EVITECH has installed a people counting system in order to count at demonstrations, from a camera installed on a high point, over the street where the demonstration was coming. The system was counting people crossing a virtual line across the street.

The counting was activated once the head figures of the demonstration were in sight in the street, and last until the cleaning trucks came, taking the papers and other itmes left in the street.

This is the curve of people passing, minute by minute, of this demonstration that last for approximately one hour, with the main demonstration stream direction (the main curve), as well as the people in the reverse direction (the small curve). The latter is due to people wandering in the street, as well as to people coming with the demonstration, walking back a few steps, and passing again in front of the counting point. It could be interesting to consider the subtraction of the two curves (to take into consideration the spread between the two curves instead of the demonstration stream curve), because :

- for casual people wandering in the street, there must be a symmetry between both directions, in order to subtract a goos estimate of people not demonstrating,

- for people demonstrating but going back and forward again, they should not be counted twice.

Anyway, the resulting figur (3700 people) was counted again manually from the video record, which showed a counting precision higher than 95% over the whole demonstration.