public abstract void setProperties (Hashtable properties);
}

Constants

COMPLETESCANLINES

public final static int COMPLETESCANLINES

Hint flag for the setHints(int) method; indicates that the image will be delivered one or more scanlines at a time.

IMAGEABORTED

public final static int IMAGEABORTED

Status flag for the imageComplete(int) method indicating that the loading process for the image aborted.

IMAGEERROR

public final static int IMAGEERROR

Status flag for the imageComplete(int) method indicating that an error happened during image loading.

RANDOMPIXELORDER

public final static int RANDOMPIXELORDER

Hint flag for the setHints(int) method; indicates that the pixels will be delivered in no particular order.

SINGLEFRAME

public final static int SINGLEFRAME

Hint flag for the setHints(int) method; indicates that the image consists of a single frame.

SINGLEFRAMEDONE

public final static int SINGLEFRAMEDONE

Status flag for the imageComplete(int) method indicating a single frame of the image has loaded.

SINGLEPASS

public final static int SINGLEPASS

Hint flag for the setHints(int) method; indicates that each pixel will be delivered once (i.e., the producer will not make multiple passes over the image).

STATICIMAGEDONE

public final static int STATICIMAGEDONE

Status flag for the imageComplete(int) method indicating that the image has fully and successfully loaded, and that there are no additional frames.

TOPDOWNLEFTRIGHT

public final static int TOPDOWNLEFTRIGHT

Hint flag for the setHints(int) method; indicates that pixels will be delivered in a top to bottom, left to right order.

Interface Methods

imageComplete

public abstract void imageComplete (int status)

Parameters	status	Image loading status flags.
Description	Called when the image, or a frame of an image sequence, is complete to report the completion status.

setColorModel

public abstract void setColorModel (ColorModel model)

Parameters	model	The color model for the image.
Description	Tells the ImageConsumer the color model used for most of the pixels in the image.

setDimensions

public abstract void setDimensions (int width, int height)

Parameters	width	Width for image.
	height	Height for image.
Description	Tells the consumer the image's dimensions.

setHints

public abstract void setHints (int hints)

Parameters	hints	Image consumption hints.
Description	Gives the consumer information about how pixels will be delivered.

setPixels

public abstract void setPixels (int x, int y, int width,
int height, ColorModel model, byte[] pixels, int offset,
int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Description	Delivers a rectangular block of pixels to the image consumer.
public abstract void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Description	Delivers a rectangular block of pixels to the image consumer.

setProperties

public abstract void setProperties (Hashtable properties)

Parameters	properties	The properties for the image.
Description	Delivers a Hashtable that contains the image's properties.

22.7 ImageFilter

Description

The ImageFilter class sits between the ImageProducer and ImageConsumer as an image is being created to provide a filtered version of that image. Image filters are always used in conjunction with a FilteredImageSource. As an implementer of the ImageConsumer interface, an image filter receives pixel data from the original image's source and delivers it to another image consumer. The ImageFilter class implements a null filter (i.e., the new image is the same as the original); to produce a filter that modifies an image, create a subclass of ImageFilter.

Class Definition

public class java.awt.image.ImageFilter
    extends java.lang.Object
    implements java.awt.image.ImageConsumer, java.lang.Cloneable {

  // Variables
  protected ImageConsumer consumer;

  // Constructors
  public ImageFilter();

  // Instance Methods
  public Object clone();
  public ImageFilter getFilterInstance (ImageConsumer ic);
  public void imageComplete (int status);
  public void resendTopDownLeftRight (ImageProducer ip);
  public void setColorModel (ColorModel model);
  public void setDimensions (int width, int height);
  public void setHints (int hints);
  public void setPixels (int x, int y, int width, int height,
      ColorModel model, byte[] pixels, int offset, int scansize);
  public void setPixels (int x, int y, int width, int height,
      ColorModel model, int[] pixels, int offset, int scansize);
  public void setProperties (Hashtable properties);
}

Protected Variables

consumer

protected ImageConsumer consumer

The consumer variable is a reference to the actual ImageConsumer for the Image.

