QT drawpixmap and DrawImage blur problem

drawPixmap and drawImage When the picture is displayed , If the picture has zoom , There will be ambiguity , For example, a 100x100
The picture of is displayed to 30x30 Region , At this time, there will be blur . as follows ：

Actual picture ：

This problem is the pixel distortion caused by the display of large images into small images .
When we're in 1080 A clear picture is displayed on the screen 2k Blurred images may also appear on the screen , The reason is also the distortion of scaling pixels caused by large images being displayed as small images or larger images .
resolvent ： According to the size to be displayed , Our code scales it in advance , Prevent it from scaling automatically .

QPainter p(this);

p.setPen(QColor(208,208,208));
p.setBrush(Qt::white);
p.setRenderHint(QPainter::Antialiasing);
QPainterPath path;
path.addEllipse(this->rect());
p.setClipPath(path);

p.drawEllipse(this->rect());
qreal pixelRatio = p.device()->devicePixelRatioF(); //  Get the resolution ratio of different displays , Prevent image distortion at different resolutions 
m_logopix = m_logopix.scaled(QSize(width() * pixelRatio, height() *pixelRatio)
                             , Qt::IgnoreAspectRatio, Qt::SmoothTransformation);// Zoom the picture to the display size at the current resolution ,SmoothTransformation Smoothing .
p.drawPixmap(this->rect(),m_logopix);

The effect after treatment is as follows ：