feature request: capture image from screen

[drzraf]

I'd be interested into introducing my current screen/virtual desktop as a source in the pipeline.
https://doc.qt.io/qt-5.11/qpixmap.html
With a configurable delay in ms (and virtual desktop number), it would allow, eg subtraction, of the (expected) screen output from camera-originated image of the projection of that screen.

[l00mi]

I like the idea!

[drzraf]

Did you have a look at the corresponding PR?

[l00mi]

@drzraf Sorry, I will do my best to have a look next week! Thank you already for the efforts.

(I see that travis does not run through. Is this a blip or do we need to fix the pipeline?)