title: how to convert cv:Mat to vector<float> descriptors?
body: <p>I met a problem when communicating with my pales in TCP. I received the data processed in an asn1 struct such as :</p>
  
  <pre><code>Mat ::= SEQUENCE {
          numrows   INTEGER,
          numcols   INTEGER,
          data      BIT STRING,
          type      INTEGER       
      } 
  </code></pre>
  
  <p>I can construct a matrix which is cv::mat. However, now I need query it in this format: vector descriptors. So my question is how can I convert mat to this vector?</p>