Random slowdown of BufferedImage painting.

Question

Relying on another thread that dealed with painting background image in GUI using Borders, I wrote a custom Border that display an image in the background. This is quite smart and stylish, it works and looks beautifull, except that.....
I get sometimes a slowdown (on specific images) in painting. I mean : if I resize the window that contain the JPanel with my "ImageBorder", or if I hide then re-make visible this window, with a lot of images it is cool but with some specific images (always the same files) is take 100% CPU for 3 to 10s.
It is not size-dependant as I suspected, cause somme huge images repaint quick as some small ones repaint slow qith 100% CPU.
It is not type-dependant (TYPE_INT_XXX or TYPE_BYTE_YYY or other) as I thought... I believed first that images with Alpha-channel where slower but is it false : huges TYPE_CUSTOM png images with alpha channel repaint faster than a specific TYPE_3BYTE_BGR small jpeg image...
So is there a bug in J2SE 1.4 (I'm using Hotspot 1.4.1-b21, mixed mode) ?
Or is my code wrong ? Is it possible to predict wich images will slow down painting process ?
package jro.gui.border;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import javax.imageio.ImageIO;
import javax.swing.border.Border;
* A border with a background image for GUI enhancement...
* @author Kilwch
public class ImageBorder implements Border {
     private BufferedImage aImage;
     private ImageBorder(){
     public ImageBorder(BufferedImage backgroundImage){
          aImage=backgroundImage;
     /* (non-Javadoc)
      * @see javax.swing.border.Border#isBorderOpaque()
     public boolean isBorderOpaque() {
          //TODO : utiliser la transparence de l'image pour d�terminer si opaque ou non
          return true;
     /* (non-Javadoc)
      * @see javax.swing.border.Border#paintBorder(java.awt.Component, java.awt.Graphics, int, int, int, int)
     public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
          if(g instanceof Graphics2D){
               Graphics2D g2d=(Graphics2D)g;
               int w=aImage.getWidth(), h=aImage.getHeight();
               if(w!=width || h!=height){
                    BufferedImageOp op=new AffineTransformOp(AffineTransform.getScaleInstance(width/(double)aImage.getWidth(),height/(double)aImage.getHeight()),AffineTransformOp.TYPE_BILINEAR);
                    //TODO PROBLEM Draw with scale op is high-CPU consuming  ! Due to Alpha channel ? Problem occured with QNS only
                    g2d.drawImage(aImage, op, x, y);
               }else
                    g2d.drawImage(aImage, null, x, y);
     /* (non-Javadoc)
      * @see javax.swing.border.Border#getBorderInsets(java.awt.Component)
     public Insets getBorderInsets(Component c) {
          return new Insets(0,0,0,0);//Copie d�fensive, car Insets a des attributs publics ! grr...
     public static void main(String[] args) {
          if(args.length<1){
               System.err.println("Missing argument : image URL/path");
               System.exit(0x80010000);
          java.net.URL imageURL=ImageBorder.class.getClassLoader().getResource(args[0]);
          if(imageURL==null){
               System.err.println("Invalid image URL/path : "+args[0]);
               System.exit(0x80020000);
          BufferedImage img;
          try{
               img=ImageIO.read(imageURL);
               StringBuffer imgMsg=new StringBuffer(256);
               imgMsg.append("Image loaded: ").append(imageURL).append("\n * type = ");
               switch(img.getType()){
                    case BufferedImage.TYPE_3BYTE_BGR: imgMsg.append("TYPE_3BYTE_BGR"); break;
                    case BufferedImage.TYPE_4BYTE_ABGR: imgMsg.append("TYPE_4BYTE_ABGR"); break;
                    case BufferedImage.TYPE_4BYTE_ABGR_PRE: imgMsg.append("TYPE_4BYTE_ABGR_PRE"); break;
                    case BufferedImage.TYPE_BYTE_BINARY: imgMsg.append("TYPE_BYTE_BINARY"); break;
                    case BufferedImage.TYPE_BYTE_GRAY: imgMsg.append("TYPE_BYTE_GRAY"); break;
                    case BufferedImage.TYPE_BYTE_INDEXED: imgMsg.append("TYPE_BYTE_INDEXED"); break;
                    case BufferedImage.TYPE_CUSTOM: imgMsg.append("TYPE_CUSTOM"); break;
                    case BufferedImage.TYPE_INT_ARGB: imgMsg.append("TYPE_INT_ARGB"); break;
                    case BufferedImage.TYPE_INT_ARGB_PRE: imgMsg.append("TYPE_INT_ARGB_PRE"); break;
                    case BufferedImage.TYPE_INT_BGR: imgMsg.append("TYPE_INT_BGR"); break;
                    case BufferedImage.TYPE_INT_RGB: imgMsg.append("TYPE_INT_RGB"); break;
                    case BufferedImage.TYPE_USHORT_555_RGB: imgMsg.append("TYPE_USHORT_555_RGB"); break;
                    case BufferedImage.TYPE_USHORT_565_RGB: imgMsg.append("TYPE_USHORT_565_RGB"); break;
                    case BufferedImage.TYPE_USHORT_GRAY: imgMsg.append("TYPE_USHORT_GRAY"); break;
                    default: imgMsg.append("unknown");
               imgMsg.append(" (type ").append(img.getType()).append(")");
               imgMsg.append("\n * Dim = ").append(img.getWidth()).append("x").append(img.getHeight());
               System.out.println(imgMsg);
          }catch(java.io.IOException pIOEx){
               System.err.println(pIOEx);
               System.exit(0x80030000);
               img=null;//Yes, thats dead code !
