Im doing steganography on android...my code is as below..

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.src);
    picw = mBitmap.getWidth();
    pich = mBitmap.getHeight();
    pix= new int[picw * pich];
    mBitmap.getPixels(pix, 0, picw, 0, 0, picw, pich);


try {               
       FileOutputStream fos = super.openFileOutput("dest.png", MODE_WORLD_READABLE);
       mBitmap.compress(CompressFormat.PNG, 100, fos);
       fos.flush();            
       fos.close();            


    }catch (Exception e) {       
      tv.setText(e.getMessage());
    } 

but whenever i save source image with Bitmap.compress() method pix[0] value before and after compression changed..so i'm unable to extract original data...please help me