private void button_similarity_Click(object sender, EventArgs e)
        {
            float[,] dtwTable;
            float score = MotionMatching.DTW(_a.Frames, _b.Frames, out dtwTable);

            Console.WriteLine(String.Format("[{0}][{1}] v.s. [{2}][{3}] ===> {4}", _a.Class, _a.Name, _b.Class, _b.Name, score));
            //DTWVisualize(dtwTable);
        }
        private void button_keyframe_Click(object sender, EventArgs e)
        {
            List <int> keyframeIndexs = MotionMatching.ExtractKeyFrame(_a.Frames);

            foreach (int index in keyframeIndexs)
            {
                HandFeatures hf = HandFeatures.ExtractFeatures(_a.Frames[index]);
                Console.WriteLine(Convert.ToString(hf.StateCode, 2));
            }
        }