With the spread of the pandemic, social distance is one of the effective measures that have proven to flatten the curve. Amidst the lockdown, there are several important sectors such as pharmaceutical, manufacturing, among others, where workers are still required to go to work every day.  We  recently created an AI-enabled social distancing detection tool that aims to help monitor social distancing at the workplace.

This AI tool is developed to complement their efforts, as well as help ensure social distancing protocol in workplaces.

The technical methodology of this tool involves three main steps, which are: 

• Calibration 
• Detection and 
• Measurement. 

Calibration

Calibration is the first step of the pipeline, which works by computing the transform, specifically the homography that morphs a perspective view into a bird’s-eye view. In the below snap of video, we can notice an instance of the birds-eye view at the right corner.

In this process, the simplest calibration method involves selecting four points in the perspective view and mapping them to the corners of a rectangle in the bird’s-eye view. The process assumes that every person is standing on the same flat ground plane. 

Detection

Detection is the second step of the pipeline that involves applying a pedestrian detector to the perspective views to draw a bounding box around each pedestrian. For this process, we can use an open-source pedestrian detection network based on the Faster R-CNN architecture. 

Measurement

This is the third step of the pipeline, where the (x, y) location of the bounding box for each person has been estimated in the bird’s-eye view. So the last step is to compute the bird’s eye view distance between every pair of people and scale the distances by the scaling factor estimated from calibration. The people whose distance is below the minimum acceptable distance has been depicted in red, and the rest are coloured as green, and a line is drawn between the people to emphasize this measure. 

How The Tool Works?

This AI detection tool can be integrated into security camera systems in factories. The tool then starts monitoring the working environment with a few easy calibration steps. According to the company, the detector could highlight people whose distance is below the minimum acceptable distance in red, and draw a line between them to emphasize this. The system will also be able to issue an alert to remind people to keep a safe distance if the protocol is violated.