WPF- write writeablebitmap to image

private Image WriteableBitmapToImage(WriteableBitmap wriBmp)
{
    Image bmp = null;
    using (MemoryStream outStream = new MemoryStream())
    {
        var enc = new BmpBitmapEncoder();
        enc.Frames.Add(BitmapFrame.Create(wriBmp));
        enc.Save(outStream);
        bmp = new Bitmap(outStream);
    }
    return bmp;
}