Constructors

ImageFilter

public ImageFilter()

Description

Constructs an empty ImageFilter instance.

Instance Methods

clone

public Object clone()

Overrides

Object.clone() Returns A copy of the ImageFilter instance.

getFilterInstance

public ImageFilter getFilterInstance (ImageConsumer ic)

Parameters	ic	The consumer in question.
Returns	A copy of the ImageFilter instance.
Description	Returns the filter that will do the filtering for ic.

imageComplete

void imageComplete (int status)

Parameters	status	Image loading completion status flags.
Implements	ImageConsumer.imageComplete(int)
Description	Called by the ImageProducer to indicate an image's completion status. ImageFilter passes these flags to the consumer unchanged.

resendTopDownLeftRight

public void resendTopDownLeftRight (ImageProducer ip)

Parameters	ip	The ImageProducer generating the original image.
Description	Called by the ImageConsumer to ask the filter to resend the image data in the top-down, left-to-right order. In ImageFilter, this method calls the same method in the ImageProducer, thus relaying the request.

setColorModel

void setColorModel (ColorModel model)

Parameters	model	The color model for the image.
Implements	ImageConsumer.setColorModel(ColorModel)
Description	Sets the image's color model.

setDimensions

void setDimensions (int width, int height)

Parameters	width	Width for image.
	height	Height for image.
Implements	ImageConsumer.setDimensions(int, int)
Description	Sets the image's dimensions.

setHints

void setHints (int hints)

Parameters	hints	Image consumption hints.
Implements	ImageConsumer.setHints(int)
Description	Called by the ImageProducer to deliver hints about how the image data will be delivered. ImageFilter passes these hints on to the ImageConsumer.

setPixels

void setPixels (int x, int y, int width, int height,
ColorModel model, byte[] pixels, int offset, int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Implements	ImageConsumer.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Delivers a rectangular block of pixels to the ImageFilter. ImageFilter passes these pixels on to the consumer unchanged.
void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Implements	ImageConsumer.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Delivers a rectangular block of pixels to the ImageFilter. ImageFilter passes these pixels on to the consumer unchanged.

setProperties

void setProperties (Hashtable properties)

Parameters	properties	The properties for the image.
Implements	ImageConsumer.setProperties(Hashtable)
Description	Initializes the image's properties. ImageFilter adds the property “filter” to the Hashtable, and passes the result on to the image consumer; the value of the property is the string returned by the filter's toString() method. If the property “filter” is already in the Hashtable, ImageFilter adds the string returned by its toString() method to the value already associated with that property.

22.8 ImageObserver

Description

ImageObserver is an interface that provides constants and the callback mechanism to receive asynchronous information about the status of an image as it loads.

Interface Definition

public abstract interface java.awt.image.ImageObserver {

  // Constants
  public static final int ABORT;
  public static final int ALLBITS;
  public static final int ERROR;
  public static final int FRAMEBITS;
  public static final int HEIGHT;
  public static final int PROPERTIES;
  public static final int SOMEBITS;
  public static final int WIDTH;

  // Interface Methods
  public abstract boolean imageUpdate (Image image, int infoflags,
     int x, int y, int width, int height);
}

Constants

ABORT

public static final int ABORT

The ABORT flag indicates that the image aborted during loading. An attempt to reload the image may succeed, unless ERROR is also set.

ALLBITS

public static final int ALLBITS

The ALLBITS flag indicates that the image has completely loaded successfully.

The x, y, width, and height arguments to imageUpdate() should be ignored.

ERROR

public static final int ERROR

The ERROR flag indicates that an error happened during the image loading process. An attempt to reload the image will fail.

FRAMEBITS

public static final int FRAMEBITS

The FRAMEBITS flag indicates that a complete frame of a multi-frame image has loaded. The x, y, width, and height arguments to imageUpdate() should be ignored.

HEIGHT

public static final int HEIGHT

The HEIGHT flag indicates that the height information is available for an image; the image's height is in the height argument to imageUpdate().

PROPERTIES

public static final int PROPERTIES

The PROPERTIES flag indicates that the properties information is available for an image.

