From the little I've looked into machine vision cameras, part of the machine vision world is you usually get raw, uncompressed video from the cameras; it's not like MJPEG, MPEG or h264. They are usually attached by USB cable, though Catagory 5/6 cable is becoming more common. But it's not usually TCP transport, but a UTP protocol called GigE.
Sometimes they're sold with housings and sometimes just as boards with images sensors on them.
The idea behind machine vision cameras seems to be high speed, complete images for detailed analysis. They can be looking for imperfections on circuits boards, cracks in bottles at a bottling plant, or reading addresses on letters at the post office for routing, all at high speeds. Most times you're using some custom software you developed or specialized software for MV applications.
Everytime I've talked to a machine vision company about security applications and vice versa we were definitely speaking different languages. But I think more machine vision manufacturers are looking to grow into the security space. And there may be uses there. They're often small for what they are. Being able to buy boards with sensors allows you to design your own housing for say covert use. And some are startng to come out with general TCPIP compatobilie and I think RTSP streaming.
That's the little I know.