title: converting Mat to iplimage* in opencv
body: <p>I am new in opencv and c++. what is the difference between  iplimage and  iplimage*?
  I used cvHaarDetectObjects that need  iplimage* in arg[1]. I have a frame in the format of Mat. how could I convert Mt to  iplimage*? (I found  a way to convert mat to iplimage but not to iplimage*).</p>
  
  <p>the true one is :</p>
  
  <pre><code>iplimage* frame=cvLoadImage("1.jpg");
  objects = cvHaarDetectObjects( frame, face_cascade, storage, scale_factor, 1 );
  </code></pre>
  
  <hr>
  
  <p>but I want to use:</p>
  
  <pre><code>Mat frame;
  //some functions are performed on frame
  objects = cvHaarDetectObjects( frame, face_cascade, storage, scale_factor, 1 );
  </code></pre>