MainClass.java Source code

Introduction

Here is the source code for MainClass.java

Source

import java.applet.Applet;
import java.awt.Button;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.FilteredImageSource;
import java.awt.image.ImageProducer;
import java.awt.image.RGBImageFilter;

public class MainClass extends Applet implements ActionListener {
    private Image originalImage, filteredImage;

    private Button btn = new Button("FILTER");

    private GrayFilter cropFilter = new GrayFilter();

    public void init() {
        originalImage = getImage(getDocumentBase(), "emily.gif");
        MediaTracker tracker = new MediaTracker(this);
        tracker.addImage(originalImage, 0);
        try {
            tracker.waitForAll();
        } catch (Exception e) {
        }
        filteredImage = originalImage;
        btn.addActionListener(this);
        add(btn);
    }

    public void actionPerformed(ActionEvent ev) {
        filter();
        repaint();
    }

    private void filter() {
        ImageProducer producer = originalImage.getSource();
        producer = new FilteredImageSource(producer, cropFilter);
        filteredImage = createImage(producer);
    }

    public void paint(Graphics g) {
        g.drawImage(originalImage, 10, 50, this);
        g.drawImage(filteredImage, 271, 50, this);

    }
}

class GrayFilter extends RGBImageFilter {
    int nCalls;

    public GrayFilter() {
        canFilterIndexColorModel = true;
    }

    public void setFast(boolean fast) {
        canFilterIndexColorModel = fast;
    }

    public int filterRGB(int x, int y, int rgb) {
        int red = (rgb & 0x00ff0000) >> 16;
        int green = (rgb & 0x0000ff00) >> 8;
        int blue = (rgb & 0x000000ff);

        int mean = (red + green + blue) / 3;
        return 0xff000000 | mean << 16 | mean << 8 | mean;
    }
}