No abstract

This paper describes a wearable augmented reality system using positioning infrastructures and a pedometer. To realize augmented reality systems, the position and orientation of user's viewpoint should be obtained in real time. The proposed system measures the orientation of user's viewpoint by an inertial sensor and the user's position using positioning infrastructures in environments and a pedometer. The system specifies the user's position using the position ID received from RFID tags or IrDA markers which are the components of positioning infrastructures. When the user goes away from them, the user's position is alternatively estimated by using a pedometer. We have developed a navigation system using the proposed techniques and have proven the feasibility of the system with experiments.

This paper proposes a vision-based augmented reality system with correct representation of attached and cast shadows. To realize a seamless augmented reality system, we need to resolve a number of problems. Especially, the geometric and photometric registration problems are important. These problems require to estimate the positions of light sources and user's viewpoint. The proposed system resolves the problems using a 3D marker which combines a 2D square marker and a mirror ball. The 2D marker and the mirror ball are used to estimate the relationship between the real and virtual worlds and the positions of light sources in the real world, respectively.

This paper describes a localization method for wearable computer users. To realize applications of wearable computers like a navigation system, the position of a user is required for location-based services. Many localization methods in indoor environments have been proposed. One of the methods estimates user's position using IR beacons or visual markers. However, these methods have same problems concerning power supply and/or undesirable visual effects. In order to avoid the problems, we propose a new localization method which is based on using an IR camera and invisible markers consisting of translucent retro-reflectors. In the proposed method, to extract the regions of the markers from the captured images stably, the camera captures the reflection of IR LEDs which are flashed on and off synchronously.

In annotation overlay applications using augmented reality (AR), view management is widely used for improving readability and intelligibility of the annotations. In order to recognize the visible portions of objects in the user's view, the positions, orientations, and shapes of the objects should be known in the case of conventional view management methods. However, it is difficult for a wearable AR system to obtain the positions, orientations and shapes of objects because the target object is usually moving or non-rigid. In this paper, we propose a view management method to overlay annotations of moving or non-rigid objects for networked wearable AR. The proposed method obtains positions and shapes of target objects via a network in order to estimate the visible portions of the target objects in the user's view. Annotations are located by minimizing penalties related to the overlap of an annotation, occlusion of target objects, length of a line between the annotation and the target object, and distance of the annotation in sequential frames. Through experiments, we have proven that the prototype system can correctly provide each user with annotations on multiple users of wearable AR systems.