SOMEBITS

public static final int SOMEBITS

The SOMEBITS flag indicates that the image has started loading and some pixels are available. The bounding rectangle for the pixels that have been delivered so far is indicated by the x, y, width, and height arguments to imageUpdate().

WIDTH

public static final int WIDTH

The WIDTH flag indicates that the width information is available for an image; the image's width is in the width argument to imageUpdate().

Interface Methods

imageUpdate

public abstract boolean imageUpdate (Image image, int
infoflags, int x, int y, int width, int height)

Parameters	image	Image that is being loaded.
	infoflags	The ImageObserver flags for the information that is currently available.
	x	Meaning depends on infoflags that are set.
	y	Meaning depends on infoflags that are set.
	width	Meaning depends on infoflags that are set.
	height	Meaning depends on infoflags that are set.
Returns	true if image has completed loading (successfully or unsuccessfully), false if additional information needs to be loaded.
Description	Provides the callback mechanism for the asynchronous loading of images.

22.9 ImageProducer

Description

ImageProducer is an interface that provides the methods necessary for the production of images and the communication with classes that implement the ImageConsumer interface.

Interface Definition

public abstract interface java.awt.image.ImageProducer {

  // Interface Methods
  public abstract void addConsumer (ImageConsumer ic);
  public abstract boolean isConsumer (ImageConsumer ic);
  public abstract void removeConsumer (ImageConsumer ic);
  public abstract void requestTopDownLeftRightResend (ImageConsumer ic);
  public abstract void startProduction (ImageConsumer ic);
}

Interface Methods

addConsumer

public abstract void addConsumer (ImageConsumer ic)

Parameters	ic	An ImageConsumer that wants to receive image data.
Description	Registers an ImageConsumer as interested in image information.

isConsumer

public abstract boolean isConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to check.
Returns	true if ImageConsumer has registered with the ImageProducer, false otherwise.

removeConsumer

public abstract void removeConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to remove.
Description	Removes an ImageConsumer from registered consumers for this ImageProducer.

requestTopDownLeftRightResend

public abstract void requestTopDownLeftRightResend
(ImageConsumer ic)

Parameters	ic	ImageConsumer to communicate with.
Description	Requests the retransmission of the image data in top-down, leftto- right order.

startProduction

public abstract void startProduction (ImageConsumer ic)

Parameters	ic	ImageConsumer to communicate with.
Description	Registers ImageConsumer as interested in image information and tells ImageProducer to start sending the image data immediately.

22.10 IndexColorModel

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 3size+start, if hasalpha is false; if hasalpha is true, colorMap.length must be at least 4size+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 3size+start, if hasalpha is false; if hasalpha is true, colorMap.length must be at least 4size+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.

22.11 MemoryImageSource

Description

The MemoryImageSource class allows you to create images completely in memory. You provide an array of data; it serves as an image producer for that data. In the 1.1 release, new methods support using this class for animation (notably setAnimated() and the various overrides of newPixels()).

Class Definition

public class java.awt.image.MemoryImageSource extends java.lang.Object implements java.awt.image.ImageProducer { // Constructors public MemoryImageSource (int w, int h, ColorModel cm, byte[] pix, int off, int scan); public MemoryImageSource (int w, int h, ColorModel cm, byte[] pix, int off, int scan, Hashtable props); public MemoryImageSource (int w, int h, ColorModel cm, int[] pix, int off, int scan); public MemoryImageSource (int w, int h, ColorModel cm, int[] pix, int off, int scan, Hashtable props); public MemoryImageSource (int w, int h, int[] pix, int off, int scan); public MemoryImageSource (int w, int h, int[] pix, int off, int scan, Hashtable props); // Instance Methods public synchronized void addConsumer (ImageConsumer ic); public synchronized boolean isConsumer (ImageConsumer ic); public void newPixels(); public synchronized void newPixels (int x, int y, int w, int h); public synchronized void newPixels (int x, int y, int w, int h, boolean framenotify); public synchronized void newPixels (byte[] newpix, ColorModel newmodel, int offset, int scansize); public synchronized void newPixels (int[] newpix, ColorModel newmodel, int offset, int scansize); public synchronized void removeConsumer (ImageConsumer ic); public void requestTopDownLeftRightResend (ImageConsumer ic); public synchronized void setAnimated (boolean animated); public synchronized void setFullBufferUpdates (boolean fullbuffers); public void startProduction (ImageConsumer ic); }

