https://pimylifeup.com/raspberry-pi-tensorflow-lite/
list of dependancies
python -m pip install opencv-python
pip3 install opencv-python sudo apt-get install libcblas-dev sudo apt-get install libhdf5-dev sudo apt-get install libhdf5-serial-dev sudo apt-get install libatlas-base-dev sudo apt-get install libjasper-dev sudo apt-get install libqtgui4 sudo apt-get install libqt4-test sudo apt-get install libportaudio2 pip install -U numpy
try cap = cv2.VideoCapture(-1) if camera is issue. make sure restarted first.