Lily
Lily

Reputation: 6022

Qt jpg image display

I want to display .jpg image in an Qt UI. I checked it online and found https://doc.qt.io/archives/qt-4.8/qt-widgets-imageviewer-example.html. I thought Graphics View will do the same, and also it has codec to display video. How to display images using Graphics View? I went through the libraries, but because I am a totally newbie in Qt, I can't find a clue to start with. Can you direct me to some resources/examples on how to load and display images in Qt?

Thanks.

Upvotes: 61

Views: 180969

Answers (7)

Wojciech Bederski
Wojciech Bederski

Reputation: 3922

#include ...

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QGraphicsScene scene;
    QGraphicsView view(&scene);
    QGraphicsPixmapItem item(QPixmap("c:\\test.png"));
    scene.addItem(&item);
    view.show();
    return a.exec();
}

This should work. :) List of supported formats can be found here

Upvotes: 45

Ben L
Ben L

Reputation: 7068

You could attach the image (as a pixmap) to a label then add that to your layout...

...

QPixmap image("blah.jpg");

QLabel *imageLabel = new QLabel();
imageLabel->setPixmap(image);

mainLayout.addWidget(imageLabel);

...

Apologies, this is using Jambi (Qt for Java) so the syntax is different, but the theory is the same.

Upvotes: 59

aiutopia.dev
aiutopia.dev

Reputation: 852

Using QPainter and QImage to paint on a window-widget (QMainWindow) (just another method)

class MainWindow : public QMainWindow
{    
    public:
        MainWindow();
    protected:
        void paintEvent(QPaintEvent* event) override;

    protected:
        QImage image = QImage("/path/to/image.jpg");
};

// for convenience resize window to image size
MainWindow::MainWindow()
{
    setMinimumSize(image.size());
}

void MainWindow::paintEvent(QPaintEvent* event)
{
    QPainter painter(this);
    QRect rect = event->rect();
    painter.drawImage(rect, image, rect);
}


int main(int argc, char** argv)
{
    QApplication a(argc, argv);

    MainWindow mainWindow;
    mainWindow.show();
    return a.exec();
}

Upvotes: 3

zar
zar

Reputation: 12247

  1. Add Label (a QLabel) to the dialog where you want to show the image. This QLabel will actually display the image. Resize it to the size you want the image to appear.

  2. Add the image to your resources in your project.

  3. Now go into QLabel properties and select the image you added to resources for pixmap property. Make sure to check the next property scaledContents to shrink the image in the size you want to see it.

That's all, the image will now show up.

Upvotes: 5

Oogle berries
Oogle berries

Reputation: 41

I understand your frustration the " Graphics view widget" is not the best way to do this, yes it can be done, but it's almost exactly the same as using a label ( for what you want any way) now all the ways listed do work but...

For you and any one else that may come across this question he easiest way to do it ( what you're asking any way ) is this.

QPixmap pix("Path\\path\\entername.jpeg");
    ui->label->setPixmap(pix);

}

Upvotes: 4

Vanuan
Vanuan

Reputation: 33472

I want to display .jpg image in an Qt UI

The simpliest way is to use QLabel for this:

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);
    QLabel label("<img src='image.jpg' />");
    label.show();
    return a.exec();
}

Upvotes: 3

user251390
user251390

Reputation: 141

If the only thing you want to do is drop in an image onto a widget withouth the complexity of the graphics API, you can also just create a new QWidget and set the background with StyleSheets. Something like this:

MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent)
{
    ...
    QWidget *pic = new QWidget(this);
    pic->setStyleSheet("background-image: url(test.png)");
    pic->setGeometry(QRect(50,50,128,128));
    ...
}

Upvotes: 14

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