Save image in Windows store apps

public static void SaveImage(Stream imageStream, string fileName, int orientation, int quality)
{
    using (var isolatedStorage = IsolatedStorageFile.GetUserStoreForApplication())
    {
        if (isolatedStorage.FileExists(fileName))
            isolatedStorage.DeleteFile(fileName);

        IsolatedStorageFileStream fileStream = isolatedStorage.CreateFile(fileName);
        BitmapImage bitmap = new BitmapImage();
        bitmap.SetSource(imageStream);

        WriteableBitmap wb = new WriteableBitmap(bitmap);
        wb.SaveJpeg(fileStream, wb.PixelWidth, wb.PixelHeight, orientation, quality);
        fileStream.Close();
    }
}