AForge Imaging finding Rectagles in Image - aforge

Question

I'm able to find the rectangles if the image is created in paint..
I'm not able to find the rectangles in Sanp shot or Screen Shot taken
It's not recognizing Rectangle in Snapshot imagees...
Pls help me
string path = "D:\\testc.png";
Bitmap image = (Bitmap)Bitmap.FromFile(path);
BlobCounter blobCounter = new BlobCounter();
blobCounter.FilterBlobs = true;
blobCounter.MinHeight = 1;
blobCounter.MinWidth = 1;
blobCounter.ProcessImage(image);
Blob[] blobs = blobCounter.GetObjectsInformation();
var retcs = blobCounter.GetObjects(image,true);
SimpleShapeChecker shapeChecker = new SimpleShapeChecker();
foreach (var blob in blobs)
{
List<IntPoint> edgePoints = blobCounter.GetBlobsEdgePoints(blob);
List<IntPoint> cornerPoints;
// use the shape checker to extract the corner points
if (shapeChecker.IsQuadrilateral(edgePoints, out cornerPoints))
{
// only do things if the corners form a rectangle
if (shapeChecker.CheckPolygonSubType(cornerPoints) == PolygonSubType.Rectangle)
{
// here i use the graphics class to draw an overlay, but you
// could also just use the cornerPoints list to calculate your
// x, y, width, height values.
List<Point> Points = new List<Point>();
foreach (var point in cornerPoints)
{
Points.Add(new Point(point.X, point.Y));
}
Graphics g = Graphics.FromImage(image);
g.DrawPolygon(new Pen(Color.Red, 5.0f), Points.ToArray());
image.Save("D:\\result.png");
}
}
}