We thought that connecting an Arduino to a Raspberry Pi was overkill, but one thing caught our attention. [Jan Stevens] mentions that the RPi is less expensive than the Ethernet Shield.

Fortunately, one of the things the Arduino can do that the Raspberry Pi can't is connect with analog components out of the ...

A Raspberry Pi with a camera is ... Google also has a vision processor for the Pi, too. It has a lot of capability but assumes you are connecting to a Pi.