This filter removes all but the red values in an image : Image « 2D Graphics « Java Tutorial

1. Java Tutorial
2. 2D Graphics
3. Image

import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageFilter;
import java.awt.image.RGBImageFilter;

import javax.swing.ImageIcon;


class GetRedFilter extends RGBImageFilter {
  public GetRedFilter() {
    canFilterIndexColorModel = true;
  }
  public int filterRGB(int x, int y, int rgb) {
    if (x == -1) {
    }
    return rgb & 0xffff0000;
  }
}

public class Main {
  public static void main(String[] argv) throws Exception {
    Image image = new ImageIcon("image.gif").getImage();
    ImageFilter filter = new GetRedFilter();
    FilteredImageSource filteredSrc = new FilteredImageSource(image.getSource(), filter);
    image = Toolkit.getDefaultToolkit().createImage(filteredSrc);
  }
}

16.26.Image
	16.26.1.	Draw Image
	16.26.2.	Resize an image
	16.26.3.	Load Image and scale it
	16.26.4.	Flush an image
	16.26.5.	Reading an Image or Icon from a File
	16.26.6.	Get the dimensions of the image; these will be non-negative
	16.26.7.	Draw an Icon object
	16.26.8.	Scaling a Drawn Image
	16.26.9.	Shearing a Drawn Image
	16.26.10.	Rotating a Drawn Image
	16.26.11.	Translating a Drawn Image
	16.26.12.	Creates PNG images of the specified color that fade from fully opaque to fully transparent
	16.26.13.	Determining If an Image Has Transparent Pixels
	16.26.14.	Getting the Color Model of an Image
	16.26.15.	Filtering the RGB Values in an Image
	16.26.16.	Flip an image
	16.26.17.	Blur our image: Blur means an unfocused image
	16.26.18.	A reflected image: effect makes an illusion as if the image was reflected in water
	16.26.19.	Use PixelGrabber class to acquire pixel data from an Image object
	16.26.20.	Calculation of the mean value of an image
	16.26.21.	This filter removes all but the red values in an image
	16.26.22.	Using mediatracker to pre-load images
	16.26.23.	Create a grayscale image with Java 2D tools
	16.26.24.	Shrinking an image by skipping pixels
	16.26.25.	Get average of a set of images
	16.26.26.	Enlarging an image by pixel replication
	16.26.27.	A 3x3 kernel that blurs an image.
	16.26.28.	A 3x3 kernel that sharpens an image.
	16.26.29.	A 3x3 kernel that embosses an image.
	16.26.30.	Brighten the image by 30%
	16.26.31.	Darken the image by 10%
	16.26.32.	Create a filter that can modify any of the RGB pixel values in an image.
	16.26.33.	Gray scale image operation