팝업창 생성하기 위해서

public void GoImgPopUp() {
     ImageView one=(ImageView)findViewById(R.id.i1);
  Bitmap mmm = one.getDrawingCache();

    BitmapDrawable bmpResized = BitmapResize(50);

    LayoutInflater factory = LayoutInflater.from(this);
    final View Dialer = factory.inflate(R.layout.introdu, null);

    Activity mCurrentView = null;
  final ImageView LFImage = (ImageView) mCurrentView.findViewById(R.id.i1);

    LFImage.setImageDrawable(bmpResized);

   AlertDialog.Builder alert = new AlertDialog.Builder(this);
    alert.setView(Dialer);
   
    AlertDialog alert_goImgDlg = alert.create();
    alert_goImgDlg.show();
 }
 public BitmapDrawable BitmapResize(int i){

         Bitmap bitmapOrg = null;
   int width = bitmapOrg.getWidth();

         int height = bitmapOrg.getHeight();
         int newWidth = 400;
         int newHeight = 600;
        
   
         float scaleWidth = ((float) newWidth) / width;
         float scaleHeight = ((float) newHeight) / height;
        
 
         Matrix matrix = new Matrix();
 
         matrix.postScale(scaleWidth, scaleHeight);     

         Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0, width, height, matrix, true);

         BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);
         return bmd;
 }

onClicke메소드에는 대충

else if (v.getId() == R.id.one){
   
   AlertDialog alert_goImgDlg = null;
   GoImgPopUp();
  } //one은 이미지뷰입니다.

이렇게 선언해주었는데요

..

FATAL EXCEPTION : MAIN

java.lang.nullpointerexception

에러가 뜹니다. 위 코딩에서 잘못된 부분이 있나요?ㅠ