Human fall detection in videos via boosting and fusing statistical features of appearance, shape and motion dynamics on Riemannian manifolds with applications to assisted living

Artikel i vetenskaplig tidskrift, 2016

This paper addresses issues in fall detection from videos. It is commonly observed that a falling person undergoes large appearance change, shape deformation and physical displacement, thus the focus here is on the analysis of these dynamic features that vary drastically in camera views while a person falls onto the ground. A novel approach is proposed that performs such analysis on Riemannian manifolds, detecting falls from a single camera with arbitrary view angles. The main novelties of this paper include: (a) representing the dynamic appearance, shape and motion of a target person each being points moving on a different Riemannian manifold; (b) characterizing the dynamics of different features by computing velocity statistics of their corresponding manifold points, based on geodesic distances; (c) employing a feature weighting approach, where each statistical feature is weighted according to the mutual information; (d) fusing statistical features learned from different manifolds with a two-stage ensemble learning strategy under a boosting framework. Experiments have been conducted on two video datasets for fall detection. Tests, evaluations and comparisons with 6 state-of-the-art methods have provided support to the effectiveness of the proposed method.