public void RotateImage2(Bitmap bitmap, Double angle)
        {
            angle = angle % 360;
            if (angle > 180)
                angle -= 360;

            double originX = pictureBox1.Image.Width / 2;
            double originY = pictureBox1.Image.Height / 2;

            Bitmap newImg = new Bitmap((int)Math.Sqrt(bitm.Height * bitm.Height + bitm.Width * bitm.Width), (int)Math.Sqrt(bitm.Height * bitm.Height + bitm.Width * bitm.Width));
            double newx, newy;
            int x, y;
            for (x = 0; x < bitm.Width; x++)
            {
                for (y = 0; y < bitm.Height; y++)
                {
                    newx = (x - originX) * Math.Cos(angle) - (y - originY) * Math.Sin(angle) + originX;
                    newy = (x - originY) * Math.Sin(angle) + (y - originY) * Math.Cos(angle) + originY;
                    newImg.SetPixel((int)newx, (int)newy, bitm.GetPixel(x, y));
                }
            }
            bitm = newImg;
            pictureBox1.Image = new Bitmap(bitm);
        }