People counters have evolved over the decades like most electronics. Becoming more accurate, robust and reliable. Likewise the cost has also come down as the technologies become more widespread.
The earliest people counters were the manual clickers. Still used today in some instances. This requires someone standing close by to literally count everyone that passes by. As you can imagine, this is quite labour intensive, requiring the person with the clicker to not get distracted. Accuracy will vary greatly as human error will play a big part.
StoreTech started in 1998 and was one of the first companies to count people in retail environments. We understood the benefit of knowing how many people were entering your store could provide invaluable insight and allow the store to objectively measure and optimise performance.
Electronic people counters
The first electronic people counter used where break beam devices, these were mounted horizontal across an entrance. A count would be registered when a person breaks the beam. This issue with these devices is that more than one person walking in side by side would only be counted as one. It is also possible to block the device and therefore the system is inoperable.
From early 2005 new manufactures started producing thermal counters. These devices would be installed overhead and use an array of sensors that detect heat sources within their field of view. Early devices required a data collection unit or Headcount box to store each count and send the data back to a back-office PC or server.
Similar to Betamax and VHS so there are thermal and video technologies both capable of providing people count data. Video counters use complex algorithms and camera imaging to count the number of people in their view.
It's worth noting that unlike overhead thermal or video counters, CCTV devices are generally installed at an oblique angle, this can hinder the field of view and cause issues with accuracy if used as a people counter in addition to a security device.
Another recent addition to the people counter sector is using Wi-Fi detection to count smartphones and other devices with Wi-Fi turned on. This is very much 'sample' data and although won't give an accurate absolute count of the number of people entering your store or space it can provide new metrics that is not possible with traditional people counters. This includes repeat visits, 1st time visits, passer-by, dwell and bounce metrics.
The most recent technological advances have allowed manufacturers to use 'time of flight’ technology. You may have heard about this in smartphone cameras. This technology in people counters like a laser tape measure. Active infrared Time of Flight technology is used to measure the time difference between pulses leaving and returning to give a measure of distance. An array of pulses gives a height map of the scene and allows for a more accurate constantly updating view of the field. With excellent handling of dwelling/stationary targets, immune to lighting variation, unaffected by background patterns we now have people counters with an accuracy level of >99%.
