title: Cannot build OpenCV  file
body: <p>I'm trying to build this code</p>
  
  <pre><code>#include "stdafx.h"
  #include &lt;iostream&gt;
  
  #include &lt;math.h&gt;
  #include "opencv2/core/core_c.h"
  #include "opencv2/core/core.hpp"
  #include "opencv2/imgproc/imgproc_c.h"
  #include "opencv2/imgproc/imgproc.hpp"
  #include "opencv2/highgui/highgui_c.h"
  #include "opencv2/highgui/highgui.hpp"
  
  using namespace std;
  
  int _tmain(int argc, _TCHAR* argv[])
  {   
      int pixel;
  
      Mat matC1_32S;
  
      return 0;
  }
  </code></pre>
  
  <p>and I'm getting an error:</p>
  
  <pre><code>1&gt;c:\test1\test1\test1.cpp(21): error C2065: 'Mat' : undeclared identifier
  1&gt;c:\test1\test1\test1.cpp(21): error C2146: syntax error : missing ';' before identifier 'matC1_32S'
  1&gt;c:\test1\test1\test1.cpp(21): error C2065: 'matC1_32S' : undeclared identifier
  </code></pre>
  
  <p>What additional includes should I have? or somethind else?</p>