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  4. Declaration of function and use it

Declaration of function and use it

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  • J jsulm
    21 Jul 2016, 11:42

    @gauravsharma0190 Can you post the code and mark the line where it crashes?

    G Offline
    G Offline
    gauravsharma0190
    wrote on 21 Jul 2016, 12:00 last edited by gauravsharma0190
    #78

    @jsulm
    Mainwindow.cpp

    void MainWindow::on_onTrackball_clicked()
    {
        int threshold_value = 0;
        int threshold_type = 3;
        int const max_value = 255;
        int const max_type = 4;
       // int const max_BINARY_value = 255;
    
        Mat src, src_gray, dst;
      //  char* window_name = "Threshold Demo";
    
        //char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
        //char* trackbar_value = "Value";
    
    
    
    
        /// Load image
        src = imread( "/home/pi/Desktop/b4.jpg");
    
    
          /// Convert the image to Gray
          cvtColor( src, src_gray, CV_BGR2GRAY );
    
          /// Create a window to display results
          namedWindow( "Threshold", CV_WINDOW_AUTOSIZE );
    
          /// Create Trackbar to choose type of Threshold
          createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
    
          createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
    
          /// Call the function to initialize
    @@@   ***Threshold_Demo( 0, 0)***
    
    
    }
    

    onTrack.h

    #ifndef ONTRACKBALL_H_
    #define ONTRACKBALL_H_
      void Threshold_Demo( int, void* );
    #endif
    

    ontrack.cpp

    void Threshold_Demo( int, void* )
    {
      /* 0: Binary
         1: Binary Inverted
         2: Threshold Truncated
         3: Threshold to Zero
         4: Threshold to Zero Inverted
       */
    
    @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
    
      imshow("Threshold", dst );
    

    Here @---> Error

    J 1 Reply Last reply 21 Jul 2016, 12:04
    0
    • G gauravsharma0190
      21 Jul 2016, 12:00

      @jsulm
      Mainwindow.cpp

      void MainWindow::on_onTrackball_clicked()
      {
          int threshold_value = 0;
          int threshold_type = 3;
          int const max_value = 255;
          int const max_type = 4;
         // int const max_BINARY_value = 255;
      
          Mat src, src_gray, dst;
        //  char* window_name = "Threshold Demo";
      
          //char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
          //char* trackbar_value = "Value";
      
      
      
      
          /// Load image
          src = imread( "/home/pi/Desktop/b4.jpg");
      
      
            /// Convert the image to Gray
            cvtColor( src, src_gray, CV_BGR2GRAY );
      
            /// Create a window to display results
            namedWindow( "Threshold", CV_WINDOW_AUTOSIZE );
      
            /// Create Trackbar to choose type of Threshold
            createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
      
            createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
      
            /// Call the function to initialize
      @@@   ***Threshold_Demo( 0, 0)***
      
      
      }
      

      onTrack.h

      #ifndef ONTRACKBALL_H_
      #define ONTRACKBALL_H_
        void Threshold_Demo( int, void* );
      #endif
      

      ontrack.cpp

      void Threshold_Demo( int, void* )
      {
        /* 0: Binary
           1: Binary Inverted
           2: Threshold Truncated
           3: Threshold to Zero
           4: Threshold to Zero Inverted
         */
      
      @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
      
        imshow("Threshold", dst );
      

      Here @---> Error

      J Online
      J Online
      jsulm
      Lifetime Qt Champion
      wrote on 21 Jul 2016, 12:04 last edited by
      #79

      @gauravsharma0190 What are src_gray, dst, threshold_value, max_BINARY_value,threshold_type? Where are they defined and initialized? Please note: these are NOT same as in MainWindow::on_onTrackball_clicked()!

      void Threshold_Demo( int, void* )
      {
        /* 0: Binary
           1: Binary Inverted
           2: Threshold Truncated
           3: Threshold to Zero
           4: Threshold to Zero Inverted
         */
      
      @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
      
        imshow("Threshold", dst );
      
      

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

      G 1 Reply Last reply 22 Jul 2016, 04:24
      0
      • J jsulm
        21 Jul 2016, 12:04

