I've 3 cameras that support people counting and 1 camera with facial recognition.
People counting past a line will keep triggering if someone keeps walking back/fourth (outside of the blue box boundary).
People counting in area works well enough, but obviously once they are out then back in the camera FOV they get counted again.
Facial recognition to count doesn't really count on Dahua's systems....
Facial recognition is based off a percentage of similarity to another face model. If two people look very similar the system gets confused or if the two snapshots of the same person is not within (e.g.) 90% it counts them as two seperate people.
So truly, Dahua's own systems don't have anything (yet) to uniquely count individuals.
Maybe Dahua's VMS's systems or Luxriot VMS have something to link matches of the same person and automatically enroll newly seen faces.
Regardless, Facial recognition is a topic which makes people worry of 'big brother watching' and I would be careful using it for a commercial venue. Putting it on T&C's is one thing but some government's have banned the use.
Typical example of concert event entry has networked ticket scanners and a central database knows how many people have scanned in, and how many have scanned out.
Policy is you cannot come in with a ticket that has already been scanned in or has not been scanned out (people trying to pass their ticket through the fence to let another person in).
There is other methods of counting, such as WiFi or bluetooth sniffing. It's common for almost every smartphone to search for avaliable wifi networks, so you just need your wifi to count the number of devices asking for it's SSID.
That said, I know those types of cams exist and I have not investigated them too closely. Do you know how well they work @looney2ns ? What about the unique faces aspect? Have you used the Dahua you linked to?
