import java.applet.*;
import java.awt.*;
import java.awt.image.*;


public class imagedemo extends Applet
{
// load an array of images and wait for them to be completely loaded
public Image[] load_images(String namelist[])
{ int len = namelist.length;
  MediaTracker tr = new MediaTracker(this);
  int id=1;
  Image ar[] = new Image[len];
  for(int i=0;i<len;i++)
  {  Image im =  getImage(getDocumentBase(),namelist[i]+".jpg");
	 tr.addImage(im,id);
     id++;
	 ar[i] = im;
 }
 try { tr.waitForAll(); }   catch (InterruptedException e)  { };
 return(ar);
}
// composite two images
public Image Composite(Component who,Image im,Image mask)
  {
  int w = im.getWidth(who);
   int h = im.getHeight(who);
   int ipix[] = new int[w*h];
   int mpix[] = new int[w*h];
   boolean gotfg = false;
   boolean gotma = false;
   try {
	  // note that there are problems with pixelgrabber from images created with
	  // createimage, but apparently not with images from loadimage
      gotfg = new PixelGrabber(im,0,0,w,h,ipix,0,w).grabPixels();
      gotma = new PixelGrabber(mask,0,0,w,h,mpix,0,w).grabPixels();
   }
   catch (InterruptedException e) {}
   if(gotfg && gotma)
   	{for(int i=0;i<w*h;i++)
	    {int ma = 0xff - (mpix[i]&0xff);		// center pixel
	     int fg = ipix[i];
	     ipix[i] = (fg&0xffffff)|(ma<<24);
	    }
    Image fin =who.createImage(new MemoryImageSource(w,h,ipix,0,w));
    return(fin);
   	}
   System.out.println("Composite failed");
 
   return(im);
  }

Image images[]=null;
Image combined = null;

String imageNames[] = { "demoimage","demomask" };
public void init()
{	images=load_images(imageNames);
	combined=Composite(this,images[0],images[1]);
}
public void paint(Graphics gc)
{	if(combined!=null)
	{	int w = getWidth();
		int h = getHeight();
		int iw = combined.getWidth(this);
		int ih = combined.getHeight(this);
		double yscale = 0.7;
		int xcell = w/3;
		int ycell = (int)(xcell*0.7);
		int inset = xcell/10;
		gc.setColor(new Color(0.7f,0.7f,0.9f));
		gc.fillRect(0,0,w,h);
		gc.drawImage(images[0],inset,inset,xcell-2*inset,ycell-2*inset,this);
		gc.drawImage(images[1],xcell+inset,inset,xcell-2*inset,ycell-2*inset,this);
		gc.drawImage(combined,2*xcell+inset,inset,xcell-2*inset,ycell-2*inset,this);
	}
	}		
}