        @gauravsharma0190 What are src_gray, dst, threshold_value, max_BINARY_value,threshold_type? Where are they defined and initialized? Please note: these are NOT same as in MainWindow::on_onTrackball_clicked()!

        void Threshold_Demo( int, void* )
        {
          /* 0: Binary
             1: Binary Inverted
             2: Threshold Truncated
             3: Threshold to Zero
             4: Threshold to Zero Inverted
           */
        
        @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
        
          imshow("Threshold", dst );
        
        
        G Offline
        G Offline
        gauravsharma0190
        wrote on 22 Jul 2016, 04:24 last edited by
        #80

        @jsulm
        Hey Good morning
        These are defined in the same function .cpp files.
        Yes These are not in mainwindow

        J 1 Reply Last reply 22 Jul 2016, 04:27
        0
        • G gauravsharma0190
          22 Jul 2016, 04:24

          @jsulm
          Hey Good morning
          These are defined in the same function .cpp files.
          Yes These are not in mainwindow

          J Online
          J Online
          jsulm
          Lifetime Qt Champion
          wrote on 22 Jul 2016, 04:27 last edited by
          #81

          @gauravsharma0190 Did you initialize these variables? Do they have correct values when you call threshold()?

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

          G 1 Reply Last reply 22 Jul 2016, 05:21
          0
          • J jsulm
            22 Jul 2016, 04:27

            @gauravsharma0190 Did you initialize these variables? Do they have correct values when you call threshold()?

            G Offline
            G Offline
            gauravsharma0190
            wrote on 22 Jul 2016, 05:21 last edited by
            #82

            @jsulm
            Yes i initialize these with correct values.

            J 1 Reply Last reply 22 Jul 2016, 05:29
            0
            • G gauravsharma0190
              22 Jul 2016, 05:21

              @jsulm
              Yes i initialize these with correct values.

              J Online
              J Online
              jsulm
              Lifetime Qt Champion
              wrote on 22 Jul 2016, 05:29 last edited by
              #83

              @gauravsharma0190 Are you sure? Did you verify using debugger? If they have correct values then I don't know why it's crashing...

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

              G 1 Reply Last reply 22 Jul 2016, 06:00
              1
              • J jsulm
                22 Jul 2016, 05:29

                @gauravsharma0190 Are you sure? Did you verify using debugger? If they have correct values then I don't know why it's crashing...

                G Offline
                G Offline
                gauravsharma0190
                wrote on 22 Jul 2016, 06:00 last edited by
                #84

                @gauravsharma0190 said:

                void MainWindow::on_onTrackball_clicked()
                {
                int threshold_value = 0;
                int threshold_type = 3;
                int const max_value = 255;
                int const max_type = 4;
                // int const max_BINARY_value = 255;

                Mat src, src_gray, dst;
                

                // char* window_name = "Threshold Demo";

                //char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
                //char* trackbar_value = "Value";
                
                
                
                
                /// Load image
                src = imread( "/home/pi/Desktop/b4.jpg");
                
                
                  /// Convert the image to Gray
                  cvtColor( src, src_gray, CV_BGR2GRAY );
                
                  /// Create a window to display results
                  namedWindow( "Threshold", CV_WINDOW_AUTOSIZE );
                
                  /// Create Trackbar to choose type of Threshold
                  createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
                
                  createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
                
                  /// Call the function to initialize
                

                @@@ Threshold_Demo( 0, 0)

                }

                When I Comment the line Threshold _demo everything went OK!!!
                Results are coming but when i uncomment it everything crashes.

                J 1 Reply Last reply 22 Jul 2016, 06:16
                0
                • M Offline
                  M Offline
                  mrjj
                  Lifetime Qt Champion
                  wrote on 22 Jul 2016, 06:10 last edited by
                  #85

                  Hi
                  I have a teory ;)

                  namedWindow

                  void namedWindow(const string& winname, int flags=WINDOW_AUTOSIZE )

                  It wants a ref, so i assume that the crash is that
                  // char* window_name = "Threshold Demo";

                  will run out of scope

                  where as
                  namedWindow( "Threshold", CV_WINDOW_AUTOSIZE );
                  There "Threshold" is managed by the compiler and wont run out.