Constructors

MemoryImageSource

public MemoryImageSource (int w, int h, ColorModel cm,
byte[] pix, int off, int scan)

Parameters	w	Width of the image being created.
	h	Height of the image being created.
	cm	ColorModel of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.
public MemoryImageSource (int w, int h, ColorModel cm, byte[] pix, int off, int scan, Hashtable props)
Parameters	w	Width of the image being created.
	h	Height of the image being created.
	cm	ColorModel of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
	props	Hashtable of properties associated with image.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.
public MemoryImageSource (int w, int h, ColorModel cm, int[] pix, int off, int scan)
Parameters	w	Width of the image being created.
	h	Height of the image being created.
	cm	ColorModel of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.
public MemoryImageSource (int w, int h, ColorModel cm, int[] pix, int off, int scan, Hashtable props)
Parameters	w	Width of the image being created.
	h	Height of the image being created.
	cm	ColorModel of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
	props	Hashtable of properties associated with image.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.
public MemoryImageSource (int w, int h, int[] pix, int off, int scan)
Parameters	w	Width of the image being created.
	h	Height of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.
public MemoryImageSource (int w, int h, int[] pix, int off, int scan, Hashtable props)
Parameters	w	Width of the image being created.
	h	Height of the image being created.
	pix	Array of pixel information.
	off	The offset of the first pixel in the array; elements prior to this pixel are ignored.
	scan	The number of pixels per scan line in the array.
	props	Hashtable of properties associated with image.
Description	Constructs a MemoryImageSource object with the given parameters to serve as an ImageProducer for a new image.

Class Methods

addConsumer

public synchronized void addConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer requesting image data.
Implements	ImageProducer.addConsumer(ImageConsumer)
Description	Registers an ImageConsumer as interested in Image information.

isConsumer

public synchronized boolean isConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to check.
Returns	true if ImageConsumer is registered with this ImageProducer, false otherwise.
Implements	ImageProducer.isConsumer(ImageConsumer)

newPixels

public synchronized void newPixels()

Description	Notifies the MemoryImageSource that there is new data available. The MemoryImageSource notifies all ImageConsumers that there is new data, sending the full rectangle and notifying the consumers that the frame is complete.
public synchronized void newPixels (int x, int y, int w, int h, boolean framenotify)
Parameters	x	x coordinate of the top left corner of the new image data.
	y	y coordinate of the top left corner of the new image data.
	w	Width of the new image data.
	h	Height of the new image data.
Description	Notifies the MemoryImageSource that there is new data available. The MemoryImageSource notifies all ImageConsumers that there is new data in the rectangle described by x, y, w, and h. The consumers are notified that the frame is complete.
public synchronized void newPixels (int x, int y, int w, int h, boolean framenotify)
Parameters	x	x coordinate of the top left corner of the new image data.
	y	y coordinate of the top left corner of the new image data.
	w	Width of the new image data.
	h	Height of the new image data.
	framenotify	Determines whether this is a complete frame or not.
Description	Notifies the MemoryImageSource that there is new data available. The MemoryImageSource notifies all ImageConsumers that there is new data in the rectangle described by x, y, w, and h. If framenotify is true, the consumers will also be notified that a frame is complete.
public synchronized void newPixels (byte[] newpix, ColorModel newmodel, int offset, int scansize)
Parameters	newpix	New array of image data.
	newmodel	The color model to use for the new data.
	offset	Offset into the data array
	scansize	Size of each line.
Description	Changes the image data for this MemoryImageSource and notifies its ImageConsumers that new data is available.
public synchronized void newPixels (int[] newpix, ColorModel newmodel, int offset, int scansize)
Parameters	newpix	New array of image data.
	newmodel	The color model to use for the new data.
	offset	Offset into the data array
	scansize	Size of each line.
Description	Changes the image data for this MemoryImageSource and notifies its ImageConsumers that new data is available.

