grid view image not convert in to pdf

Cs code is

protected void LinkButton1_Click(object sender, EventArgs e)
{
int rindex = (((GridViewRow)(((LinkButton)(sender)).Parent.BindingContainer))).RowIndex;
string IId = GridView1.DataKeys[rindex]["Id"].ToString();
Download1(IId);
string strFileName = "test.pdf";
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment;filename=" + strFileName + "");
Response.Cache.SetCacheability(HttpCacheability.NoCache);

StringWriter sw = new StringWriter();
HtmlTextWriter hw = new HtmlTextWriter(sw);
GridView1.RenderControl(hw);
string s = sw.ToString().Replace("%20", " ");
s = Regex.Replace (s, "\r\n", string.Empty);
s = Regex.Replace(s, "\t", string.Empty);
s = Regex.Replace(s, " ", string.Empty);
s = Regex.Replace(s, HTML_TAG_PATTERN, string.Empty);
StringReader sr = new StringReader(s);
Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);
HTMLWorker htmlparser = new HTMLWorker(pdfDoc);
PdfWriter.GetInstance(pdfDoc, Response.OutputStream);
pdfDoc.Open();
htmlparser.Parse(sr);
pdfDoc.Close();
Response.Write(pdfDoc);
Response.End();
}

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
string id = GridView1.DataKeys[e.Row.RowIndex].Value.ToString();
DataTable dt = con.GetData("select * from Download where Id='" + id + "'");
if (dt.Rows.Count > 0)
{
System.Web.UI.WebControls.Image img = (System.Web.UI.WebControls.Image)e.Row.FindControl("Image1");
string url = "Download/" + dt.Rows[0]["Photo1"].ToString();
img.ImageUrl = GetUrl(url);
}
}


}
public void Download1(string id)
{
string i = id;
DataTable dt = con.GetData("select * from Download where Id='" + i + "'");
if (dt != null)
{
GridView1.DataSource = dt;
GridView1.DataBind();
GridView1.AllowPaging = false;
return;
}
}
protected string GetUrl(string imagepath)
{

string[] splits = Request.Url.AbsoluteUri.Split('/');

if (splits.Length >= 2)
{

string url = splits[0] + "//";

for (int i = 2; i < splits.Length - 1; i++)
{

url += splits[i];

url += "/";

}

return url + imagepath;

}

return imagepath;

}
This code expport text properly but never image
what i do
plz help