title: How to get contentType from System.Drawing.Imaging.ImageFormat
body: <p>If I have Bitmap and it has RawFormat property.</p>
  
  <p>How can I get Content Type from this ImageFormat object?</p>
  
  <pre><code>Bitmap image = new Bitmap(stream);
  ImageFormat imageFormat = image.RawFormat;
  //string contentType = ?
  </code></pre>