OpenCV linking undefined References

IJoulz

Hi all,

i have read many already existing topics, but i haven't found one that fixes my issue.

I want to use OpenCV in my project but i can not resolve some undefined references.
I am using the default 'Desktop Qt 6.6.0 MinGW 64-bit' kit.

.pro:

...
win32:CONFIG(release, debug|release): LIBS += -L$$(OpenCV_DIR)/x64/vc16/lib/ -lopencv_world480
else:win32:CONFIG(debug, debug|release): LIBS += -L$$(OpenCV_DIR)/x64/vc16/lib/ -lopencv_world480d

INCLUDEPATH += $$(OpenCV_DIR)/include
DEPENDPATH += $$(OpenCV_DIR)/include
...

Usage of OpenCV in a class:

...
#include <opencv2/opencv.hpp>

class OpenCVHelper : public QObject
{
    Q_OBJECT

public:
    OpenCVHelper();
    ~OpenCVHelper();

    cv::Mat m_rawCameraImage;
    cv::VideoCapture m_camera;
};

Errors:

undefined reference to `cv::Mat::Mat()'
undefined reference to `cv::VideoCapture::VideoCapture()'
... and some other Stuff like their respective destructors.

The OpenCV_DIR Enviroment variable holds 'C:\OpenCV\opencv\build'.

Can someone point me in the correct direction, how i can include this lib correctly?
(The Includepath works btw)

Thank you in advance.

Christian Ehrlicher

@IJoulz said in OpenCV linking undefined References:

I am using the default 'Desktop Qt 6.6.0 MinGW 64-bit' kit.

Why do you try to link against msvc libs then?

LIBS += -L$$(OpenCV_DIR)/x64/vc16/lib/ -lopencv_world480

You can not mix MSVC and MinGW c++ libraries.

IJoulz

@Christian-Ehrlicher Well, that explains it *facepalm*.
I didnt catch that.