                  To test this, please move
                  char* window_name = "Threshold Demo";

                  OUTSIDE the function so it last longer than function call.

                  1 Reply Last reply
                  0
                  • G gauravsharma0190
                    22 Jul 2016, 06:00

                    @gauravsharma0190 said:

                    void MainWindow::on_onTrackball_clicked()
                    {
                    int threshold_value = 0;
                    int threshold_type = 3;
                    int const max_value = 255;
                    int const max_type = 4;
                    // int const max_BINARY_value = 255;

                    Mat src, src_gray, dst;
                    

                    // char* window_name = "Threshold Demo";

                    //char* trackbar_type = "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted";
                    //char* trackbar_value = "Value";
                    
                    
                    
                    
                    /// Load image
                    src = imread( "/home/pi/Desktop/b4.jpg");
                    
                    
                      /// Convert the image to Gray
                      cvtColor( src, src_gray, CV_BGR2GRAY );
                    
                      /// Create a window to display results
                      namedWindow( "Threshold", CV_WINDOW_AUTOSIZE );
                    
                      /// Create Trackbar to choose type of Threshold
                      createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
                    
                      createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
                    
                      /// Call the function to initialize
                    

                    @@@ Threshold_Demo( 0, 0)

                    }

                    When I Comment the line Threshold _demo everything went OK!!!
                    Results are coming but when i uncomment it everything crashes.

                    J Online
                    J Online
                    jsulm
                    Lifetime Qt Champion
                    wrote on 22 Jul 2016, 06:16 last edited by
                    #86

                    @gauravsharma0190 Please take a closer look at this code:

                    void MainWindow::on_onTrackball_clicked()
                    {
                    int threshold_value = 0;
                    int threshold_type = 3;
                    int const max_value = 255;
                    int const max_type = 4;
                    // int const max_BINARY_value = 255;
                    // These variables are LOCAL!
                    Mat src, src_gray, dst;
                    

                    You use local variables in void MainWindow::on_onTrackball_clicked(). All these variables exist only in that function: Mat src, src_gray, dst;
                    In Threshold_Demo() these variable are not visible (I have no idea why your code compiles? You probably defined these variables somewhere else again). I already pointed out this issue in one of my previous posts.

                    void Threshold_Demo( int, void* )
                    {
                      /* 0: Binary
                         1: Binary Inverted
                         2: Threshold Truncated
                         3: Threshold to Zero
                         4: Threshold to Zero Inverted
                       */
                    // src_gray, dst, threshold_value, max_BINARY_value,threshold_type are GLOBAL! Where are they defined?
                    @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                    

                    Please make really sure src_gray, dst, threshold_value, max_BINARY_value,threshold_type have valid values when you call threshold( )! Use debugger for this.

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

                    G 1 Reply Last reply 22 Jul 2016, 07:10
                    1
                    • J jsulm
                      22 Jul 2016, 06:16

                      @gauravsharma0190 Please take a closer look at this code:

                      void MainWindow::on_onTrackball_clicked()
                      {
                      int threshold_value = 0;
                      int threshold_type = 3;
                      int const max_value = 255;
                      int const max_type = 4;
                      // int const max_BINARY_value = 255;
                      // These variables are LOCAL!
                      Mat src, src_gray, dst;
                      

                      You use local variables in void MainWindow::on_onTrackball_clicked(). All these variables exist only in that function: Mat src, src_gray, dst;
                      In Threshold_Demo() these variable are not visible (I have no idea why your code compiles? You probably defined these variables somewhere else again). I already pointed out this issue in one of my previous posts.

                      void Threshold_Demo( int, void* )
                      {
                        /* 0: Binary
                           1: Binary Inverted
                           2: Threshold Truncated
                           3: Threshold to Zero
                           4: Threshold to Zero Inverted
                         */
                      // src_gray, dst, threshold_value, max_BINARY_value,threshold_type are GLOBAL! Where are they defined?
                      @@threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                      

                      Please make really sure src_gray, dst, threshold_value, max_BINARY_value,threshold_type have valid values when you call threshold( )! Use debugger for this.

