title: Undefined reference to 'cvCreateKalman'
body: <p>I've been working on a simple Qt C++ OpenCV app and I want to integrate a Kalman filter.
  I include:</p>
  
  <pre><code>opencv/cv.h;opencv/highgui.h and opencv/cxcore.h;
  </code></pre>
  
  <p>in my .pro file I have:</p>
  
  <blockquote>
    <p>INCLUDEPATH += -I/usr/include/opencv LIBS += -lopencv_core \
    -lopencv_highgui \
    -lopencv_imgproc</p>
  </blockquote>
  
  <p>However, when I do this <code>CvKalman* kalman = cvCreateKalman(8,4,0);</code> I just get undefined reference to <code>cvCreateKalman</code> and collect2: ld returned 1 exit status. Compile output doesn't provide additional info. </p>
  
  <p>I tried finding help online but Google wasn't really helpful. I also tried to include additional <code>OpenCV</code> libs like ml or object tracking but nothing happened.</p>
  
  <p>It seems a bit weird to me that <code>CvKalman</code> and <code>cvCreateKalman</code> are available in the autocomplete since right after loading the original libs...</p>
  
  <p>Any help would be greatly appreciated!
  Thanks.</p>