Monitoring progress when performing filter operations on images

Question

Hi,
I am working on Java2D and making some image filters using classes like ImageFilter etc. Now For simple filters I want to get the progress status while the filteting is in progress, so that I can show a progress bar in the GUI.
For this I do not have much idea. I think we can use the ImageConsumer interface, so that if the class implementing that interface list itself as an image consumer with the filter operation. Here is two way I have tried implanting this:
1st way:
Class MyConsumer implements ImageConsumer
int width,height;
int percentProgress;
Public image processImage(Image srcImage, ImageFilter filter){
FilteredImageSource fis: new FilteredImageSource(srcImage.getSource(),filter());
//should we do this?
fis.addConsumer(this);
//or this?
srcimage.addConsumer(this)
Image destImage = this.createImage(fis);
return destImage;
//implementing methods of imageConsumer
//we get the width and height of the new destImage (or do we get the dimension of the srcImage here??)
public void setDimensions(int width, int height){
this.width=width;
this.height=height;
public void setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize){
// Is this the correct way of obtaining the progress????
progressPercent=(y*100)/height;
//We also have empty implementation of other ImageConsumer methods after this
--------------------------------------------------------------2nd way, let?s say we use a smooth filter and replace the processImage(..) method above with the one below (the other methods being same):
Public image processImage(Image srcImage){
float[] SHARPEN3x3 = {      0.f, -1.f, 0.f,
                            -1.f, 5.0f, -1.f,
                            0.f, -1.f, 0.f};
BufferedImage dstbimg = new
              BufferedImage(iw,ih,BufferedImage.TYPE_INT_RGB);
Kernel kernel = new Kernel(3,3,SHARPEN3x3);
ConvolveOp cop = new ConvolveOp(kernel,
                                ConvolveOp.EDGE_NO_OP,
                                null);
//should we do this?
dst.addConsumer(this);
//or this?
srcImage.addConsumer(this);
cop.filter(srcImage,destImage);
return destImage;
}Now I do get a progressPercent. But when the percent is 100%, the destimage does not return, that means the operation is not yet complete.
So is this the correctw ay, or is there any other way to know the progress of the flter operation.
Also I extended the ImageFilter class and overrode its setPixel method as:
public void setPixels(int x, int y, int w, int h, ColorModel model, int[] pixels, int off, int scansize){
int progressPercent=(y*100)/height;
System.out.println("progress in image filter:"+progressPercent);
//I simply print out the progress and let the super perform the filter operation
super.setPixels(x, y,w, h, model, pixels, off, scansize);
//should I do this below? This calls the imageconsumer's setpixels
//that I implement in the MyConsumer class
consumer. setPixels(x, y,w, h, model, pixels, off, scansize);
}I observe that the setPixel method of MyImageFilter is called several times even for the same scan lines, and even after percentProgress is 100%, the process runs again for 2-4 times. So the filtering operation scans the lines several times to finally perform the filtering, and as such the percentProgress is incorrect.
Can anybody guide me. Is this approach okay and needs to be modified a bit, or there is a different approach to obtain the progress from a filter operation?
I would finally want the same progress from other operations like LookupOp, ConvolveOp, AffineTransformOp, ColorConvertOp, RescaleOp.
Thanks in advance
Tanveer
DrLaszloJamf, are you there? I am sure you are one of them who can help me in this.
anyone can send me a private message too at [email protected]

Answer 1

Please somebody let me know how to get the progress of imagefilter operation using convolveOp.filter(...) or Filteredimagesource. I waant to display the progress i a JProgressbar.