Declaration of function and use it

gauravsharma0190 · wrote on 15 Jul 2016, 06:38

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 );
}

gauravsharma0190 · 15 Jul 2016, 06:50

@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

jsulm · 15 Jul 2016, 07:11

@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.

gauravsharma0190 · J jsulm 15 Jul 2016, 06:50

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

gauravsharma0190 · J jsulm 15 Jul 2016, 06:50

@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;
}

}
}

jsulm · 18 Jul 2016, 06:16

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*) !

gauravsharma0190 · 18 Jul 2016, 06:19

@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.

jsulm · wrote on 18 Jul 2016, 06:19

@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).

jsulm · 18 Jul 2016, 06:56

@gauravsharma0190 Shouldn't

void CannyThreshold(int, void)

be

void CannyThreshold(int, void*)

?

gauravsharma0190 · wrote on 18 Jul 2016, 06:25

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

gauravsharma0190 · 18 Jul 2016, 07:02

@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.

gauravsharma0190 · 18 Jul 2016, 07:05

@gauravsharma0190 said:

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

jsulm · wrote on 18 Jul 2016, 07:05

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

jsulm · 18 Jul 2016, 08:38

@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!

gauravsharma0190 · 18 Jul 2016, 08:42

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

mrjj · 18 Jul 2016, 11:44

@gauravsharma0190

Are you sure ?
it really, really looks like you do :)

gauravsharma0190 · M mrjj 18 Jul 2016, 08:42

@mrjj
sir i again improving it.
as

void MainWindow::on_pushButton_6_clicked()
{
   /* Mat src , dst;


 //   char* source_window = "Source image";
   // char* equalized_window = "Equalized Image";

    /// Load image
    src = imread( "/home/pi/Desktop/b4.jpg" );



    /// Convert to grayscale
    cvtColor( src, src, CV_BGR2GRAY );

    /// Apply Histogram Equalization
    equalizeHist( src, dst );

    /// Display results
    namedWindow( "source", CV_WINDOW_NORMAL );
    namedWindow( "equalized", CV_WINDOW_NORMAL );

    imshow( "source", src );
    imshow( "equalized", dst );

    /// Wait until user exits the program
  //  waitKey(0);*/



    Mat src_base, hsv_base;
    Mat src_test1, hsv_test1;
    Mat src_test2, hsv_test2;
    Mat hsv_half_down;

    /// Load three images with different environment settings

    src_base = imread( "/home/pi/Desktop/b4.jpg" );
    src_test1 = imread( "/home/pi/Desktop/b4.jpg" );
    src_test2 = imread( "/home/pi/Desktop/b3.jpg" );

    /// Convert to HSV
    cvtColor( src_base, hsv_base, COLOR_BGR2HSV );
    cvtColor( src_test1, hsv_test1, COLOR_BGR2HSV );
    cvtColor( src_test2, hsv_test2, COLOR_BGR2HSV );

    hsv_half_down = hsv_base( Range( hsv_base.rows/2, hsv_base.rows - 1 ), Range( 0, hsv_base.cols - 1 ) );

    /// Using 50 bins for hue and 60 for saturation
    int h_bins = 50; int s_bins = 60;
    int histSize[] = { h_bins, s_bins };

    // hue varies from 0 to 179, saturation from 0 to 255
    float h_ranges[] = { 0, 180 };
    float s_ranges[] = { 0, 256 };

    const float* ranges[] = { h_ranges, s_ranges };

    // Use the o-th and 1-st channels
    int channels[] = { 0, 1 };


    /// Histograms
    MatND hist_base;
    MatND hist_half_down;
    MatND hist_test1;
    MatND hist_test2;

    /// Calculate the histograms for the HSV images
    calcHist( &hsv_base, 1, channels, Mat(), hist_base, 2, histSize, ranges, true, false );
    normalize( hist_base, hist_base, 0, 1, NORM_MINMAX, -1, Mat() );

    calcHist( &hsv_half_down, 1, channels, Mat(), hist_half_down, 2, histSize, ranges, true, false );
    normalize( hist_half_down, hist_half_down, 0, 1, NORM_MINMAX, -1, Mat() );

    calcHist( &hsv_test1, 1, channels, Mat(), hist_test1, 2, histSize, ranges, true, false );
    normalize( hist_test1, hist_test1, 0, 1, NORM_MINMAX, -1, Mat() );

    calcHist( &hsv_test2, 1, channels, Mat(), hist_test2, 2, histSize, ranges, true, false );
    normalize( hist_test2, hist_test2, 0, 1, NORM_MINMAX, -1, Mat() );

    /// Apply the histogram comparison methods
    for( int i = 0; i < 4; i++ )
    {
        int compare_method = i;
        double base_base = compareHist( hist_base, hist_base, compare_method );
        double base_half = compareHist( hist_base, hist_half_down, compare_method );
        double base_test1 = compareHist( hist_base, hist_test1, compare_method );
        double base_test2 = compareHist( hist_base, hist_test2, compare_method );

        printf( " Method [%d] Perfect, Base-Half, Base-Test(1), Base-Test(2) : %f, %f, %f, %f \n", i, base_base, base_half , base_test1, base_test2 );
    }




    }



void MainWindow::on_onTrackball_clicked()
{

    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";



    /// Load image
    src = imread( "/home/pi/Desktop/b4.jpg");
     /// 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_NORMAL );

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

    /// Show the image
    CannyThreshold(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_AUTOSIZE );
    imshow("calcHist Demo", histImage );
  imwrite("calcHist Demo2.jpg", histImage);
    waitKey(-1);


  }


...
This is new improved code .but there are error or build issue
1.In member function'void mainwindow::on_on_trackball_clicked()
****canny Thresol was not declered in this scope .(function which i declare and define in .h and .c file.
unsed variable 'edgeThresh'.

mrjj · 18 Jul 2016, 11:55

@gauravsharma0190 said:

CannyThreshold

this function ?
CannyThreshold
that you call with
CannyThreshold(0, 0);

and you do include the .h file where its defined?

gauravsharma0190 · 18 Jul 2016, 12:32

@mrjj
it is defined as

///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 );
}

.....
thus i include ontrack.h in mainwindow.cpp code.
but error occurs.
Why??
i can't understand.

mrjj · wrote on 18 Jul 2016, 12:00

I dont understand either.
Seems fine.
try to define a test function
as in
ontrack.h
void mytest();
and call that from main.

If that is still not known, it means that mainwinow do not really include ontrack.h for some reason.