@Override
 protected void onDestroy() {
   super.onDestroy();
   if (rotateBitmap != null) {
     rotateBitmap.recycle();
   }
 }
 private void clearImageView() {
   imageView.clear();
   if (rotateBitmap != null) {
     rotateBitmap.recycle();
   }
   System.gc();
 }