private static void Main() { using (var img = new Array2D <byte>(400, 400)) using (var ht = new DlibDotNet.HoughTransform(300)) using (var win = new ImageWindow()) using (var win2 = new ImageWindow()) { var angle1 = 0d; var angle2 = 0d; while (true) { angle1 += Math.PI / 130; angle2 += Math.PI / 400; var rect = img.Rect; var cent = rect.Center; var arc = Point.Rotate(cent, cent + new Point(90, 0), angle1 * 180 / Math.PI); var tmp2 = arc + new Point(500, 0); var tmp3 = arc - new Point(500, 0); var l = Point.Rotate(arc, tmp2, angle2 * 180 / Math.PI); var r = Point.Rotate(arc, tmp3, angle2 * 180 / Math.PI); Dlib.AssignAllPixels(img, 0); Dlib.DrawLine(img, l, r, 255); using (var himg = new Array2D <int>()) { var offset = new Point(50, 50); var hrect = Dlib.GetRect(ht); var box = Rectangle.Translate(hrect, offset); // Now let's compute the hough transform for a subwindow in the image. In // particular, we run it on the 300x300 subwindow with an upper left corner at the // pixel point(50,50). The output is stored in himg. ht.Operator(img, box, himg); // Now that we have the transformed image, the Hough image pixel with the largest // value should indicate where the line is. So we find the coordinates of the // largest pixel: using (var mat = Dlib.Mat(himg)) { var p = Dlib.MaxPoint(mat); // And then ask the ht object for the line segment in the original image that // corresponds to this point in Hough transform space. var line = ht.GetLine(p); // Finally, let's display all these things on the screen. We copy the original // input image into a color image and then draw the detected line on top in red. using (var temp = new Array2D <RgbPixel>()) { Dlib.AssignImage(img, temp); var p1 = line.Item1 + offset; var p2 = line.Item2 + offset; Dlib.DrawLine(temp, p1, p2, new RgbPixel { Red = 255 }); win.ClearOverlay(); win.SetImage(temp); // Also show the subwindow we ran the Hough transform on as a green box. You will // see that the detected line is exactly contained within this box and also // overlaps the original line. win.AddOverlay(box, new RgbPixel { Green = 255 }); using (var jet = Dlib.Jet(himg)) win2.SetImage(jet); } } } } } }