How to convert emf to ImageSource in WPF?

using (Stream stream = new MemoryStream(bytes))
                    {
                        stream.Position = 0;
                        Metafile mimg = new Metafile(stream);

                        using (Stream streamEx = new MemoryStream())
                        {
                            mimg.Save(streamEx, ImageFormat.Png);//Almost four seconds 
                            streamEx.Position = 0;

                            img = new BitmapImage();
                            img.BeginInit();
                            img.StreamSource = streamEx;
                            img.CreateOptions = BitmapCreateOptions.IgnoreColorProfile;
                            img.CacheOption = BitmapCacheOption.OnLoad;
                            img.EndInit();
                        }
                    }

using (Stream stream = new MemoryStream(bytes))
                   {
                       stream.Position = 0;
                       System.Drawing.Bitmap bitmap = new System.Drawing.Bitmap(stream);//Almost three seconds

                       myImg1.Source = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(
                                       bitmap.GetHbitmap(),
                                       IntPtr.Zero,
                                       new Int32Rect(0, 0, RcBill.Width, RcBill.Height),
                                       BitmapSizeOptions.FromEmptyOptions());
                       NativeMethods.DeleteObject(bitmap.GetHbitmap());
                   }