Display Watermark on Existing ASP.Net Image on Page Load using C# and VB.Net

Hi

Please refer below code.

HTML

<div>
    <asp:Image ID="Image1" runat="server" ImageUrl="~/Images/Chrysanthemum.jpg" />
</div>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        string watermarkText = "© aspsnippet.com";
        string fileName = Server.MapPath(Image1.ImageUrl);
        FileStream fs = new FileStream(fileName, FileMode.Open);
        using (Bitmap bmp = new Bitmap(fs, false))
        {
            using (Graphics grp = Graphics.FromImage(bmp))
            {
                Brush brush = new SolidBrush(Color.Red);
                Font font = new System.Drawing.Font("Arial", 30, FontStyle.Bold, GraphicsUnit.Pixel);
                SizeF textSize = new SizeF();
                textSize = grp.MeasureString(watermarkText, font);
                Point position = new Point((bmp.Width - ((int)textSize.Width + 10)), (bmp.Height - ((int)textSize.Height + 10)));
                grp.DrawString(watermarkText, font, brush, position);


                using (MemoryStream memoryStream = new MemoryStream())
                {
                    bmp.Save(memoryStream, ImageFormat.Png);
                    string base64String = Convert.ToBase64String(memoryStream.ToArray());
                    string imageUrl = "data:image/png;base64," + base64String;
                    Image1.Attributes.Add("src", imageUrl);
                }
            }
        }
    }
}

VB.Net

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
    If Not Me.IsPostBack Then
        Dim watermarkText As String = "© aspsnippet.com"
        Dim fileName As String = Server.MapPath(Image1.ImageUrl)
        Dim fs As FileStream = New FileStream(fileName, FileMode.Open)

        Using bmp As Bitmap = New Bitmap(fs, False)

            Using grp As Graphics = Graphics.FromImage(bmp)
                Dim brush As Brush = New SolidBrush(Color.Red)
                Dim font As Font = New System.Drawing.Font("Arial", 30, FontStyle.Bold, GraphicsUnit.Pixel)
                Dim textSize As SizeF = New SizeF()
                textSize = grp.MeasureString(watermarkText, font)
                Dim position As Point = New Point((bmp.Width - (CInt(textSize.Width) + 10)), (bmp.Height - (CInt(textSize.Height) + 10)))
                grp.DrawString(watermarkText, font, brush, position)

                Using memoryStream As MemoryStream = New MemoryStream()
                    bmp.Save(memoryStream, ImageFormat.Png)
                    Dim base64String As String = Convert.ToBase64String(memoryStream.ToArray())
                    Dim imageUrl As String = "data:image/png;base64," & base64String
                    Image1.Attributes.Add("src", imageUrl)
                End Using
            End Using
        End Using
    End If
End Sub

Screenshot