removeConsumer

public void removeConsumer (ImageConsumer ic)

Parameters	ic	ImageConsumer to remove.
Implements	ImageProducer.removeConsumer(ImageConsumer)
Description	Removes an ImageConsumer from registered consumers for this ImageProducer.

requestTopDownLeftRightResend

public void requestTopDownLeftRightResend (ImageConsumer
ic)

Parameters	ic	ImageConsumer requesting image data.
Implements	ImageProducer.requestTopDownLeftRightResend(ImageConsumer)
Description	Requests the retransmission of the Image data in top-down, left-to-right order.

setAnimated

public void setAnimated (boolean animated)

Parameters	animated	Flag indicating whether this image is animated.
Description	To use this MemoryImageSource for animation, call setAnimated(true). The newPixels() methods will not work otherwise.

setFullBufferUpdates

public void setFullBufferUpdates (boolean fullbuffers)

Parameters	fullbuffers	true to send full buffers; false otherwise.
Description	This method is only important for animations; i.e., you should call setAnimated(true) before using this function. If you do request to send full buffers, then any rectangle parameters passed to newPixels() will be ignored and the entire image will be sent to the consumers.

startProduction

public void startProduction (ImageConsumer ic)

Parameters	ic	ImageConsumer requesting image data.
Implements	ImageProducer.startProduction(ImageConsumer)
Description	Registers ImageConsumer as interested in Image information and tells ImageProducer to start sending the image data immediately.

22.12 PixelGrabber

Description

The PixelGrabber class is an ImageConsumer that captures the pixels from an image and saves them in an array.

Class Definition

public class java.awt.image.PixelGrabber extends java.lang.Object implements java.awt.image.ImageConsumer { // Constructors public PixelGrabber (Image img, int x, int y, int w, int h, boolean forceRGB); public PixelGrabber (Image image, int x, int y, int width, int height, int[] pixels, int offset, int scansize); public PixelGrabber (ImageProducer ip, int x, int y, int width, int height, int[] pixels, int offset, int scansize); // Instance Methods public synchronized void abortGrabbing(); public synchronized ColorModel getColorModel();

public synchronized int getHeight(); public synchronized Object getPixels(); public synchronized int getStatus(); public synchronized int getWidth(); public boolean grabPixels() throws InterruptedException; public synchronized boolean grabPixels (long ms) throws InterruptedException; public synchronized void imageComplete (int status); public void setColorModel (ColorModel model); public void setDimensions (int width, int height); public void setHints (int hints); public void setPixels (int x, int y, int width, int height, ColorModel model, byte[] pixels, int offset, int scansize); public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize); public void setProperties (Hashtable properties); public synchronized void startGrabbing(); public synchronized int status(); }

Constructors

PixelGrabber

public PixelGrabber (Image img, int x, int y, int w, int h, boolean forceRGB)

Parameters	img	Image to use as source of pixel data.
	x	x-coordinate of top-left corner of pixel data.
	y	y-coordinate of top-left corner of pixel data.
	w	Width of pixel data.
	h	Height of pixel data.
	forceRGB	true to force the use of the RGB color model; false otherwise.
Description	Constructs a PixelGrabber instance to grab the specified area of the image.
public PixelGrabber (Image image, int x, int y, int width, int height, int[] pixels, int offset, int scansize)
Parameters	image	Image to use as source of pixel data.
	x	x-coordinate of top-left corner of pixel data.
	y	y-coordinate of top-left corner of pixel data.
	width	Width of pixel data.
	height	Height of pixel data.
	pixels	Where to store pixel data when grabPixels() called.
	offset	Offset from beginning of each line in pixels array.
	scansize	Size of each line of data in pixels array.
Description	Constructs a PixelGrabber instance to grab the specified area of the image and store the pixel data from this area in the array pixels[].
public PixelGrabber (ImageProducer ip, int x, int y, int width, int height, int[] pixels, int offset, int scansize)
Parameters	ip	ImageProducer to use as source of pixel data.
	x	x-coordinate of top-left corner of pixel data.
	y	y-coordinate of top-left corner of pixel data.
	width	Width of pixel data.
	height	Height of pixel data.
	pixels	Where to store pixel data when grabPixels() called.
	offset	Offset from beginning of each line in pixels array.
	scansize	Size of each line of data in pixels array.
Description	Constructs a PixelGrabber instance to grab data from the specified area of the image generated by an ImageProducer and store the pixel data from this area in the array pixels[].

