在对矩形进行检测后，如何提取斑点

'//处理图像私有void ProcessImage(Bitmap位图)｛//锁定图像BitmapData =位图。LockBits (新建矩形(0,0，位图)宽度,bitmap.Height),ImageLockMode。读写,bitmap.PixelFormat);

        // step 2 - locating objects
        BlobCounter blobCounter = new BlobCounter();
        blobCounter.FilterBlobs = true;
        blobCounter.MinHeight = 5;
        blobCounter.MinWidth = 5;
        blobCounter.ObjectsOrder = ObjectsOrder.Size;
        blobCounter.ProcessImage(bitmapData);
        Blob[] blobs = blobCounter.GetObjectsInformation();
        bitmap.UnlockBits(bitmapData);
        // step 3 - check objects' type and highlight
        SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
        Graphics g = Graphics.FromImage(bitmap);
        Pen redPen = new Pen(Color.Red, 2);       // quadrilateral
        for (int i = 0, n = blobs.Length; i < n; i++)
        {
            List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blobs[i]);
            List<IntPoint> corners;
            // use the shape checker to extract the corner points
            if (shapeChecker.IsQuadrilateral(edgePoints,out corners ))
            {
                // only do things if the corners form a rectangle
                if (shapeChecker.CheckPolygonSubType(corners) == PolygonSubType.Rectangle)
                {
                    g.DrawPolygon(redPen, ToPointsArray(corners));
                }
            }
        }

        redPen.Dispose();
        g.Dispose();
        // put new image to clipboard
        Clipboard.SetDataObject(bitmap);
        // and to picture box
        pictureBox1.Image = bitmap;
       }

    }`In [this link][0] array of rectangles was detected. Now, my question is how do I extract the rectangle from the image. My scenario is I detect the rectangular License plate of a car (colored image converted to binary  ) in the image and draw with red the location of the plate.

现在我想从图像中提取用红色绘制的盘子。我该怎么做呢?

由于我的图像是二值图像，我已经应用了扩展来获得正确的LP候选，所有候选都在图像中被成功识别，但我无法使用ExtractBiggestBlob方法提取它们。

请帮助。提前感谢。