asp. net Implementation of generating thumbnails and watermarking original images

In this paper, the method of generating thumbnails and watermarking original images by asp. net is described. Share it for your reference, as follows:

using System.IO;
using System.Drawing.Imaging;
private void Button1_ServerClick(object sender, System.EventArgs e) 
{
  Graphics g=null;
  System.Drawing.Image upimage=null;
  System.Drawing.Image thumimg=null;
  System.Drawing.Image simage=null;
  Bitmap outputfile=null;
  try 
  {
    string extension = Path.GetExtension(File1.PostedFile.FileName).ToUpper();
    string filename = DateTime.Now.ToString("yyyyMMddhhmmss");
    string smallpath = Server.MapPath(".")+"/smallimg/";
    string bigpath = Server.MapPath(".")+"/bigimg/";
    int width,height,newwidth,newheight;
    System.Drawing.Image.GetThumbnailImageAbort callb =new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
    if(!Directory.Exists(smallpath))
    Directory.CreateDirectory(smallpath);
    if(!Directory.Exists(bigpath))
    Directory.CreateDirectory(bigpath);
    Stream upimgfile = File1.PostedFile.InputStream;
    string simagefile = Server.MapPath("a8logo.jpg"); // File to be watermarked 
    simage=System.Drawing.Image.FromFile(simagefile);
    upimage= System.Drawing.Image.FromStream(upimgfile); // Uploaded pictures 
    width = upimage.Width;
    height = upimage.Height;
    if(width>height) 
    {
      newwidth=200;
      newheight =(int)((double)height/(double)width * (double)newwidth);
    } else 
    {
      newheight=200;
      newwidth=(int)((double)width/(double)height * (double)newheight);
    }
    thumimg = upimage.GetThumbnailImage(newwidth,newheight,callb,IntPtr.Zero);
    outputfile=new Bitmap(upimage);
    g=Graphics.FromImage(outputfile);
    g.DrawImage(simage,new Rectangle(upimage.Width-simage.Width,upimage.Height-simage.Height,upimage.Width,upimage.Height),0,0,upimage.Width,upimage.Height,GraphicsUnit.Pixel);
    string newpath = bigpath + filename + extension; // Original graph path 
    string thumpath = smallpath + filename + extension; // Thumbnail path 
    outputfile.Save(newpath);
    thumimg.Save(thumpath);
    outputfile.Dispose();
  }
  catch(Exception ex) 
  {
    throw ex;
  }
  finally 
  {
    if(g!=null)
    g.Dispose();
    if(thumimg!=null)
    thumimg.Dispose();
    if(upimage!=null)
    upimage.Dispose();
    if(simage!=null)
    simage.Dispose();
  }
}
public bool ThumbnailCallback() 
{
  return false;
}

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I hope this article is helpful to everyone's asp. net programming.