title: Screen Capture in PNG Format Works, but not BMP Format
body: <p>I'm using the code below to capture the screen with a game running</p>
  
  <pre><code>public static Bitmap CaptureScreen()
  {
      DxScreenCapture cap = new DxScreenCapture();
      var surface = cap.CaptureScreen();
  
      Bitmap png;
      using (DataStream stream = Surface.ToStream(surface, ImageFileFormat.Bmp))
      {
          png = new Bitmap(stream);
          png.Save(@"C:\Temp\MyFile.bmp");
      }
  
      return png;
  }
  </code></pre>
  
  <p>When saving as <code>ImageFileFormat.Bmp</code>, the saved file is entirely black.  If I change the format to <code>ImageFileFormat.Png</code> (and the file extension to .png), the image saves just fine.</p>
  
  <p>Why can I save in PNG format, but not in BMP format?</p>