[Paper] Measurement of Viewing Distance and Posture Using the Front Cameras of Digital Devices to Support Children's Health

Abstract

The use of digital devices, especially for school learning, is growing rapidly. Although the use of digital devices has positive effects, their prolonged use can lead to visual fatigue, myopia, and physical fatigue. To address these concerns, we developed functions to measure viewing distance and posture by capturing the user's face and body position using the front camera of their digital devices. Furthermore, we derived an approximation equation to determine the viewing distance based on the interpupillary distance of the captured image and examined its validity. To measure posture, we proposed a method to determine whether the observer is leaning forward or upright. Using the developed functions, the simultaneous time-series measurement data of viewing distance and postural change were graphically presented, demonstrating that it is possible to presume the observer's condition and provide appropriate health support. Moreover, the application of the proposed measurement method in school learning was discussed.