Enhancement: Green text on black background

[exgtfnum]

I recently got a LCD drawing tablet.
These don't display images and are more like a whiteboard/etchasketch.
By pressing on the screen the crystals will rotate to reflect green light.
The only electronics being a clear/reset button.

This app seems to think a transition from dark to light is a line so all text gets converted into only it's outline.

I'd like if my green text on black background would get converted into black text on white background.

Ignore the flash, I usually only do this in well lit rooms

[rauferd]

More generally speaking, an option to invert images before processing would be nice.