求教！SQLite存取图片问题！

我最近刚开始研究WP7，在用SQLite存取图片时遇到个问题，希望高手们指点。

图片转换成二进制存到SQLite时是 byte[14361]，读出来时却成了byte[13]，数据库里图片存储格式是Blob。Why？

这是我的代码：

//把图片转换成二进制存入sqlite
        private byte[] SetPicture()
        {
            BitmapImage bit = new BitmapImage(new Uri("image.jpg", UriKind.Relative));
            Image image = new Image();
            image.Source = bit;
            this.image1.Source = bit;
            WriteableBitmap bmp = new WriteableBitmap(image.Source as BitmapSource);


            byte[] byteArray;

            using (MemoryStream stream = new MemoryStream())
            {

                bmp.SaveJpeg(stream, bmp.PixelWidth, bmp.PixelHeight, 0, 100);

                byteArray = stream.ToArray();
            }
            return byteArray;
        }

private void PhoneApplicationPage_Loaded(object sender, RoutedEventArgs e)
        {
           SQLiteConnection mySqliteDB = new SQLiteConnection("SQLiteDB");
           mySqliteDB.Open();
           SQLiteCommand cmd = mySqliteDB.CreateCommand("select*from FriendTable");
           IEnumerable<Friend> list = cmd.ExecuteQuery<Friend>();
           List<FriendPct> listfd = new List<FriendPct>();
            foreach(Friend item in list.ToList())
            {
                FriendPct fp = new FriendPct();
                fp.ID = item.ID;
                fp.Name=item.Name;
                fp.Phone = item.Phone;
                fp.Picture = GetPath(item.Picture);
                fp.Class = item.Class;
                fp.Firsttime = item.Firsttime;
                fp.Lasttime = item.Lasttime;
                fp.Callcount = item.Callcount;
                fp.Grade = item.Grade;
                fp.Popcount = item.Popcount;
                listfd.Add(fp);
            }
            this.Files.ItemsSource = listfd;
        }
        //二进制数组转图片
        public static Image GetPath(byte[] b)
        {
            try
            {
                BitmapImage bit = new BitmapImage();
                Stream ms = new MemoryStream(b);
                bit.SetSource(ms);
                Image img = new Image();
                img.Source = bit;
                ms.Flush();
                ms.Close();
                return img;
            }
            catch (Exception ex)
            {
                return null;
            }
        }

上面IEnumerable<Friend> list。。。。list中返回的Picture为什么是byte[13]呢？