How to assign Imagebox image to Entity object for Saving in Database.

[SEhtesham]

Hi,
i have successfully able to load Image to imagebox in my Silverlight Application.Now i want to assign that selected image to the object that is carrying data to Service file to save records.
Below is my Code.
Code for how im Browsing n selecting Image.

 private void btnBrowse_Click(object sender, RoutedEventArgs e)
        {
OpenFileDialog objFileDialog = new OpenFileDialog();
            bool? IsSelected = objFileDialog.ShowDialog();
            objFileDialog.Filter = "Pictures (*.jpg)|*.jpg";
            objFileDialog.FilterIndex = 1;
            if (IsSelected == true)
            {
 
                BitmapImage bitImage = new BitmapImage();
                bitImage.SetSource(objFileDialog.File.OpenRead());
                image1.Source = bitImage;
                //Image1 is object of Image
            }  
}
Code of Object that is carrying Data to Save Method in Service File.
private void btnSave_Click(object sender, RoutedEventArgs e)
        {
 
var objAlumni = new ServiceReference1.Alumni_Registration();
  objAlumni.AY_ID = newAcadYearId;
  objAlumni.CellNo = txtCellNo.Text;
  objAlumni.ImageId = ;
  services.AlumniRegAsync(objAlumni);
}
 

Please suggest how should i assign my Selected Image to object objAlumni