在Android中，如何根据检测器获取的点在QR上绘制矩形？

Question

我正在尝试使用Android中的Google视觉api制作QR码扫描仪。我成功地检测到QR码并获取了内容，我正在使用 Detector 类来检测QR。扫描后，我停止相机预览，并想在扫描的QR周围画一个方框。为此，我从探测器类中获取了扫描QR点（X，Y坐标）。但是这些点与相机源预览中的QR图像不匹配。 Here is an screenshot of scanned QR

下面是当检测到QR时将调用的方法，在这种方法中，我要获取QR码，然后停止摄像头并调用带有QR位置的绘制矩形方法来绘制一个代替QR码的框

 @Override
 public void receiveDetections(Detector.Detections<Barcode> detections) 
 {
     final SparseArray<Barcode> qrCodes = detections.getDetectedItems();
     final Detector.Detections<Barcode> frame =   detections;

            if (qrCodes.size() != 0 )
            {
                scannerDetector.release();
                Handler handler = new Handler(Looper.getMainLooper());
                handler.post(new Runnable()
                {
                    @Override
                    public void run() 
                    {
                        cameraSource.stop();//Stopping the camera after a QR is detected

                        for (int i = 0; i < qrCodes.size(); i++)
                        {
                            final int key = qrCodes.keyAt(i);

                            // this gives the rect co-ordinates of the detected QR
                            Rect rect = qrCodes.get(key).getBoundingBox();

                            drawRectangle(rect);                            

                            break;
                        }
                    }

                });
             }
 } 

 private void drawRectangle(final Rect rect)
 {
   runOnUiThread(new Runnable()
   {
       @Override
       public void run()
       {
          // detected frame is a constraint layout and view returned from Draw Rectangle class will be  added as its subview
           detectedFrame.addView(new DrawRectangle(QRCodeScannerActivity.this, rect)); 
       }
   });
 }

我在这里用我从探测器获得的矩形坐标绘制一个盒子。

public class DrawRectangle extends View
{ 
Rect rect;
public DrawRectangle(Context context, Rect rect )
{
    super(context);
    this.rect = rect;
}

@Override
protected void onDraw(Canvas canvas)
 {
    super.onDraw(canvas);

    Paint paint = new Paint();

    //Rectangle
    paint.setColor(Color.BLUE);
    paint.setStrokeWidth(5);
    paint.setStyle(Paint.Style.STROKE);

    try
    {

       canvas.drawRect(rect,paint);
    }
    catch (Exception e)
    {

    }
  }
}