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Qt 5.6.1 with Opencv

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  • J joeQ
    9 Aug 2017, 06:32

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

    N Offline
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    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
    0
    • 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

      J Offline
      J Offline
      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.

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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.

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                  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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                    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"

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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

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                        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

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                          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
                          0
                          • 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
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                              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

                              16/20

                              10 Aug 2017, 10:12

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