I want to use opencv inside a QWidget on an QMainwindow interactively

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I want to interact with the image - annotation, draw lines, circles, get coordinates, etc. - inside a QWidget on an QMainwindow interactively

Actual behaviour showing an image must be converted to qpixmap, which is not interactive

win7, x64, opencv 4.2.0.32, python 3.7

I found this: https://www.kurokesu.com/main/2016/08... and if a camera view works also an cv.Window should work somehow ... is there any help or is this the wrong place? It also would help if somebody knows that this does not work at all.