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Declaration of function and use it

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  • mrjjM mrjj

    well you should make a pair of .h and .cpp files for the opencv stuff
    lets call it myopenvc.h and myopenvc.cpp

    in h. you can declare the function u want rest of program to use

    void setupOPENVC();

    and in .cpp

    void setupOPENVC() {
    // the code from the old c- main. !
    src = imread( argv[1] );
    xxxx
    }

    then in Mainwindow.cpp
    #include "myopencv.h"

    and now u can call your function
    void mainwidow::Process_image_clicke()
    {
    setupOPENVC();
    }

    ps:
    In event driven programs. ( like Qt)
    stuff like
    waitKey(0);
    or FOREVER loops are not to be used as it
    will freeze the program and it stops working.

    G Offline
    G Offline
    gauravsharma0190
    wrote on last edited by
    #21

    @mrjj Hello i did it sir.
    but error occurs.

    1 Reply Last reply
    0
    • jsulmJ jsulm

      @gauravsharma0190 I don't understand the problem. Qt is not a programming language. You use C++ with qt. So you define and use your function/method as any other function/method in C++.
      I already gave you an example showing how to use a push button to execute a method when the button is clicked. Isn't that what you want to do?
      Please explain what is the problem! Maybe some code?

      G Offline
      G Offline
      gauravsharma0190
      wrote on last edited by
      #22

      @jsulm Yes sir see i have a c code of opencv which process the image.
      Now my problem is i want to use this code with qt as when button is pressed my push button calls the function of that C code in which main part of Process is defined.
      Here is the C code.
      #include "opencv2/imgproc/imgproc.hpp"
      #include "opencv2/highgui/highgui.hpp"
      #include <stdlib.h>
      #include <stdio.h>

      using namespace cv;

      /// Global variables

      Mat src, src_gray;
      Mat dst, detected_edges;

      int edgeThresh = 1;
      int lowThreshold;
      int const max_lowThreshold = 100;
      int ratio = 3;
      int kernel_size = 3;
      char* window_name = "Edge Map";

      /**

      @function CannyThreshold
      @brief Trackbar callback - Canny thresholds input with a ratio 1:3
      /
      void CannyThreshold(int, void)
      {
      /// Reduce noise with a kernel 3x3
      blur( src_gray, detected_edges, Size(3,3) );
      /// Canny detector
      Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

      /// Using Canny's output as a mask, we display our result
      dst = Scalar::all(0);

      src.copyTo( dst, detected_edges);
      imshow( window_name, dst );
      }

      /** @function main /
      int main( int argc, char* argv )
      {
      /// Load an image
      src = imread( argv[1] );

      if( !src.data )
      { return -1; }

      /// Create a matrix of the same type and size as src (for dst)
      dst.create( src.size(), src.type() );

      /// Convert the image to grayscale
      cvtColor( src, src_gray, CV_BGR2GRAY );

      /// Create a window
      namedWindow( window_name, CV_WINDOW_AUTOSIZE );

      /// Create a Trackbar for user to enter threshold
      createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );

      /// Show the image
      CannyThreshold(0, 0);

      /// Wait until user exit program by pressing a key
      waitKey(0);

      return 0;
      }
      Now i make a Push button Name Process_image in MainWindow.ui and connect to slot as clicked() by right clicking of mouse.
      here comes the slot to mainwindow.cpp
      void mainwidow::Process_image_clicke()
      {
      }
      Now i don't understand how to make function of my C code and use it in Pusebutton.

      jsulmJ 1 Reply Last reply
      0
      • G gauravsharma0190

        @jsulm Yes sir see i have a c code of opencv which process the image.
        Now my problem is i want to use this code with qt as when button is pressed my push button calls the function of that C code in which main part of Process is defined.
        Here is the C code.
        #include "opencv2/imgproc/imgproc.hpp"
        #include "opencv2/highgui/highgui.hpp"
        #include <stdlib.h>
        #include <stdio.h>

        using namespace cv;

        /// Global variables

        Mat src, src_gray;
        Mat dst, detected_edges;

        int edgeThresh = 1;
        int lowThreshold;
        int const max_lowThreshold = 100;
        int ratio = 3;
        int kernel_size = 3;
        char* window_name = "Edge Map";

        /**

        @function CannyThreshold
        @brief Trackbar callback - Canny thresholds input with a ratio 1:3
        /
        void CannyThreshold(int, void)
        {
        /// Reduce noise with a kernel 3x3
        blur( src_gray, detected_edges, Size(3,3) );
        /// Canny detector
        Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

