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Qt 5.6.1 with Opencv

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  • N navya.dubey
    9 Aug 2017, 06:25

    @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"

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    joeQ
    wrote on 9 Aug 2017, 06:32 last edited by
    #6

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

    Just do it!

    N 1 Reply Last reply 9 Aug 2017, 06:40
    0
    • J joeQ
      9 Aug 2017, 06:32

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

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      N Offline
      navya.dubey
      wrote on 9 Aug 2017, 06:40 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

      J 1 Reply Last reply 9 Aug 2017, 06:47
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      • N navya.dubey
        9 Aug 2017, 06:40

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

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        joeQ
        wrote on 9 Aug 2017, 06:47 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 9 Aug 2017, 06:54
        1
        • J joeQ
          9 Aug 2017, 06:47

          @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.

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          navya.dubey
          wrote on 9 Aug 2017, 06:54 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.

          J 1 Reply Last reply 9 Aug 2017, 06:59
          0
          • N navya.dubey
            9 Aug 2017, 06:54

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

            J Offline
            J Offline
            joeQ
            wrote on 9 Aug 2017, 06:59 last edited by
            #10

            @navya.dubey

            did you include opencv head files?

            Just do it!

            1 Reply Last reply
            0
            • S Offline
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              SGaist
              Lifetime Qt Champion
              wrote on 9 Aug 2017, 07:41 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 10 Aug 2017, 06:43
              2
              • S SGaist
                9 Aug 2017, 07:41

                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
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                navya.dubey
                wrote on 10 Aug 2017, 06:43 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
                • S Offline
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                  SGaist
                  Lifetime Qt Champion
                  wrote on 10 Aug 2017, 07:20 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 10 Aug 2017, 09:38
                  0
                  • S SGaist
                    10 Aug 2017, 07:20

                    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 10 Aug 2017, 09:38 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?

                    M 1 Reply Last reply 10 Aug 2017, 09:46
                    0
                    • N navya.dubey
                      10 Aug 2017, 09:38

                      @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?

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                      M Offline
                      mrjj
                      Lifetime Qt Champion
                      wrote on 10 Aug 2017, 09:46 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 10 Aug 2017, 10:12
                      0
                      • M mrjj
                        10 Aug 2017, 09:46

                        @navya.dubey
                        Hi

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

                        N Offline
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                        navya.dubey
                        wrote on 10 Aug 2017, 10:12 last edited by mrjj 8 Oct 2017, 10:16
                        #16

                        Where to add it

                        M 1 Reply Last reply 10 Aug 2017, 10:17
                        0
                        • N navya.dubey
                          10 Aug 2017, 10:12

                          Where to add it

                          M Offline
                          M Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on 10 Aug 2017, 10:17 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 10 Aug 2017, 10:19
                          0
                          • M mrjj
                            10 Aug 2017, 10:17

                            @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 10 Aug 2017, 10:19 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?

                            M 1 Reply Last reply 10 Aug 2017, 10:22
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                            • N navya.dubey
                              10 Aug 2017, 10:19

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

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                              mrjj
                              Lifetime Qt Champion
                              wrote on 10 Aug 2017, 10:22 last edited by mrjj 8 Oct 2017, 10:22
                              #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
                              • S Offline
                                S Offline
                                SGaist
                                Lifetime Qt Champion
                                wrote on 10 Aug 2017, 20:56 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
                                0

                                15/20

                                10 Aug 2017, 09:46

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