In context of camera sensors, commonly means “Image Signal Processor”.

https://en.wikipedia.org/wiki/Image_processor

Much of the advancement in modern digital cameras is at the ISP layer, for example Apple invest massively here each year to improve the iPhone’s cameras.

At the very least, the sensors on the Tesla appear to have no IR filter on key cameras (orange cast on side cameras etc) to improve low light performance. Virtually al consumer grade webcams will have an IR filter, so it’s not quite grab a crappy webcam and shove in the car as some comments suggest!

Tesla do also have a custom ISP, it’s part of the custom silicon chip in their standard fit “FSD computer” stack:

https://en.wikichip.org/wiki/tesla_(car_company)/fsd_chip