I think some of the ways that computer vision differs from human vision is that while we see “meaning”, computer sees only the math behind it. Because human vision is very semantic, for example when we look at a video we instantly see a person, a mood or a story. But for a computer that same video is just a massive dump of pixel data and color coordinates. Because the computer has zero clue if it’s looking at a human or something else until we write an algorithm to prove it. To help the computer see what we’re interested in we can use cheats like background subtraction, where the computer compares a live shot to a blank photo of the room to spot what’s new or frame differencing to track motion by subtracting one frame from the next.
The fact that computer vision is rooted in military surveillance really colors how it’s used in interactive art. I think because computer vision was born in military and law enforcement labs, they are designed to track and monitor. That’s why they bring a sense of control to interactive arts. For example, in works like Myron Krueger’s Videoplace the tracking is used for play. It turns your body into a paintbrush, giving you a role in the digital world. Also, projects like Suicide Box show that surveillance can be used to track the tragic social phenomena that the government might ignore.