To use the same version of code I am stepping through here, make sure to

git checkout v3

at the command line.

You can also view it online. The difference between v2 and v3 is spelled out here.

I don't call it out in the video, but starting with v3, I moved the image processing tools we are using to a separate package called Lodgepole. You'll need to install it to run the code from this point. Navigate to the installation directory of your choice, then at the command line:

git clone https://gitlab.com/brohrer/lodgepole.git
python3 -m pip install -e lodgepole