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Java AWT Reference by John Zukowski

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22

java.awt.image Reference

22.1 AreaAveragingScaleFilter images

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.

See Also

ColorModel, ReplicateScaleFilter

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(); images 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() images

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.

See Also

DirectColorModel, IndexColorModel, Object

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.

See Also

ColorModel, Hashtable, ImageFilter

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.

See Also

ColorModel

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.

See Also

ImageFilter, ImageConsumer, ImageProducer, Object

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.

See Also

ColorModel, Hashtable, ImageFilter, PixelGrabber, Object

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.

See Also

Cloneable, ColorModel, CropImageFilter, Hashtable, ImageConsumer, ImageProducer, Object, ReplicateImageFilter, RGBImageFilter

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.

See Also

Component, Image, Object

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.

See Also

FilteredImageSource, Image, ImageConsumer, ImageFilter, MemoryImageSource, Object

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 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

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(); images public synchronized void newPixels (int x, int y, int w, int h); images public synchronized void newPixels (int x, int y, int w, int h, boolean framenotify); images public synchronized void newPixels (byte[] newpix, ColorModel newmodel, int offset, int scansize); images public synchronized void newPixels (int[] newpix, ColorModel newmodel, int offset, int scansize); images public synchronized void removeConsumer (ImageConsumer ic); public void requestTopDownLeftRightResend (ImageConsumer ic); public synchronized void setAnimated (boolean animated); images public synchronized void setFullBufferUpdates (boolean fullbuffers); images 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() images

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) images
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) images
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) images
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) images
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) images

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) images

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.

See Also

ColorModel, Hashtable, ImageConsumer, ImageProducer, Object

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); images 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(); images public synchronized ColorModel getColorModel(); images

public synchronized int getHeight(); images public synchronized Object getPixels(); images public synchronized int getStatus(); images public synchronized int getWidth(); images 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(); images public synchronized int status(); images }

Constructors

PixelGrabber

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

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() images

Description Stops the PixelGrabber's image-grabbing process.

getColorModel

public synchronized ColorModel getColorModel() images

Returns The color model the PixelGrabber is using for its array.

getHeight

public synchronized int getHeight() images

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

getPixels

public synchronized Object getPixels() images

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() images

Returns A combination of ImageObserver flags indicating what data is available.

getWidth

public synchronized int getWidth() images

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() images

Description Starts the PixelGrabber's image-grabbing process.

status

public synchronized int status () images

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

See Also

ColorModel, Hashtable, Image, ImageConsumer, ImageProducer, InterruptedException, MemoryImageSource, Object

22.13 ReplicateScaleFilter images

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.

See Also

ColorModel, Hashtable, ImageConsumer, ImageFilter, ImageProducer

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.

See Also

ColorModel, ImageFilter

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