title: emulated external storage (sdcard0) and mounted external storage (sdcard1)
body: <p>As far as I know, there are three types of storage among Android devices. Internal storage, emulated external storage and mounted external storage, like SD-Card.
  SO what the differences between them.
  My problems is that I want to scan images from external storage, so how to support these different kinds of devices. </p>
  
  <p>If a devices has both emulated external storage (sdcard0) and mounted external storage (sdcard1) how to scan both of them.
  Until now my code snippet looks like below,</p>
  
  <pre><code>        "/DCIM",
          "/DCIM/Camera",
          "/DCIM/100MEDIA",
          // Many Samsung phones mount the external sd card to /sdcard/external_sd
          "/external_sd/DCIM",
          "/external_sd/DCIM/Camera",
          "/external_sd/DCIM/100MEDIA"
  </code></pre>
  
  <p>anyone can help maintain the list. Or maybe the better way is to use some SDK build in methods instead of hard coded.</p>
  
  <p>Any advice will be appreciated.</p>