        /// Using Canny's output as a mask, we display our result
        dst = Scalar::all(0);

        src.copyTo( dst, detected_edges);
        imshow( window_name, dst );
        }

        /** @function main /
        int main( int argc, char* argv )
        {
        /// Load an image
        src = imread( argv[1] );

        if( !src.data )
        { return -1; }

        /// Create a matrix of the same type and size as src (for dst)
        dst.create( src.size(), src.type() );

        /// Convert the image to grayscale
        cvtColor( src, src_gray, CV_BGR2GRAY );

        /// Create a window
        namedWindow( window_name, CV_WINDOW_AUTOSIZE );

        /// Create a Trackbar for user to enter threshold
        createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );

        /// Show the image
        CannyThreshold(0, 0);

        /// Wait until user exit program by pressing a key
        waitKey(0);

        return 0;
        }
        Now i make a Push button Name Process_image in MainWindow.ui and connect to slot as clicked() by right clicking of mouse.
        here comes the slot to mainwindow.cpp
        void mainwidow::Process_image_clicke()
        {
        }
        Now i don't understand how to make function of my C code and use it in Pusebutton.

        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #23

        @gauravsharma0190 Well, you can put that C code in

        void mainwidow::Process_image_clicke()
        {
            // Put C code here
        }
        

        But I'm not sure whether you should remove waitKey(0); as it could be problematic in a Qt program.

        https://forum.qt.io/topic/113070/qt-code-of-conduct

        G 1 Reply Last reply
        2
        • jsulmJ jsulm

          @gauravsharma0190 Well, you can put that C code in

          void mainwidow::Process_image_clicke()
          {
              // Put C code here
          }
          

          But I'm not sure whether you should remove waitKey(0); as it could be problematic in a Qt program.

          G Offline
          G Offline
          gauravsharma0190
          wrote on last edited by
          #24

          @jsulm
          i put it into Process_image_click()
          {
          //code
          }
          but error occurs.
          as ontrackball function not declare

          jsulmJ 1 Reply Last reply
          0
          • G gauravsharma0190

            @jsulm
            i put it into Process_image_click()
            {
            //code
            }
            but error occurs.
            as ontrackball function not declare

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #25

            @gauravsharma0190 What is ontrackball? Where is it declared? Do you have to include a header file where it is declared?

            https://forum.qt.io/topic/113070/qt-code-of-conduct

            G 1 Reply Last reply
            0
            • G Offline
              G Offline
              gauravsharma0190
              wrote on last edited by
              #26

              Yes it is function which is declare in the Opencv C code.
              Here is the function.
              @brief Trackbar callback - Canny thresholds input with a ratio 1:3
              /
              void onTrackball(int, void)
              {
              /// Reduce noise with a kernel 3x3
              blur( src_gray, detected_edges, Size(3,3) );
              /// Canny detector
              Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

              /// Using Canny's output as a mask, we display our result
              dst = Scalar::all(0);

              src.copyTo( dst, detected_edges);
              imshow( window_name, dst );
              }

              1 Reply Last reply
              0
              • jsulmJ jsulm

                @gauravsharma0190 What is ontrackball? Where is it declared? Do you have to include a header file where it is declared?

                G Offline
                G Offline
                gauravsharma0190
                wrote on last edited by
                #27

                @jsulm Yes it is function which is declare in the Opencv C code.
                Here is the function.
                @brief Trackbar callback - Canny thresholds input with a ratio 1:3
                /
                void onTrackball(int, void)
                {
                /// Reduce noise with a kernel 3x3
                blur( src_gray, detected_edges, Size(3,3) );
                /// Canny detector
                Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

                /// Using Canny's output as a mask, we display our result
                dst = Scalar::all(0);

                src.copyTo( dst, detected_edges);
                imshow( window_name, dst );
                }

                less than a minute ago

                jsulmJ 1 Reply Last reply
                0
                • G gauravsharma0190

                  @jsulm Yes it is function which is declare in the Opencv C code.
                  Here is the function.
                  @brief Trackbar callback - Canny thresholds input with a ratio 1:3
                  /
                  void onTrackball(int, void)
                  {
                  /// Reduce noise with a kernel 3x3
                  blur( src_gray, detected_edges, Size(3,3) );
                  /// Canny detector
                  Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

                  /// Using Canny's output as a mask, we display our result
                  dst = Scalar::all(0);

                  src.copyTo( dst, detected_edges);
                  imshow( window_name, dst );
                  }

                  less than a minute ago

                  jsulmJ Offline
                  jsulmJ Offline
                  jsulm
                  Lifetime Qt Champion
                  wrote on last edited by
                  #28

                  @gauravsharma0190 Where is this function declared? In which header file? "function not declared" means the function is not known. You have to make it visible including the header file. It is the same story as in C.

                  https://forum.qt.io/topic/113070/qt-code-of-conduct

                  G 2 Replies Last reply
                  0
                  • jsulmJ jsulm

                    @gauravsharma0190 Where is this function declared? In which header file? "function not declared" means the function is not known. You have to make it visible including the header file. It is the same story as in C.

