Transparent Graphics Object

Question

Alright, I have one graphics object that draws all of the main elements of the screen, and I have a buffered image that is modified through a second graphics object. I want to know how to make the background for the second object transparent, so that if I drew something onto it, then drew the buffered image into the main graphics object, I'd be able to see all the drawing done in the original graphics object behind the uncovered areas, sort of like an overlay. Code examples are highly appreciated. Thanks in advance for any replies.
(PS: Right now when I draw the image, it covers up the entire screen with the color grey, making it impossible to see the objects behind it.)

Answer 1

I wrote example for AWT because in SWING it can be done very easy. Run this code, it runs fine. Use only your image files.
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Color;
import java.awt.image.BufferedImage;
import java.awt.*;
import java.awt.event.*;
public class ImageTest extends Canvas implements WindowListener {
public static void main(String[] args) {
Frame frame = new Frame("Image testing");
ImageTest instance = new ImageTest();
frame.add(instance);
frame.addWindowListener(instance);
frame.pack();
frame.setVisible(true);
public Dimension getPreferredSize() {
return new Dimension(256, 256);
BufferedImage backgroundImage;
BufferedImage alphaImage;
void initImage() {
Image img = getToolkit().createImage("D:\\temp\\JavaTests\\viewcode.jpg");
Image bkImage = getToolkit().createImage("D:\\temp\\JavaTests\\SolarEclipse.jpg");
MediaTracker Mt = new MediaTracker(this);
Mt.addImage(img, 0);
Mt.addImage(bkImage, 1);
try{
Mt.waitForAll();
}catch(Exception e){};
BufferedImage bi = new BufferedImage(img.getWidth(this), img.getHeight(this), BufferedImage.TYPE_4BYTE_ABGR);
alphaImage = new BufferedImage(bkImage.getWidth(this), bkImage.getHeight(this), BufferedImage.TYPE_4BYTE_ABGR);
Graphics gr = bi.getGraphics();
gr.drawImage(img, 0, 0, this);
backgroundImage = (BufferedImage)bi;
gr = alphaImage.getGraphics();
gr.drawImage(bkImage, 0, 0, bkImage.getWidth(this)/2, bkImage.getHeight(this)/2, bkImage.getWidth(this)/2, bkImage.getHeight(this)/2, bkImage.getWidth(this), bkImage.getHeight(this), this);
Color bl = new Color(0, 0, 0);
for (int x=0; x<bkImage.getWidth(this); x++)
for (int y=0; y<alphaImage.getHeight(this); y++) {
Color c = new Color(alphaImage.getRGB(x,y));
int r = c.getRed();//x*4;
int g = c.getGreen();//y*4;
int b = c.getBlue();//255 - (x+y)*2;//Math.abs(y*8-255);
// Make transparent colors, which look like black
int a = (r == b && g == b && r < 100 && g < 100 && b < 100)?0:255;
int vv = (a<<24) | (r<<16) | (g<<8) | b;
alphaImage.setRGB(x, y, vv);
public void paint(Graphics gfx) {
if (backgroundImage == null)
initImage();
gfx.drawImage(backgroundImage, 0, 0, this);
int i = 0;
int delta = 100;
gfx.drawImage(alphaImage, i, i, this);
gfx.drawImage(alphaImage, i + delta, i + delta, this);
gfx.drawImage(alphaImage, i + delta*2, i + delta*2, this);
gfx.drawImage(alphaImage, i + delta*3, i + delta*3, this);
gfx.drawImage(alphaImage, i + delta*4, i + delta*4, this);
gfx.drawImage(alphaImage, i + delta*5, i + delta*5, this);
void exitForm(java.awt.event.WindowEvent evt) {
System.exit(0);
public void windowActivated(java.awt.event.WindowEvent windowEvent) {
public void windowClosed(java.awt.event.WindowEvent windowEvent) {
public void windowClosing(java.awt.event.WindowEvent windowEvent) {
System.exit(0);
public void windowDeactivated(java.awt.event.WindowEvent windowEvent) {
public void windowDeiconified(java.awt.event.WindowEvent windowEvent) {
public void windowIconified(java.awt.event.WindowEvent windowEvent) {
public void windowOpened(java.awt.event.WindowEvent windowEvent) {