Abstract: Based on investigation of human motion modeling technology, a Period based modeling method is proposed. In this method, an assumption of human joints motion patterns is introduced, which points out every joints relative motion is limited on a half-sphere surface, then a half-sphere model is used to represent motion data. Then concept of Period is proposed, and in order to reduce data scale, the motion trajectory is approximated by multi group of Period sequence. At last, human action matching and recognition is reached. Experiments show that this method can raise the accuracy and efficiency of human action recognition.

Key words: action recognition, half-sphere model, Period sequence, trajectory approximation