                    G Offline
                    G Offline
                    gauravsharma0190
                    wrote on last edited by
                    #29

                    @jsulm i Declare it in mainwindow.h
                    file as void onTrackball.
                    and i will send you all my code which i did .

                    1 Reply Last reply
                    0
                    • jsulmJ jsulm

                      @gauravsharma0190 Where is this function declared? In which header file? "function not declared" means the function is not known. You have to make it visible including the header file. It is the same story as in C.

                      G Offline
                      G Offline
                      gauravsharma0190
                      wrote on last edited by
                      #30

                      @jsulm
                      Here i am sending you my all code.
                      **

                      • /////main.cpp///**
                        #include "mainwindow.h"
                        #include <QApplication>
                        #include<QSplashScreen>
                        #include<QTimer>
                        #include<opencv2/highgui/highgui.hpp>
                        #include<opencv2/core/core.hpp>
                        #include<opencv2/opencv.hpp>
                        using namespace cv;
                        using namespace std;
                        int main(int argc, char *argv[])
                        {

                        QApplication a(argc, argv);
                        QSplashScreen *splash =new QSplashScreen;
                        splash->setPixmap(QPixmap("/home/pi/Desktop/ceeri1.jpg"));
                        splash->show();

                        MainWindow w;
                        QTimer::singleShot(3500,splash,SLOT(close()));

                        QTimer::singleShot(3500,&w,SLOT(show()));

                        //w.show();

                        return a.exec();
                        }
                        ////mainwindow.h
                        #ifndef MAINWINDOW_H
                        #define MAINWINDOW_H

                      #include <QMainWindow>
                      //using namespace cv;
                      namespace Ui {
                      class MainWindow;
                      }

                      class MainWindow : public QMainWindow
                      {
                      Q_OBJECT

                      public:
                      explicit MainWindow(QWidget *parent = 0);
                      ~MainWindow();

                      private slots:
                      void showTime();

                      void on_pushButton_5_clicked();
                      

                      void onTrackball_clicked(int,void*);

                      private:
                      Ui::MainWindow *ui;
                      };

                      #endif // MAINWINDOW_H
                      ///mainwindow.c

                      #include "mainwindow.h"
                      #include "ui_mainwindow.h"
                      #include<opencv2/opencv.hpp>
                      #include <opencv2/highgui/highgui.hpp>
                      #include <opencv2/core/core.hpp>
                      #include<QFileDialog>
                      #include<QMessageBox>
                      #include <iostream>
                      #include <string>
                      #include <fstream>
                      #include<time.h>
                      #include<QTimer>
                      #include<QDateTime>
                      using namespace cv;
                      using namespace std;
                      MainWindow::MainWindow(QWidget *parent) :
                      QMainWindow(parent),
                      ui(new Ui::MainWindow)
                      {
                      ui->setupUi(this);
                      QTimer *timer=new QTimer(this);
                      connect(timer,SIGNAL(timeout()),this,SLOT(showTime()));
                      timer->start();
                      QDateTime dateTime=QDateTime::currentDateTime();
                      QString datetimetext=dateTime.toString();
                      ui->DateTime->setText(datetimetext);

                      }
                      ////////Time///////////////
                      void MainWindow:: showTime()
                      {
                      QTime time=QTime::currentTime();
                      QString time_text=time.toString("hh : mm : ss");
                      if((time.second() % 2)==0)
                      {
                      time_text[3] =' ';
                      time_text[8] =' ';
                      }
                      ui->Digital->setText(time_text);

                      }

                      MainWindow::~MainWindow()
                      {
                      delete ui;
                      }

                      void MainWindow::on_pushButton_4_clicked()
                      {

                      }

                      void MainWindow::on_pushButton_5_clicked()
                      {
                      QString filename=QFileDialog::getOpenFileName(
                      this,
                      tr("Open file") ,
                      "/home/pi/Desktop",
                      tr("All files(*.png *.jpg)"));

                      QMessageBox::information(this,tr("Filename"),filename);
                      if(QString::compare(filename,QString())!=0)
                      {
                          QImage image;
                          bool valid=image.load(filename);
                          if(valid)
                          {
                              image=image.scaledToWidth(ui->Picture->width(),Qt::SmoothTransformation);
                              ui->Picture->setPixmap(QPixmap::fromImage(image));
                      
                          }
                      

                      void MainWindow::onTrackball_clicked(int,void*)
                      {
                      //Here wite the all function//
                      ///Now how to put this code in this.

