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));
}
}
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.
Filters an IndexColorModel object by running each entry in its
color tables through the filterRGB function that RGBImageFilter
subclasses must provide.
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.
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.
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.
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.
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
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.
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.
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.
canFilterIndexColorModel
RGBImageFilter()
filterIndexColorModel(IndexColorModel)
origmodel
RGBImageFilter
setColorModel