In this article I will explain how to convert text or string to Image format in ASP.Net
HTML Markup
Below is the HTML markup of the page where I have a TextBox where the text to be converted will be entered, a Button control to trigger the conversion process and an Image Control to display the converted image.
<html xmlns="">
<head runat="server">
    <form id="form1" runat="server">
    <asp:TextBox runat="server" ID="txtText"></asp:TextBox>
    <asp:Button ID="btnConvert" runat="server" Text="Convert" OnClick="btnConvert_Click" />
    <hr />
    <asp:Image ID="imgText" runat="server" Visible="false" />
You will need to inherit the following namespaces
using System.Drawing.Text;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
using System.Drawing.Imaging;
Imports System.Drawing.Text
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.IO
Imports System.Drawing.Imaging
Text String to Image Conversion
The below code converts the text string to a JPEG Image file. The image file that is generated is saved on the disk and then the image is displayed in Image Control.
protected void btnConvert_Click(object sender, EventArgs e)
    string text = txtText.Text.Trim();
    Bitmap bitmap = new Bitmap(1, 1);
    Font font = new Font("Arial", 25, FontStyle.Regular, GraphicsUnit.Pixel);
    Graphics graphics = Graphics.FromImage(bitmap);
    int width = (int)graphics.MeasureString(text, font).Width;
    int height = (int)graphics.MeasureString(text, font).Height;
    bitmap = new Bitmap(bitmap, new Size(width, height));
    graphics = Graphics.FromImage(bitmap);
    graphics.SmoothingMode = SmoothingMode.AntiAlias;
    graphics.TextRenderingHint = TextRenderingHint.AntiAlias;
    graphics.DrawString(text, font, new SolidBrush(Color.FromArgb(255, 0, 0)), 0, 0);
    string fileName = Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) + ".jpg";
    bitmap.Save(Server.MapPath("~/images/") + fileName, ImageFormat.Jpeg);
    imgText.ImageUrl = "~/images/" + fileName;
    imgText.Visible = true;
Protected Sub btnConvert_Click(sender As Object, e As System.EventArgs)
    Dim text As String = txtText.Text.Trim()
    Dim bitmap As New Bitmap(1, 1)
    Dim font As New Font("Arial", 25, FontStyle.Regular, GraphicsUnit.Pixel)
    Dim graphics As Graphics = graphics.FromImage(bitmap)
    Dim width As Integer = CInt(graphics.MeasureString(text, font).Width)
    Dim height As Integer = CInt(graphics.MeasureString(text, font).Height)
    bitmap = New Bitmap(bitmap, New Size(width, height))
    graphics = graphics.FromImage(bitmap)
    graphics.SmoothingMode = SmoothingMode.AntiAlias
    graphics.TextRenderingHint = TextRenderingHint.AntiAlias
    graphics.DrawString(text, font, New SolidBrush(Color.FromArgb(255, 0, 0)), 0, 0)
    Dim fileName As String = Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) & ".jpg"
    bitmap.Save(Server.MapPath("~/images/") & fileName, ImageFormat.Jpeg)
    imgText.ImageUrl = "~/images/" & fileName
    imgText.Visible = True
End Sub

Convert Text String to Image in ASP.Net using C# and VB.Net