Saving QImage

[thgis]

Hi.

I have a problem saving a QImage.
It is generated from a QGraphicsScene via the following code:

QImage image(_scene->sceneRect().size().toSize(), QImage::Format_RGB32);
QPainter painter(&image);
_scene->render(&painter);
image.save(filename);

QImage image(_scene->sceneRect().size().toSize(), QImage::Format_RGB32);
QPainter painter(&image);
_scene->render(&painter);
image.save(filename);

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_scene is a QGraphicsScene*
and filename is a non empty string with the format("filename.png")

image.save(filename) always return false.

Another place in my program I save a QImage generated by setting individual pixels in the QImage and that works fine. (The format here is also .png)

I have tried different formats by changing the filename from filename.png to filename.tiff and so on.

Any ideas?

[mattc]

Are you sure the scene is not empty? QImage::save() returns false if both width and height == 0

[thgis]

I will check that tomorrow. Thanks for the suggestion.

[thgis]

I've checked that the image has the correct size and it all looks right.

Any other suggestions?

[mattc]

The following works fine for me, I can see no difference with your code:

#include <QApplication>
#include <QImage>
#include <QPainter>
#include <QGraphicsScene>
 
int main(int argc, char** argv)
{
    QApplication app(argc, argv);
 
    QGraphicsScene* scene = new QGraphicsScene();
    scene->setSceneRect(0, 0, 2, 2);
 
    QImage img(scene->sceneRect().size().toSize(), QImage::Format_RGB32);
 
    QPainter painter(&img);
    scene->render(&painter);
 
    bool b = img.save("test.png");
 
    Q_ASSERT(b);
 
    return 0;
}

#include <QApplication>
#include <QImage>
#include <QPainter>
#include <QGraphicsScene>

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

    QGraphicsScene* scene = new QGraphicsScene();
    scene->setSceneRect(0, 0, 2, 2);

    QImage img(scene->sceneRect().size().toSize(), QImage::Format_RGB32);

    QPainter painter(&img);
    scene->render(&painter);

    bool b = img.save("test.png");

    Q_ASSERT(b);

    return 0;
}

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[thgis]

Thank you so much mattc for all your effort...

Unfortunately I had made a major error in the construction of the filename... stupid... After correcting this it seems to work fine....

very sorry for wasting everyones time...