Count persons in a crowd

Hi all.
Congratulations for this amazing Project.
My brother work with wood measures in forests and FieldimageR will help him. In the other side, I am firefighter and would like to estimate the number of persons in a crowding (like a manifestation, music show, soccer game).
Is it possible use FIELDimageR to do this work (count people)?
Thanks in advanced.

Ulisses