Automatic detection of repetitive actions in a video

In this paper we propose a method to locate inloop repetitions in a video. An in-loop repetition consists in repeating the same action(s) many times consecutively. The proposed method adapts and uses the auto-correlation method YIN, originally proposed to find the fundamental frequency in audio signals. Based on this technique, we propose a method that generates a matrix where repetitions correspond to triangle-shaped zones of low values in this matrix (we called YIN-Matrix). Locating these triangles leads to locate video segments that enclose a repetition as well as to extract their parameters. In order to evaluate our method, we used a standard evaluation method that shows the error rates compared to ground-truth information. According to this evaluation method, our method shows promising results that nominate it to form a solid base for future works.