title: Scale image with css to both width and height to scale
body: <p>The bounding box is approx 1000x600, and some images are 500x100,
  while some others are 400x100 (extreme examples). Now I'd like to
  scale both up to the maximum size the bounding box is capable to
  handle, but keep them to scale.</p>
  
  <pre><code>img {
    width: 100%;
    height: 100%;
  }
  </code></pre>
  
  <p>Won't keep the image to scale.</p>