DKD–DAD: a novel framework with discriminative kinematic descriptor and deep attention-pooled descriptor for action recognition

Abstract

In order to improve action recognition accuracy, the discriminative kinematic descriptor and deep attention-pooled descriptor are proposed. Firstly, the optical flow field is transformed into a set of kinematic fields with more discriminativeness. Subsequently, two kinematic features are constructed, which more accurately depict the dynamic characteristics of action subject from the multi-order divergence and curl fields. Secondly, by introducing both of the tight-loose constraint and anti-confusion constraint, a discriminative fusion method is proposed, which guarantees better within-class compactness and between-class separability, meanwhile reduces the confusion caused by outliers. Furthermore, a discriminative kinematic descriptor is constructed. Thirdly, a prediction-attentional pooling method is proposed, which accurately focuses its attention on the discriminative local regions. On this basis, a deep attention-pooled descriptor (DKD–DAD) is constructed. Finally, a novel framework with discriminative kinematic descriptor and deep attention-pooled descriptor is presented, which comprehensively obtains the discriminative dynamic and static information in a video. Consequently, accuracies are improved. Experiments on two challenging datasets verify the effectiveness of our methods.