Multi-view pedestrian tracking improves with fewer cameras

GRACE: Geometry- and Ray-Aware Camera-Efficient Multi-View Pedestrian Tracking

Computer Vision and Pattern Recognition

Summary

Tracking people using cameras is easier with many cameras, but using fewer cameras cuts costs. The authors introduce GRACE, a method that helps track pedestrians accurately even with just two cameras. It combines different types of 3D and bird’s-eye view features and conditions on each camera’s direction to improve tracking. Their method reduces errors and keeps track of people better than earlier approaches.

What this means in practice

Authors

Taigo Sakai, Kazuhiro Hotta, Hiroki Kouno, Naoki Kato

Abstract

Reducing the number of cameras reduces the deployment cost but removes views that correct BEV responses stretched away from true pedestrian positions by projection and short score drops that can split tracks} in Bird's-Eye View (BEV) tracking. We introduce GRACE, a camera-efficient multi-view tracker with three components. Volumetric-Guided Fusion combines homography-based BEV features with features lifted through 3D space. Ray Conditioning exposes each camera's viewing direction to the fusion network. Its tracking component, BEV Track Recovery (BTR), uses low-confidence detections only to continue existing tracks. The same detections cannot start new tracks. With two WildTrack cameras, GRACE improves MOTA from 83.54 for TrackTacular, our baseline, to 91.07.