Maintaining a 1-bit Bridge

Trying out a Python program that dealt with images did remind me how I’d got another program in that language working. Closer yet to the arrival of macOS 10.15 “Catalina” and its retirement of all “32-bit applications,” I decided to reassure myself of my potential replacement for something between an utility and a diversion for me, a program that can render an image with the peculiar nostalgia of “1-bit,” black-and-white Atkinson dithering.
( Many software steps ahead )