Emotion Loss Attacking: Adversarial Attack Perception for Skeleton based on Multi-dimensional Features
Feng Liu, Qing Xu, Qijian Zheng
TL;DR
This work addresses the vulnerability of skeleton-based action recognizers to adversarial perturbations by proposing a multi-dimensional distance that fuses bone-length preservation, bone-angle changes, joint-speed dynamics, and emotion features. An ADMM-based constrained optimization framework is used to generate imperceptible adversarial skeleton sequences, with explicit untargeted and targeted classification losses. Experiments on NTU RGB+D and Kinetics-400 across multiple GC N-based models demonstrate high attack success with lower perturbations than baselines, and indicate that emotion features can modestly enhance imperceptibility and effectiveness. The approach also provides a new metric for measuring skeletal motion distance and offers implications for improving robustness of skeleton-based perception systems.
Abstract
Adversarial attack on skeletal motion is a hot topic. However, existing researches only consider part of dynamic features when measuring distance between skeleton graph sequences, which results in poor imperceptibility. To this end, we propose a novel adversarial attack method to attack action recognizers for skeletal motions. Firstly, our method systematically proposes a dynamic distance function to measure the difference between skeletal motions. Meanwhile, we innovatively introduce emotional features for complementary information. In addition, we use Alternating Direction Method of Multipliers(ADMM) to solve the constrained optimization problem, which generates adversarial samples with better imperceptibility to deceive the classifiers. Experiments show that our method is effective on multiple action classifiers and datasets. When the perturbation magnitude measured by l norms is the same, the dynamic perturbations generated by our method are much lower than that of other methods. What's more, we are the first to prove the effectiveness of emotional features, and provide a new idea for measuring the distance between skeletal motions.
