i think this can be easy be done… setup your own imgproxy or picsur server. in #snort i think you can add already your own imgproxy server.
it would be great if the apps allow to add the own server to host pictures.

GitHub
GitHub - CaramelFur/Picsur: An easy to use, selfhostable image sharing service like Imgur with built in converting
An easy to use, selfhostable image sharing service like Imgur with built in converting - CaramelFur/Picsur
GitHub
GitHub - imgproxy/imgproxy: Fast and secure standalone server for resizing, processing, and converting images on the fly
Fast and secure standalone server for resizing, processing, and converting images on the fly - imgproxy/imgproxy