import java.awt.*;
import java.awt.image.*;
import java.applet.*;
public class ShadowImage extends Applet {
private Image picture;
public void init() {
String filename = this.getParameter("imagefile");
Image src = this.getImage(getDocumentBase(), filename);
this.picture = this.createImage(new FilteredImageSource(src.getSource(),
new ShadowFilter(this.getSize().width, this.getSize().height)));
}
public void paint (Graphics g) {
g.drawImage(this.picture, 0, 0, this);
}
}
canFilterIndexColorModel to true.
Each pixel must be treated individually. Also notice that this filter has a constructor. Although I'm not required provide a constructor for this subclass, I can if it's useful.
import java.awt.image.*;
public class ShadowFilter extends RGBImageFilter {
private double edge;
public ShadowFilter(int width, int height) {
edge = Math.sqrt(width*width + height*height);
}
public int filterRGB(int x, int y, int rgb) {
double fraction = 1.0 - Math.sqrt(x*x + y*y)/edge;
if (fraction <= 0) return 0xFF000000;
int red = rgb & 0x00FF0000;
red >>>= 16;
int green = rgb & 0x0000FF00;
green >>>= 8;
int blue = rgb & 0x0000FF;
int r = (int) (red * fraction);
int g = (int) (green * fraction);
int b = (int) (blue * fraction);
return (0x000000FF << 24) | (r << 16) | (g << 8) | b;
}
}