C#图像处理

    Response.Clear();  

   Bitmap imgOutput = new Bitmap(100, 50);  

   Graphics gic = Graphics.FromImage(imgOutput); 

   gic.Clear(Color.BlueViolet); 

   gic.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias; 

   gic.DrawString("渐变图形", new Font("黑体",16,FontStyle.Italic),new SolidBrush(Color.White),new PointF(2,2));  

   gic.FillRectangle(new System.Drawing.Drawing2D.LinearGradientBrush(new Point(0,0), new Point(100,50), Color.FromArgb(0,0,0,0),Color.FromArgb(255,255,255,255)),0,0,100,50);  

   imgOutput.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); 

   gic.Dispose();  

   imgOutput.Dispose();  

   Response.End();  

二、对图片进行反转

    System.Drawing.Image drawp_w_picpath = System.Drawing.Image.FromFile(photopath);//photopath表示图片的物理地址

   drawp_w_picpath.RotateFlip(RotateFlipType.Rotate270FlipNone);

    if(File.Exists(photopath))

   {

        File.SetAttributes(photopath,FileAttributes.Normal);

        File.Delete(photopath);

   }

   drawp_w_picpath.Save(photopath,System.Drawing.Imaging.ImageFormat.Jpeg);

   drawp_w_picpath.Dispose();

三、对图片进行缩放

    System.Drawing.Image drawp_w_picpath = System.Drawing.Image.FromFile(photopath);

   Bitmap imgOutput = new Bitmap(drawp_w_picpath,60,30);

   imgOutput.Save(newphotppath, System.Drawing.Imaging.ImageFormat.Jpeg);  

   imgOutput.Dispose();  

   Response.End(); 

其他还有一些画线、画矩形、画圆等的函数和方法都可以在System.Drawing中找到；