title: How to use imagemagick to give background and dimensions to my screenshot?
body: <p>I am new to Image Magick but am trying to get it to convert my image to a size and background pleasant for Twitter. The qualities I'm going for are as follows:</p>
  <ul>
  <li><p>my overall canvas size 16:9, so about 1200x675</p>
  </li>
  <li><p>my actual screenshot centered and about 3/4 the width</p>
  </li>
  <li><p>background texture of my choosing</p>
  <p>My latest attempt is with the following, but it doesn't seem to actually make any noticeable changes.</p>
  </li>
  </ul>
  <pre><code>convert ds.png -adaptive-resize 1200 -size 1200x675 -texture ~/Pictures/DoctorWho/horizon.jpg -gravity Center ds.png
  </code></pre>