                      ////////This is the code i have to input in this push button////
                      Mat src, src_gray;
                      Mat dst, detected_edges;

                      int edgeThresh = 1;
                      int lowThreshold;
                      int const max_lowThreshold = 100;
                      int ratio = 3;
                      int kernel_size = 3;
                      char* window_name = "Edge Map";

                      /**

                      @function CannyThreshold
                      @brief Trackbar callback - Canny thresholds input with a ratio 1:3
                      /
                      void CannyThreshold(int, void)
                      {
                      /// Reduce noise with a kernel 3x3
                      blur( src_gray, detected_edges, Size(3,3) );
                      /// Canny detector
                      Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );

                      /// Using Canny's output as a mask, we display our result
                      dst = Scalar::all(0);

                      src.copyTo( dst, detected_edges);
                      imshow( window_name, dst );
                      }

                      /** @function main /
                      int main( int argc, char* argv )
                      {
                      /// Load an image
                      src = imread( argv[1] );

                      if( !src.data )
                      { return -1; }

                      /// Create a matrix of the same type and size as src (for dst)
                      dst.create( src.size(), src.type() );

                      /// Convert the image to grayscale
                      cvtColor( src, src_gray, CV_BGR2GRAY );

                      /// Create a window
                      namedWindow( window_name, CV_WINDOW_AUTOSIZE );

                      /// Create a Trackbar for user to enter threshold
                      createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );

                      /// Show the image
                      CannyThreshold(0, 0);

                      /// Wait until user exit program by pressing a key
                      waitKey(0);

                      return 0;
                      }

                      }
                      }
                      
                      1 Reply Last reply
                      0
                      • jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #31

                        Sorry, but the code you posted is invalid C/C++! First of all: why do you have 2 main functions?
                        Why did you put other functions inside void MainWindow::onTrackball_clicked(int,void*)? This is not going to compile and I'm not going to fix it for you. How familiar are you actually with C/C++?
                        What you have to do is: do not put the C function definitions inside void MainWindow::onTrackball_clicked(int,void*), instead put them inside another source code file and header, include the header file in MainWindow and then call the functions in void MainWindow::onTrackball_clicked(int,void*). As an alternative you can have those C functions in MainWindow.cpp but not inside void MainWindow::onTrackball_clicked(int,void*) !

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                        G 1 Reply Last reply
                        1
                        • jsulmJ jsulm

                          Sorry, but the code you posted is invalid C/C++! First of all: why do you have 2 main functions?
                          Why did you put other functions inside void MainWindow::onTrackball_clicked(int,void*)? This is not going to compile and I'm not going to fix it for you. How familiar are you actually with C/C++?
                          What you have to do is: do not put the C function definitions inside void MainWindow::onTrackball_clicked(int,void*), instead put them inside another source code file and header, include the header file in MainWindow and then call the functions in void MainWindow::onTrackball_clicked(int,void*). As an alternative you can have those C functions in MainWindow.cpp but not inside void MainWindow::onTrackball_clicked(int,void*) !

                          G Offline
                          G Offline
                          gauravsharma0190
                          wrote on last edited by
                          #32

                          @jsulm
                          i don't put these function definition inside voidmainwindow::ontrackball
                          but i am asking you how can i call that function inside my void mainwindow::ontrackball

                          void CannyThreshold(int, void)
                          {
                          /// Reduce noise with a kernel 3x3
                          blur( src_gray, detected_edges, Size(3,3) );
                          /// Canny detector
                          Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
                          
                          /// Using Canny's output as a mask, we display our result
                          dst = Scalar::all(0);
                          
                          src.copyTo( dst, detected_edges);
                          imshow( window_name, dst );
                          }
                          

                          Mean i hyave done .cpp and .h file of this and include in my code both.

                          jsulmJ 2 Replies Last reply
                          0
                          • G gauravsharma0190

                            @jsulm
                            i don't put these function definition inside voidmainwindow::ontrackball
                            but i am asking you how can i call that function inside my void mainwindow::ontrackball

                            void CannyThreshold(int, void)
                            {
                            /// Reduce noise with a kernel 3x3
                            blur( src_gray, detected_edges, Size(3,3) );
                            /// Canny detector
                            Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
                            
                            /// Using Canny's output as a mask, we display our result
                            dst = Scalar::all(0);
                            
                            src.copyTo( dst, detected_edges);
                            imshow( window_name, dst );
                            }
                            

                            Mean i hyave done .cpp and .h file of this and include in my code both.

