Help to make opencv's dll and LabVIEW's Call Library function node understanding each others

Question

Hi, i have a little problem trying to use a C++ opencv's dll in labview. I wrote a really simple and stupid dll just to try to understand how it works the call library function node. Here the header code:
#ifdef GENERICDLL_EXPORTS
#define GENERICDLL_API __declspec(dllexport)
#else
#define GENERICDLL_API __declspec(dllimport)
#endif
#include "stdafx.h"
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <string.h>
#include <stdio.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
// Questa classe è esportata da Generic DLL.dll
class GENERICDLL_API CGenericDLL {
public:
int Summ(int a, int b);
int Sott(int a, int b);
int opencv(int a);
// TODO: aggiungere qui i metodi.
 and here the .cpp:
// Generic DLL.cpp: definisce le funzioni esportate per l'applicazione DLL.
#include "stdafx.h"
#include "Generic DLL.h"
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <string.h>
#include <stdio.h>
#include <opencv/cv.h>
#include <opencv/highgui.h>
using namespace cv;
using namespace std;
// Esempio di variabile esportata
GENERICDLL_API int nGenericDLL=0;
// Funzioni esportate.
GENERICDLL_API int Summ(int a, int b)
return a+b;
GENERICDLL_API int Sott(int a, int b)
return a - b;
GENERICDLL_API int opencv(int a)
const string ind = "C:\\Users\\sviluppo\\Desktop\\Tuli.bmp";
const string ind_2 = "C:\\Users\\sviluppo\\Desktop\\Tuli_Gray.bmp";
//Mat image;
return 5;
i can call all the three simple functions in labview with this easy code. No problem at all. If i uncomment the line "Mat image;" the call library function node doesn't work and i receive the error:
"The library specified for this node cannot be found or cannot be loaded. Right-click the Call Library Function node and select Configure, then choose the correct library name or path."
I think that is a problem of dependencies between opencv libraries but i dont know how to manage this. Any ideas?
Thank you for yours time,
Francesco.

Answer 1

Hello Francesco,
I'm having exactly the same problem as you. I created a DLL that I can easily access from LabView. If I add one line and include "imgproc.hpp" (the only one I need), then LV gives me the same error you had. I read the thread Loura linked to, but I don't see how people actually take care of the dependecies (Klemen's examples did not work for me for the same reason, even though I recompiled the .cpp). Could you explain in detail what you did to make it work?
Thanks