How to convert QPainter(self) to QImage?

lachdanan

I want to apply blur to a version of my painted circle to be placed under the original circle for additional effect. Because I couldn't find a way to directly apply a blur filter to QPainter, or the widget, I found this method:

blur = QtWidgets.QGraphicsBlurEffect()
blur.setBlurRadius(20)
result = applyEffectToImage(img, blur)
result.save(r"N:/sample.bmp")

        
def applyEffectToImage(src, effect):
    scene = QtWidgets.QGraphicsScene()
    item = QtWidgets.QGraphicsPixmapItem()
    item.setPixmap(QPixmap.fromImage(src))
    item.setGraphicsEffect(effect)
    scene.addItem(item)
    res = QImage(src.size(), QImage.Format_ARGB32)
    res.fill(Qt.transparent)
    ptr = QPainter(res)
    scene.render(ptr, QRectF(), QRectF(0,0, src.width(), src.height()) )
    return res

But if I create an img and pass it to QPainter, it will have the same artifact shown here:
https://forum.qt.io/topic/111004/how-to-mask-a-widget-by-a-single-color-for-transparency/14

So I must use QPainter(self).

How can I convert my QPainter(self) to a QImage?

I just want to draw a circle (which I did), blur it, place this blurry version under the original circle. Is there a simpler or better way to do this other than this?

Thanks in advance.

Kent-Dorfman

QPainter(self) is highly dependent upon what self is. Have you reviewed the QPainter and QPaintDevice documentation?

eyllanesc

You seem to not understand what QPainter is or what it does, QPainter is a painter who paints on a canvas(self object) that can be a QImage, QPixmap, QWidget, etc. so you cannot convert the painter into QImage, what you can do is convert the canvas to QImage.

eyllanesc

From what I understand you you want to have a QImage that shows a circle where the filter blur was applied. I am right?