System proves Fuzhou's green credentials

Binhai New Town in the southeastern part of Fuzhou, capital of Fujian province, is blessed with beautiful sea views and a 35-kilometer coastline. It is also home to a national wetland reserve, which serves as a habitat for several endangered migratory birds, including the Chinese crested tern and the black-faced spoonbill.

An intelligent imaging system was introduced last month to monitor and protect the environment in the coastal area. Using two Gigapixel-level smart cameras, an innovative unstructured camera array known as an UnstructuredCam and a set of gigapixel-level complex scene visual analysis solutions, the system now acts as a kind of "smart coast guard".

The UnstructuredCam is capable of making high-resolution, real-time and full color video recordings of the activities of large crowds of people spread over a wide area, according to Fang Lu, an associate professor at Tsinghua University's Department of Electronic Engineering. Fang leads the team working with a company called ZoheTec to develop and run the system in Binhai.

Inspired by human cognitive functions, Fang said she and the team developed the unstructured array camera system by adopting a hierarchical modular design with multi-scale hybrid cameras making up the different modules. Intelligent computation was also introduced into the system.

Unlike conventional single cameras, the UnstructuredCam removes the optical limitations of a single camera and paves the way for high-performance imaging by making use of both micro-cameras and computation to stitch together multiple images. "This system reduces hardware costs, enables high-resolution and long-term monitoring of dynamic wide-area scenes and performs multi-scale, human-centric studies for the assessment of human behavior at the individual level and crowd behavior at the mass level," Fang said.

To protect privacy, she added that the high-quality data obtained will be processed to remove faces before being transmitted to the public cloud.

Fang said that a system capable of delivering high-resolution wide-FoV video data has great potential for predicting crowd dynamics, which plays an important role in risk prevention for large-scale events.

"Based on the joint global and local observation of dynamic large-scale scenes, our system can predict the abnormal behavior of an individual, group or crowd by detecting and tracking thousands of parallel targets over long distances within 1 kilometer," she said.

The system benefits from the rapid development of artificial intelligence and fifth-generation mobile networks, and Fang said that a high-performance intelligent imaging system will boost applications like public security, Earth observation, digital twinning and virtual reality, as well as environmental protection.

The system is now responsible for safeguarding shoreline security by identifying distant ships and sending alerts of possible invaders.

At the system's management center, imaging of the entire bay can be viewed in real-time on a large screen. In addition, it is easy to zoom in on objects and magnify their details. All vessels, seashore sewage outlets and even floating waste can be seen clearly.

"You may have seen similar screens in the management centers of many cities, but their imaging is recorded by hundreds or even thousands of individual cameras located in different places, resulting in incomplete imaging and an inaccurate understanding of large-scale, complex scenes," Fang said.

However, her system has a smart "brain" capable of analyzing a scene clearly. When sea waste is detected, the system automatically analyzes the amount, size and location and sends an alert to the seashore sanitation team. It is also capable of evaluating the cleanup by comparing before and after data.

Since it was put into service, more than 10,000 pieces of waste have been removed over the past two months.

Statistics show that waste density has been successfully reduced by 10 percent compared with the same period last year.

Apart from Binhai, the system is being applied to other projects as well, including preparations for the 2022 Beijing Winter Olympics, the Yangtze finless porpoise protection program in Nanjing, Jiangsu province, and environmental protection efforts in the Qinling Mountains in Gansu province.

"China has made remarkable achievements in environmental protection in the last few decades, but it also faces a challenge in maintaining a harmonious relationship between humans and wild animals, which have increased rapidly in numbers as a result of protection efforts," Fang said.

Pointing to raids by wild boars in many regions as an example, she suggested her system was a good solution for the precautionary monitoring and analysis of the activities of wild animals.

Compared with traditional imaging systems, which are demanding and mainly depend on drones, Fang said her system is able to easily and effectively prevent the destruction of human-animal conflict, as it runs 24 hours a day and monitors animal behavior over a wide area and long distances while not disturbing the animals.

Yang Jie contributed to this story.