                      G Offline
                      G Offline
                      gauravsharma0190
                      wrote on 22 Jul 2016, 07:10 last edited by
                      #87

                      @jsulm
                      Hey the ontrack.cpp file has these variable defined i havn't sent you full code
                      here it is

                      #include"onTrack.h"
                      #include<imgproc.hpp>
                       using namespace cv;
                      using namespace std;
                      int threshold_value=0;
                      int threshold_type=3;
                      int const max_BINARY_value=255;
                      Mat src_gray,dst;
                      
                      void Threshold_Demo( int, void* )
                      {
                        /* 0: Binary
                           1: Binary Inverted
                           2: Threshold Truncated
                           3: Threshold to Zero
                           4: Threshold to Zero Inverted
                         */
                      
                        threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                      
                        imshow( window_name, dst );
                      }
                      ......
                      J 1 Reply Last reply 22 Jul 2016, 07:28
                      0
                      • G gauravsharma0190
                        22 Jul 2016, 07:10

                        @jsulm
                        Hey the ontrack.cpp file has these variable defined i havn't sent you full code
                        here it is

                        #include"onTrack.h"
                        #include<imgproc.hpp>
                         using namespace cv;
                        using namespace std;
                        int threshold_value=0;
                        int threshold_type=3;
                        int const max_BINARY_value=255;
                        Mat src_gray,dst;
                        
                        void Threshold_Demo( int, void* )
                        {
                          /* 0: Binary
                             1: Binary Inverted
                             2: Threshold Truncated
                             3: Threshold to Zero
                             4: Threshold to Zero Inverted
                           */
                        
                          threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                        
                          imshow( window_name, dst );
                        }
                        ......
                        J Online
                        J Online
                        jsulm
                        Lifetime Qt Champion
                        wrote on 22 Jul 2016, 07:28 last edited by
                        #88

                        @gauravsharma0190 That is the problem I'm talking all the time! You do not initialize src_gray,dst from ontrack.cpp, so you use not properly initialized variables in Threshold_Demo(). As I said in MainWindow::on_onTrackball_clicked() you use local variables rc_gray,dst, not the ones from ontrack.cpp!
                        So, again where are these variables initialized?

                        // Where are they initialized?
                        Mat src_gray,dst;
                        
                        void Threshold_Demo( int, void* )
                        {
                          /* 0: Binary
                             1: Binary Inverted
                             2: Threshold Truncated
                             3: Threshold to Zero
                             4: Threshold to Zero Inverted
                           */
                        

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

                        G 1 Reply Last reply 22 Jul 2016, 08:55
                        0
                        • J jsulm
                          22 Jul 2016, 07:28

                          @gauravsharma0190 That is the problem I'm talking all the time! You do not initialize src_gray,dst from ontrack.cpp, so you use not properly initialized variables in Threshold_Demo(). As I said in MainWindow::on_onTrackball_clicked() you use local variables rc_gray,dst, not the ones from ontrack.cpp!
                          So, again where are these variables initialized?

                          // Where are they initialized?
                          Mat src_gray,dst;
                          
                          void Threshold_Demo( int, void* )
                          {
                            /* 0: Binary
                               1: Binary Inverted
                               2: Threshold Truncated
                               3: Threshold to Zero
                               4: Threshold to Zero Inverted
                             */
                          
                          G Offline
                          G Offline
                          gauravsharma0190
                          wrote on 22 Jul 2016, 08:55 last edited by
                          #89

                          @jsulm said:

                          That is the problem I'm talking all the time! You do not initialize src_gray,dst from ontrack.cpp, so you use not properly initialized variables in Threshold_Demo(). As I said in MainWindow::on_onTrackball_clicked() you use local variables rc_gray,dst, not the ones from ontrack.cpp!
                          So, again where are these variables initialized?

