In the past people have used very different forms of directions depending on how those directions were acquired. If a person is giving another person directions in a familiar area, he will frequently use landmarks to describe the route [10]. If the person gets the route from a personal navigation system though, it will be displayed on a map and make use of street names for the directions.

There are currently two primary ways of viewing location specific information in-situ on hand-held mobile device screens: using a see-through augmented reality interface and using a touch-based interface with panoramas. The two approaches use fundamentally different interaction metaphors: an AR-style of interacting where the user holds up the device and physically moves it to change views of the world, and a touch-based technique where panorama navigation is independent of the physical world. We have investigated how this difference in interaction technique impacts a user's spatial understanding of the mixed reality world. Our study found that AR-style interaction provided better spatial understanding overall, while touch-based interaction changed the experience to have more similar characteristics to interaction in a separate virtual environment.

This work introduces techniques to facilitate large-scale Augmented Reality (AR) experiences in unprepared outdoor environments. We develop a shape-based object detection framework that works with limited texture and can robustly handle extreme illumination and occlusion issues. The contribution of this work is a purely geometric approach for detecting marker-like objects under difficult and realistic outdoor conditions. We demonstrate these techniques for mobile AR experiences by detecting and tracking star-shaped pentagrams embedded in the Hollywood Walk of Fame at 30Hz on a Nokia N900 phone.

This paper presents methodology for integrating a small, single-point laser range finder into a wearable augmented reality system. We first present a way of creating object-aligned annotations with very little user effort. Second, we describe techniques to segment and pop-up foreground objects. Finally, we introduce a method using the laser range finder to incrementally build 3D panoramas from a fixed observerpsilas location. To build a 3D panorama semi-automatically, we track the systempsilas orientation and use the sparse range data acquired as the user looks around in conjunction with real-time image processing to construct geometry around the userpsilas position. Using full 3D panoramic geometry, it is possible for new virtual objects to be placed in the scene with proper lighting and occlusion by real world objects, which increases the expressivity of the AR experience.

One of the main goals of anywhere augmentation is the development of automatic algorithms for scene acquisition in augmented reality systems. In this paper, we present Envisor, a system for online construction of environment maps in new locations. To accomplish this, Envisor uses vision-based frame to frame and landmark orientation tracking for long-term, drift-free registration. For additional robustness, a gyroscope/compass orientation unit can optionally be used for hybrid tracking. The tracked video is then projected into a cubemap frame by frame. Feedback is presented to the user to help avoid gaps in the cubemap, while any remaining gaps are filled by texture diffusion. The resulting environment map can be used for a variety of applications, including shading of virtual geometry and remote presence.

This paper evaluates different display devices for selection or annotation tasks in augmented reality (AR). We compare three different display types - a head mounted display and two hand held displays. The first hand held display is configured as a magic lens where the user sees the augmented space directly behind the display. The second hand held display is configured to be used at waist level (as one would commonly hold a tablet computer) but the view is still of the scene in front of the user. Making a selection or annotation in AR requires two distinct tasks by the user. First, the user must find the real (or virtual) object they want to mark. Second, the user must move a cursor to the object's location. We test and compare our three representative displays with respect to both tasks. We found that using a hand held display in the magic lens configuration was faster for cursor movement than either of the other two displays. There was no significant difference among the displays regarding the amount of time it took users to search for either physical or virtual objects.

We present a mobile augmented reality system for outdoor annotation of the real world. To reduce user burden, we use aerial photographs in addition to the wearable system's usual data sources (position, orientation, camera and user input). This allows the user to accurately annotate 3D features with only a few simple interactions from a single position by aligning features in both their first-person viewpoint and in the aerial view. We examine three types of aerial photograph features - corners, edges, and regions - that are suitable for a wide variety of useful mobile augmented reality applications, and are easily visible on aerial photographs. By using aerial photographs in combination with wearable augmented reality, we are able to achieve much higher accuracy 3D annotation positions than was previously possible from a single user location.