The method or operation is not implemented while reading image from Database linq

if (objTblStudent.Photo != null)
{
    picStudPhoto.Image = byteArrayToImage(objTblStudent.Photo); // <-- Error
}

public Image byteArrayToImage(byte[] byteArrayIn)
{
    MemoryStream ms = new MemoryStream(byteArrayIn);
    Image returnImage = Image.FromStream(ms);
    return returnImage;
}

private Image byteArrayToImage(System.Data.Linq.Binary binary)
{
    throw new NotImplementedException();
}