refresh a QLabel and QImage

[rafik]

Hello,
i have a serious problem, when i choose an image to display in a Qwidget (fentroi), it is displayed but the problem when i choose another it can't refresh and it can't display the new image, ,and im working on binarisation and the threshold didn't refresh too i assume that because the QImage that i load is the cause because it dosen't refresh too.

here my code
fenetrePrincipale.h (MainWindow)

#ifndef FENETREPRINCIPALE_H
#define FENETREPRINCIPALE_H
#include <QtWidgets>
#include "traitement.h"
class FenetrePrincipale : public QMainWindow
{
    Q_OBJECT
public :
    FenetrePrincipale();
public slots :
    void ouvrir();
    void traiter();
    void traiterOtsu();
private:
    QString nomFichier;
    QWidget fentroi;
    QWidget fenSec;
 
 
 
};
 
#endif // FENETREPRINCIPALE_H

#ifndef FENETREPRINCIPALE_H
#define FENETREPRINCIPALE_H
#include <QtWidgets>
#include "traitement.h"
class FenetrePrincipale : public QMainWindow
{
    Q_OBJECT
public :
    FenetrePrincipale();
public slots :
    void ouvrir();
    void traiter();
    void traiterOtsu();
private:
    QString nomFichier;
    QWidget fentroi;
    QWidget fenSec;



};

#endif // FENETREPRINCIPALE_H

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fenetrePricipale.cpp

#include "traitement.h"
#include "otsu.h"
#include "fenetreprincipale.h"
 
FenetrePrincipale::FenetrePrincipale(): QMainWindow()
{
 
 
    QMenu *menuFichier = menuBar()->addMenu("Fichier");
    QAction *actionOuvrir = new QAction("Ouvrir", this);
    QAction *actionQuitter = new QAction("Quitter", this);
    menuFichier->addAction(actionOuvrir);
    menuFichier->addAction(actionQuitter);
 
    QMenu *menuTraitement = menuBar()->addMenu("Traitement");
    QAction *actionBinarisation = new QAction("Binarisation", this);
    menuTraitement->addAction(actionBinarisation);
 
    QObject::connect(actionOuvrir, SIGNAL(triggered(bool)), this, SLOT(ouvrir()));
    QObject::connect(actionQuitter, SIGNAL(triggered(bool)), this, SLOT(close()));
 
    QObject::connect(actionBinarisation, SIGNAL(triggered(bool)), this, SLOT(traiterOtsu()));
    QObject::connect(this, SIGNAL(changer()), this, SLOT(afficher()));
}
void FenetrePrincipale::ouvrir()
{
   nomFichier = QFileDialog::getOpenFileName(this, tr("Open File"),"C:/Users/amine/Downloads");
 
   QLabel *label =new QLabel(&fentroi);
   label->setGeometry(100,100,400,400);
   QImage image1(nomFichier);
   QPixmap pixmap;
   pixmap.convertFromImage(image1);
   label->setPixmap(pixmap);
   fentroi.show(); // fentroi (fenetre qui affiche l'image) attribut de fenetre principale
   label->update();
 
}
 
void FenetrePrincipale::traiterOtsu()
{
    OtsuAlgo traitement(nomFichier);
    traitement.binarisation();
    QImage *im = new QImage(traitement.getImage());
    QLabel *label = new QLabel(&fenSec);
    label->setGeometry(100,100, 400, 400);
    label->setPixmap(QPixmap::fromImage(*im));
    QLCDNumber *lcd = new QLCDNumber(&fenSec);
    lcd->move(70,70);
    lcd->setSegmentStyle(QLCDNumber::Flat);
    lcd->display(traitement.getSeuil());
    fenSec.show();
}

#include "traitement.h"
#include "otsu.h"
#include "fenetreprincipale.h"

FenetrePrincipale::FenetrePrincipale(): QMainWindow()
{


    QMenu *menuFichier = menuBar()->addMenu("Fichier");
    QAction *actionOuvrir = new QAction("Ouvrir", this);
    QAction *actionQuitter = new QAction("Quitter", this);
    menuFichier->addAction(actionOuvrir);
    menuFichier->addAction(actionQuitter);

    QMenu *menuTraitement = menuBar()->addMenu("Traitement");
    QAction *actionBinarisation = new QAction("Binarisation", this);
    menuTraitement->addAction(actionBinarisation);

    QObject::connect(actionOuvrir, SIGNAL(triggered(bool)), this, SLOT(ouvrir()));
    QObject::connect(actionQuitter, SIGNAL(triggered(bool)), this, SLOT(close()));

    QObject::connect(actionBinarisation, SIGNAL(triggered(bool)), this, SLOT(traiterOtsu()));
    QObject::connect(this, SIGNAL(changer()), this, SLOT(afficher()));
}
void FenetrePrincipale::ouvrir()
{
   nomFichier = QFileDialog::getOpenFileName(this, tr("Open File"),"C:/Users/amine/Downloads");

   QLabel *label =new QLabel(&fentroi);
   label->setGeometry(100,100,400,400);
   QImage image1(nomFichier);
   QPixmap pixmap;
   pixmap.convertFromImage(image1);
   label->setPixmap(pixmap);
   fentroi.show(); // fentroi (fenetre qui affiche l'image) attribut de fenetre principale
   label->update();

}

void FenetrePrincipale::traiterOtsu()
{
    OtsuAlgo traitement(nomFichier);
    traitement.binarisation();
    QImage *im = new QImage(traitement.getImage());
    QLabel *label = new QLabel(&fenSec);
    label->setGeometry(100,100, 400, 400);
    label->setPixmap(QPixmap::fromImage(*im));
    QLCDNumber *lcd = new QLCDNumber(&fenSec);
    lcd->move(70,70);
    lcd->setSegmentStyle(QLCDNumber::Flat);
    lcd->display(traitement.getSeuil());
    fenSec.show();
}

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please if someone can help me and thanks

[ChrisW67]

Your code keeps creating a new label every time it want to update the image. You should be calling setPixmap() on the same QLabel every time.

[rafik]

Thanks a lot Mr ChrisW67

[anda_skoa]

And you don't want to leak the image by allocating it on the heap like you do right now in line 44.

Cheers,
_