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Qt 5.6.1 with Opencv

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  • N navya.dubey

    @joeQ
    I am so sorry but I didn't get the meaning of -L and -l . I have just included the whole path and it says" not found"

    joeQJ Offline
    joeQJ Offline
    joeQ
    wrote on last edited by
    #6

    @navya.dubey
    use / try again, not use \ in the path string.

    Just do it!

    N 1 Reply Last reply
    0
    • joeQJ joeQ

      @navya.dubey
      use / try again, not use \ in the path string.

      N Offline
      N Offline
      navya.dubey
      wrote on last edited by
      #7

      @joeQ the problem still remains the same now the .pro file is not showing error but .cpp shows
      0_1502260775727_Screenshot (7).png

      joeQJ 1 Reply Last reply
      0
      • N navya.dubey

        @joeQ the problem still remains the same now the .pro file is not showing error but .cpp shows
        0_1502260775727_Screenshot (7).png

        joeQJ Offline
        joeQJ Offline
        joeQ
        wrote on last edited by
        #8

        @navya.dubey

        Hi guys, Can you be careful? Please to read you pro file code. why did you use debug lib twice?

        I said not to use \ in any path. Please check you code carefully.

        Just do it!

        N 1 Reply Last reply
        1
        • joeQJ joeQ

          @navya.dubey

          Hi guys, Can you be careful? Please to read you pro file code. why did you use debug lib twice?

          I said not to use \ in any path. Please check you code carefully.

          N Offline
          N Offline
          navya.dubey
          wrote on last edited by
          #9

          @joeQ
          I tried with / as well as with \ and the problem is same anyhow.
          I deleted the repetition, problem still remains.

          joeQJ 1 Reply Last reply
          0
          • N navya.dubey

            @joeQ
            I tried with / as well as with \ and the problem is same anyhow.
            I deleted the repetition, problem still remains.

            joeQJ Offline
            joeQJ Offline
            joeQ
            wrote on last edited by
            #10

            @navya.dubey

            did you include opencv head files?

            Just do it!

            1 Reply Last reply
            0
            • SGaistS Offline
              SGaistS Offline
              SGaist
              Lifetime Qt Champion
              wrote on last edited by
              #11

              Hi,

              In addition to all the good clues @joeQ provided, the main problem here is: trying to build an application with MinGW and link to a C++ library built with Visual Studio. It's not possible. You have to use a MinGW build of OpenCV to link to your application. Or use a VS build of Qt to link to your OpenCV lib built with Visual Studio. Note that prior to Visual Studio 2017, you also have to exactly match the versions of Visual Studio used to build everything C++ you might use in your project.

              VS2017 has backward compatibility but only with VS2015.

              Interested in AI ? www.idiap.ch
              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

              N 1 Reply Last reply
              2
              • SGaistS SGaist

                Hi,

                In addition to all the good clues @joeQ provided, the main problem here is: trying to build an application with MinGW and link to a C++ library built with Visual Studio. It's not possible. You have to use a MinGW build of OpenCV to link to your application. Or use a VS build of Qt to link to your OpenCV lib built with Visual Studio. Note that prior to Visual Studio 2017, you also have to exactly match the versions of Visual Studio used to build everything C++ you might use in your project.

                VS2017 has backward compatibility but only with VS2015.

                N Offline
                N Offline
                navya.dubey
                wrote on last edited by
                #12

                @SGaist hey I tried to build opencv using cmake following this tutorial
                https://www.youtube.com/watch?v=ZOSu-2Oju-A
                there are several errors while building the code 0_1502347280180_Screenshot (8).png
                I followed all the steps in the video but the output is not same as of the video tutorial, I hope you understood the basic problem please help.

                1 Reply Last reply
                0
                • SGaistS Offline
                  SGaistS Offline
                  SGaist
                  Lifetime Qt Champion
                  wrote on last edited by
                  #13

                  You have to tell CMake where to find Qt in order for it to build its libhighgui with the Qt backend.

                  Interested in AI ? www.idiap.ch
                  Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                  N 1 Reply Last reply
                  0
                  • SGaistS SGaist

                    You have to tell CMake where to find Qt in order for it to build its libhighgui with the Qt backend.

                    N Offline
                    N Offline
                    navya.dubey
                    wrote on last edited by
                    #14

                    @SGaist how to tell cmake where to find qt because I have set the environment variables of the system to know the location of mingw compiler in qt.
                    what to do next?

                    mrjjM 1 Reply Last reply
                    0
                    • N navya.dubey

                      @SGaist how to tell cmake where to find qt because I have set the environment variables of the system to know the location of mingw compiler in qt.
                      what to do next?

                      mrjjM Offline
                      mrjjM Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on last edited by
                      #15

                      @navya.dubey
                      Hi

                      like
                      cmake .. -DCMAKE_PREFIX_PATH="C:\Qt\5.7\msvc2015\lib\cmake\Qt5"

                      N 1 Reply Last reply
                      0
                      • mrjjM mrjj

                        @navya.dubey
                        Hi

                        like
                        cmake .. -DCMAKE_PREFIX_PATH="C:\Qt\5.7\msvc2015\lib\cmake\Qt5"

                        N Offline
                        N Offline
                        navya.dubey
                        wrote on last edited by mrjj
                        #16

                        Where to add it

                        mrjjM 1 Reply Last reply
                        0
                        • N navya.dubey

                          Where to add it

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #17

                          @navya.dubey
                          Sorry, i miss scrolled and edited your post.

                          You use it as commandline option when you call cmake as shown

                          N 1 Reply Last reply
                          0
                          • mrjjM mrjj

                            @navya.dubey
                            Sorry, i miss scrolled and edited your post.

                            You use it as commandline option when you call cmake as shown

                            N Offline
                            N Offline
                            navya.dubey
                            wrote on last edited by
                            #18

                            @mrjj You mean I have to go to the location where CMake is present and then I have to execute this command, right?

                            mrjjM 1 Reply Last reply
                            0
                            • N navya.dubey

                              @mrjj You mean I have to go to the location where CMake is present and then I have to execute this command, right?

                              mrjjM Offline
                              mrjjM Offline
                              mrjj
                              Lifetime Qt Champion
                              wrote on last edited by mrjj
                              #19

                              @navya.dubey

                              No, you make sure there is path to cmake
                              then you go to the project folder where the Cmake.tx file is and then
                              call cmake

                              if no paths, you can fully tell

                              c:\programfile\whatever\cmake .. OPTION

                              Same way as done here
                              https://forum.qt.io/topic/82074/creating-a-multi-purpose-node-editor-if-there-is-none-available/20
                              its also a Cmake project

                              1 Reply Last reply
                              0
                              • SGaistS Offline
                                SGaistS Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on last edited by
                                #20

                                You can also add that using the GUI you showed in your post.

                                Interested in AI ? www.idiap.ch
                                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                                1 Reply Last reply
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