I uploaded files modified from Shantnu Tiwari's Python For Engineers (PyEng) respository.
Specifically, the Image_Video subdirectory has sample programs, which I modified to use matplotlib.pyplot's imshow() insead of OpenCV's imshow().
This is not ideal, but got the programs further along in the absense of a working OpenCV on Ubuntu.
The next step was to avoid the GUI altogether and use OpenCV's imwrite() to save images to a file.  The pyplot examples are left in, but commented out for reference.