Electrically switching between horizontal and vertical light polarization
In the simplest form just use two digital cameras, one with a vertical polarizer and one with a horizontal polarizer. Use a beam splitter if you need an exact duplicate image on both cameras.  Then run both video signals to the inputs of an analog switch/multiplexor (or a reversed biased diode switch*) and then digitally select the needed polarity signal as the single output. 

*https://www.google.com/search?q=diode+switch+for+RF&amp;biw=1549&amp;bih=730&amp;tbm=isch&amp;tbo=u&amp;source=univ&amp;sa=X&amp;ved=0CCgQsARqFQoTCN2i6YGY88gCFYNZPgodb1AEkQ