                          // Where are they initialized?
                          Mat src_gray,dst;

                          void Threshold_Demo( int, void* )
                          {
                          /* 0: Binary
                          1: Binary Inverted
                          2: Threshold Truncated
                          3: Threshold to Zero
                          4: Threshold to Zero Inverted
                          */

                          I initalized it in Mainwindow::onTrackBall_clicked().
                          I am sending you.
                          mainWindow.cpp*******

                          #include "mainwindow.h"
                          #include "ui_mainwindow.h"
                          #include<opencv2/opencv.hpp>
                          #include <opencv2/highgui/highgui.hpp>
                          #include <opencv2/core/core.hpp>
                          #include <opencv2/imgproc/imgproc.hpp>
                          #include<QFileDialog>
                          #include<QMessageBox>
                          #include <iostream>
                          #include<QProcess>
                          #include "onTrackBall.h"
                          #include<syscall.h>
                          #include<signal.h>
                          #include <string>
                          #include<stdlib.h>
                          #include<sys/ioctl.h>
                          #include <fstream>
                          #include<time.h>
                          #include<QTimer>
                          #include<QDateTime>
                          //#include"onTrackBall.h"
                          //#include"onTrackBall.c"
                          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);
                          
                          }
                          void MainWindow::on_onTrackball_clicked()
                          {
                              int threshold_value = 0;
                              int threshold_type = 3;
                              int const max_value = 255;
                              int const max_type = 4;
                             // int const max_BINARY_value = 255;
                          
                              Mat src, src_gray;
                          
                          
                          
                          
                          
                              /// Load image
                              src = imread( "/home/pi/Desktop/b4.jpg");
                          
                          
                                /// Convert the image to Gray
                                cvtColor( src, src_gray, CV_BGR2GRAY );
                          
                                /// Create a window to display results
                                namedWindow( "Threshold", CV_WINDOW_NORMAL );
                          
                                /// Create Trackbar to choose type of Threshold
                                createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
                          
                                createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
                          
                                /// Call the function to initialize
                              Threshold_Demo( 0, 0 );
                          
                          
                              /// Separate the image in 3 places ( B, G and R )
                              vector<Mat> bgr_planes;
                              split( src, bgr_planes );
                          
                              /// Establish the number of bins
                              int histSize = 256;
                          
                              /// Set the ranges ( for B,G,R) )
                              float range[] = { 0, 256 } ;
                              const float* histRange = { range };
                          
                              bool uniform = true;
                              bool accumulate = false;
                          
                              Mat b_hist, g_hist, r_hist;
                          
                              /// Compute the histograms:
                              calcHist( &bgr_planes[0], 1, 0, Mat(), b_hist, 1, &histSize, &histRange, uniform, accumulate );
                              calcHist( &bgr_planes[1], 1, 0, Mat(), g_hist, 1, &histSize, &histRange, uniform, accumulate );
                              calcHist( &bgr_planes[2], 1, 0, Mat(), r_hist, 1, &histSize, &histRange, uniform, accumulate );
                          
                              // Draw the histograms for B, G and R
                              int hist_w = 512; int hist_h = 400;
                             int bin_w = cvRound( (double) hist_w/histSize );
                          
                              Mat histImage( hist_h, hist_w, CV_8UC3, Scalar( 0,0,0) );
                          
                              /// Normalize the result to [ 0, histImage.rows ]
                              normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                              normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                              normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                          
                              /// Draw for each channel
                              for( int i = 1; i < histSize; i++ )
                              {
                                  line( histImage, Point( bin_w*(i-1), hist_h - cvRound(b_hist.at<float>(i-1)) ) ,
                                                   Point( bin_w*(i), hist_h - cvRound(b_hist.at<float>(i)) ),
                                                   Scalar( 255, 0, 0), 2, 8, 0  );
                                  line( histImage, Point( bin_w*(i-1), hist_h - cvRound(g_hist.at<float>(i-1)) ) ,
                                                   Point( bin_w*(i), hist_h - cvRound(g_hist.at<float>(i)) ),
                                                   Scalar( 0, 255, 0), 2, 8, 0  );
                                  line( histImage, Point( bin_w*(i-1), hist_h - cvRound(r_hist.at<float>(i-1)) ) ,
                                                   Point( bin_w*(i), hist_h - cvRound(r_hist.at<float>(i)) ),
                                                   Scalar( 0, 0, 255), 2, 8, 0  );
                              }
                          
