Resize Image before Uploading

For this task we use some library and method.

Steps:

1. Create a sample ASP.NET Website, add new web form.
   
   
2. Paste the below design code into aspx page.
   
   1. <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
   3. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
   4. <html xmlns="http://www.w3.org/1999/xhtml">
   5. <head runat="server">
   6. <title></title>
   7. </head>
   8. <body>
   9. <form id="form1" runat="server">
   10. <div>
   11. <asp:FileUpload ID="FileUpload1" runat="server" />
   12. <br />
   13. <asp:Button ID="Button1" runat="server" Text="Upload" onclick="Button1_Click" />
   14. <br />
   15. <!-- To display the Size of image -->
   16. <span>Size Before Resize : </span>
   17. <asp:Label ID="Label1" runat="server" Text=""></asp:Label>
   18. <br />
   19. <span>Size After Resize : </span>
   20. <asp:Label ID="Label2" runat="server" Text=""></asp:Label>
   21. <br />
   22. <!-- To display the Resize Image -->
   23. <asp:Image ID="Image1" runat="server" />
   24. </div>
   25. </form>
   26. </body>
   27. </html>
3. Now use the following code into Button1_Click event on aspx.cs page:
   
   1. protected void Button1_Click(object sender, EventArgs e)
   2. {
   3. // Check file exist or not
   4. if (FileUpload1.PostedFile != null)
   5. {
   6. // Check the extension of image
   7. string extension = Path.GetExtension(FileUpload1.FileName);
   8. if (extension.ToLower() == ".png" || extension.ToLower() == ".jpg")
   9. {
   10. Stream strm=FileUpload1.PostedFile.InputStream;
   11. using (var image = System.Drawing.Image.FromStream(strm))
   12. {
   13. // Print Original Size of file (Height or Width)
   14. Label1.Text = image.Size.ToString();
   15. int newWidth = 240; // New Width of Image in Pixel
   16. int newHeight = 240; // New Height of Image in Pixel
   17. var thumbImg = new Bitmap(newWidth, newHeight);
   18. var thumbGraph = Graphics.FromImage(thumbImg);
   19. thumbGraph.CompositingQuality = CompositingQuality.HighQuality;
   20. thumbGraph.SmoothingMode = SmoothingMode.HighQuality;
   21. thumbGraph.InterpolationMode = InterpolationMode.HighQualityBicubic;
   22. var imgRectangle = new Rectangle(0, 0, newWidth, newHeight);
   23. thumbGraph.DrawImage(image, imgRectangle);
   24. // Save the file
   25. string targetPath = Server.MapPath(@"~\Images\") + FileUpload1.FileName;
   26. thumbImg.Save(targetPath, image.RawFormat);
   27. // Print new Size of file (height or Width)
   28. Label2.Text = thumbImg.Size.ToString();
   29. //Show Image
   30. Image1.ImageUrl = @"~\Images\" + FileUpload1.FileName;
   31. }
   32. }
   33. }
   34. }
   Note: Before using above code you must use the Following Namespace:
   
   1. using System.Drawing;
   2. using System.Drawing.Drawing2D;
   3. using System.IO;

4. Now run the website and upload and image.
   
   

Thanks for reading.