Annotation at a distance in augmented reality

Outdoor Augmented Reality (AR) allows mobile computer users to see and interact with virtual content that is located in and registered to the real world around them. A common example of a use for this is a tourism guide where users are presented with extra information about buildings or other objects in the real world and that information is co-located with the real world objects. A natural way to make this concept even more powerful is to create a way for users to add new content while mobile. With such functionality, users would be able to write restaurant review, leave personal notes, or author any other kind of content they wanted, in a similar way to how users can now create their own content on the web. This dissertation looks at several components of building a successful system to allow users to position new annotations, while using a wearable AR system. Before we discuss our system to position annotations, we first must define what an annotation is. To do this, we have built a taxonomy of annotation that defines annotation and also explores many of the characteristics of different types of annotation. We use AR applications from a variety of application domains to support our findings. The first component of building a system for AR annotation that we examine is choosing which hardware to use. This is a difficult question because there are several competing motivations for choosing different types of hardware. With this in mind, we explore different choices and present an evaluation comparing different display setups for the task of annotation. Choosing the right hardware is not suffficient to create a successful AR annotation system however, it is also necessary to provide fast and intuitive techniques that work well with the chosen hardware platform, to create the annotations. We present new techniques for annotating distant objects from a static location, allowing the annotation process to be faster and less complicated than in previous work. We also discuss different types of applications that annotation of distant objects allows, and propose two example applications. The first one uses our annotation construction techniques to build a tour guide of a local attraction. Our second example application uses and extends our annotation techniques to automatically build a partial or complete model of the environment around a static user. This model can then be used to enhance the AR experience by having the real world objects that have been modeled occlude virtual objects in the scene.