how to solve a generic error occurred in gdi+.

Question

When the below code I m trying div to  convert image  geting error..plz help

 

protected void ExportToImage(object sender, EventArgs e)

{

//string text = hfImageData.UniqueID;

string base64 = Request.Form[hfImageData.UniqueID].Split(',')[1];

byte[] bytes = Convert.FromBase64String(base64);

Response.Clear();

Response.ContentType = "image/png";

Response.AddHeader("Content-Disposition", "attachment; filename=HTML.png");

Response.Buffer = true;

Response.Cache.SetCacheability(HttpCacheability.NoCache);

Response.BinaryWrite(bytes);

Bitmap bitmap = new Bitmap(1, 1);

Graphics graphics = Graphics.FromImage(bitmap);

Font font = new Font("Arial", 25, FontStyle.Regular, GraphicsUnit.Pixel);

int width = (int)graphics.MeasureString(base64, font).Width;

int height = (int)graphics.MeasureString(base64, font).Height;

bitmap = new Bitmap(bitmap, new Size(width, height));

graphics = Graphics.FromImage(bitmap);

string fileName = Path.GetFileNameWithoutExtension(Path.GetRandomFileName()) + ".jpg";

bitmap.Save(Server.MapPath("~/images/") + fileName, ImageFormat.Jpeg); // hear  i m getting error 

Response.End();

}