Combining Densely Sampled Form and Motion for Human Action Recognition

We present a method for human action recognition from video, which exploits both form (local shape) and motion (local flow). Inspired by models of the human visual system, the two feature sets are processed independently in separate channels. The form channel extracts a dense local shape representation from every frame, while the motion channel extracts dense optic flow from the frame and its immediate predecessor. The same processing pipeline is applied in both channels: feature maps are pooled locally, down-sampled, and compared to a collection of learnt templates, yielding a vector of similarity scores. In a final step, the two score vectors are merged, and recognition is performed with a discriminative classifier. In an evaluation on two standard datasets our method outperforms the state-of-the-art, confirming that the combination of form and motion improves recognition.