HTML5 Adaptive Images

<!-- using picture element -->
<picture alt="image title">
   <source src=hi_resolution.png media="min-width:800px">
   <source src=mid_resolution.png media="min-width:480px">
   <source src=low_resolution.png>
      <!-- fallback for browsers without support -->
      <img src=mid_resolution.png alt="image title">
</picture>

<!-- using srcset attribute -->
<img src="low_resolution.jpg" srcset="hi_resolution.jpg 2x, veryhi_resolution.jpg 6.5x" alt="title">