KHARMA : A KML / HTML Architecture for Mobile Augmented Reality Applications

Widespread future adoption of augmented reality technology will rely on a broadly accessible standard for authoring and distributing content with, at a minimum, the flexibility and interactivity provided by current web authoring technologies. The growing number of augmented reality platforms for mobile devices suggests that a single browser for viewing this content may be just over the horizon. The ideal solution for fostering broader adoption is an open architecture that empowers millions of web authors by leveraging the tools and content already available to them. We introduce KHARMA, an open architecture based on KML for geospatial, marker and relative referencing combined with standard browser supported HTML5 and JavaScript technologies for content development and delivery. Our main contribution is a re-conceptualization of KML that turns HTML content formerly confined to balloons into first-class elements in the scene. We introduce a namespace extension, KARML that gives authors extensive control over the presentation of HTML content and its spatial relationship to other content. This combination lets users rapidly develop and host rich interactive mobile augmented reality content using existing HTML authoring tools, client-side JavaScript scripting, AJAX-style database communications and multi-user session-controlled HTTP webhosting. This architecture also introduces a bridging strategy for content delivery on commodity mobile devices based on the use of surveyed geographic locations and synthetic backgrounds. A reference browser implemented for the iPhone platform is described along with a number of ongoing projects that are using the technology.