Cascaded Multi-Task Learning of Head Segmentation and Density Regression for RGBD Crowd Counting

Abstract

In this paper we propose a novel regression based RGBD crowd counting method. Compared with previous RGBD crowd counting methods which mainly exploit depth cue to facilitate person/head detection, our approach adopts density map regression and is more robust to severe occlusion under dense crowded scenarios. We develop a cascaded depth-aware counting network that jointly performs head segmentation and density map regression. Our network explicitly feeds depth map at each stage so that depth cues are sufficiently exploited. The multi-task strategy allows the network to explicitly attent to foreground regions of a crowd scene and improve density regression. To generate the ground truth of head segmentation and density map, we propose a head scale estimation method according to the basic geometric assumption and camera projection function. Experiments on two public RGBD crowd counting benchmarks, ShanghaiTechRGBD dataset and MICC dataset show that the proposed method achieves new state-of-the-art on both datasets. Further, our method can be easily extended to RGB datasets and achieves comparable performances on WorldExpo'10 dataset and UCF-QNRF dataset.