I added a similar web server example to my bb_epaper project. This one does image compression on the ESP32 through a self-hosted web interface. The user uploads a 1-bit per pixel Windows BMP file and gets back a Group5 (my compression) compressed file as either binary or C HEX values.
https://github.com/bitbank2/bb_epaper
The ESP32 is capable of doing quite a bit on its own. I'm sure I'll expand on this type of project in the near future.