Steps to implement this task 

Please follow the following steps to implement the desired task

•    Add two aspx files in the project and give named as Default.aspx and DynamicImage.aspx.
•    Write down following aspx script code to design user interface on Default aspx.

<div style="height: 486px; width: 872px">     
        <asp:Image ID="Image1" runat="server" Height="432px" Width="866px" />
        <br />
        <asp:TextBox ID="TextBox1" runat="server"
            style="margin-left: 26px; margin-top: 17px" Width="183px"></asp:TextBox>
&nbsp;
        <asp:Button ID="Button1" runat="server" onclick="Button1_Click"
            style="margin-left: 21px; margin-top: 15px" Text="Enter Image URL"
            Width="136px" />    
    </div> 

•    At the click event of Button1 writes down the following code.           

        Image1.ImageUrl = "DynamicImage.aspx?path=" + TextBox1.Text;

•    At the load event of DynamicImage.aspx write down the following code
  

protected void Page_Load(object sender, EventArgs e)
        {
               string path = Request.QueryString[0];
               if (path != null)
              {
                     System.Drawing.Bitmap img = new System.Drawing.Bitmap(path);
               img.Save(Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
              }
        }

The output of the following code

After clicking Enter Image URL button following output will be displayed