title: Code::Blocks return error when using OpenCV "undefined reference to `cvFree_'|" in C
body: <pre><code>/home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvDecRefData':|
  main.c|| undefined reference to `cvFree_'|
  main.c|| undefined reference to `cvFree_'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvGetRow':|
  main.c|| undefined reference to `cvGetRows'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvGetCol':|
  main.c|| undefined reference to `cvGetCols'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvReleaseMatND':|
  main.c|| undefined reference to `cvReleaseMat'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvSubS':|
  main.c|| undefined reference to `cvAddS'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvCloneSeq':|
  main.c|| undefined reference to `cvSeqSlice'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvSetNew':|
  main.c|| undefined reference to `cvSetAdd'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvGetSetElem':|
  main.c|| undefined reference to `cvGetSeqElem'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvEllipseBox':|
  main.c|| undefined reference to `cvEllipse'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvFont':|
  main.c|| undefined reference to `cvInitFont'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvReadIntByName':|
  main.c|| undefined reference to `cvGetFileNodeByName'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvReadRealByName':|
  main.c|| undefined reference to `cvGetFileNodeByName'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvReadStringByName':|
  main.c|| undefined reference to `cvGetFileNodeByName'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvReadByName':|
  main.c|| undefined reference to `cvGetFileNodeByName'|
  main.c|| undefined reference to `cvRead'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvContourPerimeter':|
  main.c|| undefined reference to `cvArcLength'|
  /home/piotr/Dokumenty/Projekt antybulglar/main.o||In function `cvCalcHist':|
  main.c|| undefined reference to `cvCalcArrHist'|
  ||=== Build failed: 18 error(s), 0 warning(s) (0 minute(s), 0 second(s)) ===|
  </code></pre>
  
  <p>I,ve tried to install it in many ways for example:
  <a href="https://www.youtube.com/watch?v=MqQB5KKJCh0" rel="nofollow">https://www.youtube.com/watch?v=MqQB5KKJCh0</a></p>
  
  <p>And still nothing.</p>