          javax.swing.JFrame testFrame=new javax.swing.JFrame();
          testFrame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
          testFrame.setTitle("Test frame for "+ImageBorder.class.getName());
          testFrame.setSize(img.getWidth(), img.getHeight());
          ((javax.swing.JPanel)testFrame.getContentPane()).setBorder(new ImageBorder(img));
          testFrame.getContentPane().setLayout(new BorderLayout());
          javax.swing.JLabel [] l={new javax.swing.JLabel(args[0]),new javax.swing.JLabel()};
          l[0].setForeground(new java.awt.Color(0x00,0x00,0x66,0xC0));
          l[0].setBackground(new java.awt.Color(0xFF,0xFF,0x99,0x30));
          l[0].setOpaque(true);
          testFrame.getContentPane().add(l[0], BorderLayout.NORTH);
          testFrame.getContentPane().add(l[1], BorderLayout.CENTER);
          testFrame.setVisible(true);
}

Answer 1

I've just tried out the VolatileImage. It is a partial workaround for my problem :
1) the very first paint of my VolatileImage (and next "first paint after contentLost") takes bloody ages, because I need to create a BufferedImage first (from an URL).
2)Then, each time I need to resize my VolatileImage (because I want it to fit the JFrame's content pane), I have to recreate it, so I re-use the BufferedImage that is the source data, and it re-takes bloody ages.
3) it is OK since the content of VolatileImage is not lost. So minimize/restore the parent JFrame does not slow down repaint anymore, hiding the parent JFrame with another window then putting it back to front does not slow repaint anymore.
4)Big Alpha problem : The volatile image is used to paint the borders of the content pane. Imagine now your content pane contains a yellow JLabel with 75% transparency : when another window passes over the JLabel, it look ugly (the window lets dirty marks). It seems that transparent components does not refresh with the underlying image like expected.
(Note that I know where the slowdown occurs in the paint method : it occurs during image resize (scaling with BufferedImageOp). But I repeat, only on specific images, regardless of their size&colordepth. As I always need a BufferedImage to "remember" the picture to paint on VolatileImage, the slowdown occurs less often, but still occurs)
Test it for the 4th problem (1st and 2nd come along with specifig images only), passing an image path as 1st arg (note the path is relative to current dir or any classpath dir as I'm using getRessource method):
package jro.gui.border;
import java.awt.BorderLayout;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.geom.AffineTransform;
import java.awt.image.AffineTransformOp;
import java.awt.image.BufferedImage;
import java.awt.image.BufferedImageOp;
import java.awt.image.VolatileImage;
import javax.imageio.ImageIO;
import javax.swing.border.Border;
* A border with a background image for GUI enhancement...
* @author rousseau_j
public class VolatileImageBorder implements Border {
     private VolatileImage aVImage;
     private BufferedImage aStaticImage;
     private VolatileImageBorder(){
     public VolatileImageBorder(BufferedImage backgroundImage){
          aStaticImage=backgroundImage;
     /* (non-Javadoc)
      * @see javax.swing.border.Border#isBorderOpaque()
     public boolean isBorderOpaque() {
          //TODO : utiliser la transparence de l'image pour d�terminer si opaque ou non
          return true;
     /* (non-Javadoc)
      * @see javax.swing.border.Border#paintBorder(java.awt.Component, java.awt.Graphics, int, int, int, int)
     public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
          if((g instanceof Graphics2D)&& c!=null){
               Graphics2D g2d=(Graphics2D)g;
               if(aVImage==null){
                    aVImage=c.createVolatileImage(width, height);
               int w=aVImage.getWidth(), h=aVImage.getHeight();
               if(w!=width || h!=height){
                    aVImage=c.createVolatileImage(width, height);
               do{
                    int returnCode = aVImage.validate(c.getGraphicsConfiguration());
                    if (returnCode == VolatileImage.IMAGE_RESTORED) {
                         renderOffscreen(c, x, y, width, height);
                    } else if (returnCode == VolatileImage.IMAGE_INCOMPATIBLE) {
                         aVImage = c.createVolatileImage(width, height);
                         renderOffscreen(c, x, y, width, height);
                    g2d.drawImage(aVImage, 0, 0, c);
               }while(aVImage.contentsLost());
     private void renderOffscreen(Component c, int x, int y,int width,  int height){
          System.out.print("renderOffscreen{");//TEST
          do{
               System.out.print("do{...");//TEST
               if(aVImage.validate(c.getGraphicsConfiguration())==VolatileImage.IMAGE_INCOMPATIBLE){
                    aVImage=c.createVolatileImage(width, height);
               Graphics2D vImgG2d=aVImage.createGraphics();
               int w=aStaticImage.getWidth(), h=aStaticImage.getHeight();
               if(w!=width || h!=height){
                    //TODO : option pour une redim d�finitive si image trop grande
                    BufferedImageOp op=new AffineTransformOp(AffineTransform.getScaleInstance(width/(double)aStaticImage.getWidth(),height/(double)aStaticImage.getHeight()),AffineTransformOp.TYPE_BILINEAR);
                    //TODO PROBLEM Draw with scale op is high-CPU consuming  ! Due to Alpha channel ? Problem occured with QNS only
                    vImgG2d.drawImage(aStaticImage, op, x, y);
               }else
               vImgG2d.drawImage(aStaticImage, null, x, y);
               vImgG2d.dispose();
               System.out.print("...}while; ");//TEST
          }while(aVImage.contentsLost());
          System.out.println("}\n");//TEST
     /* (non-Javadoc)
      * @see javax.swing.border.Border#getBorderInsets(java.awt.Component)
     public Insets getBorderInsets(Component c) {
          return new Insets(0,0,0,0);//Copie d�fensive, car Insets a des attributs publics ! grr...
