Question

I’m currently trying to play around with OpenCV but I ran into a bit of trouble..
I use the qt ide with mingw to compile my applications.

My code looks like this:

#include “highgui.h”

int main( int argc, char** argv ) 
{
    IplImage* img1 = cvLoadImage( argv[1] );
    cvNamedWindow( “Example”, CV_WINDOW_AUTOSIZE );
    cvShowImage( “Example”, img1 );
    cvWaitKey(0);
    cvReleaseImage( &img1 );
    cvDestroyWindow( “Example” );
    return(0);
}

And this is in my .pro file:

INCLUDEPATH += "E:/OpenCV2MinGWBuild/install/include/"
INCLUDEPATH += "E:/OpenCV2MinGWBuild/install/include/opencv/"
INCLUDEPATH += "E:/OpenCV2MinGWBuild/install/include/opencv2/"
LIBS += -L"E:/OpenCV2MinGWBuild/install/lib/" -lopencv_calib3d231.dll -lopencv_contrib231.dll -lopencv_core231.dll

The libraries are .a-s(the dll is in the name part of the lib, it’s not an extension).. I know that .a libraries are linux specific but mingw sould be able to use them right?

I built the OpenCV libraries with mingw, but I can’t get them to link to my Qt application..
MinGW can see the header files just fine, but not the libraries.
I always get “undefined reference to cvShowImage'", "undefined reference tocvNamedWindow'” (etc)errors..

Any help is appreciated!
Thnx!

Answer 1

The dll.a are not static library files they are stubs for the dynamic linked .dll – you need to rebuild OpenCv to use static libs .lib and link those directly with your code