VR360 Subtitling: Requirements, Technology and User Experience

As with every service, immersive media needs to be accessible. While a plethora of accessibility solutions and guidelines exist for traditional media services, this is not yet true when it comes to immersive media. This article focuses on filling this gap for VR360 video subtitling, as a key access service to be integrated in this recent, but widespread, medium. After reviewing the state-of-the-art, the paper elaborates on a set of key challenges and requirements to efficiently subtitle VR360 videos. Based on these findings, the paper presents technological solutions to efficiently address and meet the identified challenges and requirements, respectively, in a standard-compliant manner. Finally, the paper reports on a set of user tests aimed at shedding some light with regard to four key aspects when it comes to VR360 video subtitling: 1) comfortable viewing fields; 2) presentation modes; 3) guiding methods; and 4) (re-)presentation of non-speech information. In conjunction, the contributions of the paper are expected to become a valuable resource for the interested audience in this field, including users with accessibility needs, the scientific and development community, service providers and standardization bodies.