title: Bitmap PNG save without modifications
body: <p>I am attempting to load a PNG image into a Bitmap and save it without modifications.</p>
  
  <p>I tried something along these lines:</p>
  
  <pre><code>var png = Bitmap.FromFile("t_02.png");
  png.Save("t_02_out.png", ImageFormat.Png);
  </code></pre>
  
  <p>I also tried:</p>
  
  <pre><code>var png = Bitmap.FromFile("t_02.png");
  png.Save("t_02_out.png");
  </code></pre>
  
  <p>In either case, the original 233kb file procuded a 356kb image. What am I doing wrong?</p>