I've found a wonderful project on GitHub

https://github.com/igrr/esp32-cam-demo

,which utilize ESP32 (not PICO) and ESP32-WROVER (senior brother of ESP32-WROOM32, which has larger SRAM) but I guessed it will work also on ESP32-PICO-D4 so I made....

The board with Camera and tiny OLED display (64x32 pixels, SSD1306). The test code can work as a standalone webcam and very useful for IP address indication.

As shown in the above test shot, not HD quality but enough to surveillance or some data acquisition applications...

Actual operation is already presented in the following movie... Have fun!