Instance Methods

abortGrabbing

public synchronized void abortGrabbing()

Description

Stops the PixelGrabber's image-grabbing process.

getColorModel

public synchronized ColorModel getColorModel()

Returns

The color model the PixelGrabber is using for its array.

getHeight

public synchronized int getHeight()

Returns

The height of the grabbed image, or -1 if the height is not known.

getPixels

public synchronized Object getPixels()

Returns	The array of pixels.
Description	Either a byte array or an integer array is returned, or null if the size and format of the image are not yet known. Because the PixelGrabber may change its mind about what ColorModel it's using, different calls to this method may return different arrays until the image acquisition is complete.

getStatus

public synchronized int getStatus()

Returns

A combination of ImageObserver flags indicating what data is available.

getWidth

public synchronized int getWidth()

Returns

The width of the grabbed image, or -1 if the width is not known.

grabPixels

public boolean grabPixels() throws InterruptedException

Throws	InterruptedException
		If image grabbing is interrupted before completion.
Returns	true if the image has completed loading, false if the loading process aborted or an error occurred.
Description	Starts the process of grabbing the pixel data from the source and storing it in the array pixels[] from constructor. Returns when the image is complete, loading aborts, or an error occurs.
public synchronized boolean grabPixels (long ms) throws InterruptedException
Parameters	ms	Milliseconds to wait for completion.
Returns	true if image has completed loading, false if the loading process aborted, or an error or a timeout occurred.
Throws	InterruptedException
		If image grabbing is interrupted before completion.
Description	Starts the process of grabbing the pixel data from the source and storing it in the array pixels[] from constructor. Returns when the image is complete, loading aborts, an error occurs, or a timeout occurs.

imageComplete

public synchronized void imageComplete (int status)

Parameters	status	Image loading completion status flags.
Implements	ImageConsumer.imageComplete(int)
Description	Called by the ImageProducer to indicate that the image has been delivered.

setColorModel

void setColorModel (ColorModel model)

Parameters	model	The color model for the image.
Implements	ImageConsumer.setColorModel(ColorModel)
Description	Does nothing.

setDimensions

void setDimensions (int width, int height)

Parameters	width	Width for image.
	height	Height for image.
Implements	ImageConsumer.setDimensions(int, int)
Description	Does nothing.

setHints

void setHints (int hints)

Parameters	hints	Image consumption hints.
Implements	ImageConsumer.setHints(int)
Description	Does nothing.

setPixels

void setPixels (int x, int y, int width, int height,
ColorModel model, byte[] pixels, int offset, int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Implements	ImageConsumer.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Called by the ImageProducer to deliver pixel data from the image.
void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Implements	ImageConsumer.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Called by the ImageProducer to deliver pixel data from the image.

setProperties

void setProperties (Hashtable properties)

Parameters	properties	The properties for the image.
Implements	ImageConsumer.setProperties(Hashtable)
Description	Does nothing.

startGrabbing

public synchronized void startGrabbing()

Description

Starts the PixelGrabber's image-grabbing process.

status

public synchronized int status ()

Returns

The ImageObserver flags OR'ed together representing the available information about the image. Replaced by getStatus().

22.13 ReplicateScaleFilter

Description

The ReplicateScaleFilter class uses a simple-minded algorithm to scale an image. If the image is to be reduced, rows and columns of pixels are removed. If the image is to be expanded, rows and columns are duplicated (replicated).

