title: Conversion from PointCloud to Mat
body: <p>Let's say I initialize a point-cloud. I want to store its RGB channels in opencv's Mat data-type. How can I do that?</p>
  
  <pre><code>pcl::PointCloud&lt;pcl::PointXYZRGBA&gt;::Ptr cloud (new pcl::PointCloud&lt;pcl::PointXYZRGBA&gt;);   //Create a new cloud
  pcl::io::loadPCDFile&lt;pcl::PointXYZRGBA&gt; ("cloud.pcd", *cloud);
  </code></pre>