                            jsulmJ Offline
                            jsulmJ Offline
                            jsulm
                            Lifetime Qt Champion
                            wrote on last edited by
                            #33

                            @gauravsharma0190 Like this?

                            CannyThreshold(1, nullptr);
                            

                            So, what exactly is the problem?
                            In the code you posted you DID put these function definitions inside void MainWindow::onTrackball_clicked(int,void*) (just check what you posted).

                            https://forum.qt.io/topic/113070/qt-code-of-conduct

                            1 Reply Last reply
                            0
                            • G gauravsharma0190

                              @jsulm
                              i don't put these function definition inside voidmainwindow::ontrackball
                              but i am asking you how can i call that function inside my void mainwindow::ontrackball

                              void CannyThreshold(int, void)
                              {
                              /// Reduce noise with a kernel 3x3
                              blur( src_gray, detected_edges, Size(3,3) );
                              /// Canny detector
                              Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
                              
                              /// Using Canny's output as a mask, we display our result
                              dst = Scalar::all(0);
                              
                              src.copyTo( dst, detected_edges);
                              imshow( window_name, dst );
                              }
                              

                              Mean i hyave done .cpp and .h file of this and include in my code both.

                              jsulmJ Offline
                              jsulmJ Offline
                              jsulm
                              Lifetime Qt Champion
                              wrote on last edited by
                              #34

                              @gauravsharma0190 Shouldn't

                              void CannyThreshold(int, void)
                              

                              be

                              void CannyThreshold(int, void*)
                              

                              ?

                              https://forum.qt.io/topic/113070/qt-code-of-conduct

                              G 1 Reply Last reply
                              0
                              • G Offline
                                G Offline
                                gauravsharma0190
                                wrote on last edited by
                                #35

                                ok now i will send you refresh code just wait.
                                Thank you.
                                i will send you refresh code and errors.

                                1 Reply Last reply
                                0
                                • jsulmJ jsulm

                                  @gauravsharma0190 Shouldn't

                                  void CannyThreshold(int, void)
                                  

                                  be

                                  void CannyThreshold(int, void*)
                                  

                                  ?

                                  G Offline
                                  G Offline
                                  gauravsharma0190
                                  wrote on last edited by
                                  #36

                                  @jsulm
                                  hey here is the code i have done with that.
                                  /////main.cpp////

                                  #include<opencv2/highgui/highgui.hpp>
                                  #include<opencv2/core/core.hpp>
                                  #include<opencv2/opencv.hpp>
                                  using namespace cv;
                                  using namespace std;
                                  int main(int argc, char *argv[])
                                  {
                                  
                                      QApplication a(argc, argv);
                                      QSplashScreen *splash =new QSplashScreen;
                                      splash->setPixmap(QPixmap("/home/pi/Desktop/ceeri1.jpg"));
                                      splash->show();
                                  
                                      MainWindow w;
                                      QTimer::singleShot(3500,splash,SLOT(close()));
                                  
                                      QTimer::singleShot(3500,&w,SLOT(show()));
                                  
                                    //w.show();
                                  
                                      return a.exec();
                                  }
                                  

                                  ///mainwindow.h///

                                  #ifndef MAINWINDOW_H
                                  #define MAINWINDOW_H
                                  
                                  #include <QMainWindow>
                                  //using namespace cv;
                                  namespace Ui {
                                  class MainWindow;
                                  }
                                  
                                  class MainWindow : public QMainWindow
                                  {
                                  Q_OBJECT
                                  
                                  public:
                                  explicit MainWindow(QWidget *parent = 0);
                                  ~MainWindow();
                                  
                                  private slots:
                                  void showTime();
                                  
                                  void on_pushButton_5_clicked();
                                  void onTrackball_clicked(int,void*);
                                  
                                  private:
                                  Ui::MainWindow *ui;
                                  };
                                  
                                  #endif // MAINWINDOW_H
                                  

                                  ///ontrack.h///

                                  #ifndef __ONTRACK_h
                                  #define __ONTRACK_h
                                  void cannyThresold(int,void*);
                                  #endif
                                  

                                  ///ontrack.cpp

                                  #include "ontrack.h"
                                  #include<opencv2/opencv.hpp>
                                  #include <opencv2/highgui/highgui.hpp>
                                  #include <opencv2/core/core.hpp>
                                  void CannyThreshold(int, void)
                                  {
                                  /// Reduce noise with a kernel 3x3
                                  blur( src_gray, detected_edges, Size(3,3) );
                                  /// Canny detector
                                  Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
                                  
                                  /// Using Canny's output as a mask, we display our result
                                  dst = Scalar::all(0);
                                  
                                  src.copyTo( dst, detected_edges);
                                  imshow( window_name, dst );
                                  }
                                  

