Download and install opencv
Debian/Ubuntu -
sudo apt-get install python-opencv
Red Hat/Fedora/OpenSUSE-
dnf install numpy opencv*
Install Selenium Webdriver
pip install selenium
Download geckodriver
https://github.com/mozilla/geckodriver/releases
Extract the folder and copy the 'geckodriver' file into '/usr/local/bin'
Use 'sudo chmod +x /usr/local/bin/geckodriver' to permit execute.