Retrieving binary back to image and from database and save into a folder using WPF

I have successfully converted image to binary and saved it into the database using linq to sql WPF and now i want to retrieve it back to image format and save it to a specific folder in computer.

i have read many blogs and articles which retrieves the image binary from database and then shows it into the PictureBox, what i want to do is to select the image and save it to a specific folder using linq to sql.

code which i have tried so far for uploading an image:

private void Browse_Click(object sender, RoutedEventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.DefaultExt = ".jpg";
            ofd.Filter = "Image File (.jpg) | *.jpg";

            Nullable<bool> result = ofd.ShowDialog();

            if(result == true)
            {
                string fileName = ofd.FileName;
                _txtFileName.Text = fileName;
            }
        }

        private void Upload_Click(object sender, RoutedEventArgs e)
        {
            using(ImageDataContext db=new ImageDataContext())
            {
                image_data img = new image_data();

                img.image = ConverImageToBinary(_txtFileName.Text);

                try
                {
                    db.image_datas.InsertOnSubmit(img);
                    db.SubmitChanges();

                    MessageBox.Show("Picture Upload Successfully", "Success", MessageBoxButton.OK, MessageBoxImage.Exclamation);
                }

                catch(Exception ex)
                {
                    MessageBox.Show(ex.Message);
                }
            }
        }

        public static byte[] ConverImageToBinary(string convertedImage)
        {
            try
            {
                FileStream fs = new FileStream(convertedImage, FileMode.Open, FileAccess.Read);

                BinaryReader br = new BinaryReader(fs);

                byte[] image = br.ReadBytes((int)fs.Length);

                br.Close();

                fs.Close();

                return image;
            }

            catch(Exception ex)
            {
                throw ex;//MessageBox.Show(ex.Message, "error", MessageBoxButton.OK, MessageBoxImage.Exclamation);
            }
        }