ASP.NET MVC Image in response output stream. Not working

I want to display an image directly into the view and so I am calling an action method and writing the image in output stream.

But I am getting error saying "The image cannot be displayed as it contains error". I am sure the image is generating properly but not sure whats wrong with my controller code.. had anyone came across such scenario?

Thanks in advance..

Here is my controller action

[ChildActionOnly]
    public ActionResult GetCaptcha()
    {
        try
        {

            this.Session["CaptchaImageText"] = GenerateRandomCode();
            // Create a CAPTCHA image using the text stored in the Session object.
            RandomImage ci = new RandomImage(this.Session
                ["CaptchaImageText"].ToString(), 200, 60);
            // Change the response headers to output a JPEG image.
            this.Response.Clear();
            this.Response.ContentType = "image/jpeg";
            // Write the image to the response stream in JPEG format.

            using (MemoryStream ms = new MemoryStream())
            {
                ci.Image.Save(ms, ImageFormat.Jpeg);
                ms.WriteTo(this.Response.OutputStream);
            }

            // ci.Image.Save(this.Response.OutputStream, ImageFormat.Jpeg);
            // Dispose of the CAPTCHA image object.
            ci.Dispose();
        return new EmptyResult();

        }
        catch (Exception ex)
        {
            ex = null;
            return null;
        }

    }

And here is how I am calling the action method from view

<tr><td> <iframe>  @{ Html.Action("GetCaptcha"); } </iframe>  </td></tr>