Extraction and alignment evaluation of motion beats for street dance

The coordination between the dancer´s movement and the accompaniment of music is an important element of dance performance. In this paper, we propose a system for coordination evaluation of street dance. Given a dance video clip as input, the system first extracts motion beats from the video and then measures how well the motion beats correlate with the music beats. The motion beats are obtained by analyzing the speed and the change of direction of the dancer´s movement. Unlike most previous work, which mainly focuses on 2D motion trajectory analysis, our system provides a more efficient and accurate dance movement analysis by using the 3D joint data of the dancer acquired by Kinect. Another distinction of our system is that, for beat correlation, it considers not only the underlying steady beat of music but also the groove pattern that gives the propulsive rhythmic feel of the music. We believe the differentiation of music beats into these two categories leads to a finer dance coordination evaluation. The test video clips for performance evaluation are generated by professional dancers. The average F-score of our system is about 80%.