Ann Arbor startup tracks social distancing efforts around the world using street camera footage

Voxel51 Ann Arbor

The Voxel51 team working at HQ in Ann Arbor (pre-coronavirus).Voxel51

ANN ARBOR, MI — As social distancing becomes increasingly common across the globe, an Ann Arbor startup is tracking just how intensely communities are trying to avoid contact and limit the spread of the new coronavirus in some of the world’s busiest places.

Voxel51, a company that services the artificial intelligence industry for image and video processing and understanding, was founded by Jason Corso, a professor of electrical and computer engineering at the University of Michigan. Two weeks ago, Corso said he and his team began tracking physical distancing at locations like Times Square in New York, Miami Beach, Abbey Road in London and the Ruthven Museums Building at UM.

“The street cams are public on the internet, so we can just connect to them and pull the data from them,” Corso said. “We found ones that had a good feed, looking at interesting places, but also had historical data that we could access because it’s important for our (physical distancing index) analysis.”

The physical distancing index, or PDI, measures the amount of human activity in an image, Corso said, including pedestrians, cars, bicycles and motorcycles. A computer detects those objects and counts them, and each location is given a PDI score once every 15 minutes.

The researchers recently added graphs to each location to show its PDI, as well as the number of cases and deaths over time. So far, Corso said there is a sharp drop-off for each feed right around mid-March, when many states and countries began issuing stay-at-home orders. There are some areas during certain times, however, where there have been spikes in activity.

“The weather’s getting nice and people sort of need to go outdoors, so the (camera) that’s at the Jersey Shore at Seaside Heights, you actually see a large uptick two weekends ago when it was 70 degrees or something,” Corso said.

In Ann Arbor, there is no historical data for the street camera the team is using, so the graphs only go back until April 4. The PDI for the area shown is nearly zero, while the number of COVID-10 cases and deaths has continued to rise in the area.

Most of the graphs on the website show the PDI dropping while the number of cases rises. In a few months, Corso and his team are hoping to see the opposite — the PDI increase while the number of cases declines.

Corso said Voxel51′s project protects people’s privacy. The PDI is simply a number, so there’s no notion of individual identity. Corso said all of the video on the website is already public, pulled from websites like YouTube and Earthcam, and the platform is deployed in a cloud provider with “best-in-class” security, so Corso and his team are not worried about someone breaking into it.

The website also has state-of-the-art redaction capabilities, Corso said, which includes blurring faces and images on the footage that is stored.

So far, Corso said there are hundreds of visitors to the site each day, including some who are returning to watch different street cams. He said his team is adding new feeds from different locations, and the company is accepting requests to add locations or specific installations of the system for local government and taxpayer usage.

“We’re certainly seeing a lot of interest in what the website can offer, and we couldn’t be more pleased that we’re doing something to help, even if it’s only public awareness,” Corso said.

More information on Voxel51 can be found here.





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