Class Definition

public class ReplicateScaleFilter
    extends java.awt.image.ImageFilter {

  // Variables
  protected int destHeight;
  protected int destWidth;
  protected Object outpixbuf;
  protected int srcHeight;
  protected int srcWidth;
  protected int[] srccols;
  protected int[] srcrows;

  // Constructor
  public ReplicateScaleFilter(int width, int height);

  // Instance Methods
  public void setDimensions (int w, int h);
  public void setPixels(int x, int y, int w, int h, ColorModel model,
      byte[] pixels, int off, int scansize);
  public void setPixels(int x, int y, int w, int h, ColorModel model,
      int[] pixels, int off, int scansize);

public void setProperties(Hashtable props);
}

Variables

destHeight

protected int destHeight

Height of the scaled image.

destWidth

protected int destWidth

Width of the scaled image.

outpixbuf

protected Object outpixbuf

An internal buffer.

srcHeight

protected int srcHeight

Height of the original image.

srcWidth

protected int srcWidth

Width of the original image.

srccols

protected int[] srccols

Internal array used to map incoming columns to outgoing columns.

srcrows

protected int[] srcrows

Internal array used to map incoming rows to outgoing rows.

Constructor

ReplicateScaleFilter

public ReplicateScaleFilter (int width, int height)

Parameters	width	Width of scaled image.
	height	Height of scaled image.
Description	Constructs a ReplicateScaleFilter that scales the original image to the specified size. If both width and height are -1, the destination image size will be set to the source image size. If either one of the parameters is -1, it will be set to preserve the aspect ratio of the original image.

Instance Methods

setDimensions

public void setDimensions (int w, int h)

Parameters	w	Width of the source image.
	h	Height of the source image.
Overrides	ImageFilter.setDimensions(int, int)
Description	Sets the size of the source image.

setPixels

void setPixels (int x, int y, int w, int h, ColorModel
model, byte[] pixels, int off, int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	w	Width of the rectangle of pixel data delivered with this method call.
	h	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	off	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; scales these pixels and delivers them to any ImageConsumers.
void setPixels (int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	w	Width of the rectangle of pixel data delivered with this method call.
	h	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	off	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Receives a rectangle of image data from the ImageProducer; scales these pixels and delivers them to any ImageConsumers.

setProperties

public void setProperties (Hashtable props)

Parameters	props	The properties for the image.
Overrides	ImageFilter.setProperties(Hashtable)
Description	Adds the “rescale” image property to the properties list.

22.14 RGBImageFilter

Description

RGBImageFilter is an abstract class that helps you filter images based on each pixel's color and position. In most cases, the only method you need to implement in subclasses is filterRGB(), which returns a new pixel value based on the old pixel's color and position. RGBImageFilter cannot be used to implement filters that depend on the value of neighboring pixels, or other factors aside from color and position.

Class Definition

public abstract class java.awt.image.RGBImageFilter
    extends java.awt.image.ImageFilter {

  // Variables
  protected boolean canFilterIndexColorModel;

protected ColorModel newmodel;
  protected ColorModel oldmodel;

  // Instance Methods
  public IndexColorModel filterIndexColorModel (IndexColorModel icm);
  public abstract int filterRGB (int x, int y, int rgb);
  public void filterRGBPixels (int x, int y, int width,
      int height, int[] pixels, int off, int scansize);
  public void setColorModel (ColorModel model);
  public void setPixels (int x, int y, int width, int height,
      ColorModel model, byte[] pixels, int offset, int scansize);
  public void setPixels (int x, int y, int width, int height,
      ColorModel model, int[] pixels, int offset, int scansize);
  public void substituteColorModel (ColorModel oldModel,
      ColorModel newModel);
}

Variables

canFilterIndexColorModel

protected boolean canFilterIndexColorModel

Setting the canFilterIndexColorModel variable to true indicates the filter can filter IndexColorModel images. To filter an IndexColorModel, the filter must depend only on color, not on position.

newmodel

protected ColorModel newmodel

A place to store a new ColorModel.

origmodel

protected ColorModel origmodel

A place to store an old ColorModel.

