Hello,
Hope you are doing well. I have done image downsizing before in Matlab as a favor to my friend who creates 360 virtual tours. I myself have extensive knowledge of python as well, so I will be able to understand your code in depth. I have conceptual knowledge of compression algorithms (like Adaptive dictionary algorithms and DEFLATE, for images).
I will share with you my documentation skills as well in personal message.
I hope to hear back from you.
Appreciate your time. Thank you!