Hey there,

I've came across this awesome script and wanted to use it.
Unfortunately Python 2 is dead and out of support now.

To be able to still use this script, I've ported everything to Python 3.
Unfortunately I have not get any update on my pull request so I'm opening here a issue.

Changes have been made on opencv-calls. Also some decoding stuff due to the internal changes from Python 2 to 3.
The zbar-bindings seem to not work in Python 3 anymore, so I switched to pyzbar.
Besides I think there was a crash on the preview()-function. I've fixed it by checking if data exists and is not None.

Hope this is helpful.

Best Regards
Konstantin