What is the Vision Sensor based on?

Was just curious about the internals of the Vision Sensor, especially seeing as it seems to perform all image processing on-board. This is in stark contrast to most other camera solutions, which directly attach to the main computer, which in this case would be the V5 Brain. I remember someone telling me somewhere that it was based on some Kickstarter camera that communicated with Arduino and Raspberry Pis over SPI, but I can’t seem to remember exactly what it was.

Any help figuring this out would be much appreciated, thanks

IIRC it’s based on the original pixy (aka “cmucam5”):