Some files of how to use OpenCV in ftc. It is a bit more advanced than other stuff on the internet.
Installation OpenCV https://github.com/OpenFTC/EasyOpenCV#installation-instructions-android-studio
It is recommended to use Ftc Dashboard for debugging. It will provide you a live camera/webcam feed on your pc. It is not hard to install at all.
Info https://acmerobotics.github.io/ftc-dashboard/
Installation https://acmerobotics.github.io/ftc-dashboard/gettingstarted