How to render a scaled SVG to a QImage?

Question

There is a QSvgRenderer class in QtSvg module which can render image onto QPaintDevice. This one can be QImage. In that c

Answer 1

Just give your QImage the desired size. The SVG renderer will scale to fit the whole image.

#include 
#include 
#include 
#include 

// In your .pro file:
// QT += svg 

int main(int argc, char **argv)
{
    // A QApplication instance is necessary if fonts are used in the SVG
    QApplication app(argc, argv);

    // Load your SVG
    QSvgRenderer renderer(QString("./svg-logo-h.svg"));

    // Prepare a QImage with desired characteritisc
    QImage image(500, 200, QImage::Format_ARGB32);
    image.fill(0xaaA08080);  // partly transparent red-ish background

    // Get QPainter that paints to the image
    QPainter painter(&image);
    renderer.render(&painter);

    // Save, image format based on file extension
    image.save("./svg-logo-h.png");
}

This will create an 500x200 PNG image from the passed in SVG file.

Example output with an SVG image from the SVG logos page: