title: Ordering OpenCv contours in C++
body: <p>I have found contours out of a binary image with findContours, putting them in a 2d vector.This is what i've done:</p>
  
  <pre><code>vector&lt;vector&lt;Point&gt;&gt; contours;
  findContours(image,contours,CV_RETR_EXTERNAL,CV_CHAIN_APPROX_NONE);
  </code></pre>
  
  <p>Now i want to sort them from biggest to smaller:how can i handle this?
  Thanks all!</p>