title: Opencv2 cvtColor() does not work
body: <p>I am using OpenCV2 on Ubuntu 12.04. I can successfully run image read-display codes.
  However I am not able to run codes with inbuilt functions eg. cvtColor()</p>
  
  <pre><code>#include &lt;opencv2/core/core.hpp&gt;
  #include &lt;opencv2/highgui/highgui.hpp&gt;
  
  #include &lt;stdio.h&gt;
  
  int main(int argc, char *argv[])
  {
      cv::Mat image = cv::imread("img.jpg");
  
      if( image.data == NULL )
      {
          printf( "file cannot be loaded\n");
          return 1;
      }
  
      cv::namedWindow("My");
      cv::imshow("My", image);
  
      cv::Mat result;
      cv::cvtColor(image, result, CV_BGR2Luv);
  
      cv::imwrite("outImg.jpg", result);
  
      cv::waitKey(0);
  
      return 0;
  }
  </code></pre>
  
  <p>I am using Qt-creator for my OpenCV
  After compiling with --libs, --cflags I get following compiler error:</p>
  
  <pre><code>make: Entering directory `/home/swaroop/Work/ai-junkies/cuda/uc_davis/opencv2.x/OpenCV2Test'
  g++ -g -c -pipe -O2 -Wall -W -D_REENTRANT -DQT_WEBKIT -DQT_NO_DEBUG -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4 -I/usr/include/opencv -I. -o main.o main.cpp
  main.cpp: In function 'int main(int, char**)':
  main.cpp:22:29: error: 'CV_BGR2Luv' was not declared in this scope
  main.cpp:22:39: error: 'cvtColor' was not declared in this scope
  </code></pre>
  
  <p>Please help me fix this.</p>