実験のコード片 void MainWindow::paintEvent(QPaintEvent *){ QPainter painter(this); QTime timer; QImage image(256, 256, QImage::Format_ARGB32); QPixmap pixmap(QPixmap::fromImage(image)); timer.start(); for (int i = 0; i < 10000; ++i){ painter.drawImage(0, 0, image, 0, 0, 128, 128); } qDebug() << "QImage" << timer.elapsed(); timer.start(); for (int i = 0; i < 10000; ++i){ painter.drawPixmap(0, 0, pixmap, 0