In Virtual Reality (VR) applications, understanding how users explore the visual content is important in order to optimize content creation and distribution, develop user-centric services, or even to detect disorders in medical applications. In this paper, we propose a graph-based method to identify clusters of users who are attending the same portion of spherical content, within one frame or a series of frames. With respect to other clustering methods, the proposed solution takes into account the spherical geometry of the content and correctly identifies clusters that group viewers who actually display the same portion of spherical content. Results, carried out by using a set of publicly available VR user navigation patterns, show that the proposed method identifies more meaningful clusters, i.e., clusters of users who are consistently attending the same portion of spherical content, with respect to other methods.

Additional Metadata
Keywords Virtual Reality, 360◦ video, User behaviour analysis, Data clustering
Citation
Rossi, S, De Simone, F, Frossard, P, & Toni, L. (2018). Spherical clustering of users navigating 360-degree content.