Your Security Cameras Can Count Your Customers, Without Recording Anyone

Most stores, malls and parking lots already have cameras. They record, someone looks when something goes wrong, and the footage is overwritten after a while.

Those same cameras are watching something valuable every day: how many people come in, when, and from which way. Counting it doesn’t need new hardware. It needs software that counts and then forgets.

What you can learn

Shoppers by the hour. When does the store actually fill up? Is Tuesday afternoon worth staffing like Saturday? Counting people through the entrance, every quarter hour, answers that with numbers instead of a manager’s impression.

Conversion. Put the count of people who walked in next to the number of sales from your register, hour by hour. If the store is busy but sales are flat at certain hours, the problem is inside the store: staffing, queues, stock or layout.

Families and children. For a mall, a toy store or a restaurant, families are their own audience. A camera at street level, close to the entrance, can tell adults and children apart, so you know whether a kids’ event or a school holiday really brought families in.

Which entrance, which way. A mall with four entrances, a store with a front door and a parking-lot door: count each one, in both directions, and you’ll know where people really come from. Direction also tells you in from out, so you can see how many people are inside right now.

Cars and bikes. A camera on the parking lot or the street counts vehicles and cyclists the same way: how full the lot gets, when, and whether a bike rack would be used.

How it works

The camera sends its live video stream (most IP security cameras can). Counting software:

1. Finds each person, bicycle and vehicle in every frame, with an object detection model.
2. Follows each one from frame to frame, by where it was and where it’s heading.
3. Counts it once when it crosses a line you drew, such as the doorway, in the direction it was going.
4. Keeps the count by the quarter hour, and nothing else.

You can watch this happen in Passerby, a working example of such a tool I built. It runs on live public traffic cameras, or on a video of your own: press Try your own video, pick a clip of a doorway or a sidewalk from your phone, draw a line, and watch the counts. Your video is counted in your browser and never uploaded.

Counting without recording

Counting people is sensitive, and it should be. A footfall counter doesn’t need to know who anyone is:

• No faces, no plates. The model finds “a person” or “a car”; it doesn’t recognize anyone.
• No recordings. Each frame is looked at and thrown away. Only the numbers are stored.
• Counts only in the reports. A spreadsheet of quarter hours, with nothing in it that identifies a person.

Rules on cameras in shops and public places differ by country and state. A sign at the entrance is often expected, and in some places required, so check what applies to you before you start counting.

Limits

Counts from a camera are estimates. A camera mounted high above the door, with people walking under it, works best; one looking across a crowd, where people hide each other, undercounts. Bright sunlight in a doorway and very low light lower the count too. Test a camera for a day against a hand count before trusting its numbers.

Try it

Open Passerby, then try a clip of your own entrance.

Run a store, a mall or a parking lot and want to know your real footfall? Tell me what your cameras can see.