                              /// Display
                              namedWindow("calcHist Demo", CV_WINDOW_NORMAL );
                              imshow("calcHist Demo", histImage );
                            imwrite("calcHist Demo2.jpg", histImage);
                          waitKey(-1);
                          
                          
                            }
                          ...
                          J 1 Reply Last reply 22 Jul 2016, 09:26
                          0
                          • G gauravsharma0190
                            22 Jul 2016, 08:55

                            @jsulm said:

                            That is the problem I'm talking all the time! You do not initialize src_gray,dst from ontrack.cpp, so you use not properly initialized variables in Threshold_Demo(). As I said in MainWindow::on_onTrackball_clicked() you use local variables rc_gray,dst, not the ones from ontrack.cpp!
                            So, again where are these variables initialized?

                            // Where are they initialized?
                            Mat src_gray,dst;

                            void Threshold_Demo( int, void* )
                            {
                            /* 0: Binary
                            1: Binary Inverted
                            2: Threshold Truncated
                            3: Threshold to Zero
                            4: Threshold to Zero Inverted
                            */

                            I initalized it in Mainwindow::onTrackBall_clicked().
                            I am sending you.
                            mainWindow.cpp*******

                            #include "mainwindow.h"
                            #include "ui_mainwindow.h"
                            #include<opencv2/opencv.hpp>
                            #include <opencv2/highgui/highgui.hpp>
                            #include <opencv2/core/core.hpp>
                            #include <opencv2/imgproc/imgproc.hpp>
                            #include<QFileDialog>
                            #include<QMessageBox>
                            #include <iostream>
                            #include<QProcess>
                            #include "onTrackBall.h"
                            #include<syscall.h>
                            #include<signal.h>
                            #include <string>
                            #include<stdlib.h>
                            #include<sys/ioctl.h>
                            #include <fstream>
                            #include<time.h>
                            #include<QTimer>
                            #include<QDateTime>
                            //#include"onTrackBall.h"
                            //#include"onTrackBall.c"
                            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);
                            
                            }
                            void MainWindow::on_onTrackball_clicked()
                            {
                                int threshold_value = 0;
                                int threshold_type = 3;
                                int const max_value = 255;
                                int const max_type = 4;
                               // int const max_BINARY_value = 255;
                            
                                Mat src, src_gray;
                            
                            
                            
                            
                            
                                /// Load image
                                src = imread( "/home/pi/Desktop/b4.jpg");
                            
                            
                                  /// Convert the image to Gray
                                  cvtColor( src, src_gray, CV_BGR2GRAY );
                            
                                  /// Create a window to display results
                                  namedWindow( "Threshold", CV_WINDOW_NORMAL );
                            
                                  /// Create Trackbar to choose type of Threshold
                                  createTrackbar( "Type: \n 0: Binary \n 1: Binary Inverted \n 2: Truncate \n 3: To Zero \n 4: To Zero Inverted","Threshold", &threshold_type, max_type, Threshold_Demo );
                            
                                  createTrackbar( "value","Threshold", &threshold_value, max_value, Threshold_Demo );
                            
                                  /// Call the function to initialize
                                Threshold_Demo( 0, 0 );
                            
                            
                                /// Separate the image in 3 places ( B, G and R )
                                vector<Mat> bgr_planes;
                                split( src, bgr_planes );
                            
                                /// Establish the number of bins
                                int histSize = 256;
                            
                                /// Set the ranges ( for B,G,R) )
                                float range[] = { 0, 256 } ;
                                const float* histRange = { range };
                            
                                bool uniform = true;
                                bool accumulate = false;
                            
                                Mat b_hist, g_hist, r_hist;
                            
                                /// Compute the histograms:
                                calcHist( &bgr_planes[0], 1, 0, Mat(), b_hist, 1, &histSize, &histRange, uniform, accumulate );
                                calcHist( &bgr_planes[1], 1, 0, Mat(), g_hist, 1, &histSize, &histRange, uniform, accumulate );
                                calcHist( &bgr_planes[2], 1, 0, Mat(), r_hist, 1, &histSize, &histRange, uniform, accumulate );
                            
