Class java.awt.image.RGBImageFilter - JDK 5 Documentation v1.1.8, Java 2 SDK 英文文档

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Class java.awt.image.RGBImageFilter

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

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, getRGBdefault

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.
newmodel
origmodel

RGBImageFilter()

filterIndexColorModel(IndexColorModel): Filters an IndexColorModel object by running each entry in its color tables through the filterRGB function that RGBImageFilter subclasses must provide.
filterRGB(int, int, int): Subclasses must specify a method to convert a single input pixel in the default RGB ColorModel to a single output pixel.
filterRGBPixels(int, int, int, int, int[], int, int): Filters a buffer of pixels in the default RGB ColorModel by passing them one by one through the filterRGB method.
setColorModel(ColorModel): 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.
setPixels(int, int, int, int, ColorModel, byte[], int, int): If the ColorModel object is the same one that has already been converted, then simply passes the pixels through with the converted ColorModel.
setPixels(int, int, int, int, ColorModel, int[], int, int): 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.
substituteColorModel(ColorModel, ColorModel): Registers two ColorModel objects for substitution.

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, filterRGB, IndexColorModel

RGBImageFilter

 public RGBImageFilter()

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, 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:: getRGBdefault, filterRGB

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:: getRGBdefault, filterRGBPixels

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:: getRGBdefault, filterRGBPixels

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:: getRGBdefault, filterRGBPixels

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