Robust Pedestrian Tracking With Severe Occlusions in Public Spaces Using 3D Point Clouds

The increasing need for pedestrian tracking within public and commercial domains necessitates innovative solutions that respect privacy concerns. Traditional surveillance methods employing RGB video footage for the monitoring of pedestrian movements have raised significant privacy issues, attributed to their capability to easily identify individuals. This paper shifts focus towards the utilization of 3D point cloud data as a less intrusive alternative for pedestrian monitoring, which inherently minimizes the risk of individual identification. Notwithstanding, traditional tracking methodologies frequently encounter difficulties in environments characterized by high pedestrian density, where occlusions caused by individuals obscuring one another from the sensors’ perspective are commonplace. This research introduces an advanced approach leveraging 3D point cloud data to address the challenges inherent in pedestrian tracking. A particular obstacle addressed is the frequent obstruction caused by pedestrians, who may be accompanied by objects such as baby strollers and/or luggage, thus complicating their detection and tracking when positioned behind others or in close proximity to the sensors. Such scenarios significantly undermine the efficacy of pedestrian segmentation and tracking, particularly in the context of Kalman-Filter-based methodologies. To mitigate these challenges, the proposed solution incorporates a method to spatially enhance the missing segments within the framework of Kalman-Filter-based multi-object tracking. The effectiveness of this approach has been rigorously assessed through the application of 3D point cloud data derived from diverse real-world settings, including laboratory environments, shopping mall entrances, and a densely populated urban area in Kita-ku, Osaka City, during a festival event.