Important: Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

Qt and opencv 3.4 error



  • Hello,
    I was trying to run the opencv program in qt. When i run as a console application it works fine.
    But when i include the above in widget it gives me error as follows:
    dialog.obj:-1: error: LNK2019: unresolved external symbol "void __cdecl cv::fastFree(void *)" (?fastFree@cv@@YAXPEAX@Z) referenced in function "public: __cdecl cv::Mat::~Mat(void)" (??1Mat@cv@@QEAA@XZ)
    dialog.obj:-1: error: LNK2019: unresolved external symbol "private: char * __cdecl cv::String::allocate(unsigned __int64)" (?allocate@String@cv@@AEAAPEAD_K@Z) referenced in function "public: __cdecl cv::String::String(char const *)" (??0String@cv@@QEAA@PEBD@Z)

    I am qt using msvc 64 bit and my qt 64 bit.

    I have also build opencv library on 64-bit visual studio 2017


  • Qt Champions 2019

    @Kira Do you link your app against opencv libraries?



  • @Kira you may have an issue with the order of OpenCV's libraries and how they linked. You may want to take a look at this example as a guideline of how the libraries show be referred in your .pro file.


Log in to reply