Ne pouvez pas créer de fichier OpenCV - Stack Overflow

I'm trying to build this code

#include "stdafx.h"
#include <iostream>

#include <math.h>
#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;
}

and I'm getting an error:

1>c:\test1\test1\test1.cpp(21): error C2065: 'Mat' : undeclared identifier
1>c:\test1\test1\test1.cpp(21): error C2146: syntax error : missing ';' before identifier 'matC1_32S'
1>c:\test1\test1\test1.cpp(21): error C2065: 'matC1_32S' : undeclared identifier

What additional includes should I have? or somethind else?

You aren't providing a namespace for Mat. This will work if you link to the OpenCV libraries when you compile:

#include "stdafx.h"
#include <iostream>

#include <math.h>
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace std;
int _tmain(int argc, _TCHAR* argv[]) {
   int pixel;

   cv::Mat matC1_32S;

   return 0;
}

Or you can add using namespace cv; before _tmain so that you don't have to preface every appearance.

Also, you're overdoing the #include statements. You don't need the *_c.h files. (Maybe you added those when you were trying to figure out why Mat wasn't declared.)

Thank you for help, but to make it work I actually had also to include the following

#ifdef _DEBUG 
  #pragma comment(lib, "opencv_core231d.lib") 
  #pragma comment(lib, "opencv_highgui231d.lib") 
  #pragma comment(lib, "opencv_imgproc231d")
  #pragma comment(lib, "opencv_objdetect231d.lib")

#else 
  #pragma comment(lib, "opencv_core231.lib") 
  #pragma comment(lib, "opencv_highgui231.lib") 
  #pragma comment(lib, "opencv_imgproc231.lib")
  #pragma comment(lib, "opencv_objdetect231.lib")

#endif 

I understand why I need 'using namespace cv, but why do I need this stuff with pragma, despite that I provided libraries path in the project properties. ('m using VisualStudio 10

you have to go to properties >> C/C++ >> Avanced >> Compile As and choose Compile as C++ code /TP I did it. It works.

I'm trying to build this code

#include "stdafx.h"
#include <iostream>

#include <math.h>
#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;
}

and I'm getting an error:

1>c:\test1\test1\test1.cpp(21): error C2065: 'Mat' : undeclared identifier
1>c:\test1\test1\test1.cpp(21): error C2146: syntax error : missing ';' before identifier 'matC1_32S'
1>c:\test1\test1\test1.cpp(21): error C2065: 'matC1_32S' : undeclared identifier

What additional includes should I have? or somethind else?

You aren't providing a namespace for Mat. This will work if you link to the OpenCV libraries when you compile:

#include "stdafx.h"
#include <iostream>

#include <math.h>
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/highgui/highgui.hpp"

using namespace std;
int _tmain(int argc, _TCHAR* argv[]) {
   int pixel;

   cv::Mat matC1_32S;

   return 0;
}

Or you can add using namespace cv; before _tmain so that you don't have to preface every appearance.

Also, you're overdoing the #include statements. You don't need the *_c.h files. (Maybe you added those when you were trying to figure out why Mat wasn't declared.)

Thank you for help, but to make it work I actually had also to include the following

#ifdef _DEBUG 
  #pragma comment(lib, "opencv_core231d.lib") 
  #pragma comment(lib, "opencv_highgui231d.lib") 
  #pragma comment(lib, "opencv_imgproc231d")
  #pragma comment(lib, "opencv_objdetect231d.lib")

#else 
  #pragma comment(lib, "opencv_core231.lib") 
  #pragma comment(lib, "opencv_highgui231.lib") 
  #pragma comment(lib, "opencv_imgproc231.lib")
  #pragma comment(lib, "opencv_objdetect231.lib")

#endif 

I understand why I need 'using namespace cv, but why do I need this stuff with pragma, despite that I provided libraries path in the project properties. ('m using VisualStudio 10

you have to go to properties >> C/C++ >> Avanced >> Compile As and choose Compile as C++ code /TP I did it. It works.

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