The system automatically discovers thousands of network cameras in public spaces. After the system discovers cameras, a computer program saves image data and downloads videos about every 10 minutes. Data recorded from these cameras are sent to cloud data centers for processing.
The discovered cameras are a subset of a much larger system developed in Lu's lab in 2016, called the Continuous Analysis of Many CAMeras (CAM2). The CAM2 system is the world's largest camera network, accessing more than 120,000 cameras worldwide in settings ranging from public parking garages to highways.
The cameras that Lu's lab has discovered for studying the effects of COVID-19 restrictions focus on places typically dominated by pedestrians.
Lu and his collaborators have been using the system and artificial intelligence tools to see how policies have affected crowd size over time. The data also is helping to build models for human interactions and the spread of disease.