Problems in Three-Dimensional Measurement of Japanese Kenjutsu Using Existing Sensing Devices

This paper shows problems when we perform three-dimensional measurements of Japanese kenjutsu that is one of the intangible cultural heritage using consumer-level sensing devices. We did test measurements using Perception neuron and Kinect v2. To evaluate the feasibility of these devices, we recorded three-dimensional information of nukitsuke and shoumen-giri that are basic motions to evaluate the feasibility of these devices. The experimental results showed that both devices have significant problems. Perception neuron had position errors and accumulated errors though it was calibrated before measurements. The frame rate and the resolution for depth sensing of Kinect v2 could not sufficient record the sword motions. On the other hand, a visible camera that can capture 240 frames per a second reduced the number of missing frames by recording sword motions. The result showed that it is important to merge visible images obtained by a high-frame-rate camera with three-dimensional sensing device output to achieve three-dimensional measurements of Japanese kenjutsu.