In this Post Online Crop Uploaded Image and Save to Server in Asp.Net

Important Namespaces
-----------------------

using System.IO;
using System.Drawing;

-----------------------

Page Load Coding
------------------

 Image2.Visible = false;

-----------------

Upload Button Click Event
--------------------------

 string uploadFileName = "";
        string uploadFilePath = "";
        if (FileUpload1.HasFile)
        {
            string ext = Path.GetExtension(FileUpload1.FileName).ToLower();
            if (ext == ".jpg" || ext == ".jpeg" || ext == ".gif" || ext == ".png")
            {
                uploadFileName = Guid.NewGuid().ToString() + ext;
                uploadFilePath = Path.Combine(Server.MapPath("~/Images"), uploadFileName);
                try
                {
                    FileUpload1.SaveAs(uploadFilePath);
                    Image1.ImageUrl = "~/Images/" + uploadFileName;
                    Panel1.Visible = true;
                }
                catch (Exception ex)
                {
                    Label3.Text = "Error! Please try again.";
                }
            }
            else
            {
                Label3.Text = "Selected file type not allowed!";
            }
        }
        else
        {
            Label3.Text = "Please select file first!";
        }

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Crop and Save Image Button Click Event
-------------------------------------


string fileName = Path.GetFileName(Image1.ImageUrl);
        string filePath = Path.Combine(Server.MapPath("~/Images"), fileName);
        string cropFileName = "";
        string cropFilePath = "";
        if (File.Exists(filePath))
        {
            System.Drawing.Image orgImg = System.Drawing.Image.FromFile(filePath);
            Rectangle CropArea = new Rectangle(Convert.ToInt32(X.Value),Convert.ToInt32(Y.Value),Convert.ToInt32(W.Value),Convert.ToInt32(H.Value));
            try
            {
                Bitmap bitMap = new Bitmap(CropArea.Width, CropArea.Height);
                using (Graphics g = Graphics.FromImage(bitMap))
                {
                    g.DrawImage(orgImg, new Rectangle(0, 0, bitMap.Width, bitMap.Height), CropArea, GraphicsUnit.Pixel);
                }
                cropFileName = "crop_" + fileName;
                cropFilePath = Path.Combine(Server.MapPath("~/Images"), cropFileName);
                bitMap.Save(cropFilePath);
                // Response.Redirect("~/Images/" + cropFileName, false);
                Image2.ImageUrl = "~/Images/" + cropFileName;
                Image2.Visible = true;
                Label4.Text = "File Has Been Croped and Saved to Server ";
            }
            catch (Exception ex)
            {
                throw;
            }
        }


===========================

Hidden Field

				<asp:HiddenField ID="X" runat="server" />
                                <asp:HiddenField ID="Y" runat="server" />
                                <asp:HiddenField ID="W" runat="server" />
                                <asp:HiddenField ID="H" runat="server" />

-------------------

Coding for Jquery

<link href="Scripts/jquery.Jcrop.css" rel="stylesheet" />
             <script src="http://code.jquery.com/jquery-1.10.2.min.js" type="text/javascript"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery-jcrop/2.0.4/js/Jcrop.min.js"></script>
    <link rel="Stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/jquery-jcrop/2.0.4/css/Jcrop.css" />
            <script type="text/javascript">
                $(document).ready(function () {
                    $('#<%=Image1.ClientID%>').Jcrop({
                        onSelect: SelectCropArea
                    });
                });
                function SelectCropArea(c) {
                    $('#<%=X.ClientID%>').val(parseInt(c.x));
                    $('#<%=Y.ClientID%>').val(parseInt(c.y));
                    $('#<%=W.ClientID%>').val(parseInt(c.w));
                    $('#<%=H.ClientID%>').val(parseInt(c.h));
                }
            </script>