Instance Methods

filterIndexColorModel

public IndexColorModel filterIndexColorModel
(IndexColorModel icm)

Parameters	icm	Color model to filter.
Returns	Filtered color model.
Description	Helper method for setColorModel() that runs the entire color table of icm through the filterRGB() method of the subclass. Used only if canFilterIndexColorModel is true, and the image uses an IndexColorModel.

filterRGB

public abstract int filterRGB (int x, int y, int rgb)

Parameters	x	x-coordinate of pixel data.
	y	y-coordinate of pixel data.
	rgb	Color value of pixel to filter.
Returns	New color value of pixel.
Description	Subclasses implement this method to provide a filtering function that generates new pixels.

filterRGBPixels

public void filterRGBPixels (int x, int y, int width, int
height, int[] pixels, int off, int scansize)

Parameters	x	x-coordinate of top-left corner of pixel data within entire image.
	y	y-coordinate of top-left corner of pixel data within entire image.
	width	Width of pixel data within entire image.
	height	Height of pixel data within entire image.
	pixels	Image data.
	off	Offset from beginning of each line in pixels array.
	scansize	Size of each line of data in pixels array.
Description	Helper method for setPixels() that filters each element of the pixels buffer through the subclass's filterRGB() method.

setColorModel

public void setColorModel (ColorModel model)

Parameters	model	The color model for the image.
Overrides	ImageFilter.setColorModel(ColorModel)
Description	Sets the image's color model.

setPixels

public void setPixels (int x, int y, int width, int
height, ColorModel model, byte[] pixels, int offset, int
scansize)

Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, byte[], int, int)
Description	Called by the ImageProducer to deliver a rectangular block of pixels for filtering.
public void setPixels (int x, int y, int width, int height, ColorModel model, int[] pixels, int offset, int scansize)
Parameters	x	x-coordinate of top-left corner of pixel data delivered with this method call.
	y	y-coordinate of top-left corner of pixel data delivered with this method call.
	width	Width of the rectangle of pixel data delivered with this method call.
	height	Height of the rectangle of pixel data delivered with this method call.
	model	Color model of image data.
	pixels	Image data.
	offset	Offset from beginning of the pixels array.
	scansize	Size of each line of data in pixels array.
Overrides	ImageFilter.setPixels(int, int, int, int, ColorModel, int[], int, int)
Description	Called by the ImageProducer to deliver a rectangular block of pixels for filtering.

substituteColorModel

public void substituteColorModel (ColorModel oldModel,
ColorModel newModel)

Parameters	oldModel	New value for origmodel variable.
	newModel	New value for newmodel variable.
Description	Helper method for setColorModel() to initialize the protected variables newmodel and origmodel.

22

java.awt.image Reference

22.1 AreaAveragingScaleFilter

Description

Class Definition

Constructor

AreaAveragingScaleFilter

Instance Methods

setHints

setPixels

See Also

22.2 ColorModel

Description

Class Definition

ProtectedVariables

pixel_bits

Constructors

ColorModel

Class Methods

getRGBdefault

Instance Methods

finalize

getAlpha

getBlue

getGreen

getPixelSize

getRed

getRGB

See Also

22.3 CropImageFilter

Description

Class Definition

Constructors

CropImageFilter

Instance Methods

setDimensions

setPixels

setProperties

See Also

22.4 DirectColorModel

Description

Class Definition

Constructors

DirectColorModel

Instance Methods

getAlpha

getAlphaMask

getBlue

getBlueMask

getGreen

getGreenMask

getRed

getRedMask

getRGB

See Also

22.5 FilteredImageSource

Description

Class Definition

Constructors

FilteredImageSource

Class Methods

addConsumer

isConsumer

removeConsumer

requestTopDownLeftRightResend

startProduction

See Also

22.6 ImageConsumer

Description

Interface Definition

Constants

COMPLETESCANLINES

IMAGEABORTED

IMAGEERROR

RANDOMPIXELORDER

SINGLEFRAME

SINGLEFRAMEDONE

SINGLEPASS

STATICIMAGEDONE

TOPDOWNLEFTRIGHT