Earlier quoted context omitted.
Has to be online since it is proxied via an online backend which does the actual black-and-white conversion etc. I have some ideas for letting users point the device directly to a local URL, but I don't want to commit to any promises on that front. You could try using something like https://ngrok.com , that's what I sometimes use for testing.
Hm, I see. I’m pretty sure I can figure out how to serve a greyscale image. I suggest making that proxy explicit in your docs. You suggest using HTTPS and an obscure URL to keep our data “secret” but then you’re literally processing our content and could be doing anything with it.
It's not quite greyscale, it has to be in a specific binary black-and-white representation, but definitely do-able if documented. Or I could publish a little python library.
Just thinking out loud here.