Error
ImportError: libcblas.so.3: cannot open shared object file: No such file or directory
ImportError: libjasper.so.1: cannot open shared object file: No such file or directory
Solution
pip3 install opencv-python
sudo apt-get install libatlas-base-dev
sudo apt-get install libjasper-dev
sudo apt-get install libqtgui4
sudo apt-get install python3-pyqt5
sudo apt-get install libqt4-test
Other
Pillow might also be interesting for image processing.
# installation
pip3 install Pillow