People counter

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A people counter is a device used to measure the number and direction of people traversing a certain passage or entrance per unit time. The device is often used at the entrance of a building so that the total number of visitors can be recorded.

Use Cases[edit]

Retail Stores[edit]

In retail stores, people counters are part of their essential business intelligence metrics.

Conversion Rate - The use of people counting systems in the retail environment is necessary to calculate the conversion rate, i.e., the percentage of a store's visitors that makes purchases. This is the key performance indicator of a store's performance and is superior to traditional methods, which only take into account sales data. Together, traffic counts and conversion rates how a store arrived at sales, e.g., if year-over-year sales are down, did fewer people visit the store, or did fewer people buy?

Marketing Effectiveness - Shopping mall marketing professionals rely on visitor statistics to measure their marketing. Often, shopping mall owners measure marketing effectiveness with sales, and also use visitor statistics to scientifically measure marketing effectiveness. Marketing metrics such as CPM (Cost Per Thousand) and SSF (Shoppers per Square Foot) are performance indicators that shopping mall owners monitor to determine rent according to the total number of visitors to the mall or according to the number of visitors to each individual store in the mall.

Staff Planning - Accurate visitor counting is also useful in the process of optimizing staff shifts; Staff requirements are often directly related to density of visitor traffic and services such as cleaning and maintenance are typically done when traffic is at its lowest.

Stadiums and Venues[edit]

For safety, public locations are often rated to hold a certain number of people. Accurate people counting is used to ensure that the building is below the safe level of occupancy. Although, no people counting system is 100% accurate and therefore must not be entirely relied upon for the purposes of health & safety, an electronic people counting system offers a relatively accurate means of managing capacity.

Museums and Libraries[edit]

Many non-profit organizations use visitor counts as evidence when making applications for finance. In cases where tickets are not sold, such as in museums and libraries, counting is either automated, or staff keep a log of how many clients use different services.

Business Intelligence Metrics[edit]

People counters can offer businesses more than just the people walking in and out of the stores. By combining Video counting and WiFi counting, the new generation people counters can offer other business metrics that could potentially offer new insights; especially for the retail industry.


The number of people coming in and out of the venue.

Window Conversion Rate[edit]

Window Conversion Rate is the percentage of shoppers who came into the store over the people of people who walk passed the outside of the store. With WiFi counting shops can estimate the number of people walked passed the store. While revenue and footfall are important, the number of people who walked pass the store often reflects the true potential of the store location. The Window Conversion Rate often depends on the attractiveness of the shop window design and the effectiveness of marketing campaigns.

Visit Duration[edit]

Visit Duration is the amount of time visitors stay in the venue. WiFi counting has the ability to track the time when a person carrying a smartphone has entered the venue and when that same person has left the venue. This is an important metric for retailers as many shoppers tend to buy more if they stay longer inside the shop. Visit Duration is often reflects the type of customers are coming into the store and the level of customer service the shoppers are receiving.

Returning Customers[edit]

The number of people came into the store who had visited the store previously. WiFi counting has the ability to remember the Unique WiFi beacon signal id emitted by shoppers, so if a shopper had previously visit the store, the counter would flag the person as a Returning Customer.

Cross Shopping[edit]

The number of shoppers who came into the store had previously visited other stores of the same chain.


Many different technologies are used in people counter devices, such as infrared beams, thermal imaging, computer vision and WiFi counting.[1]

1st Generation - Beam Counters[edit]

Infrared beams The simplest form of counter is a single, horizontal infrared beam across an entrance which is typically linked to a small LCD display unit at the side of the doorway. Such a beam counts a 'tick' when the beam is broken, therefore it is normal to divide the 'ticks' by two to get visitor numbers. Beam Counters usually require a receiver or a reflector mounted opposite the unit with a typical range from 2.5 metres (8 ft 2 in) to 6 metres (20 ft). Despite its limitations, infrared counters are still widely used, primarily due to its low cost and simplicity of installation.


  • Non-directional counts
  • Can't discern people walking side-by-side
  • Can be blocked by people standing in an entrance

2nd Generation: Networked Footfall Counters[edit]

Thermal counting Thermal imaging systems use array sensors which detect heat sources. These systems are typically implemented using embedded technology and are mounted overhead for high accuracy. A well tuned thermal counter can achieve accuracy of 80-95%. Before the advance of video counting technology, thermal counting was the most popular counting technology in the market.


  • Narrow field of view - cannot cover wide entrance
  • Cannot be used with ceiling heights below 3.0m
  • Susceptible to weather conditions
  • Difficult to determine the area the sensor is measuring[2]
  • Requires costly on-site accuracy tuning[3]

Video counting Computer vision carries out its processes inside an embedded device. This reduces network bandwidth requirements as only the counting data has to be sent over the network. Robust and adaptive algorithms has been developed to provide excellent counting accuracy for both outdoor and indoor counting using computer vision. Multilayer Background Subtraction, based on colour and texture, is considered the most robust algorithm available for varying shadows and lighting conditions.[4] With the advances in image processing, video count can achieve 90-95% in various lighting environments. The use of artificial intelligence and pattern recognition functions can further enhance its accuracy.

Stereoscopic vision can help to identify the height of the person coming into the store; e.g. child or pets. Whilst there is no evidence stereoscopic vision does improve the accuracy of the counter, it is often used in queue counting and studying customer behaviours inside the shops.


  • Cannot count accuracy in dark environments such as nightclubs[citation needed]

3rd Generation: Video Counting + WiFi counting[edit]

Distinguishes distance from the door detected by the signal strength

With the rising popularity of WiFi-enabled smartphones, the third generation counters collect WiFi beacon signals from shoppers' smartphone and add a number of important business metrics for businesses,especially for the retail industry. According to Gartner, retailers are expected to upgrade their counting system to the third generation WiFi enabled counters. WiFi counting

WiFi Counting uses WiFi receiver to pick up unique WiFi beacon signals emitted from the smartphones. It could pick up WiFi signals up to 100 metres away. While not all people carry a smartphone, WiFi counting can produce statistically significant metrics due to the large sample size available. WiFi counting is gaining popularity in the retail industry due to the additional business metrics it could offer to retailer: store front conversion, visit duration, returning customers and cross shopping.