private void Page_Load(object sender, System.EventArgs e)
  {
   ImgReduceCutOut(64,64,"1.jpg","2.jpg");
  }

  /// <summary>
  /// 缩小裁剪图片
  /// </summary>
  /// <param name="int_Width">要缩小裁剪图片宽度</param>
  /// <param name="int_Height">要缩小裁剪图片长度</param>
  /// <param name="input_ImgUrl">要处理图片路径</param>
  /// <param name="out_ImgUrl">处理完毕图片路径</param>
  public void ImgReduceCutOut(int int_Width,int int_Height,string input_ImgUrl,string out_ImgUrl)
  {

   int CutOut_Width=0; // 裁剪的宽度
   int CutOut_Height=0; // 裁剪的高度
   int level = 100; //缩略图的质量 1-100的范围

   CutOut_Width=int_Width;
   CutOut_Height=int_Height;

   System.Drawing.Image oldimage = System.Drawing.Image.FromFile(Server.MapPath(input_ImgUrl));
   Bitmap bm=new Bitmap(oldimage);

   ImageCodecInfo[] ImageCode=ImageCodecInfo.GetImageEncoders();
   ImageCodecInfo ii=null;
   foreach(ImageCodecInfo i in ImageCode)
   {
    if(i.MimeType=="image/jpeg") ii=i;
   }
   EncoderParameters ep=new EncoderParameters();
   ep.Param[0]=new EncoderParameter(Encoder.Quality,(long)level);

   Rectangle cloneRect = new Rectangle(20,20, CutOut_Width, CutOut_Height);
   PixelFormat format = bm.PixelFormat;
   Bitmap cloneBitmap = bm.Clone(cloneRect, format);

   cloneBitmap.Save(Server.MapPath(out_ImgUrl),ii,ep);
  }