Hello, i want to make a project to count how many people enter and exit the room. It is not just detecting function but also counting the numbers. So if the person enter the room, it is +1, and viceversa if the person goes out from the room, it is -1. If 3 persons enter the room at the same time, it is +3. So if a person just stands on the door without intention to go in, it wont count. What kind of sensor or vision systems i can use for this kind of project? Thanks in advance.