     public static void main(String[] args) {
          if(args.length<1){
               System.err.println("Missing argument : image URL/path");
               System.exit(0x80010000);
          java.net.URL imageURL=VolatileImageBorder.class.getClassLoader().getResource(args[0]);
          if(imageURL==null){
               System.err.println("Invalid image URL/path : "+args[0]);
               System.exit(0x80020000);
          BufferedImage img;
          try{
               img=ImageIO.read(imageURL);
               StringBuffer imgMsg=new StringBuffer(256);
               imgMsg.append("Image loaded: ").append(imageURL).append("\n * type = ");
               switch(img.getType()){
                    case BufferedImage.TYPE_3BYTE_BGR: imgMsg.append("TYPE_3BYTE_BGR"); break;
                    case BufferedImage.TYPE_4BYTE_ABGR: imgMsg.append("TYPE_4BYTE_ABGR"); break;
                    case BufferedImage.TYPE_4BYTE_ABGR_PRE: imgMsg.append("TYPE_4BYTE_ABGR_PRE"); break;
                    case BufferedImage.TYPE_BYTE_BINARY: imgMsg.append("TYPE_BYTE_BINARY"); break;
                    case BufferedImage.TYPE_BYTE_GRAY: imgMsg.append("TYPE_BYTE_GRAY"); break;
                    case BufferedImage.TYPE_BYTE_INDEXED: imgMsg.append("TYPE_BYTE_INDEXED"); break;
                    case BufferedImage.TYPE_CUSTOM: imgMsg.append("TYPE_CUSTOM"); break;
                    case BufferedImage.TYPE_INT_ARGB: imgMsg.append("TYPE_INT_ARGB"); break;
                    case BufferedImage.TYPE_INT_ARGB_PRE: imgMsg.append("TYPE_INT_ARGB_PRE"); break;
                    case BufferedImage.TYPE_INT_BGR: imgMsg.append("TYPE_INT_BGR"); break;
                    case BufferedImage.TYPE_INT_RGB: imgMsg.append("TYPE_INT_RGB"); break;
                    case BufferedImage.TYPE_USHORT_555_RGB: imgMsg.append("TYPE_USHORT_555_RGB"); break;
                    case BufferedImage.TYPE_USHORT_565_RGB: imgMsg.append("TYPE_USHORT_565_RGB"); break;
                    case BufferedImage.TYPE_USHORT_GRAY: imgMsg.append("TYPE_USHORT_GRAY"); break;
                    default: imgMsg.append("unknown");
               imgMsg.append(" (type ").append(img.getType()).append(")");
               imgMsg.append("\n * Dim = ").append(img.getWidth()).append("x").append(img.getHeight());
               System.out.println(imgMsg);
          }catch(java.io.IOException pIOEx){
               System.err.println(pIOEx);
               System.exit(0x80030000);
               img=null;//Yes, thats dead code !
          javax.swing.JFrame testFrame=new javax.swing.JFrame();
          testFrame.setDefaultCloseOperation(javax.swing.JFrame.EXIT_ON_CLOSE);
          testFrame.setTitle("Test frame for "+VolatileImageBorder.class.getName());
          testFrame.setSize(img.getWidth(), img.getHeight());
          ((javax.swing.JPanel)testFrame.getContentPane()).setBorder(new VolatileImageBorder(img));
          testFrame.getContentPane().setLayout(new BorderLayout());
          javax.swing.JLabel [] l={new javax.swing.JLabel(args[0]),new javax.swing.JLabel()};
          l[0].setForeground(new java.awt.Color(0x00,0x00,0x66,0xC0));
          l[0].setBackground(new java.awt.Color(0xFF,0xFF,0x99,0x30));
          l[0].setOpaque(true);
          testFrame.getContentPane().add(l[0], BorderLayout.NORTH);
          testFrame.getContentPane().add(l[1], BorderLayout.CENTER);
          testFrame.setVisible(true);
}