                                  //Here Comes Mainwindow.cpp///

                                  #include "ui_mainwindow.h"
                                  #include<opencv2/opencv.hpp>
                                  #include <opencv2/highgui/highgui.hpp>
                                  #include <opencv2/core/core.hpp>
                                  #include "ontrack.h"
                                  #include<QFileDialog>
                                  #include<QMessageBox>
                                  #include <iostream>
                                  #include <string>
                                  #include <fstream>
                                  #include<time.h>
                                  #include<QTimer>
                                  #include<QDateTime>
                                  using namespace cv;
                                  using namespace std;
                                  MainWindow::MainWindow(QWidget *parent) :
                                  QMainWindow(parent),
                                  ui(new Ui::MainWindow)
                                  {
                                  ui->setupUi(this);
                                  QTimer *timer=new QTimer(this);
                                  connect(timer,SIGNAL(timeout()),this,SLOT(showTime()));
                                  timer->start();
                                  QDateTime dateTime=QDateTime::currentDateTime();
                                  QString datetimetext=dateTime.toString();
                                  ui->DateTime->setText(datetimetext);
                                  
                                  }
                                  ////////Time///////////////
                                  void MainWindow:: showTime()
                                  {
                                  QTime time=QTime::currentTime();
                                  QString time_text=time.toString("hh : mm : ss");
                                  if((time.second() % 2)==0)
                                  {
                                  time_text[3] =' ';
                                  time_text[8] =' ';
                                  }
                                  ui->Digital->setText(time_text);
                                  
                                  }
                                  
                                  MainWindow::~MainWindow()
                                  {
                                  delete ui;
                                  }
                                  
                                  void MainWindow::on_pushButton_4_clicked()
                                  {
                                  
                                  }
                                  
                                  void MainWindow::on_pushButton_5_clicked()
                                  {
                                  QString filename=QFileDialog::getOpenFileName(
                                  this,
                                  tr("Open file") ,
                                  "/home/pi/Desktop",
                                  tr("All files(*.png *.jpg)"));
                                  
                                  QMessageBox::information(this,tr("Filename"),filename);
                                  if(QString::compare(filename,QString())!=0)
                                  {
                                      QImage image;
                                      bool valid=image.load(filename);
                                      if(valid)
                                      {
                                          image=image.scaledToWidth(ui->Picture->width(),Qt::SmoothTransformation);
                                          ui->Picture->setPixmap(QPixmap::fromImage(image));
                                  
                                      }
                                  void MainWindow::onTrackball_clicked(int,void*)
                                  {
                                  
                                  
                                  Mat src, src_gray;
                                  Mat dst, detected_edges;
                                  
                                  int edgeThresh = 1;
                                  int lowThreshold;
                                  int const max_lowThreshold = 100;
                                  int ratio = 3;
                                  int kernel_size = 3;
                                  char* window_name = "Edge Map";
                                  
                                  
                                  
                                  @function CannyThreshold
                                  @brief Trackbar callback - Canny thresholds input with a ratio 1:3
                                  /
                                  
                                  
                                  /// Load an image
                                  src = imread( argv[1] );
                                  
                                  if( !src.data )
                                  { return -1; }
                                  
                                  /// Create a matrix of the same type and size as src (for dst)
                                  dst.create( src.size(), src.type() );
                                  
                                  /// Convert the image to grayscale
                                  cvtColor( src, src_gray, CV_BGR2GRAY );
                                  
                                  /// Create a window
                                  namedWindow( window_name, CV_WINDOW_AUTOSIZE );
                                  
                                  /// Create a Trackbar for user to enter threshold
                                  createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );
                                  
                                  /// Show the image
                                  CannyThreshold(0, 0);
                                  
                                  }
                                  }
                                  ...
                                  But error occurs defination of function outside the class.
                                  G 1 Reply Last reply
                                  0
                                  • G gauravsharma0190

                                    @jsulm
                                    hey here is the code i have done with that.
                                    /////main.cpp////

                                    #include<opencv2/highgui/highgui.hpp>
                                    #include<opencv2/core/core.hpp>
                                    #include<opencv2/opencv.hpp>
                                    using namespace cv;
                                    using namespace std;
                                    int main(int argc, char *argv[])
                                    {
                                    
                                        QApplication a(argc, argv);
                                        QSplashScreen *splash =new QSplashScreen;
                                        splash->setPixmap(QPixmap("/home/pi/Desktop/ceeri1.jpg"));
                                        splash->show();
                                    
                                        MainWindow w;
                                        QTimer::singleShot(3500,splash,SLOT(close()));
                                    
                                        QTimer::singleShot(3500,&w,SLOT(show()));
                                    
