If you only need a BitmapSource (or an ImageSource), you can use GDI's CreateBitmapIndirect function and WPF interop's Imaging.CreateBitmapSourceFromHBitmap Method , something like this:

  static BitmapSource FromBITMAP(ref BITMAP bmp)
  {
        Int32Rect rect = new Int32Rect(0, 0, bmp.Width, bmp.Height);
        IntPtr hbitmap = CreateBitmapIndirect(ref bmp);
        if (hbitmap == IntPtr.Zero)
            return null;

        try
        {
            return Imaging.CreateBitmapSourceFromHBitmap(hbitmap, IntPtr.Zero, rect, BitmapSizeOptions.FromEmptyOptions());
        }
        finally
        {
            DeleteObject(hbitmap);
        }
  }

  [DllImport("gdi32.dll", SetLastError = true)]
  public static extern IntPtr CreateBitmapIndirect(ref BITMAP lpbm);

  [DllImport("gdi32.dll", SetLastError = true)]
  public static extern bool DeleteObject(IntPtr hObject);