US Patent 9922483 Monitoring occupancy of a space

A queue monitoring system for monitoring persons queuing to use electronic transaction apparatus, wherein the apparatus comprises at least one user interface, the system comprising one or more cameras for providing data relating to persons queuing and processing apparatus configured to process the data to determine one or more parameters of the queue, wherein the processing apparatus is additionally configured to receive from the electronic apparatus information that is conveyed to the user interface and to use this information in processing the data.