C#图像处理的多种方法

private void 打开ToolStripMenuItem_Click(object sender, EventArgs e)
    {
      OpenFileDialog open = new OpenFileDialog();
      open.Filter = "所有文件|*.*";
      if (open.ShowDialog() == DialogResult.OK)
      {
        Bitmap im = new Bitmap(open.FileName);
        pictureBox1.Image = im;
        //pictureBox1.SizeMode = PictureBoxSizeMode.StretchImage;
      }
    }

private void bMPToolStripMenuItem_Click(object sender, EventArgs e)
    {
      Bitmap box = new Bitmap(pictureBox1.Image);
      SaveFileDialog sv1 = new SaveFileDialog();
      sv1.Filter = "bmp|*.bmp";
      sv1.ShowDialog();
      string str = sv1.FileName;
      box.Save(str, System.Drawing.Imaging.ImageFormat.Bmp);
    }
 
private void jPEGToolStripMenuItem_Click(object sender, EventArgs e)
    {
      Bitmap box = new Bitmap(pictureBox1.Image);
      SaveFileDialog sv1 = new SaveFileDialog();
      sv1.Filter = "jpeg文件|*.jpeg";
      sv1.ShowDialog();
      string str = sv1.FileName;
      box.Save(str, System.Drawing.Imaging.ImageFormat.Jpeg);
    }

private void 灰度ToolStripMenuItem_Click(object sender, EventArgs e)
    {
      pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
      Color c = new Color();
      Bitmap b1 = new Bitmap(pictureBox1.Image);
      int rr, gg, bb, cc;
      for (int i = 0; i < pictureBox1.Image.Width; i++) 
      {
        for (int j = 0; j < pictureBox1.Image.Height; j++)
        {
          c = b1.GetPixel(i, j);
          rr = c.R;
          gg = c.G;
          bb = c.B;
          cc = (int)((rr + gg + bb) / 3);
          if (cc < 0) cc = 0;
          if (cc > 255) cc = 255;
          Color nc = Color.FromArgb(cc, cc, cc);
          b1.SetPixel(i, j, nc);
        }
      }
      pictureBox2.Refresh();
      pictureBox2.Image = b1;
    }
private void 灰度图像存储ToolStripMenuItem_Click(object sender, EventArgs e)
    {
 
      if (pictureBox2.Image != null)
      {
        Bitmap box = new Bitmap(pictureBox2.Image);
        SaveFileDialog sv1 = new SaveFileDialog();
        sv1.Filter = "bmp文件|*.bmp";
        sv1.ShowDialog();
        string str = sv1.FileName;
        box.Save(str, System.Drawing.Imaging.ImageFormat.Bmp);
        //pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
      }
      else MessageBox.Show("没有生成灰度图像");
    }

private void 转化ToolStripMenuItem_Click(object sender, EventArgs e)
    {
      //Bitmap m = new Bitmap(pictureBox1.Width, pictureBox1.Height);
      Bitmap map=new Bitmap(pictureBox1.Image);
      Color c;
      for (int i = 0; i < map.Height; i++)
      {
        for (int j = 0; j < map.Width; j++)
        {
          c = map.GetPixel(j, i);
          if (c.R > 100) c = Color.FromArgb(255, 255, 255); //红色分量值大于100则设成白色
          else c = Color.Black;
          map.SetPixel(j, i, c);
        }
      }
      pictureBox2.Image = map;
      pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
    }

private void 对比ToolStripMenuItem_Click(object sender, EventArgs e)
    { 
      Color c = new Color();
      Bitmap box1 = new Bitmap(pictureBox1.Image);
      int lev=30, wid=170;
      int[] map = new int[256];
      for(int i=0;i<=lev;i++)
      {
        map[i]=0;
      }
      for (int i=lev;i<=wid;i++) //对比度增强
      {
        map[i] = (int)((i * 1.0 - lev) / wid * 255);
      }
      for (int i = lev + wid; i < 256; i++)
      {
        map[i] = 255;
      }
      int gray;
      for (int i = 0; i < box1.Width; i++)
      {
        for (int j = 0; j < box1.Height; j++)
        {
          c = box1.GetPixel(i, j);
          gray = c.R;
          c = Color.FromArgb(map[gray], map[gray], map[gray]);
          box1.SetPixel(i, j, c);
        }
      }
      pictureBox2.Image = box1;
      pictureBox2.SizeMode = PictureBoxSizeMode.StretchImage;
 }