Faster rendering of QImage in QGraphicsView using QGraphicsPixmapItem

When redering a QImage with Format RGB888 or pure 8 bit Grayscale, i first create a QPixmap and set it to a QGraphicsPixmapItem, which belongs to a QGraphicsview as follows:

QImage image; //assume it contains a RGB888 or 8bit Grayscale Image with FullHD resolution.
graphicsPixmapItem->setPixmap( QPixmap::fromImage(image) ); // graphicsPixmapItem is added in the QGraphicsView

The whole process takes about 7 or more milliseconds on a i7 6700K Processor that runs with up to 4GHZ.

It seems that Qt is converting the Image to RGB32 before displaying it.

My Question is: Cant Qt provide a way to render the content directly more efficient without any conversion?

I wrote an OpenGL Renderer that takes the image as it is and directly renders it. It does not take more than 1ms.

When building applications that display multiple images this would be very helpful without wasting computational ressources.