                                      //w.show();
                                    
                                        return a.exec();
                                    }
                                    

                                    ///mainwindow.h///

                                    #ifndef MAINWINDOW_H
                                    #define MAINWINDOW_H
                                    
                                    #include <QMainWindow>
                                    //using namespace cv;
                                    namespace Ui {
                                    class MainWindow;
                                    }
                                    
                                    class MainWindow : public QMainWindow
                                    {
                                    Q_OBJECT
                                    
                                    public:
                                    explicit MainWindow(QWidget *parent = 0);
                                    ~MainWindow();
                                    
                                    private slots:
                                    void showTime();
                                    
                                    void on_pushButton_5_clicked();
                                    void onTrackball_clicked(int,void*);
                                    
                                    private:
                                    Ui::MainWindow *ui;
                                    };
                                    
                                    #endif // MAINWINDOW_H
                                    

                                    ///ontrack.h///

                                    #ifndef __ONTRACK_h
                                    #define __ONTRACK_h
                                    void cannyThresold(int,void*);
                                    #endif
                                    

                                    ///ontrack.cpp

                                    #include "ontrack.h"
                                    #include<opencv2/opencv.hpp>
                                    #include <opencv2/highgui/highgui.hpp>
                                    #include <opencv2/core/core.hpp>
                                    void CannyThreshold(int, void)
                                    {
                                    /// Reduce noise with a kernel 3x3
                                    blur( src_gray, detected_edges, Size(3,3) );
                                    /// Canny detector
                                    Canny( detected_edges, detected_edges, lowThreshold, lowThreshold*ratio, kernel_size );
                                    
                                    /// Using Canny's output as a mask, we display our result
                                    dst = Scalar::all(0);
                                    
                                    src.copyTo( dst, detected_edges);
                                    imshow( window_name, dst );
                                    }
                                    

                                    //Here Comes Mainwindow.cpp///

                                    #include "ui_mainwindow.h"
                                    #include<opencv2/opencv.hpp>
                                    #include <opencv2/highgui/highgui.hpp>
                                    #include <opencv2/core/core.hpp>
                                    #include "ontrack.h"
                                    #include<QFileDialog>
                                    #include<QMessageBox>
                                    #include <iostream>
                                    #include <string>
                                    #include <fstream>
                                    #include<time.h>
                                    #include<QTimer>
                                    #include<QDateTime>
                                    using namespace cv;
                                    using namespace std;
                                    MainWindow::MainWindow(QWidget *parent) :
                                    QMainWindow(parent),
                                    ui(new Ui::MainWindow)
                                    {
                                    ui->setupUi(this);
                                    QTimer *timer=new QTimer(this);
                                    connect(timer,SIGNAL(timeout()),this,SLOT(showTime()));
                                    timer->start();
                                    QDateTime dateTime=QDateTime::currentDateTime();
                                    QString datetimetext=dateTime.toString();
                                    ui->DateTime->setText(datetimetext);
                                    
                                    }
                                    ////////Time///////////////
                                    void MainWindow:: showTime()
                                    {
                                    QTime time=QTime::currentTime();
                                    QString time_text=time.toString("hh : mm : ss");
                                    if((time.second() % 2)==0)
                                    {
                                    time_text[3] =' ';
                                    time_text[8] =' ';
                                    }
                                    ui->Digital->setText(time_text);
                                    
                                    }
                                    
                                    MainWindow::~MainWindow()
                                    {
                                    delete ui;
                                    }
                                    
                                    void MainWindow::on_pushButton_4_clicked()
                                    {
                                    
                                    }
                                    
                                    void MainWindow::on_pushButton_5_clicked()
                                    {
                                    QString filename=QFileDialog::getOpenFileName(
                                    this,
                                    tr("Open file") ,
                                    "/home/pi/Desktop",
                                    tr("All files(*.png *.jpg)"));
                                    
                                    QMessageBox::information(this,tr("Filename"),filename);
                                    if(QString::compare(filename,QString())!=0)
                                    {
                                        QImage image;
                                        bool valid=image.load(filename);
                                        if(valid)
                                        {
                                            image=image.scaledToWidth(ui->Picture->width(),Qt::SmoothTransformation);
                                            ui->Picture->setPixmap(QPixmap::fromImage(image));
                                    
                                        }
                                    void MainWindow::onTrackball_clicked(int,void*)
                                    {
                                    
                                    
                                    Mat src, src_gray;
                                    Mat dst, detected_edges;
                                    
                                    int edgeThresh = 1;
                                    int lowThreshold;
                                    int const max_lowThreshold = 100;
                                    int ratio = 3;
                                    int kernel_size = 3;
                                    char* window_name = "Edge Map";
                                    