                                // Draw the histograms for B, G and R
                                int hist_w = 512; int hist_h = 400;
                               int bin_w = cvRound( (double) hist_w/histSize );
                            
                                Mat histImage( hist_h, hist_w, CV_8UC3, Scalar( 0,0,0) );
                            
                                /// Normalize the result to [ 0, histImage.rows ]
                                normalize(b_hist, b_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                                normalize(g_hist, g_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                                normalize(r_hist, r_hist, 0, histImage.rows, NORM_MINMAX, -1, Mat() );
                            
                                /// Draw for each channel
                                for( int i = 1; i < histSize; i++ )
                                {
                                    line( histImage, Point( bin_w*(i-1), hist_h - cvRound(b_hist.at<float>(i-1)) ) ,
                                                     Point( bin_w*(i), hist_h - cvRound(b_hist.at<float>(i)) ),
                                                     Scalar( 255, 0, 0), 2, 8, 0  );
                                    line( histImage, Point( bin_w*(i-1), hist_h - cvRound(g_hist.at<float>(i-1)) ) ,
                                                     Point( bin_w*(i), hist_h - cvRound(g_hist.at<float>(i)) ),
                                                     Scalar( 0, 255, 0), 2, 8, 0  );
                                    line( histImage, Point( bin_w*(i-1), hist_h - cvRound(r_hist.at<float>(i-1)) ) ,
                                                     Point( bin_w*(i), hist_h - cvRound(r_hist.at<float>(i)) ),
                                                     Scalar( 0, 0, 255), 2, 8, 0  );
                                }
                            
                                /// Display
                                namedWindow("calcHist Demo", CV_WINDOW_NORMAL );
                                imshow("calcHist Demo", histImage );
                              imwrite("calcHist Demo2.jpg", histImage);
                            waitKey(-1);
                            
                            
                              }
                            ...
                            J Online
                            J Online
                            jsulm
                            Lifetime Qt Champion
                            wrote on 22 Jul 2016, 09:26 last edited by
                            #90

                            @gauravsharma0190 Please read what I'm writing more carefully!
                            In Mainwindow::onTrackBall_clicked() you don't initialize them! Because you use local variables there with same names:

                            void MainWindow::on_onTrackball_clicked()
                            {
                                 // Here src and src_gray are not the same as in ontrack.cpp!
                                 // Values you're assigning here to src and src_gray are only visible here but not in ontrack.cpp!
                                Mat src, src_gray;
                            

                            I'm running out of ideas how to explain it. You should learn C++, especially the visibility and scope of variables.

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

                            G 1 Reply Last reply 22 Jul 2016, 10:28
                            1
                            • J jsulm
                              22 Jul 2016, 09:26

                              @gauravsharma0190 Please read what I'm writing more carefully!
                              In Mainwindow::onTrackBall_clicked() you don't initialize them! Because you use local variables there with same names:

                              void MainWindow::on_onTrackball_clicked()
                              {
                                   // Here src and src_gray are not the same as in ontrack.cpp!
                                   // Values you're assigning here to src and src_gray are only visible here but not in ontrack.cpp!
                                  Mat src, src_gray;
                              

                              I'm running out of ideas how to explain it. You should learn C++, especially the visibility and scope of variables.

                              G Offline
                              G Offline
                              gauravsharma0190
                              wrote on 22 Jul 2016, 10:28 last edited by
                              #91

                              @jsulm
                              You mean to say in OnTrack_clicked()
                              src and src_gray variable
                              and in ontrack.cpp
                              src_gray variable should be different.
                              I can't get you.
                              In Mainwindow::onTrackBall_clicked() you don't initialize them! Because you use local variables there with same names:

                              void MainWindow::on_onTrackball_clicked()
                              {
                              // Here src and src_gray are not the same as in ontrack.cpp!
                              // Values you're assigning here to src and src_gray are only visible here but not in ontrack.cpp!
                              Here what is local variable in it.
                              Local mean variable inside the function??
                              And globle mean en tire the programme.

