扭曲效果

 ///283,191
            Bitmap bmp = new Bitmap(pictureBox1.Image);//创建Bitmap对象
            using (Graphics g = pictureBox2.CreateGraphics())
            {
                g.Clear(pictureBox1.BackColor);
                Point p1 = new Point(0, 0);
                Point p2 = new Point(220, 0);
                Point p3 = new Point(70, 180);
                ///三点定义一个平行四边形
                Point[] p = { p1, p2, p3 };
                g.DrawImage(bmp, p);
            }