                                    
                                    
                                    @function CannyThreshold
                                    @brief Trackbar callback - Canny thresholds input with a ratio 1:3
                                    /
                                    
                                    
                                    /// Load an image
                                    src = imread( argv[1] );
                                    
                                    if( !src.data )
                                    { return -1; }
                                    
                                    /// Create a matrix of the same type and size as src (for dst)
                                    dst.create( src.size(), src.type() );
                                    
                                    /// Convert the image to grayscale
                                    cvtColor( src, src_gray, CV_BGR2GRAY );
                                    
                                    /// Create a window
                                    namedWindow( window_name, CV_WINDOW_AUTOSIZE );
                                    
                                    /// Create a Trackbar for user to enter threshold
                                    createTrackbar( "Min Threshold:", window_name, &lowThreshold, max_lowThreshold, CannyThreshold );
                                    
                                    /// Show the image
                                    CannyThreshold(0, 0);
                                    
                                    }
                                    }
                                    ...
                                    But error occurs defination of function outside the class.
                                    G Offline
                                    G Offline
                                    gauravsharma0190
                                    wrote on last edited by
                                    #37

                                    @gauravsharma0190 said:

                                    Sorry in ontrack.cpp i again add
                                    Mat src, src_gray;
                                    Mat dst, detected_edges;

                                    jsulmJ 2 Replies Last reply
                                    0
                                    • G gauravsharma0190

                                      @gauravsharma0190 said:

                                      Sorry in ontrack.cpp i again add
                                      Mat src, src_gray;
                                      Mat dst, detected_edges;

                                      jsulmJ Offline
                                      jsulmJ Offline
                                      jsulm
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #38

                                      @gauravsharma0190 Can you post the whole error message?
                                      Why do you have int and void* parameter in onTrackball_clicked which you do not use?

                                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      1 Reply Last reply
                                      1
                                      • G gauravsharma0190

                                        @gauravsharma0190 said:

                                        Sorry in ontrack.cpp i again add
                                        Mat src, src_gray;
                                        Mat dst, detected_edges;

                                        jsulmJ Offline
                                        jsulmJ Offline
                                        jsulm
                                        Lifetime Qt Champion
                                        wrote on last edited by
                                        #39

                                        @gauravsharma0190 Take a look at this:

                                        
                                        void MainWindow::on_pushButton_5_clicked()
                                        {
                                        QString filename=QFileDialog::getOpenFileName(
                                        this,
                                        tr("Open file") ,
                                        "/home/pi/Desktop",
                                        tr("All files(*.png *.jpg)"));
                                        
                                        QMessageBox::information(this,tr("Filename"),filename);
                                        if(QString::compare(filename,QString())!=0)
                                        {
                                            QImage image;
                                            bool valid=image.load(filename);
                                            if(valid)
                                            {
                                                image=image.scaledToWidth(ui->Picture->width(),Qt::SmoothTransformation);
                                                ui->Picture->setPixmap(QPixmap::fromImage(image));
                                        
                                            }
                                        void MainWindow::onTrackball_clicked(int,void*)
                                        {
                                        

                                        void MainWindow::onTrackball_clicked(int,void*) is inside void MainWindow::on_pushButton_5_clicked() - this is invalid!

                                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                                        G 1 Reply Last reply
                                        1
                                        • jsulmJ jsulm

                                          @gauravsharma0190 Take a look at this:

                                          
                                          void MainWindow::on_pushButton_5_clicked()
                                          {
                                          QString filename=QFileDialog::getOpenFileName(
                                          this,
                                          tr("Open file") ,
                                          "/home/pi/Desktop",
                                          tr("All files(*.png *.jpg)"));
                                          
                                          QMessageBox::information(this,tr("Filename"),filename);
                                          if(QString::compare(filename,QString())!=0)
                                          {
                                              QImage image;
                                              bool valid=image.load(filename);
                                              if(valid)
                                              {
                                                  image=image.scaledToWidth(ui->Picture->width(),Qt::SmoothTransformation);
                                                  ui->Picture->setPixmap(QPixmap::fromImage(image));
                                          
                                              }
                                          void MainWindow::onTrackball_clicked(int,void*)
                                          {
                                          

                                          void MainWindow::onTrackball_clicked(int,void*) is inside void MainWindow::on_pushButton_5_clicked() - this is invalid!

                                          G Offline
                                          G Offline
                                          gauravsharma0190
                                          wrote on last edited by
                                          #40

                                          @jsulm
                                          but i am not defining ontrack_clicked in push button its different.

                                          mrjjM 1 Reply Last reply
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