SDM-BSM: A fusing depth scheme for human action recognition

Depth map has shown promising capability in human action recognition, however it always be auxiliary of RGB features in previous work. As to sufficiently exploring depth map, we propose an innovative descriptor for human action recognition using solo depth data. First, Salient Depth Map (SDM) is calculated between two consecutive depth frames, which is superior for action description as it is located on salient moving objects. Moreover, Binary Shape Map (BSM) is proposed to depict the silhouettes induced by the lateral component of the scene action parallel to the image plane. Then, for implementation, a new framework as Bag-of-Map-Words is employed after concatenating SDM and BSM feature vectors. Experiments on NHA database demonstrate the superiority and high efficiency of the proposed method. We also give detailed comparisons with other features and analysis for parameters as a guidance of further applications.