java.awt.image
Class RGBImageFilter

java.lang.Object
  |
  +--java.awt.image.ImageFilter
        |
        +--java.awt.image.RGBImageFilter

Direct Known Subclasses:

GrayFilter

public abstract class RGBImageFilter

extends ImageFilter

This class provides an easy way to create an ImageFilter which modifies the pixels of an image in the default RGB ColorModel. It is meant to be used in conjunction with a FilteredImageSource object to produce filtered versions of existing images. It is an abstract class that provides the calls needed to channel all of the pixel data through a single method which converts pixels one at a time in the default RGB ColorModel regardless of the ColorModel being used by the ImageProducer. The only method which needs to be defined to create a useable image filter is the filterRGB method. Here is an example of a definition of a filter which swaps the red and blue components of an image:

	class RedBlueSwapFilter extends RGBImageFilter {
	    public RedBlueSwapFilter() {
		// The filter's operation does not depend on the
		// pixel's location, so IndexColorModels can be
		// filtered directly.
		canFilterIndexColorModel = true;
	    }

	    public int filterRGB(int x, int y, int rgb) {
		return ((rgb & 0xff00ff00)
			| ((rgb & 0xff0000) >> 16)
			| ((rgb & 0xff) << 16));
	    }
	}

 

See Also:

FilteredImageSource, ImageFilter, ColorModel.getRGBdefault()

Field Summary

protected boolean	canFilterIndexColorModel This boolean indicates whether or not it is acceptable to apply the color filtering of the filterRGB method to the color table entries of an IndexColorModel object in lieu of pixel by pixel filtering.
protected ColorModel	newmodel
protected ColorModel	origmodel

Fields inherited from class java.awt.image.ImageFilter

consumer

Constructor Summary

RGBImageFilter()

Method Summary

IndexColorModel	filterIndexColorModel(IndexColorModel icm) Filters an IndexColorModel object by running each entry in its color tables through the filterRGB function that RGBImageFilter subclasses must provide.
abstract int	filterRGB(int x, int y, int rgb) Subclasses must specify a method to convert a single input pixel in the default RGB ColorModel to a single output pixel.
void	filterRGBPixels(int x, int y, int w, int h, int[] pixels, int off, int scansize) Filters a buffer of pixels in the default RGB ColorModel by passing them one by one through the filterRGB method.
void	setColorModel(ColorModel model) If the ColorModel is an IndexColorModel, and the subclass has set the canFilterIndexColorModel flag to true, we substitute a filtered version of the color model here and wherever that original ColorModel object appears in the setPixels methods.
void	setPixels(int x, int y, int w, int h, ColorModel model, byte[] pixels, int off, int scansize) If the ColorModel object is the same one that has already been converted, then simply passes the pixels through with the converted ColorModel.
void	setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize) If the ColorModel object is the same one that has already been converted, then simply passes the pixels through with the converted ColorModel, otherwise converts the buffer of integer pixels to the default RGB ColorModel and passes the converted buffer to the filterRGBPixels method to be converted one by one.
void	substituteColorModel(ColorModel oldcm, ColorModel newcm) Registers two ColorModel objects for substitution.

Methods inherited from class java.awt.image.ImageFilter

clone, getFilterInstance, imageComplete, resendTopDownLeftRight, setDimensions, setHints, setProperties

Methods inherited from class java.lang.Object

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

Field Detail

origmodel

protected ColorModel origmodel

newmodel

protected ColorModel newmodel

canFilterIndexColorModel

protected boolean canFilterIndexColorModel

This boolean indicates whether or not it is acceptable to apply the color filtering of the filterRGB method to the color table entries of an IndexColorModel object in lieu of pixel by pixel filtering. Subclasses should set this variable to true in their constructor if their filterRGB method does not depend on the coordinate of the pixel being filtered.

See Also:

substituteColorModel(java.awt.image.ColorModel, java.awt.image.ColorModel), filterRGB(int, int, int), IndexColorModel

Constructor Detail

RGBImageFilter

public RGBImageFilter()

Method Detail

setColorModel

public void setColorModel(ColorModel model)

If the ColorModel is an IndexColorModel, and the subclass has set the canFilterIndexColorModel flag to true, we substitute a filtered version of the color model here and wherever that original ColorModel object appears in the setPixels methods. Otherwise overrides the default ColorModel used by the ImageProducer and specifies the default RGB ColorModel instead.

Overrides:

setColorModel in class ImageFilter

See Also:

ImageConsumer, ColorModel.getRGBdefault()

substituteColorModel

public void substituteColorModel(ColorModel oldcm,
                                 ColorModel newcm)

Registers two ColorModel objects for substitution. If the oldcm is encountered during any of the setPixels methods, the newcm is substituted and the pixels passed through untouched (but with the new ColorModel object).

Parameters:

oldcm - the ColorModel object to be replaced on the fly

newcm - the ColorModel object to replace oldcm on the fly

filterIndexColorModel

public IndexColorModel filterIndexColorModel(IndexColorModel icm)

Filters an IndexColorModel object by running each entry in its color tables through the filterRGB function that RGBImageFilter subclasses must provide. Uses coordinates of -1 to indicate that a color table entry is being filtered rather than an actual pixel value.

Parameters:

icm - the IndexColorModel object to be filtered

Returns:

a new IndexColorModel representing the filtered colors

filterRGBPixels

public void filterRGBPixels(int x,
                            int y,
                            int w,
                            int h,
                            int[] pixels,
                            int off,
                            int scansize)

Filters a buffer of pixels in the default RGB ColorModel by passing them one by one through the filterRGB method.

See Also:

ColorModel.getRGBdefault(), filterRGB(int, int, int)

setPixels

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

If the ColorModel object is the same one that has already been converted, then simply passes the pixels through with the converted ColorModel. Otherwise converts the buffer of byte pixels to the default RGB ColorModel and passes the converted buffer to the filterRGBPixels method to be converted one by one.

Overrides:

setPixels in class ImageFilter

See Also:

ColorModel.getRGBdefault(), filterRGBPixels(int, int, int, int, int[], int, int)

setPixels

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

If the ColorModel object is the same one that has already been converted, then simply passes the pixels through with the converted ColorModel, otherwise converts the buffer of integer pixels to the default RGB ColorModel and passes the converted buffer to the filterRGBPixels method to be converted one by one. Converts a buffer of integer pixels to the default RGB ColorModel and passes the converted buffer to the filterRGBPixels method.

Overrides:

setPixels in class ImageFilter

See Also:

ColorModel.getRGBdefault(), filterRGBPixels(int, int, int, int, int[], int, int)

filterRGB

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

Subclasses must specify a method to convert a single input pixel in the default RGB ColorModel to a single output pixel.

See Also:

ColorModel.getRGBdefault(), filterRGBPixels(int, int, int, int, int[], int, int)