Low model quality when marker tracking ar.js

Question

I ma having some strange issue. I’m using ar.js with Three.js, and when the camera is on full screen, model is less sharpy than when the camera is not on full screen. I added two pictures for comparison. Any idea why ar.js could cause this, and how can I fix it?

Code i am using (feature branch):

https://github.com/wszczepanskii/trackingArProject/tree/feature

full screen not full screen

changing camera resolution from 640x480 to higher doesn't work