What is QImage in Qt?

What is QImage in Qt?

The QImage class provides a hardware-independent image representation that allows direct access to the pixel data, and can be used as a paint device.

How do you display QImage?

Constructed QImages can be displayed in a QLabel. By setting the pixmap value of QLabel from setPixmap function, QLabel displays content of QImage. Sample project started as a QT Gui Application and contains main. cpp, ShowQImageDialog.

How do you convert QImage to QPixmap?

A QPixmap object can be converted into a QImage using the toImage() function. Likewise, a QImage can be converted into a QPixmap using the fromImage(). If this is too expensive an operation, you can use QBitmap::fromImage() instead.

How do I resize in QImage?

Re: QImage Resize To resize an image one would use QImage::scaled(). If you want to crop an image, you can use QImage::copy() and assign it to the same object you copied from.

How do you save QImage in Qt?

Saving QImage

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

How do I insert a picture into Qt?

Using Qt Designer Drag this onto the QMainWindow to add it. Next, with the Label selected, look in the right hand QLabel properties panel for the pixmap property (scroll down to the blue region). From the property editor dropdown select “Choose File…” and select an image file to insert.

How do you scale a pixmap?

You can scale the pixmap by keeping its aspect ratio every time it changes: QPixmap p; // load pixmap // get label dimensions int w = label->width(); int h = label->height(); // set a scaled pixmap to a w x h window keeping its aspect ratio label->setPixmap(p.

How do you save in QImage?

What is QPixmap?

The QPixmap class is an off-screen image representation that can be used as a paint device. The QImage class provides a hardware-independent image representation that allows direct access to the pixel data, and can be used as a paint device.