An apparatus being adapted to determine an occupancy in a designated area, said apparatus comprising a memory and a controller, said controller being configured to determine at least one passage time; wherein said passage time is a time for a detected passage into and/or out of said area based on said image stream, determine an average occupancy time, determine if a passage into said designated area is estimated to occupy the designated area by comparing the time for the passage with the average occupancy time, and determine an estimation of the present occupancy in the designated area to equal the number of such passages.