                              J 1 Reply Last reply 22 Jul 2016, 10:45
                              0
                              • G gauravsharma0190
                                22 Jul 2016, 10:28

                                @jsulm
                                You mean to say in OnTrack_clicked()
                                src and src_gray variable
                                and in ontrack.cpp
                                src_gray variable should be different.
                                I can't get you.
                                In Mainwindow::onTrackBall_clicked() you don't initialize them! Because you use local variables there with same names:

                                void MainWindow::on_onTrackball_clicked()
                                {
                                // Here src and src_gray are not the same as in ontrack.cpp!
                                // Values you're assigning here to src and src_gray are only visible here but not in ontrack.cpp!
                                Here what is local variable in it.
                                Local mean variable inside the function??
                                And globle mean en tire the programme.

                                J Online
                                J Online
                                jsulm
                                Lifetime Qt Champion
                                wrote on 22 Jul 2016, 10:45 last edited by
                                #92

                                @gauravsharma0190 No, I don't mean that they should be different. I mean the opposite: they need to be the same (but they are not).
                                Local variable is a variable which is only visible in a certain scope, for example in a function. The variables in ontrack.cpp are only visible in ontrack.cpp, but not in MainWindow. In Mainwindow::onTrackBall_clicked() you declare OTHER variables with SAME names.
                                What do you think which src_grey is used in Threshold_Demo( int, void* )? Is it the one from MainWindow::onTrackBall_clicked() or the one from ontrack.cpp?

                                // src_gray here is not the same as in MainWindow::onTrackBall_clicked()
                                Mat src_gray,dst;
                                void Threshold_Demo( int, void* )
                                {
                                  threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                                }
                                

                                Actually you should pass the data to Threshold_Demo() as parameter:

                                Mainwindow::onTrackBall_clicked()
                                {
                                    Mat src, src_gray;
                                    ...
                                    Threshold_Demo(src_grey, /*what else needs to be passed from MainWindow to this function*/);
                                    ...
                                }
                                
                                void Threshold_Demo(Mat &src_grey, ...)
                                {
                                

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

                                G 1 Reply Last reply 22 Jul 2016, 11:13
                                0
                                • J jsulm
                                  22 Jul 2016, 10:45

                                  @gauravsharma0190 No, I don't mean that they should be different. I mean the opposite: they need to be the same (but they are not).
                                  Local variable is a variable which is only visible in a certain scope, for example in a function. The variables in ontrack.cpp are only visible in ontrack.cpp, but not in MainWindow. In Mainwindow::onTrackBall_clicked() you declare OTHER variables with SAME names.
                                  What do you think which src_grey is used in Threshold_Demo( int, void* )? Is it the one from MainWindow::onTrackBall_clicked() or the one from ontrack.cpp?

                                  // src_gray here is not the same as in MainWindow::onTrackBall_clicked()
                                  Mat src_gray,dst;
                                  void Threshold_Demo( int, void* )
                                  {
                                    threshold( src_gray, dst, threshold_value, max_BINARY_value,threshold_type );
                                  }
                                  

                                  Actually you should pass the data to Threshold_Demo() as parameter:

                                  Mainwindow::onTrackBall_clicked()
                                  {
                                      Mat src, src_gray;
                                      ...
                                      Threshold_Demo(src_grey, /*what else needs to be passed from MainWindow to this function*/);
                                      ...
                                  }
                                  
                                  void Threshold_Demo(Mat &src_grey, ...)
                                  {
                                  
                                  G Offline
                                  G Offline
                                  gauravsharma0190
                                  wrote on 22 Jul 2016, 11:13 last edited by
                                  #93

                                  @jsulm
                                  OK it means src_gray value in .cpp file should be same as in mainwindow::on_Track clicked() src_gray value.
                                  Actually src_gray is image array.
                                  I did it by Define the value of src_grey in function as
                                  src=imread("/file.jpg);
                                  cvtColor( src, src_gray, CV_BGR2GRAY );
                                  so i will get src_gray value.

                                  1 Reply Last reply
                                  0

                                  87/93

                                  22 Jul 2016, 07:10

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