How to read aimage that is drawn in canvas as abyte array

Question

hi,
i'm doing image procesing in j2me.i made a negative image form the original image and draw that in the canvas/now i want to save that image.for that i'm trying like this way: i tried to read that image as byte array and store that one to the rms.while trying to read the image it throws some exception like this:
java.lang.IllegalArgumentException:
     at javax.microedition.lcdui.ImmutableImage.<init>(+11)
     at javax.microedition.lcdui.Image.createImage(+40)
     at can.commandAction(+112)
     at javax.microedition.lcdui.Display$DisplayAccessor.commandAction(+282)
     at javax.microedition.lcdui.Display$DisplayManagerImpl.commandAction(+10)
     at com.sun.midp.lcdui.DefaultEventHandler.commandEvent(+68)
     at com.sun.midp.lcdui.AutomatedEventHandler.commandEvent(+47)
     at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.run(+250)
canone know how do this please help me.i'm trying to save the image for the last one week.so please anyone help me
thanx in advance

Answer 1

here is my code:
public void paint(Graphics g)
          if(!b1)
               System.out.println("B1");
               g.setColor(255,255,255);
               g.fillRect(0,0,getWidth(),getHeight());
               try
                    offImg=Image.createImage(getWidth(),getHeight());
                    off= offImg.getGraphics();
                    dukeImg=Image.createImage("/any41.jpg");
               }catch(Exception rty){}
               imgX=getWidth()/2;
               imgY=getHeight()/2;
               off.drawImage(dukeImg,imgX,imgY,0);
               g.drawImage (offImg, imgX, imgY, Graphics.HCENTER | Graphics.VCENTER);
               System.out.println("DukeImg" +offImg.isMutable());
          else
               negativeImage(g);
          }//else if
}//paint
public void negativeImage(Graphics g)
     System.out.println("Paint");
     int rgb[]=new int[dukeImg.getWidth()*dukeImg.getHeight()];
     dukeImg.getRGB(rgb,0,dukeImg.getWidth(),0,0,dukeImg.getWidth(),dukeImg.getHeight());
     int rgb1[]=new int[rgb.length];
     for(int i=0;i<rgb.length;i++)
               rgb1=rgb[i] >>8;
               rgb1[i]=255-rgb1[i];
     }//for
     g.setColor(255,255,255);
     g.fillRect(0,0,getWidth(),getHeight());
     g.setColor(0,0,0);
     g.drawString("Negative Image ",80,80,Graphics.TOP | Graphics.LEFT);
     Image offscreen=Image.createImage(getWidth(),getHeight());
     Graphics grap=offscreen.getGraphics();
     image=Image.createRGBImage(rgb1,dukeImg.getWidth(),dukeImg.getHeight(),false);
     grap.drawImage(image,getWidth()/2,getHeight()/2,0);
     g.drawImage(offscreen,getWidth()/2,getHeight()/2,Graphics.HCENTER|Graphics.VCENTER);
     x = offscreen.getWidth();
     y = offscreen.getHeight();
     System.out.println("x "+x+"Y "+y);
     System.out.println("Created " + offscreen.isMutable());
public void commandAction(Command cod,Displayable dis)
          if(cod==open)
               b1=true;
          }//if
          else if(cod==save)
               try
                    int len=x*y;
                    System.out.println("length "+ len);
                    imgByte = new byte[10240];
                    is = new ByteArrayInputStream(imgByte,0,imgByte.length);
                    is.read(imgByte,0,imgByte.length);
                    Form form = new Form("Save Image");
                                                            im = Image.createImage(imgByte, 0, imgByte.length);
                    form.append(im);
                                                            Display.getDisplay(midlet).setCurrent(form);
               }catch(Exception ww){}
if u have someother sample codes means then please send it to me.
thanx for ur response