图像识别学习—3

Robets 算子是一种微分算子

设输入图像为f(i,j) 算子输出图像为 g(i,j)

则Roberts算子表示为差分形式：

g(x) = f(i,j)-f(i+1,j)

g(y) = f(i+1,j) - f(i,j+1)

g(i,j) = abs(gx)+ abs(gy)

这是一个Winform的代码

 private void button1_Click(object sender, EventArgs e)
        {
            Color c1 = new Color();
            Color c2 = new Color();
            Color c3 = new Color();
            Color c4 = new Color();
            int rr, gg, bb, r1, r2, r3, r4, fxr, fyr, i, j;
            int g1, g2, g3, g4, fxg, fyg, b1, b2, b3, b4, fxb, fyb;

            Bitmap box1 = new Bitmap(pictureBox1.Image);
            Bitmap box2 = new Bitmap(pictureBox2.Image);

            for (i = 0; i < pictureBox1.Image.Width - 2; i++)
            {
                for (j = 0; j < pictureBox1.Image.Height - 2; j++)
                {
                    c1 = box1.GetPixel(i, j);
                    c2 = box1.GetPixel(i + 1, j + 1);
                    c3 = box1.GetPixel(i + 1, j);
                    c4 = box1.GetPixel(i, j + 1);
                    r1 = c1.R;
                    r2 = c2.R;
                    r3 = c3.R;
                    r4 = c4.R;
                    fxr = r1 - r2;
                    fyr = r3 - r4;
                    rr = Math.Abs(fxr) + Math.Abs(fyr) + 128;
                    if (rr < 0)
                        rr = 0;
                    if (rr > 255)
                        rr = 255;
                    g1 = c1.G;
                    g2 = c2.G;
                    g3 = c3.G;
                    g4 = c4.G;
                    fxg = g1 - g2;
                    fyg = g3 - g4;
                    gg = Math.Abs(fxg) + Math.Abs(fyg) + 128;
                    if (gg < 0)
                        gg = 0;
                    if (gg > 255)
                        gg = 255;
                    b1 = c1.B;
                    b2 = c2.B;
                    b3 = c3.B;
                    b4 = c4.B;
                    fxb = b1 - b2;
                    fyb = b3 - b4;
                    bb = Math.Abs(fxb) + Math.Abs(fyb);
                    if (bb < 0)
                        bb = 0;
                    if (bb > 255)
                        bb = 255;

                    Color cc = Color.FromArgb(rr, gg, bb);
                    box2.SetPixel(i, j, cc);
                }

                pictureBox2.Refresh();
                pictureBox2.Image = box2;
            }