Even with top of line, new equipment, accuracy problems are quite significant for this application. This is sadly little more than a commercial for these compan

Even with top of line, new equipment, accuracy problems are quite significant for this application. This is sadly little more than a commercial for these companies. You need a lot of pixels. Even if you have full HD 1080p, that still means FoV 20 foot wide or less, which is quite narrow for real world, outdoor applications. You need good angles. Even if you can cover a wide area, if the person is at the edge of the shot or looking the other away or looking down (very common), accuracy plummets. You need good lighting. Even with WDR/HDR capabilities, glare is an issue with sunlight. And forget about in low light, night time conditions, the noise from gain control is a major, major issue. You are dealing with huge numbers of people. With tens or hundreds of thousands of people passing, a lot will simply look alike. It's hard for a person or a computer to make such a call, especially with bad angles, glare, etc.