title: Android image size (portrait only) for mdpi, hdpi, xhdpi, xxhdpi
body: <p>I currently work on an android project that the app is force to portrait only, I already have some design pictures and I would like to cut the image to build the UI. However, the problem is how should I scale each picture?</p>
  
  <p>What I found so far</p>
  
  <pre><code>xlarge (xhdpi): 640x960
  large (hdpi): 480x800
  medium (mdpi): 320x480
  small (ldpi): 240x320
  </code></pre>
  
  <p>But I also found</p>
  
  <pre><code>hdpi = mdpi * 1.5
  xhdpi = mdpi * 2
  xxhdpi = mdpi *3
  </code></pre>
  
  <p>but actually  the mdpi * 1.5 should be 480 * 720 ? How should I resize the picture for each resolution? thanks</p>