Android a seekbar for adjusting bitmap brightness

I have tryed many codes, and looked at Android developers but couldn't make it work. I want the seek bar to adjust my bitmap image brightness

check the example given at Increase/Decrease Brightness of Image

and do as shown below on seekbar progress changes

 int brightness;
 SeekBar seekbarbrightness=(SeekBar)findViewById(R.id.seekBar1);
 seekbarbrightness.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {

         @Override
         public void onStopTrackingTouch(SeekBar arg0) {
          // TODO Auto-generated method stub

         }

         @Override
         public void onStartTrackingTouch(SeekBar arg0) {
          // TODO Auto-generated method stub

         }

         @Override
         public void onProgressChanged(SeekBar arg0, int progress, boolean arg2) {

             // TODO Auto-generated method stub

             brightness=progress;
             Bitmap bitmap=doBrightness(originalbitmap,brightness);
             imageView.setImageBitmap(bitmap);
         }
        });