public static WriteableBitmap Overlay(WriteableBitmap bmp, WriteableBitmap overlay, Point location) { var result = bmp.Clone(); var size = new Size(overlay.PixelWidth, overlay.PixelHeight); result.Blit(new Rect(location, size), overlay, new Rect(new Point(0, 0), size), WriteableBitmapExtensions.BlendMode.Alpha); return result; }